SIRNA THERAPEUTICS INC
EXHIBIT 10.4
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<TYPE>EX-10.4
<SEQUENCE>5
<FILENAME>f20025exv10w4.htm
<DESCRIPTION>EXHIBIT 10.4
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<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><B>EXHIBIT 10.4<BR>
FOIA CONFIDENTIAL TREATMENT REQUESTED</B>
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<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><B>STRATEGIC ALLIANCE AGREEMENT</B>
</DIV>


<DIV align="Center" style="font-size: 10pt; margin-top: 6pt">Between

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<DIV align="Center" style="font-size: 10pt; margin-top: 6pt"><FONT style="font-variant: SMALL-CAPS"><B>Sirna Therapeutics, Inc.</B></FONT>

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<DIV align="Center" style="font-size: 10pt; margin-top: 6pt">&#038;

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<DIV align="Center" style="font-size: 10pt; margin-top: 6pt"><FONT style="font-variant: SMALL-CAPS"><B>Glaxo Group Limited and SmithKline Beecham<BR>
Corporation, d/b/a/Glaxosmithkline</B></FONT>

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<DIV align="Center" style="font-size: 10pt; margin-top: 6pt">Effective

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<DIV align="Center" style="font-size: 10pt; margin-top: 6pt"><B>March&nbsp;31, 2006</B>

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<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
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<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><FONT style="font-variant: SMALL-CAPS"><B>Strategic Alliance Agreement</B></FONT>
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<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><FONT style="font-variant: SMALL-CAPS"><B>This Agreement</B></FONT> is entered into on March&nbsp;31, 2006 (the <B>&#147;Effective Date&#148;) </B>between
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><FONT style="font-variant: SMALL-CAPS"><B>Smithkline Beecham Corporation, d/b/a GlaxoSmithKline</B></FONT>, a Pennsylvania corporation having
its principal place of business at One Franklin Plaza, 200 North 16<SUP style="font-size: 85%; vertical-align: text-top">th</SUP> Street,
Philadelphia, PA 19102, United States<FONT style="font-variant: SMALL-CAPS"><B>,</B></FONT> and <FONT style="font-variant: SMALL-CAPS"><B>Glaxo Group Limited</B></FONT>, a company
existing under the laws of England and Wales, having its registered office at Glaxo Wellcome House,
Berkeley Avenue, Greenford, Middlesex, UB6 0NN, England (collectively, &#147;GSK&#148;); and
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><FONT style="font-variant: SMALL-CAPS"><B>Sirna Therapeutics, Inc., </B></FONT>a Delaware Corporation, having a place of business at 185 Berry
Street, Suite&nbsp;6504, San Francisco, CA 94107 (&#147;Sirna&#148;) (collectively, the &#147;Parties&#148;).
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>Whereas</B>: Sirna has certain expertise and experience in the research, discovery, and development of
certain pharmaceuticals known as siRNAs, which have potential as therapeutics for the treatment of
diseases and conditions in humans;
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>Whereas</B>: GSK has certain expertise in the discovery, research, development and commercialization
of pharmaceuticals as therapeutic products for the treatment of diseases and conditions in humans;
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>Whereas</B>: the Parties now desire to enter into a strategic collaboration and licensing arrangement
to form an alliance for the research, development and commercialization of siRNA therapeutics in
the Respiratory Field, as described herein;
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>Whereas</B>: Under the alliance to be formed, Sirna will discover and research and perform
pre-development studies on siRNA compounds pursuant to a research collaboration as described
herein, and GSK will have exclusive worldwide rights to further develop and commercialize such
compounds as products worldwide in the Respiratory Field; and
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>Whereas: </B>Contemporaneously with the execution of this Agreement, the Parties have executed: a Stock
Purchase Agreement (the &#147;Stock Purchase Agreement&#148;).
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>Now, Therefore, </B>intending to be legally bound, the Parties hereby agree as follows.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>1. </B><FONT style="font-variant: SMALL-CAPS"><B>Definitions </B></FONT>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.1 &#147;Affiliate&#148; </B>means any entity that controls, is controlled by, or is under common control
with a Party. An entity &#147;controls&#148; another if it owns more than fifty percent (50%) of the
outstanding voting securities of a corporation or entity or has a comparable equity interest in any
other type of entity, or has the power by contract or otherwise to direct the management and the
policies of a corporation or entity.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.2 &#147;Allergan Agreement&#148; </B>means a Strategic Alliance Agreement entered into between Sirna and
Allergan, Inc., in September&nbsp;2005, including without limitation any amendments or addendums
thereto, to exclusively pursue RNAi-based therapeutics in the Ocular Field.
</DIV>


<P align="center" style="font-size: 10pt">1
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<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
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<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.3 &#147;Alliance Manager&#148; </B>has the meaning set forth in Section&nbsp;2.3(c).
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.4 &#147;Backup Compound&#148; </B>means a &#091;***&#093;<B>* </B>that the JSC has selected as a backup candidate for
Development.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.5 &#147;Candidate Selection&#148; </B>means &#091;***&#093;* activities on a particular &#091;***&#093;*. For the avoidance of
doubt, the Candidate Selection milestone event hereunder will be deemed achieved if &#091;***&#093;*
activities, such as &#091;***&#093;* studies, are initiated by GSK.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.6 &#147;Cocktail siRNA Compound&#148; </B>means a composition of matter comprising two or more siRNAs as active
ingredients, which composition: (a)&nbsp;is specifically designed against one or more Collaboration
Targets and (b)&nbsp;was known as of the Effective Date or is discovered pursuant to the Research
Collaboration under this Agreement subsequent to the Effective Date, to be active against such
Collaboration Targets in the Respiratory Field.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.7 &#147;Collaboration Compound&#148; </B>means a Compound, a Cocktail siRNA Compound and/or a Multi-Functional
siRNA Compound.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.8 &#147;Collaboration Target&#148; </B>means a Target which is &#091;***&#093;* target within the Respiratory Field
designated by GSK for collaboration under this Agreement in accordance with &#091;***&#093;* hereof and the
applicable Program of Work as described in the applicable Schedule under the Research Plan. The
Collaboration Targets include all Sirna Targets, all Public Domain Targets and all GSK Targets
selected and designated by GSK for inclusion under the Research Plan.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.9 &#147;Combination Target Compound&#148; </B>means a Target Compound which is either a Cocktail siRNA Compound
or a Multi-Functional siRNA Compound that targets (a)&nbsp;at least one &#091;***&#093;* and at least one &#091;***&#093;*,
or (b)&nbsp;at least one &#091;***&#093;* and at least one &#091;***&#093;*.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.10 &#147;Compound&#148; </B>means a composition of matter comprising a single siRNA as an active ingredient,
which composition (a)&nbsp;is or was specifically designed against one or more Collaboration Targets and
(b)&nbsp;was known as of the Effective Date or is discovered pursuant to the Research Collaboration
under this Agreement subsequent to the Effective Date, to be active against such Collaboration
Targets in the Respiratory Field.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.11 &#147;Confidential Information&#148; </B>means all proprietary information disclosed by one Party to another
and as further set forth in Section&nbsp;5.6(e) and Article&nbsp;10 hereof.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.12 &#147;Controlled&#148; or &#147;Controls&#148; </B>means, with respect to any material, data, information, know-how,
patent or other intellectual property right, that a Party owns, co-owns, or has a license to such
material, data, information, or intellectual property right and has the ability to grant a license,
or a sublicense to such material, data, information, or intellectual property right to the other
Party under this Agreement and its Affiliates and sublicensees for use or application in the Field
without violating an agreement with, or infringing any rights of, a Third Party.
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herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
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<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.13 &#147;Cost of Goods&#148; or &#147;COGS&#148; </B>means the cost of resources required to manufacture Collaboration
Compound in accordance with this Agreement and/or the terms and conditions of a separate
manufacturing and supply agreement to be entered into by the Parties as contemplated by Section&nbsp;8.2
hereof, calculated in accordance with Sirna&#146;s accounting methods consistently applied, which
methodology will be calculated in compliance with U.S. generally accepted accounting principles
(GAAP). Cost would include materials, components, &#091;***&#093;* for the manufacture of bulk drug and
Compounds. For the avoidance of doubt, Sirna should &#091;***&#093;*.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.14 </B>A patent <B>&#147;Covers&#148; </B>a composition or method if the patent has not expired and if the composition
or method would infringe, but for this Agreement, at least one Valid Claim of the patent and a
court or other authority of competent jurisdiction has not held the claim to be invalid or
unenforceable. A patent application &#147;Covers&#148; a composition or method if the composition or method
would infringe a claim of the application were a patent to issue thereon which recites the claim.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.15 &#147;Development Plan&#148; </B>means a plan &#091;***&#093;<B>* </B>for the development of a Lead Compound &#091;***&#093;*.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.16 &#147;Development&#148; </B>means the activities to be conducted &#091;***&#093;*, with the objective of developing
and commercializing a &#091;***&#093;* Licensed Product for use and sale in the Respiratory Field &#091;***&#093;*.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.17 &#147;Drug&#148; </B>means a composition intended for use in the cure, mitigation, treatment, or prevention
of disease.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.18 &#147;Drug Delivery Device&#148; or &#147;DDD&#148; </B>means a mechanical device or apparatus for delivering Target
Compound or Licensed Product to a person, which Drug Delivery Device, in the absence of a Drug
would have no therapeutic utility and is not ingested.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.19 &#147;Drug Formulation System&#148; or &#147;DFS&#148; </B>means a substrate, encapsulant or combination of excipients
intended to deliver a Target Compound or Licensed Product to a Drug&#146;s site of action in a person,
which Drug Formulation System, in the absence of a Drug, would have no therapeutic utility.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.20 &#147;FDA&#148; </B>means the U.S. Food and Drug Administration, or any Regulatory Authority that is the
successor thereto.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.21 </B>&#091;***&#093;*
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.22 &#147;First Commercial Sale&#148; </B>means in any country, the first sale of a Licensed Product after
required Marketing Approvals have been granted by the Regulatory Authority of that country.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.23 &#147;FTE&#148; </B>means one full time-equivalent research and/or development employee, with qualifications
in the relevant field, defined as &#091;***&#093;* scientific hours of effort per year. The FTE
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<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
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<DIV align="left" style="font-size: 10pt; margin-top: 6pt">rate will be &#091;***&#093;* to be adjusted upward at a rate of &#091;***&#093;* per year every year on the
anniversary of the Effective Date.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.24 &#147;GSK Drug Delivery Device</B>&#148; or &#147;<B>GSK DDD</B>&#148; means a Drug Delivery System Controlled by GSK
independent of Sirna.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.25 &#147;GSK Drug Formulation System&#148; or &#147;GSK DFS&#148; </B>means a Drug Formulation System Controlled by GSK
independent of Sirna.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.26 &#147;GSK Know-How&#148; </B>means all scientific and technical information, &#091;***&#093;* the assays used to carry
out research relating to any of the &#091;***&#093;*, so far as such information is solely developed and
Controlled by GSK or its Affiliates and GSK is not prevented by a contractual obligation existing
as of the Effective Date from licensing or disclosing such information to Sirna.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.27 &#147;GSK Patents&#148; </B>means any patent or patent application or allowed claim of a patent application
existing as of the Effective Date or arising during and pursuant to the Research Collaboration,
which is developed and Controlled by GSK or its Affiliates, that pertains specifically to any
Collaboration Target or to any Collaboration Compound, Backup Compounds, or any Lead Compound or
Licensed Product, or any GSK DDD or GSK DFS pertaining specifically to any of the foregoing,
wherein the practice of subject matter recited in a claim therein is necessary or useful for GSK or
Sirna to carry out its activities under this Agreement, and any continuations,
continuations-in-part, reissues, reexaminations, or divisionals thereof, and any extensions of term
or supplemental protection certificates directed thereto, and all foreign and P.C.T. equivalents
and counterparts thereof.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.28 &#147;GSK Target&#148; </B>means a Target &#091;***&#093;<B>* </B>within the Respiratory Field, &#091;***&#093;* under this Agreement
&#091;***&#093;*.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.29 &#147;GSK Target Compounds&#148; </B>means &#091;***&#093;* from among the &#091;***&#093;* against a given GSK Target &#091;***&#093;*
under this Agreement for &#091;***&#093;* identification and progression under Program of Work. In the event
that &#091;***&#093;* as set forth under Section &#091;***&#093;*) for inclusion within the GSK Target Compounds, from
the relevant &#091;***&#093;* for such GSK Target. For the avoidance of doubt, GSK Target Compounds shall
consist of a &#091;***&#093;* against a Collaboration Target at any given time.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.30 &#147;Investigational New Drug&#148; or &#147;IND&#148; </B>means the application filed with the FDA to obtain
authorization from the FDA to administer an investigational drug or biological product to humans in
clinical trials.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.31 &#147;Joint Know-How&#148; </B>means all scientific and technical information, &#091;***&#093;* the assays used to
carry out research relating to any of the &#091;***&#093;*, which is developed jointly by the Parties during
and pursuant to the Research Collaboration hereunder.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.32 &#147;Joint Patent&#148; </B>means any patent or patent application or allowed claim of a patent application
arising during and pursuant to the Research Collaboration and which, as the result of joint
inventorship between the Parties on the subject matter of at least one claim therein, is
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herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
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<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
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<DIV align="left" style="font-size: 10pt; margin-top: 6pt">Controlled jointly by GSK and Sirna, and any continuations, continuations-in-part, reissues,
reexaminations, or divisionals thereof, and any extensions of term or supplemental protection
certificates directed thereto, and all foreign and P.C.T. equivalents and counterparts thereof.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.33 &#147;JSC&#148; </B>means the &#147;Joint Steering Committee&#148; as described in Section&nbsp;2.3(a).
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.34
&#147;Launch&#148; </B>means in the given country or territory, the point at which &#091;***&#093;*.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.35 &#147;Lead&#148; </B>means a Collaboration Compound &#091;***&#093;*, based on cell culture experiments, as being
active against one or more Collaboration Targets under a Program pursuant to the Research Plan and
&#091;***&#093;* for identification of the Lead Compound under the Program &#091;***&#093;*<B>.</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.36 &#147;Lead Compound&#148; </B>means a &#091;***&#093;*, with respect to a particular Collaboration Target &#091;***&#093;* for
Development by the JSC. Lead Compound shall &#091;***&#093;*.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.37 &#147;Lead Compound Criteria&#148; </B>means that set of criteria set forth in &#091;***&#093;<B>* </B>as of the Effective
Date, as attached hereto and hereby incorporated by reference, and as may be further specified by a
Program of Work under the Research Plan, for the purpose of determining the achievement of a Lead
Compound with respect to a particular Collaboration Target.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.38 &#147;Lead Criteria&#148; </B>means that set of criteria set forth in &#091;***&#093;* as of the Effective Date, as
attached hereto and hereby incorporated by reference, and as may be further specified by a Program
of Work under the Research Plan, for the purpose of determining the achievement of a Lead with
respect to a particular Collaboration Target.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.39 &#147;Licensed Product&#148; </B>means a &#091;***&#093;* any product which incorporates a &#091;***&#093;*, being progressed
for development and commercialization under this Agreement&#091;***&#093;*.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.40 &#147;Marketing Approval&#148; </B>means all approvals, licenses, registrations or authorizations of any
federal, state or local regulatory agency, department, bureau or other governmental entity,
necessary for the manufacturing, use, storage, import, transport and sale of a Licensed Product in
a regulatory jurisdiction. &#147;Marketing Approval&#148; shall be deemed to occur upon first receipt of
notice from a Regulatory Authority that a Licensed Product has been approved for commercial sale.
&#091;***&#093;*<B>.</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.41 &#147;Multi-Functional siRNA Compound&#148; </B>means a composition of matter comprising a single
double-stranded siRNA as active ingredient, wherein each strand of the siRNA targets a distinct
sequence of a gene or genes (a single Multi-Functional siRNA may be designed to target two distinct
genes or two regions of a single gene), which composition: (a)&nbsp;is specifically designed against one
or more Collaboration Targets and (b)&nbsp;was known as of the Effective Date or is discovered pursuant
to the Research Collaboration under this Agreement subsequent to the Effective Date, to be active
against such Collaboration Targets in the Respiratory Field.
</DIV>



<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD>Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">5
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.42 &#147;Net Sales&#148; </B>means, with respect to a given period of time, gross sales in such period, less
the following deductions from such gross amounts which are actually incurred, allowed or paid, and
specifically relate to Licensed Products:
</DIV>


<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>a)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>credits or allowances actually granted for damaged products, returns or
rejections of product, price adjustments and billing errors;</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>b)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>governmental and other rebates (or equivalents thereof) granted to managed
health care organizations, pharmacy benefit managers (or equivalents thereof), federal,
state/provincial, local and other governments, their agencies and purchasers and
reimbursers or to trade customers, to the extent allowed and taken;</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>c)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>normal and customary trade, cash and quantity discounts, allowances and credits
to the extent allowed or taken;</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>d)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>transportation costs, including insurance, for outbound freight related to
delivery of the product to the extent included in the gross amount invoiced and not
subject to reimbursement;</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>e)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>&#091;***&#093;<B>*</B></TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>f)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>sales taxes, VAT taxes and other taxes directly linked to sales of Licensed
Products to the extent included in the gross amount invoiced to the extent payable by
GSK and not subject to reimbursement; and</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>g)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>&#091;***&#093;*; and</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>h)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Sales between or among either Party and its Affiliates or Third Party Licensees
will be excluded from the computation of such Party&#146;s Net Sales, but the subsequent
final sales to Third Parties by such Affiliates or Third Party Licensees will be
included in the computation of Net Sales. No other costs, including without limitation
the costs incurred in the manufacturing, selling, advertising and/or distribution of
Licensed Products will be deducted in the computation of Net Sales.</TD>
</TR>

</TABLE>
</DIV>
<DIV align="left" style="font-size: 10pt; margin-top: 6pt">If a Licensed Product is sold in the form of a combination containing i) a Licensed Product and ii)
a Drug, Net Sales for such a combination product will be calculated by multiplying actual Net Sales
of the combination product by the fraction A/(A&#043;B), where &#147;A&#148; is the average list price of such
Licensed Product in the combination when sold separately and &#147;B&#148; is the total list price of such
other biologically active component in the combination when sold separately. If the Licensed
Product and the other biologically active component are not sold separately, the percentage of the
total cost of the combination product attributed to cost of the Licensed Product will be multiplied
times the average list price of the combination product to arrive at Net Sales, or alternative
method which has been mutually agreed by both Parties.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 12pt">&#091;***&#093;*
</DIV>



<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD>Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">6
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.43 </B>&#091;***&#093;*
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.44 &#147;Ocular Field&#148; </B>means &#091;***&#093;*<B>.</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.45 &#147;Patent Costs&#148; </B>means the fees and expenses paid to outside legal counsel and other third
parties, and investigation, filing, prosecution and maintenance expenses incurred by and on behalf
of a Party in connection with the filing, prosecuting, enforcing and maintaining of a patent or
application, as evidenced by supporting documentation.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.46 &#147;Phase IIa Clinical Trial&#148; </B>means a human clinical trial conducted in a targeted patient
population for a particular indication and designed to indicate clinical efficacy and safety of a
Drug, as well as to obtain an indication of the dosing regimen required, as more fully defined in
21 CFR 312.21(b).
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.47 &#147;Program&#148; or &#147;Program of Work&#148; </B>means &#091;***&#093;<B>*.</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.48 &#147;Proof of Concept&#148; or &#147;PoC&#148; </B>means &#091;***&#093;*<B>.</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.49 &#147;Public Domain Target&#148; </B>means a Target &#091;***&#093;*<B>.</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.50 &#147;Public Domain Target Compounds&#148; </B>means &#091;***&#093;* from among the &#091;***&#093;* against a given Public
Domain Target &#091;***&#093;* for Lead Compound identification and progression under a Program of Work. In
the event that &#091;***&#093;* Public Domain Target Compounds as set forth under &#091;***&#093;* for inclusion within
the Public Domain Target Compounds, from the &#091;***&#093;* resulting from the Program for such Public
Domain Target. For the avoidance of doubt, Public Domain Target Compounds shall &#091;***&#093;*<B>.</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.51 &#147;Regulatory Authority&#148; </B>means an agency or regulatory body of any government in the Territory
having the authority to regulate the sale, manufacture, marketing, testing and/or pricing of Drugs.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.52 &#147;Research Collaboration&#148; </B>means, the entire research effort as contemplated under this
Agreement, under which Sirna and GSK will conduct their respective activities and carry out their
respective obligations pursuant to the Research Plan, but excluding the Development of any Lead
Compound (or Target Compound) into a Licensed Product by GSK or the development of any Lead
Compound by Sirna under any scenario hereunder wherein Sirna acquires the right to progress the
development of such Lead Compound.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.53 &#147;Research Plan&#148; </B>means, collectively &#091;***&#093;*<B>. </B>The foregoing described in &#091;***&#093;* shall
collectively represent the activities to be conducted hereunder for the prosecution of Programs of
Work directed against the Collaboration Targets.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.54 &#147;Research Team&#148; </B>has the meaning set forth in Section&nbsp;2.3(b)(i).
</DIV>



<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD>Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">7
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.55 &#147;Research Team Leader&#148; </B>has the meaning set forth in Section&nbsp;2.3(b)(i).
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.56 &#147;Research Term&#148; </B>means &#091;***&#093;* commencing on the Effective Date, unless terminated earlier or
extended by the mutual written agreement of the Parties in accordance with the provisions of this
Agreement, during which GSK shall &#091;***&#093;*<B>.</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.57 &#147;Respiratory Field&#148; </B>means &#091;***&#093;<B>*.</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.58 &#147;RNAi&#148; or &#147;RNA interference&#148; </B>means, for the purposes of this Agreement, an endogenous
biological process wherein siRNA introduced into a cell mediates the degradation of mRNA having
sequence complementarity to the siRNA.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.59 &#147;RNAi Data&#148; </B>has the meaning set forth in Section&nbsp;7.6.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.60 &#147;Scientifically and Commercially Reasonable and Diligent Efforts&#148; </B>means those efforts
consistent with the exercise of prudent scientific and business judgment, as applied to other
research, development and commercialization programs or products or potential products having
similar scientific characteristics, similar technical profile and complexities, similar commercial
potential and challenges, and with similar development complexities and challenges, within the
relevant product lines of GSK and its Affiliates, or Sirna and its Affiliates, as the case may be,
respectively, for the Party responsible for conducting such activities. For the avoidance of
doubt, this standard shall be applied with respect to the products and programs being progressed by
that same Party whose diligence is in question.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.61 &#147;siRNA&#148; </B>means a synthetic oligonucleotide, such as a short interfering RNA, that mediates RNA
interference. siRNA is generally a double stranded oligonucleotide having sequence complementarity
to the Target RNA and mediates cleavage of the Target RNA via RNAi. siRNA may be unmodified double
stranded RNA or modified double stranded oligonucleotide with one or more chemical modification or
double stranded oligonucleotides in which every nucleotide is chemically modified.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.62 &#147;Sirna Committed Target&#148; </B>shall have the meaning set forth in Section&nbsp;3.1(e).
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.63 &#147;Sirna Know-How&#148; </B>means all scientific and technical information &#091;***&#093;* the assays and
formulations used to carry out research relating to any of the &#091;***&#093;*, so far as such information
is solely developed and Controlled by Sirna or its Affiliate(s) and Sirna is not prevented by a
contractual obligation existing as of the Effective Date from licensing or disclosing such
information to GSK .
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.64 &#147;Sirna Patents&#148; </B>means a) the patents and patent applications Controlled by Sirna or its
Affiliate(s) as listed in &#091;***&#093;*, which includes without limitation patents and patent applications
licensed from a Third Party; and b) any patent application Controlled by Sirna or its Affiliate(s)
that claims priority to any of the foregoing patents and applications; and c) any patent Controlled
by Sirna or its Affiliate(s) that issues from any of the applications described in clauses a) or b)
above; and d) any patent or patent application arising under the Research Collaboration and
</DIV>



<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">8
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">Controlled by Sirna or its Affiliate(s), that pertains to any Collaboration Target or to any
Collaboration Compound, Lead, Backup Compounds, or any Lead Compound or Licensed Product or DFS and
DDD, wherein the practice of subject matter recited in a claim therein is necessary or useful for
GSK or Sirna to carry out its activities under this Agreement; and for any of subparts a) &#151; d)
above, any continuations, continuations-in-part, reissues, reexaminations, or divisionals thereof,
and any extensions of term or supplemental protection certificates directed thereto, and all
foreign and P.C.T. equivalents and counterparts thereof.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.65 &#147;Sirna Target&#148; </B>means a Target which is &#091;***&#093;* for which Sirna Controls a patent or a patent
application or a foreign or P.C.T. equivalent or counterpart thereof, which includes a claim
directed to siRNAs or use of siRNAs against such Target, regardless of whether such claim is
existing as of the Effective Date, or thereafter during the Research Term; provided, that &#147;Sirna
Target&#148; specifically excludes any Sirna Committed Target &#091;***&#093;*<B>.</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.66 &#147;Sirna Target Compounds&#148; </B>means &#091;***&#093;* under this Agreement for Lead Compound identification
and progression under Program of Work. &#091;***&#093;*
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.67 &#147;Stock Purchase Agreement&#148; </B>means that certain agreement entered into by and between the
Parties on the same date as the Effective Date of this Agreement, and pertaining to the purchase by
GSK of certain shares of the common stock of Sirna.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.68 &#147;Subsequent Year Collaboration Targets&#148; </B>means &#091;***&#093;<B>*.</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.69 &#147;Subsequent Year Sirna Targets&#148; </B>means &#091;***&#093;*<B>.</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.70 &#147;Target&#148; </B>means a protein or combination of proteins encoded by a single gene, the expression
of which is (or may potentially be) disrupted by a siRNA, Multi-Functional siRNA Compound or
Cocktail siRNA Compound.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.71 &#147;Target Compounds&#148; </B>means the GSK Target Compounds, the Sirna Target Compounds, the Combination
Target Compounds, and/or the Public Domain Target Compounds.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.72 </B>&#091;***&#093;*
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.73 </B>&#091;***&#093;*
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.74 &#147;Term&#148; </B>shall mean the effective term of the Agreement, as defined in Section&nbsp;6.1.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.75 &#147;Territory&#148; </B>means all of the countries and territories of the world.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.76 &#147;Third Party&#148; </B>means an entity or person other than GSK or one of its Affiliates or Sirna or
one of its Affiliates.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.77 &#147;Third Party License Agreements&#148; </B>means those certain license agreements existing as of the
Effective Date to which Sirna is a party as listed in Exhibit&nbsp;D, as appended hereto.
</DIV>



<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD>Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">9
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.78 &#147;Third Party Licensee&#148; </B>means a third party, not an Affiliate, to which a Party licenses its
rights to sell Licensed Products.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.79
&#147;Valid Claim&#148; </B>means a claim within &#091;***&#093;* that has not expired, lapsed, or been cancelled or
abandoned, and that has not been donated to the public, disclaimed, or held unenforceable, invalid,
or cancelled by a court or administrative agency of competent jurisdiction in an order or decision
from which no appeal has been or was timely taken, including without limitation, through
opposition, re-examination, reissue or disclaimer.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.80 &#147;Year One Collaboration Targets&#148; </B>means &#091;***&#093;*<B>.</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.81 &#147;Year One Public Domain Targets&#148; </B>means &#091;***&#093;*<B>.</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>1.82 &#147;Year One Sirna Targets&#148; </B>means &#091;***&#093;<B>*.</B>
</DIV>


<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>2.</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD><FONT style="font-variant: SMALL-CAPS"><B>Scope and Management of the Research Collaboration</B></FONT></TD>
</TR>

</TABLE>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>2.1 In General</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">During the Research Term, the Parties will conduct their respective research activities and
obligations, as described in the Research Plan, in furtherance of the Research Collaboration
hereunder. The parties will establish a Joint Steering Committee (JSC), as described below, which
will determine the content of and approve and amend as necessary the Schedules for Programs for
each Collaboration Target. The Research Collaboration will seek to generate Lead Compounds &#091;***&#093;*
during the Research Term. In the event one or more Programs are initiated but not completed before
the end of the Research Term, subject to Section&nbsp;3.5 herein, Sirna shall continue all of such
initiated Programs until it has completed all of its obligations under such Programs of Work as
were approved by the JSC &#091;***&#093;* and the Research Term shall be extended until the date of
completion by Sirna of the last of such initiated Programs.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">The primary objective of the Research Collaboration is to generate siRNAs for topical delivery to
the respiratory tract as Lead Compounds hereunder for use in the Respiratory Field. The &#091;***&#093;*
objective of the Research Collaboration will be to generate Lead Compounds against Collaboration
Targets which are validated respiratory Targets selected and designated by GSK, with the aim of
progressing rapidly to preclinical and clinical development using either a Compound, Cocktail siRNA
Compound or Multi-Functional siRNA Compound.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>2.2 Responsibilities of the Parties</B>
</DIV>


<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>a)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD><U><I>In General</I></U>. Each Party will use Scientifically and Commercially
Reasonable and Diligent Efforts to carry out its respective activities and obligations
as specified under the Research Plan and will keep the JSC informed on the progress of
its activities under the Research Collaboration. GSK will use Scientifically and</TD>
</TR>

</TABLE>
</DIV>


<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD>Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">10
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>


<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Commercially Reasonable and Diligent Efforts to conduct the Development of any Lead
Compounds that are selected hereunder by GSK at its sole discretion, for progression
and further development and potential commercialization primarily in the
Respiratory Field &#091;***&#093;*.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>b)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD><U><I>Sirna Responsibilities</I></U>.</TD>
</TR>

</TABLE>
</DIV>

<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>(i)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Sirna will commit such employees and resources to the
collaboration as necessary to fulfill its obligations under the Research
Collaboration, as specified in the Research Plan for all Programs hereunder.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>(ii)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Sirna will be responsible for the identification, development,
synthesis and optimization of siRNA-based new chemical entities with activity
against each Collaboration Target in the Respiratory Field &#091;***&#093;<B>*</B>, as may be
further specified by the JSC in the Program of Work for such Collaboration
Target. This will include preparing specific plans, performing the work
attributable to Sirna under the Research Plan and Programs of Work hereunder
and for the Research Collaboration, and acting as project leader and requesting
GSK support when needed for all Programs. In the event that GSK requests Sirna
to assist in the identification, development, synthesis and optimization of
siRNA-based new chemical entities with activity against any Collaboration
Target outside of the Respiratory Field, and if Sirna desires to do so and has
not previously made a conflicting commitment to a Third Party, GSK and Sirna
may agree to establish an amendment to this Agreement or a new collaboration
agreement with respect to such activities.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>(iii)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Sirna will provide GSK with the Sirna Know-How and other
relevant information necessary for GSK to conduct its activities under the
Agreement, subject to any limitations or reservations in other agreements.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>(iv)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Sirna will provide input and updates with respect to the
Research Collaboration on at least a quarterly basis each year. In addition,
Sirna will provide an updated development plan with respect to any Lead or
other Collaboration Compound or Licensed Product for which Sirna obtains the
right to conduct development hereunder pursuant to Section&nbsp;3.5, as necessary
(at a minimum once per year) to the JSC for informational purposes during the
Research Term and to GSK thereafter during the Term.</TD>
</TR>

</TABLE>
</DIV>

<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>c)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD><U><I>GSK Responsibilities</I></U>.</TD>
</TR>

</TABLE>
</DIV>

<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>(i)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>GSK will commit such employees and resources as necessary to
fulfill its obligations under this Agreement.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>(ii)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>GSK shall have the right and obligation to select (and the
obligation to make the applicable milestone payments to Sirna) the Target
Compounds, and</TD>
</TR>

</TABLE>
</DIV>


<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD>Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">11
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>


<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Lead Compounds promptly after the JSC &#091;***&#093;* has decided that a Lead has met
the Lead Criteria and a Target Compound has met the Lead Compound Criteria,
respectively. GSK shall have the right &#091;***&#093;*<B>.</B></TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>(iii)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>GSK will provide Sirna with relevant GSK Know-How, equipment
(e.g., &#091;***&#093;*, as further set forth in the Research Plan) and other information
(including without limitation all reasonably necessary technology transfer and
assistance towards the establishment at Sirna &#091;***&#093;<B>* </B>as described in the
Research Plan) Controlled by GSK as reasonably necessary for Sirna to conduct
its activities under the Agreement, subject to any limitations or reservations
or obligations upon GSK due to other agreements. GSK will provide input and
updates with respect to the Programs under the Research Collaboration on at
least a quarterly basis each year.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>(iv)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>GSK shall have sole responsibility and decision-making
authority for all such matters pertaining to the Development of a Lead Compound
(or other Target Compounds as may be applicable pursuant to Section&nbsp;3.4
hereof) into a Licensed Product, in accordance with its Scientifically and
Commercially Reasonable and Diligent Efforts and the applicable terms and
conditions set forth herein.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>(v)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>GSK will provide an updated Development Plan and annual summary
reports with updates with respect to the Development of any Lead Compound (or
other Target Compounds) or Licensed Product as necessary (at a minimum once per
year) to the JSC for informational purposes during the Research Term and to
Sirna thereafter during the Term.</TD>
</TR>

</TABLE>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>2.3 </B><U><B>Management of the Collaboration</B></U>.
</DIV>


<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>a)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD><I>Joint Steering Committee</I>.</TD>
</TR>

</TABLE>
</DIV>

<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>(i)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD><U>Formation and Membership</U>. The Parties will establish
the JSC no later than thirty (30)&nbsp;days after the Effective Date. Each Party
will nominate three (3)&nbsp;members to the JSC, at least one of which from each
Party will have senior level decision-making authority within that Party.
Each Party will be free to change its representative members at any time upon
written notice to the other Party. The JSC shall remain in force for so long
as the Research Term is in effect.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>(ii)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD><U>Chairperson</U>. The JSC will be chaired by a GSK
representative during the first year of the Research Term. &#091;***&#093;* The chair
will be responsible for overseeing meetings of the JSC and may have such other
responsibilities as the JSC determines.</TD>
</TR>

</TABLE>
</DIV>


<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">12
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>


<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>(iii)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD><U>Responsibilities</U>. The JSC will be responsible for
directing and overseeing the Research Collaboration during the Research Term.
The responsibilities and authority of the JSC shall be as follows:</TD>
</TR>

</TABLE>
</DIV>

<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="10%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>(1)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Establishing, determining the content of,
reviewing, and approving each Program of Work for each Collaboration
Target selected and designated by GSK for prosecution under the Research
Collaboration, and reviewing and approving changes or further refinements
to the same or to the Lead Criteria or Lead Compound Criteria for any
Collaboration Target;</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="10%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>(2)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Monitoring all of the activities under the Research
Collaboration. The JSC will monitor the progress of research activities
under each Program of Work within the Research Plan and may at any time
request reports describing it with as much specificity as the JSC may
determine;</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="10%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>(3)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Declaration of when a relevant Collaboration
Compound has become a Lead by achievement of the Lead Criteria for
selection by GSK as a relevant Target Compound;</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="10%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>(4)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Declaration of when a Lead within the relevant
Target Compounds has become a Lead Compound (or a Backup Compounds) by
achievement of the Lead Compound Criteria; &#091;***&#093;<B>*.</B></TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="10%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>(5)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Identification, implementation and oversight of a
strategy to generate Backup Compounds for each Collaboration Target;</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="10%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>(6)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Recommendation to GSK of Lead Compounds or Backup
Compounds for progression by GSK, at GSK&#146;s sole discretion, for
Development by GSK hereunder;</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="10%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>(7)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Determination that a Collaboration Target is no
longer suitable for further research and development under the
collaboration under the relevant Program, subject to GSK&#146;s rights under
Section&nbsp;6 regarding termination of a Program;</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="10%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>(8)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Facilitating transfer of information as provided by
GSK with respect to any Licensed Products or Lead Compounds in
Development, or development thereof by Sirna pursuant to Section&nbsp;3.5;</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="10%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>(9)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Establish a process by which GSK can submit task
orders to Sirna for FTE-based research in support of Development; and</TD>
</TR>

</TABLE>
</DIV>


<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">13
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>


<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="10%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>(10)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>Establishment of an IP Subcommittee to develop,
monitor and oversee a mutually-agreed strategy with respect to filing,
prosecution and enforcement of all Sirna Patents, Sirna Know-How, GSK
Patents, GSK Know-How, Joint Patents and Joint Know-How pertaining to any
Collaboration Target, Lead, Target Compound, Lead Compound, Backup
Compounds or Licensed Product, subject to GSK&#146;s rights under Article&nbsp;9
after Development has been initiated by GSK.</TD>
</TR>

</TABLE>
</DIV>

<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>(iv)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD><U>Meetings</U>. It is contemplated that the JSC will meet a
minimum of four (4)&nbsp;times a year on an approximately quarterly basis at times
mutually convenient to both Parties. Meetings will alternate between Sirna&#146;s
and GSK&#146;s facilities, unless otherwise agreed by the Parties. The JSC may meet
more or less often at such other times as agreed by the JSC, and such
discussions may occur in person or by means of telephone or video conferences.
Each Party will bear the travel, lodging and board expenses associated with
attendance at JSC meetings by its JSC members, Research Team Leaders, Research
Team members, as appropriate. A reasonable number of representatives of either
Party who are not members of the JSC with relevant experience or expertise may
also attend JSC meetings.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>(v)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD><U>Minutes</U>. On an alternating basis between the Parties
(beginning with GSK), the Parties will assign a secretary who will be
responsible for keeping accurate minutes of the applicable JSC meeting,
including all decisions made and actions taken. Drafts of the minutes will be
delivered to the other Party&#146;s Alliance Manager within ten (10)&nbsp;business days
after the meeting for distribution to that Party&#146;s other JSC members. Each
Party has the right to request amendments to the minutes within ten (10)
business days after receiving them. The Party responsible for the minutes will
revise the minutes in accordance with all requested amendments and will provide
revised minutes to the other Party within ten (10)&nbsp;business days after receipt
of any requested amendments. Minutes are effective when approved by both
Parties.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>(vi)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD><U>Decision Making.</U> All decisions of the JSC will be
made by consensus with representatives of each Party presenting a unified
position on behalf of such Party. If the JSC is unable to reach a unanimous
decision on an issue, it will submit the issue to the Chairman of R&#038;D of GSK,
and the Chief Executive Officer of Sirna (collectively, the &#147;Executives&#148;), who
will confer and attempt in good faith during a period of thirty (30)&nbsp;days to
resolve the dispute; should these Executives fail to agree, the decision of the
GSK Executive will become the final and binding decision of the JSC on all such
matters, provided, that no such decision may impose on Sirna any obligation or
liability that is inconsistent with the expressly stated terms and provisions
of this Agreement or of the Research Plan.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>(vii)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD><U>Limitation of Powers</U>. The JSC has only those powers
that are specifically delegated to it herein, including the powers to amend by
unanimous decision</TD>
</TR>

</TABLE>
</DIV>
<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">14
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>



<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 6%">any Program attached to this Agreement as described in a Schedule to Exhibit
A, but does not have the power to amend this Agreement or to amend Exhibit&nbsp;A,
or to amend Exhibit&nbsp;B-1 or Exhibit&nbsp;B-2 (other than as Exhibit&nbsp;B-1 and/or
Exhibit&nbsp;B-2 may be further defined by a Program).
</DIV>

<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>b)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD><U><I>Research Team</I></U>.</TD>
</TR>

</TABLE>
</DIV>

<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>(i)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD><U>Research Team.</U> The Parties will assign appropriate
personnel to carry out their scientific obligations under this Agreement
(collectively known as the &#147;Research Team&#148;) in accordance with the Research
Plan. For each Research Team, GSK will assign one individual to be the research
team leader (the &#147;Research Team Leader&#148;).</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>(ii)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD><U>Responsibilities</U>. The Research Team will be
responsible, with oversight and approval by the JSC, for</TD>
</TR>

</TABLE>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 9%">1) drafting a Program of Work for each Collaboration Target,
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 9%">2) formulating and executing the specific details of the research in
accordance with the deadlines and deliverables in the Research Plan,
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 9%">3) drafting updates or modifications to the Research Plan at least annually,
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 9%">4) providing for exchange of data and results and materials relating to the
Program of Work, and
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 9%">5) facilitating a smooth transition at designation of a Lead Compound for
the Development phase.
</DIV>

<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="6%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>(iii)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>The representatives of each of the Research Teams may meet as
deemed appropriate and necessary by the respective Research Team Leader to
discuss the activities, under the Research Collaboration.</TD>
</TR>

</TABLE>
</DIV>

<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>c)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD><U><I>Alliance Management</I></U>.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD><U>Alliance Managers.</U> Each Party will assign a person who will manage the
relationship between the Parties to enable the achievement of the overall goals of
the collaboration (the &#147;Alliance Manager&#148;). Among other responsibilities, the
Alliance Manager will serve as a point of contact between the Parties and, with the
Research Team, will have responsibility for facilitating a smooth transition at
designation of a Lead Compound for the Development phase.</TD>
</TR>

</TABLE>
</DIV>

<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="left"><B>3.</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD><FONT style="font-variant: SMALL-CAPS"><B>Execution of The Research Plan</B></FONT></TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="left"><B>3.1</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD><U>Selection of Collaboration Targets</U></TD>
</TR>

</TABLE>
</DIV>
<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">15
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(a)&nbsp;Each Collaboration Target will be a Sirna Target, Public Domain Target or a GSK Target
&#091;***&#093;* for use under the Research Collaboration. GSK shall &#091;***&#093;* by providing written notice on a
Target Selection Form (a sample form is attached hereto as Exhibit&nbsp;E), of the identity of each
Collaboration Target to the JSC.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(i)&nbsp;During the first year of the Research Collaboration, GSK shall &#091;***&#093;*<B>.</B>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(ii)&nbsp;In each of the &#091;***&#093;<B>*.</B>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b)&nbsp;Prior to the Effective Date, and at any time thereafter during the Research Term, GSK
shall &#091;***&#093;*<B>.</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(c)&nbsp;Sirna will provide to GSK at GSK&#146;s written request and at each meeting of the JSC, on an
ongoing basis during the Research <BR>
Term &#091;***&#093;*<B>.</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(d)&nbsp;In the event GSK requests that Sirna identify a Multi-Functional siRNA Compound,
Combination Target Compound or a Cocktail siRNA Compound, then the Parties shall discuss &#091;***&#093;* by
way of example but not a limitation, a Multi-Functional siRNA Compound or a Cocktail siRNA Compound
targeting both &#091;***&#093;* and &#091;***&#093;* will constitute a compound against two (2)&nbsp;Collaboration Targets.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(e)&nbsp;For the purposes of this Agreement, &#147;Sirna Committed Target(s)&#148; shall mean those Targets
that, at the relevant time indicated under this Agreement, meet any one of the following criteria:
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#091;***&#093;*
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 12pt">&#091;***&#093;*
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(a)&nbsp;On a Program by Program basis, GSK shall have an &#091;***&#093;*, exercisable at GSK&#146;s sole
discretion, to obtain an exclusive, fully sublicenseable license in the Territory to &#091;***&#093;* the
Target Compounds resulting from each Program in the &#091;***&#093;* the Covenant of Exclusivity as described
in Section&nbsp;3.8(b) to apply &#091;***&#093;* the relevant Target Compounds to also include &#091;***&#093;* arising
under a given Program for any Collaboration Target. With respect to any Collaboration Target that
is a Sirna Committed Target, the rights obtained by GSK &#091;***&#093;* shall be determined in accordance
with &#091;***&#093;*<B>. </B>&#091;***&#093;* GSK as described below &#091;***&#093;*, except that the requirements &#091;***&#093;* shall not
apply to any GSK Targets, and the &#091;***&#093;* shall be deemed to be &#091;***&#093;* GSK for all GSK Targets
&#091;***&#093;*.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b)&nbsp;&#091;***&#093;* GSK for any Collaboration Target to the extent that such rights and license are
available for Sirna to grant to GSK at the time GSK seeks to exercise such option, by providing
written notice to Sirna of its intent &#091;***&#093;*; provided, however, that GSK must provide such notice
by the later of &#091;***&#093;* from the date that GSK first designated such Target as a Collaboration
Target to the JSC, or &#091;***&#093;* from the date that Sirna first provides &#091;***&#093;* for progression against
the relevant Collaboration Target. &#091;***&#093;* any Collaboration Target, GSK shall have the right to
</DIV>


<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">16
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">pursue Development of the relevant Lead Compound (or other relevant Target Compounds) against
such Collaboration Target into a Licensed Product &#091;***&#093;* the Respiratory Field.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">For the avoidance of doubt, upon designating each of the &#091;***&#093;* in accordance with this paragraph,
GSK will be deemed to have &#091;***&#093;* with respect to each of such &#091;***&#093;*, and no &#091;***&#093;*; <U>provided
however</U>, with respect to &#091;***&#093;*, in the event that &#091;***&#093;* the Respiratory Field with respect to
such &#091;***&#093;* Target Compound, then GSK shall have the obligation to &#091;***&#093;* applicable with respect
to such Target in order to develop and progress such &#091;***&#093;* Target Compounds &#091;***&#093;* the Respiratory
Field against any such &#091;***&#093;*.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(i)&nbsp;For Target Compounds against &#091;***&#093;*, and subsequent to completion of &#091;***&#093;* activities for
a Lead Compound in the Respiratory Field, GSK shall have the right to progress a &#091;***&#093;* such Target
Compound against the same Collaboration Target(s) &#091;***&#093;<B>*</B>. At GSK&#146;s request, Sirna agrees to grant
GSK a limited nonexclusive, non-sublicensable, non-transferable research license solely to carry
out &#091;***&#093;* such Collaboration Targets, certain formulation activities involving &#091;***&#093;* provided
such formulation activities &#091;***&#093;* are carried out: (a)&nbsp;solely for the purpose of evaluating &#091;***&#093;*
the feasibility of using such Target Compounds &#091;***&#093;*; and (b)&nbsp;after the completion of all
activities associated with candidate selection of a Lead Compound milestone for each such Target
Compound.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(ii)&nbsp;On a Program-by-Program basis, with respect to any &#091;***&#093;* for a Lead Compound or other
Target Compound &#091;***&#093;* against each of the &#091;***&#093;* the Lead Compounds to GSK against such Target(s)
&#091;***&#093;* with respect to such Targets and Target Compounds, including exclusivity on such Targets and
Target Compounds &#091;***&#093;*.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(c)&nbsp;In the event that GSK notifies Sirna in writing of its desire to designate as
Collaboration Targets &#091;***&#093;* for Sirna Targets which were Sirna Targets as of the Effective Date
&#091;***&#093;* to include such Sirna Targets as Collaboration Targets &#091;***&#093;* (to the extent Sirna has such
rights to grant to GSK), but in no event will the &#091;***&#093;* additional Sirna Target exceed &#091;***&#093;*.
For clarity, it is understood by the Parties that the limit &#091;***&#093;* described in the previous
sentence applies to the total consideration payable by GSK for &#091;***&#093;* the right to designate such
&#091;***&#093;* Sirna Target &#091;***&#093;*. GSK may designate such &#091;***&#093;* Sirna Targets &#091;***&#093;* with respect to
such &#091;***&#093;* Sirna Targets only during each of the &#091;***&#093;* of the Research Term provided the total
number of Collaboration Targets in each such year shall not exceed &#091;***&#093;* Targets.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>3.3. </B><U>Prosecution of Collaboration Targets.</U>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">For each Collaboration Target, Sirna will be responsible to use Scientifically and Commercially
Reasonable and Diligent Efforts with respect to the goal of identifying &#091;***&#093;* directed to the
Collaboration Target, by using its Scientifically and Commercially Reasonable and Diligent Efforts
to:
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;a) generate &#091;***&#093;* Collaboration Compounds (including Multi-Functional siRNA Compounds and
Cocktail siRNA Compounds as may be provided for in the applicable Program of Work) and/or
Combination Target Compounds directed against the Collaboration Targets based
</DIV>


<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">17
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">on cell culture screening in accordance with the Research Plan. Sirna will promptly notify
the JSC upon the generation of Leads against a Collaboration Target(s). Sirna will perform all <I>in
vitro </I>research as described in the Research Plan relating to the identification and evaluation of
Leads, and will provide to GSK data, results, Target Compounds and assays sufficient to reproduce
such research internally. All of the above efforts and activities shall be in accordance with a
Program of Work for such Collaboration Target(s) to be established by the JSC, including specific
criteria for potency, selectivity, efficacy in reducing expression of the selected Collaboration
Target(s), <I>etc</I>.; and
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;b) carry out the <I>in vivo </I>experiments attributed to Sirna as set forth under the Research Plan
under this Agreement, and to optimize, in relevant animal model systems, the relevant Target
Compounds with the goal of generating &#091;***&#093;*. Sirna will perform relevant <I>in vivo </I>research
attributed to Sirna as described in the Research Plan relating to the identification and evaluation
of the relevant Target Compounds, &#091;***&#093;<B>*</B>. All of the above efforts and activities shall be in
accordance with a Program of Work for such Collaboration Target(s) to be established by the JSC,
including specific criteria for biological activity, pharmacokinetics, lung tissue residency, <I>etc</I>.;
and
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;c) design, manufacture, and supply to GSK the relevant Lead Compound &#091;***&#093;*, in the
quantities and having the characteristics specified by the Research Plan and Programs of Work and
by &#091;***&#093;*; and
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;d) design, manufacture, and supply to GSK the relevant Target Compound, in the quantities and
having the characteristics and for the purposes specified by the Research Plan and Programs of
Work; and
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;e) prepare a Program of Work encompassing all of the goals detailed above for approval by the
JSC for each Collaboration Target, detailing the activities to be conducted by each Party in order
to generate Lead Compounds, which can subsequently be recommended to GSK for progression by GSK for
Development &#091;***&#093;*<B>.</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>3.4 </B>&#091;***&#093;*
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(a)&nbsp;In the event Sirna considers that a given Target Compound &#091;***&#093;* has met &#091;***&#093;* the Lead
Compound Criteria and should be deemed a Lead Compound &#091;***&#093;* Sirna will notify GSK in writing in
the event Sirna considers that a Target Compound has met &#091;***&#093;* the Lead Compound Criteria and
should be deemed a Lead Compound or a Backup Compounds, and GSK will promptly notify the JSC of any
GSK Know-How or Joint Know-How generated by GSK from the evaluation of such Target Compounds
against the relevant Collaboration Target.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b)&nbsp;If the &#091;***&#093;* that a Target Compound &#091;***&#093;* has met &#091;***&#093;* the Lead Compound Criteria,
such Target Compound will be deemed to be a Lead Compound &#091;***&#093;*<B>.</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(c)&nbsp;If the JSC &#091;***&#093;*, such Target Compound shall be deemed &#091;***&#093;* a Lead Compound for the
purposes of this Agreement. If the JSC &#091;***&#093;* the relevant Target Compound as a Lead
</DIV>


<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">18
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">Compound in a case where &#091;***&#093;* the Lead Compound Criteria were met, then the Parties shall
&#091;***&#093;*<B>.</B>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(d)&nbsp;If the &#091;***&#093;* that a Target Compound &#091;***&#093;* against a given Collaboration Target &#091;***&#093;*
the Lead Compound Criteria, the applicable Program against such Collaboration Target(s) shall
&#091;***&#093;* follow one of the following scenarios:
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(i)&nbsp;The JSC may unanimously agree to direct the Research Team to prepare a &#091;***&#093;* Program of
Work for the relevant Collaboration Target(s) to combine the efforts and expertise of both Parties
&#091;***&#093;*. Any such &#091;***&#093;* Program of Work shall be submitted for review and approval by the JSC, and
if approved, shall be conducted by Sirna or GSK on terms to be mutually agreed upon by the Parties.
</DIV>



<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 3%">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(A) &#091;***&#093;<B>* </B>Program of Work &#091;***&#093;* unanimously agreed by the JSC, GSK may decide, by
notice to Sirna given within thirty (30)&nbsp;days of the JSC&#146;s decision, to progress the
relevant Target Compounds into Development in the Respiratory Field &#091;***&#093;* optimization of
formulations of the Target Compounds. &#091;***&#093;* GSK shall be obligated to pay all the
applicable milestones and royalties according to Sections&nbsp;5.3 and 5.4 hereof, including
without limitation payment of Lead Compound Criteria milestone.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 3%">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(B) &#091;***&#093;* Program of Work &#091;***&#093;* unanimously agreed by the JSC and GSK decides, by
notice to Sirna given within &#091;***&#093;* of the JSC&#146;s decision, to progress the relevant Target
Compounds into Development in the Respiratory Field &#091;***&#093;* and significant &#091;***&#093;* efforts of
the relevant Target Compounds are required and are carried out by GSK &#091;***&#093;* when the
Candidate Selection milestone event is achieved, and such payment &#091;***&#093;* full to the amount
due as set forth in &#091;***&#093;*. The Candidate Selection milestone event payment, &#091;***&#093;*, as the
case may be, based on the selection of a Compound, or Multifunctional siRNA Compound or
Combination Target Compound or Cocktail siRNA Compound, respectively. GSK will also continue
to have the obligation to pay all the applicable subsequent milestones if achieved and the
applicable royalties for such Target Compounds as set forth in Sections&nbsp;5.3 and 5.4 hereof.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#091;***&#093;* to the research, development or commercialization of any Target Compounds or Licensed
Products for that Collaboration Target and, unless GSK decides to progress the relevant Target
Compounds further on its own &#091;***&#093;* and all rights that were expressly granted hereunder from Sirna
to GSK with respect specifically to such discontinued Collaboration Target(s) and associated Target
Compounds shall revert to Sirna without any further obligations to GSK.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(e)&nbsp;In the event the JSC recommends any Lead Compound for Development by GSK for any
Collaboration Target, &#091;***&#093;* initiate or progress the Development hereunder for any Lead Compound
or other Target Compound. For the avoidance of doubt, the decision by GSK &#091;***&#093;* the Development
of any particular Lead Compound or other Target Compound shall &#091;***&#093;* be deemed or construed in any
circumstance under this Agreement &#091;***&#093;* decision by GSK is made in good faith &#091;***&#093;*.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>3.5 </B><U><B>Sirna&#146;s Development Opportunity</B></U>
</DIV>



<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">19
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(a)&nbsp;In the event that, &#091;***&#093;* GSK decides &#091;***&#093;* GSK shall promptly notify Sirna in writing of
such decision, and Sirna shall &#091;***&#093;* request in writing a sublicense from GSK under GSK&#146;s
exclusive license to such compounds and such Collaboration Target to further develop and/or
commercialize such compound. &#091;***&#093;*, the exclusive, worldwide, sublicenseable license rights to
the Lead Compound, other Target Compounds or Backup Compounds and the relevant Collaboration
Target(s), or, in the alternative, to permit Sirna to progress the Lead Compound, other Target
Compounds or Backup Compounds to commercialization as a Licensed Product &#091;***&#093;*<B>. </B>Such &#091;***&#093;* at
any time until &#091;***&#093;* is attained by Sirna for the &#091;***&#093;* relevant Lead Compound, other Target
Compounds or Backup Compounds as set forth in &#091;***&#093;*.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b)&nbsp;In the event that Sirna wishes to acquire a sublicense &#091;***&#093;<B>* </B>GSK shall grant, at GSK&#146;s
sole discretion, such a license &#091;***&#093;* taking into account the other provisions of this Agreement
and any other ongoing Programs or Development activities with respect to other Collaboration
Targets, but not to be unreasonably refused, to permit Sirna to further progress &#091;***&#093;* as a
sublicensee of GSK hereunder. It shall be at GSK&#146;s sole discretion &#091;***&#093;* exclusive rights to
commercialize &#091;***&#093;* at completion of &#091;***&#093;*, or will permit Sirna to &#091;***&#093;*. In the event that
GSK &#091;***&#093;* the Lead Compound, other Target Compounds or Backup Compounds at &#091;***&#093;*, then GSK shall
&#091;***&#093;* to Sirna the &#091;***&#093;*. In the event GSK declines or fails to &#091;***&#093;* such compounds, within
&#091;***&#093;* of receiving such notification from Sirna, then GSK&#146;s &#091;***&#093;* Lead Compound, other Target
Compounds and/or Backup Compounds shall &#091;***&#093;* and Sirna shall &#091;***&#093;* any such agreement &#091;***&#093;* to
GSK as set forth in &#091;***&#093;*. Sirna shall however have the right to enter in to discussions &#091;***&#093;*
with &#091;***&#093;* regarding partnership of the Lead Compound, other Target Compounds or Backup Compounds
at any time after Sirna has &#091;***&#093;* from GSK. On at least a &#091;***&#093;* basis, or at GSK&#146;s request, but
in no case more frequently than once &#091;***&#093;*, Sirna agrees to provide &#091;***&#093;* activities against such
Lead Compounds, other Target Compounds and/or Backup Compounds. Such &#091;***&#093;* shall include, at a
minimum, a summary of &#091;***&#093;* conducted by or on behalf of Sirna, to the extent permitted by
applicable law.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(c)&nbsp;In the event that, after &#091;***&#093;* GSK decides &#091;***&#093;* of any Lead Compound, other Target
Compound or Backup Compounds hereunder, either on its own or through an Affiliate or a Third Party
sublicensee, then in such case, GSK shall &#091;***&#093;* and Sirna shall &#091;***&#093;* have a period of &#091;***&#093;* to
request the right to obtain &#091;***&#093;* GSK&#146;s exclusive license to such compounds and such Collaboration
Target to &#091;***&#093;* develop and/or commercialize such compounds &#091;***&#093;*<B>. </B>GSK shall &#091;***&#093;* taking into
account the other provisions of this Agreement and any other ongoing Programs or Development
activities with respect to other Collaboration Targets &#091;***&#093;*<B>. </B>&#091;***&#093;* shall not have the right to
&#091;***&#093;* such Lead Compounds, other Target Compounds or Backup Compounds hereunder.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><U><B>Research and Development Funding</B></U>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>3.6 </B>(a)&nbsp;Other than as expressly set forth elsewhere in this Agreement, &#091;***&#093;* all of its
activities relating to the conduct and performance of the Research Collaboration activities &#091;***&#093;*.
Other than as expressly set forth elsewhere in this Agreement, &#091;***&#093;* all of its activities
relating to the
</DIV>



<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">20
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&#091;***&#093;* in the applicable Field. In the event that Sirna carries out tasks requested by GSK &#091;***&#093;*
in the Program of Work, as exemplified in subsection (b)&nbsp;below, GSK shall &#091;***&#093;*<B>.</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b)&nbsp;Upon the approval of the JSC (following receipt by the JSC of FTE estimates), Sirna will
use its Scientifically and Commercially Reasonable and Diligent Efforts to (i)&nbsp;conduct activities
as necessary to identify one or more &#091;***&#093;* against a Collaboration Target that was formerly the
subject of a single Program hereunder using &#091;***&#093;* (ii)&nbsp;develop process and analytical development
methods for Lead Compounds or other Target Compounds to support IND filing and GMP synthesis,
stability studies, and API, and (iii)&nbsp;Sirna will be responsible for release testing and final
release of active pharmaceutical ingredient and drug product, if applicable, for which, in each of
(i) &#151; (iii), GSK will pay to Sirna research funding on an FTE basis, as specified in Section&nbsp;1.23
(plus reimbursements for all materials and reagents costs), to compensate Sirna for such work.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(c)&nbsp;Sirna will not be obligated to carry out activities and identify Target Compounds during
any year of the Research Term against more than the maximum number of Collaboration Targets that
may be selected with respect to such year nor will Sirna be obligated to carry out any activities
outside the Respiratory Field. &#091;***&#093;* GSK desires Sirna to evaluate &#091;***&#093;* Collaboration Targets
&#091;***&#093;<B>* </B>or to perform any other activities not specifically set forth in this Agreement or the
Research Plan as in effect at the relevant time, then Sirna at its sole discretion may choose to
carry out such additional activities on an FTE basis as specified in Section&nbsp;1.23 (plus
reimbursements for materials and reagents costs). Any such activities and the extent of such
funding will be based on mutual agreement of the Parties.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><U><B>Covenant of Exclusivity</B></U>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>3.7 </B>During the Research Term, neither Party will work independently or with any Third Party with
respect to the discovery, research, development or commercialization of any siRNA-based compounds
in the Respiratory Field.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>3.8 </B>(a) <U>Target Exclusivity</U>. For so long as there is any Target Compound or any Licensed
Product in &#091;***&#093;* GSK or Sirna or any of their respective Affiliates, sublicensees or permitted
assigns at any time during the Term of this Agreement against any Collaboration Target, &#091;***&#093;*
either independently or with any Third Party, or &#091;***&#093;* any right or license to &#091;***&#093;* with respect
to the discovery, research, development or commercialization of any &#091;***&#093;* Collaboration Target for
any &#091;***&#093;* or for any &#091;***&#093;* with respect to any Collaboration Target for which the &#091;***&#093;* subject
to the limitations set forth in &#091;***&#093;*.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b)&nbsp;<U>Compound Exclusivity</U>. For so long as there is any Target Compound or any Licensed
Product in &#091;***&#093;* GSK or any of its Affiliates, sublicensees or permitted assigns at any time
during the Term of this Agreement against any Collaboration Target, &#091;***&#093;* either independently or
with any Third Party, or &#091;***&#093;* any right or license to &#091;***&#093;* with respect to, the discovery,
research, development or commercialization of any of the &#091;***&#093;* Collaboration Target for any
indication in &#091;***&#093;*. In the event that for any given &#091;***&#093;* successfully achieves Lead Compound
Criteria milestone &#091;***&#093;* Leads that will be selected by GSK for &#091;***&#093;* Target Compounds, &#091;***&#093;*
</DIV>


<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">21
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">Program for such Collaboration Target for the purposes of this Section&nbsp;3.8(b), and for the
purposes of the licenses granted to GSK under Section&nbsp;4 for Target Compounds, and as otherwise
relevant under this Agreement. In the case where the &#091;***&#093;* with respect to such Collaboration
Target, the covenant in this paragraph shall apply, in addition to the Target Compounds, to all
&#091;***&#093;* the same Collaboration Target.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>3.9 </B>Notwithstanding Sections&nbsp;3.7 and 3.8 hereof, GSK and Sirna shall each be free to use any
Collaboration Target at any time for &#091;***&#093;*<B>.</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>3.10 (a) </B>During the Research Term, in the event that GSK seeks &#091;***&#093;* RNAi-based compounds as
therapeutics &#091;***&#093;*, the Parties will confer to discuss &#091;***&#093;* or the &#091;***&#093;* to &#091;***&#093;* described
above.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>(b) </B>During the Research Term, in the event that Sirna seeks &#091;***&#093;* the Parties will confer to
discuss &#091;***&#093;* or the &#091;***&#093;* to &#091;***&#093;* described above.
</DIV>


<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="left"><B>4.</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD><FONT style="font-variant: SMALL-CAPS"><B>License Grants</B></FONT></TD>
</TR>

</TABLE>
</DIV>
<DIV align="left" style="font-size: 10pt; margin-top: 6pt">Subject to the provisions of Article&nbsp;5 and in consideration for the payments to be made by GSK
under Section&nbsp;5 of this Agreement, Sirna hereby grants the following licenses to GSK:
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>4.1 </B>(a) &#091;***&#093;<B>* </B>Sirna hereby grants to GSK, during the Term, an exclusive, worldwide,
sublicenseable, license in the Territory under the Sirna Patents and the Sirna Know-How, and under
Sirna&#146;s rights in the Joint Patents and the Joint Know-How, whether existing as of the Effective
Date or arising thereafter during the Term, to research, develop and commercialize &#091;***&#093;* and to
make, have made (subject to Sirna&#146;s manufacturing rights set forth in Article&nbsp;8), use, sell, offer
for sale and import, or incorporate &#091;***&#093;*.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b)&nbsp;&#091;***&#093;* Sirna hereby grants to GSK, during the Term, an exclusive, worldwide,
sublicenseable, license in the Territory under the Sirna Patents and the Sirna Know-How, and under
Sirna&#146;s rights in the Joint Patents and the Joint Know-How, whether existing as of the Effective
Date or arising thereafter during the Term, to research, develop and commercialize &#091;***&#093;* and to
make, have made (subject to Sirna&#146;s manufacturing rights set forth in Article&nbsp;8), use, sell, offer
for sale and import, or incorporate &#091;***&#093;*. &#091;***&#093;*
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(c)&nbsp;&#091;***&#093;* Sirna hereby grants to GSK, during the Term, an exclusive, worldwide,
sublicenseable, license in the Territory under the Sirna Patents and the Sirna Know-How, and under
Sirna&#146;s rights in the Joint Patents and the Joint Know-How, whether existing as of the Effective
Date or arising thereafter during the Term, to research, develop and commercialize &#091;***&#093;* and to
make, have made (subject to Sirna&#146;s manufacturing rights set forth in Article&nbsp;8), use, sell, offer
for sale and import, or incorporate &#091;***&#093;*. &#091;***&#093;*
</DIV>
<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>4.2 </B>Sirna hereby grants to GSK during the Term, a worldwide, non-exclusive, sublicenseable, license
in the Territory, to use the Sirna Know-How but only to the extent specifically pertaining to any
&#091;***&#093;* as necessary or useful to perform the activities and responsibilities allocated to GSK
</DIV>



<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">22
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">pursuant to the Programs of Work under the Research Plan, and an exclusive, sublicenseable, license
in the Territory to use the relevant Sirna Know-How and Joint Know-How but only to the extent
specifically pertaining to any &#091;***&#093;* as necessary for the Development and commercialization of any
Lead Compound or Backup Compounds or other Target Compounds into a Licensed Product under the terms
and conditions of this Agreement.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>4.3 </B>Sirna hereby grants to GSK, during the Term, a worldwide, non-exclusive (or exclusive if
possible) and sublicenseable (if possible) sublicense in the Territory, under any patents or
know-how Controlled by Sirna which are now or which later become after the Effective Date &#091;***&#093;*
Controlled by Sirna, to the extent that any subject matter under such patent or know how &#091;***&#093;*
under this Agreement and is necessary or useful, to perform the activities and responsibilities
allocated to GSK pursuant to the Programs of Work under the Research Plan, or for the Development
of any Lead Compound or Backup Compounds or other Target Compounds into a Licensed Product, and to
make, have made (subject to Sirna&#146;s manufacturing rights set forth in Article&nbsp;8), use, sell, offer
for sale and import, or incorporate such Lead Compounds, Backup Compounds or other Target Compounds
into Licensed Products under the terms and conditions of this Agreement.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>4.4 </B>GSK hereby grants to Sirna, during the Term, a worldwide, non-exclusive license in the
Territory, under the GSK Patents and GSK Know-How but only to the extent &#091;***&#093;* as necessary to
perform the activities and responsibilities allocated to Sirna pursuant to the Programs of Work
under the Research Plan or under this Agreement.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>4.5 </B>GSK &#091;***&#093;* sublicense its rights under this Article&nbsp;4 to any of its Affiliates &#091;***&#093;*. Sirna
shall be entitled to a written copy of the final sublicense agreement to ensure that GSK will be
responsible for the performance, including all payment obligations of any &#091;***&#093;* under their
respective sub-license agreements with GSK, and to ensure that any such sublicense agreement
reflects the assumption by such &#091;***&#093;* of all other obligations of GSK under this Agreement.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>4.6 </B>During the Research Term, Sirna shall disclose to GSK &#091;***&#093;* the discovery, research and
development of Lead Compounds or Backup Compounds or other Target Compounds into Licensed Products
within a reasonable period of time after &#091;***&#093;*. Notwithstanding the foregoing, GSK &#091;***&#093;* Sirna
shall not be obligated to &#091;***&#093;* Sirna Patents or Sirna Know-How &#091;***&#093;* except under limited
circumstances relating to the &#091;***&#093;* Sections&nbsp;8.4 and 8.5.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>4.7 </B>To the extent not prohibited under Article&nbsp;3, Sirna may, independently or with/for one or more
Third Parties, pursue researching, developing, and commercializing RNAi-based compounds as
therapeutics &#091;***&#093;*, without any restrictions and obligations &#091;***&#093;*. It is understood and agreed
by the Parties that this Agreement does not confer upon Sirna any rights to use or any license
rights under any &#091;***&#093;* and provided hereunder, to research, develop or commercialize such products
independently or with/for any Third Party in such manner.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>4.8 </B>Unless expressly set forth elsewhere in this Agreement, Sirna has no rights to make, use, sell,
offer for sale or otherwise exploit any &#091;***&#093;* and Sirna may not prevent GSK from making, using,
</DIV>



<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">23
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">selling, offering for sale or otherwise exploiting any &#091;***&#093;* in any way that GSK chooses, unless
such activity would constitute infringement of a patent Controlled by Sirna Covering such &#091;***&#093;*.
</DIV>


<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="left"><B>5.</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD><FONT style="font-variant: SMALL-CAPS"><B>Payments and Royalties</B></FONT></TD>
</TR>

</TABLE>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>5.1 </B><U>Upfront Payment</U>.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;In consideration for the rights and licenses granted to GSK hereunder, and in partial
consideration for the work to be done by Sirna during the Research Term, GSK shall make
the following payment to Sirna as an upfront payment:
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;A one time only cash payment in the total amount of Six Million U.S. Dollars ($6,000,000),
which shall be due and payable within &#091;***&#093;<B>* </B>of GSK&#146;s receipt of an invoice from Sirna for such
payment on or after the Effective Date.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>5.2 </B>&#091;***&#093;*
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(a)&nbsp;In consideration for the &#091;***&#093;* and the rights obtained by GSK as a result of such &#091;***&#093;*
and where the &#091;***&#093;* is not deemed to apply hereunder for Year One Collaboration Targets, GSK shall
pay (in U.S. Dollars) to Sirna (upon the &#091;***&#093;* set forth below under Section&nbsp;5.2(a)(i)-(ii)) a
&#091;***&#093;* for each Collaboration Target as follows:
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(i)&nbsp;For <U>each</U> Sirna Target &#091;***&#093;*
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(ii)&nbsp;For <U>each</U> &#091;***&#093;*
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b)&nbsp;The &#091;***&#093;* shall be payable on a Target-by-Target, rather than Program by Program, basis,
for each Sirna Target and/or Public Domain Target against which the Target Compound was generated.
By way of example but not limitation, with respect to a Sirna Target Compound against two (2)
separate Sirna Targets, GSK shall be obligated to pay Sirna the corresponding &#091;***&#093;* for each of
the two (2)&nbsp;Sirna Targets (as set forth above) regardless of whether GSK prefers to &#091;***&#093;* against
one or both Targets. Similarly, with respect to a Public Domain Target Compound against two (2)
separate Public Domain Targets, GSK shall be obligated to pay Sirna the corresponding &#091;***&#093;* for
each Public Domain Target (as set forth above). Likewise, with respect to a Combination Target
Compound against a Sirna Target and a Public Domain Target, GSK shall pay Sirna the corresponding
&#091;***&#093;* for each Sirna Target and the Public Domain Target (as set forth above). With respect to a
Combination Target Compound which targets a GSK Target, GSK shall pay Sirna the &#091;***&#093;*.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(c)&nbsp;For the avoidance of doubt, none of the above &#091;***&#093;* shall apply to the &#091;***&#093;* with
respect to (i)&nbsp;any &#091;***&#093;*, or (ii)&nbsp;any &#091;***&#093;* unless and until GSK progresses &#091;***&#093;* Target
</DIV>


<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">24
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">Compounds in accordance with Section&nbsp;3.2(b) for use &#091;***&#093;* against any &#091;***&#093;* which is &#091;***&#093;*.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(d)&nbsp;Further, for avoidance of doubt, GSK&#146;s rights pursuant to the &#091;***&#093;* with respect to a
Collaboration Target shall become effective upon the receipt by Sirna of the applicable up-front
and any other portion of the applicable &#091;***&#093;* which is then due and payable as set forth above
under Section &#091;***&#093;*. The rights acquired by GSK pursuant to the &#091;***&#093;* shall terminate in the
event GSK &#091;***&#093;* as they become due and payable as set forth under Section &#091;***&#093;* above.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>5.3 </B><U>Milestone Payments </U>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#091;***&#093;* For each Program, upon achievement of the following milestone events, GSK will make the
applicable milestone payment described below to Sirna, within thirty (30)&nbsp;days of receipt of
Sirna&#146;s invoice on or after the date notice is received of the occurrence of such milestone event
for such Program. Except as expressly described in this Section&nbsp;5.3, the following milestones will
be paid only once for each Program, regardless of the number of Target Compounds, Lead Compounds,
Backup Compounds, or Licensed Products achieving such milestone events under the Agreement &#091;***&#093;*.
For each Program, such milestone events shall be available for the &#091;***&#093;*. For the purposes of
this Article&nbsp;5, &#091;***&#093;* for the purposes of milestone payment herein; further, the mere fact that
&#091;***&#093;* a Licensed Product for an indication by itself is &#091;***&#093;* for the purposes of milestone
payment herein. In the event that a Program was initiated hereunder to generate a Multi-Functional
siRNA Compound or Cocktail siRNA Compound or Combination Target Compound, and GSK decides to pursue
&#091;***&#093;* then GSK shall owe Sirna the &#091;***&#093;* Collaboration Targets been initiated under separate
Programs. &#091;***&#093;*for milestones that are &#091;***&#093;* in the case of any Backup Compounds or Target
Compound or Licensed Product, for any milestone &#091;***&#093;* for a particular Collaboration Target.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#091;***&#093;*
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b)&nbsp;In the event that Sirna acquires the rights to progress the development of a Collaboration
Compound hereunder pursuant to Section &#091;***&#093;*, and GSK subsequently &#091;***&#093;* develop and
commercialize such Collaboration Compound as a Licensed Product, then the milestone payments for
milestone events yet to be attained by GSK after &#091;***&#093;* shall be made by &#091;***&#093;* at the rate of
&#091;***&#093;* of the amount &#091;***&#093;*. To the extent that any of the milestone events &#091;***&#093;* have already
been achieved during the &#091;***&#093;* commencing after Sirna acquires exclusive rights to progress the
Collaboration Compound under Section &#091;***&#093;* but ending at the time GSK &#091;***&#093;* then &#091;***&#093;* that
would have been payable in respect of those milestones during such interim period that have already
been achieved
</DIV>


<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">25
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>5.4 </B><U><B>Royalties</B></U>
</DIV>



<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 3%"><U>Royalty Payments to Sirna</U>. Subject always to the other provisions of this Section
5.4, GSK shall pay to Sirna royalties as follows:
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 6%">5.4.1 Royalty Payments.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 9%">(a)&nbsp;GSK shall pay Sirna a royalty on the annual Net Sales of each Licensed
Product by GSK, its Affiliates or Third Party Sublicensees in the Territory
according to the following schedule:
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 12%">(i)&nbsp;for that portion of such annual Net Sales of a Licensed Product which
<B>&#091;***&#093;</B>* GSK shall pay to Sirna a royalty rate <BR>
of &#091;***&#093;*;
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 12%">(ii)&nbsp;for that portion of such annual Net Sales of a Licensed Product which
&#091;***&#093;* GSK shall pay to Sirna a royalty rate of &#091;***&#093;*.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 9%">&#091;***&#093;<B>*</B>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 12%">(i)&nbsp;Notwithstanding any other provision of this Agreement, or any
interpretation to the contrary, the royalty obligation &#091;***&#093;* wherein
there is &#091;***&#093;* described below in subpart &#091;***&#093;* in the country of sale
and at the time of sale which Covers the Licensed Product being sold.
However, the royalty obligation from GSK to Sirna shall &#091;***&#093;* described
&#091;***&#093;* in the country of sale.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 12%">(ii)&nbsp;Subject always to the other provisions of this Section&nbsp;5.4, the
royalty payable by GSK to Sirna shall be &#091;***&#093;* wherein the royalty
payable shall be for the &#091;***&#093;* which is applicable at the relevant time
of sale in the relevant country of sale:
</DIV>

<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="14%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left">A.</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>The royalties shown in Section
5.4 are &#091;***&#093;* at the time and in the country of sale, there is
&#091;***&#093;* that Covers the &#091;***&#093;* of the Licensed Product being
sold. &#091;***&#093;* As used in this Section&nbsp;5.4, a &#091;***&#093;* claim of a
patent or patent application means a patent claim which recites
&#091;***&#093;* or recites &#091;***&#093;* an siRNA which has &#091;***&#093;* Collaboration
Target.</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="14%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left">B.</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>The royalties shown in Section
5.4 are payable &#091;***&#093;* at the time and in the country of sale,
there is &#091;***&#093;*, but there is a &#091;***&#093;* of &#091;***&#093;* that Covers the
&#091;***&#093;* of the Licensed Product, or there is &#091;***&#093;* of a &#091;***&#093;*
that Covers an approved &#091;***&#093;*.</TD>
</TR>

</TABLE>
</DIV>


<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">26
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>


<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="14%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left">C.</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>The royalties shown in Section
5.4 are payable &#091;***&#093;* at the time and in the country of sale,
there is &#091;***&#093;* Covering a &#091;***&#093;* or there is &#091;***&#093;* of the
types described above, but there is &#091;***&#093;* within the &#091;***&#093;* in
the country of sale and at the time of sale that Covers an
approved &#091;***&#093;* Licensed Product being sold.</TD>
</TR>

</TABLE>
</DIV>
<DIV align="left" style="font-size: 10pt; margin-top: 6pt">As used in this Section&nbsp;5.4, an &#091;***&#093;* shall mean a &#091;***&#093;<B>* </B>for which the selling Party hereunder
has obtained Marketing Approval from the appropriate Regulatory Authority in such country and which
is expressly recited in a claim of a patent or which can reasonably be construed under U.S. Patent
law as being &#091;***&#093;*<B>.</B>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;5.4.2 Period of Royalty Obligation. Subject always to the other provisions of this Section
5.4 and to Section&nbsp;5.5, for each Licensed Product, the royalty obligation shall be applicable under
this Section&nbsp;5.4 and 5.5 below, on a country-by-country basis in the Territory, for a period
beginning on the date of First Commercial Sale of such Licensed Product in such country until the
date that is the later of (a)&nbsp;ten (10)&nbsp;years from the date of such First Commercial Sale of such
Licensed Product or (b)&nbsp;the expiration of the last to expire Valid Claim within a Sirna Patent
which Covers the &#091;***&#093;* Licensed Product or the &#091;***&#093;* the Licensed Product, being sold.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;5.4.3 &#091;***&#093;*
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(a)&nbsp;&#091;***&#093;* Sirna&#146;s technology platform as contemplated under this Agreement for the conduct of
the Programs of Work for all Collaboration Targets hereunder. Sirna and GSK shall &#091;***&#093;* with
respect to any Target Compound, Lead Compound, Backup Compound or Licensed Product hereunder, if
such &#091;***&#093;* and a license grant under such &#091;***&#093;* provides a &#091;***&#093;* hereunder to GSK with respect
to &#091;***&#093;* and Controlled by Sirna which &#091;***&#093;* Covers the commercialization of any of the Target
Compounds, Lead Compounds or Licensed Products.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b)&nbsp;In addition, &#091;***&#093;* the development and commercialization of Licensed Products to be sold
by Sirna, in all scenarios under Section&nbsp;3.5 or otherwise under this Agreement wherein Sirna &#091;***&#093;*
Such &#091;***&#093;* in accordance with the provisions of the applicable &#091;***&#093;* any other payments that are
otherwise due to GSK under Section &#091;***&#093;*, an amount equal to &#091;***&#093;* of royalties &#091;***&#093;* in the
event that any Target Compound, Lead Compound, Backup Compound or Licensed Product is Covered
&#091;***&#093;* by any patent, trade secret, or other legally-protectable know-how or proprietary
information, pertaining to &#091;***&#093;* successfully commercialize the Licensed Product. &#091;***&#093;*.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(c)&nbsp;&#091;***&#093;* Lead Compound, Backup Compounds, Target Compound or Licensed Product is Covered
&#091;***&#093;* by any patent, trade secret, or other legally-protectable know-how or proprietary
information, pertaining to &#091;***&#093;* necessary to overcome &#091;***&#093;* successfully commercialize the
Licensed Product. &#091;***&#093;* The Parties will cooperate in all respects with one another in assessing
the need for and concluding any&#091;***&#093;*, through the JSC via the IP Subcommittee, or through the
Alliance Managers if the JSC no longer exists. In the event of any
</DIV>


<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">27
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&#091;***&#093;* Parties as to whether any such &#091;***&#093;* the Parties shall &#091;***&#093;* Executives at GSK and
Sirna in the manner described in Article&nbsp;2. In the event that &#091;***&#093;* after a period of &#091;***&#093;* the
Parties shall &#091;***&#093;* a mutually-agreeable &#091;***&#093;*<B>. </B>If &#091;***&#093;* the Development of the Licensed
Product, then the commercially-reasonable &#091;***&#093;*<B>. </B>If the &#091;***&#093;* Third Party license is necessary,
then the costs of the license shall be &#091;***&#093;*. If, in the event of such a &#091;***&#093;* Third Party
license is not necessary, then the &#091;***&#093;*. Notwithstanding the foregoing, the Party conducting
Development may, at their sole discretion, conduct &#091;***&#093;* sharing discussions without effect on
royalty sharing discussions.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>5.5 </B>&#091;***&#093;*
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(a)&nbsp;In (i)&nbsp;any scenario wherein &#091;***&#093;* Development or commercialization of any Lead Compound,
Backup Compound or other Target Compound and, &#091;***&#093;* GSK agrees to &#091;***&#093;* continue such development
activities pursuant to Section &#091;***&#093;*, or (ii)&nbsp;any of the other scenarios under this Agreement that
would result in &#091;***&#093;* the final development and commercialization of a Licensed Product, &#091;***&#093;*
royalty payments as set forth in this Section &#091;***&#093;*, as applicable below, worldwide, provided
however &#091;***&#093;* any royalty payments in the event &#091;***&#093;* such Lead Compound, Backup Compound or
other Target Compound as provided for under Section &#091;***&#093;*.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b)&nbsp;Royalties shall be payable &#091;***&#093;* in the event that any of the scenarios described above
in Section&nbsp;5.5(a) occur, and in accordance with the following:
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 6%">(i)&nbsp;If the applicable scenario occurs anytime prior to initiation of &#091;***&#093;* a
royalty of &#091;***&#093;* of Net Sales of a Licensed Product.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 6%">(ii)&nbsp;If the applicable scenario occurs after initiation of &#091;***&#093;* a royalty of
&#091;***&#093;* of Net Sales of a Licensed Product.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 6%">(iii)&nbsp;If the applicable scenario occurs after initiation of &#091;***&#093;* a royalty of
&#091;***&#093;* of Net Sales of a Licensed Product.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt; margin-left: 6%">(iv)&nbsp;The royalties set forth in subparagraphs (i) &#150; (iii)&nbsp;of this Section&nbsp;5.5(b)
shall be payable for each such Lead Compound, Backup Compound, or other Target
Compound for which any of the relevant scenarios described above in Section&nbsp;5.5(a)
occurs.
</DIV>
<DIV align="left" style="font-size: 10pt; margin-top: 6pt">Royalties owed &#091;***&#093;* other than as set forth above under Section&nbsp;5.4.3(b), and shall be payable
during the period commencing upon the Date of First Commercial Sale &#091;***&#093;* anywhere in the
Territory and thereafter until the royalty payment term set forth in Section&nbsp;5.4.2 above.
</DIV>


<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="left"><B>5.6</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD><B>Mechanism of payment</B></TD>
</TR>

</TABLE>
</DIV>


<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">28
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(a)&nbsp;Any royalty payments due under this Agreement will be calculated and reported for each
calendar quarter, and will be paid within thirty (30)&nbsp;days of the end of each quarter. All
payments other than royalty payments will be paid within thirty (30)&nbsp;days of becoming due.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b)&nbsp;Each royalty payment will be accompanied by a report setting forth Net Sales in major
markets and the exchange rate used on royalty payable. The report will include additional details
and specific information relating to the basis for the determination of Net Sales in accordance
with GSK&#146;s then applicable practice and procedure; the report will express the value of all sales
in U.S. dollars.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(c)&nbsp;Each party will keep records relating to the sale or transfer of Licensed Products in
sufficient detail to allow each Party to confirm that royalty payments due under the Agreement are
accurate.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(d)&nbsp;All payments due under this Agreement will be paid in U.S. dollars. In determining the
value of Net Sales in U.S. dollars, the Parties will use the monthly average rate of exchange over
the calendar quarter in which Net Sales are recognized and reported by each Party&#146;s financial
accounting reporting systems in accordance with International Financial Reporting Standards
consistently applied. All payments will be made by wire transfer to a bank and account designated
in writing by the payee.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(e)&nbsp;Upon at least thirty (30)&nbsp;days&#146; prior written notice, each Party will have the right to
have an independent certified public accountant inspect the records of the other Party, its
Affiliates and Third Party Licensees, no more than once per fiscal year, during usual business
hours, for the sole purpose of and only to the extent necessary to verify the completeness and
accuracy of royalty payments that are made and in the case of GSK the COGS that are payable to
Sirna under this Agreement during the five (5)&nbsp;year period preceding the date of the notice. The
notice must identify the period of time subject to inspection; records from a period of time
already subject to an inspection pursuant to this section may not be inspected again. The
accountant must not disclose to the auditing party any information other than information relating
to completeness and accuracy of payments. Each Party will be responsible for the cost of any such
inspection and audit by an independent accounting firm on behalf of such Party, unless such
inspection and audit discloses for any calendar quarter examined that there will have been a
discrepancy of greater than five percent (5%) between the amounts reported by the other Party to be
payable hereunder and the amounts actually paid by the other Party with respect to such calendar
quarter, in which case the other Party will be responsible for the payment of the entire cost of
such inspection and audit. Each Party and its independent accounting firm agree to hold
confidential all information concerning such payments and reports and all information obtained from
the other Party, or any Affiliate or Third Party Licensee thereof in the course of any inspection
or audit hereunder, except to the extent that it is necessary for such Party to disclose such
information in order to enforce its rights under this Agreement or if required by law or any
governmental authority (including, without limitation, any stock exchange upon which such Party&#146;s
shares or other securities may be traded); <I>provided, however</I>, if such Party shall be required by
law to disclose any such Confidential Information to any other person, such Party will give prompt
notice thereof to the other Party and cooperate in all reasonable respects relating to the other
Party&#146;s efforts to impose upon any person entitled to obtain such Confidential Information such
obligations of confidentiality as may be lawfully available.
</DIV>
<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">29
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">(f)&nbsp;Any tax paid or required to be withheld by GSK for the benefit of Sirna on account of any
royalties or other payments payable to Sirna under this Agreement &#091;***&#093;*. GSK shall secure and
send to Sirna proof of any such taxes withheld and paid by GSK for the benefit of Sirna, and shall,
at Sirna&#146;s request, provide reasonable assistance to Sirna in recovering such taxes.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">(g)&nbsp;For purposes of receiving payments from GSK hereunder, Sirna will send invoices to GSK at the
following address (or such other address as GSK may designate in writing to Sirna):
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#091;***&#093;<B>*</B>
</DIV>


<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="left"><B>6.</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD><FONT style="font-variant: SMALL-CAPS"><B>Term and Termination </B></FONT></TD>
</TR>

</TABLE>
</DIV>
<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>6.1 </B>This Agreement is effective as of the Effective Date and will continue on a country-by country
basis until the later of a) ten (10)&nbsp;years after the Launch of a Licensed Product in such country
in the Territory; or b) the date in such country that a Sirna Patent no longer includes a Valid
Claim which Covers a Licensed Product. At the end of the period described in the immediately
preceding sentence (the &#147;Term&#148;) in each country, GSK will have a fully paid-up, worldwide,
exclusive and sublicenseable license to exercise in such country the rights conferred in Article&nbsp;4
and without further obligation to Sirna, except for those obligations set forth in the sections
that are stated to survive the expiration or termination of this Agreement.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>6.2 </B>Each Party may terminate this Agreement in its entirety upon written notice to the other Party
if any of the following occurs:
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;a) the other Party files a petition in bankruptcy or if the other Party is served with an
involuntary petition in bankruptcy and the involuntary petition is not dismissed within ninety (90)
days; or
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;b) the other Party is in material breach of this Agreement and fails to cure the breach within
sixty (60)&nbsp;days after receipt of a written notice describing with particularity and detail the
nature of the alleged breach from the non-breaching Party.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;In addition, upon the occurrence of a material breach of this Agreement by either Party under
this Section&nbsp;6.2 which is not cured within the applicable sixty (60)&nbsp;day cure period as described
in clause (b)&nbsp;above, the non-breaching Party shall have the right, exercisable in its discretion by
giving written notice to the breaching Party, to terminate all of the licenses and rights granted
by the non-breaching Party to the breaching Party hereunder; and in such case, the non-breaching
Party shall retain all of the licenses and other rights granted to the non-breaching Party
hereunder, subject to the applicable financial and other obligations with respect to such licenses
and other rights, as set forth in this Agreement.
</DIV>
<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>6.3 </B>&#091;***&#093;* with respect to any Program of Work with respect to any Collaboration Target or the
Development with respect to any Target Compound or Licensed Product hereunder, for &#091;***&#093;*
Termination &#091;***&#093;* will extinguish GSK&#146;s (or Sirna&#146;s, if applicable) obligation to make any
</DIV>



<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">30
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">payment under Section&nbsp;5 with respect to any event that does not occur &#091;***&#093;* with respect to the
terminated subject matter hereof, and any such termination under this Section&nbsp;6.3(a) shall be at
&#091;***&#093;* with respect to the terminated subject matter &#091;***&#093;<B>* </B>which is already due and accrued as of
the effective date of any such termination, and shall be without prejudice or adverse affect upon
GSK&#146;s other rights and licenses hereunder. For clarity, in the event that &#091;***&#093;* a particular
Lead Compound, Backup Compounds, Target Compound or Licensed Product pursuant to Section&nbsp;3, &#091;***&#093;*
terminate its obligations with respect to such &#091;***&#093;* Target Compound on a Target
Compound-by-Target Compound basis without terminating the entire Agreement.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b)&nbsp;&#091;***&#093;* with respect to one or more particular Programs or Lead Compounds and the related
Backup Compounds, Target Compounds or Licensed Products with respect to the relevant Collaboration
Targets, in the event that &#091;***&#093;* its Scientifically and Commercially Reasonable and Diligent
Efforts as required hereunder &#091;***&#093;*, that such Program(s) or Target Compounds or Licensed
Product(s) &#091;***&#093;* Development or commercialization by &#091;***&#093;*. Any such termination &#091;***&#093;* this
Section&nbsp;6.3(b) shall be effective immediately upon the receipt by &#091;***&#093;* of written notice, and
shall be at no further cost or additional liability or obligation of any kind whatsoever to &#091;***&#093;*
with respect to the &#091;***&#093;* subject matter, save for any cost or liability which is already due and
accrued as of the effective date of any such termination, and shall be without prejudice or adverse
affect upon &#091;***&#093;* hereunder.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(c)&nbsp;&#091;***&#093;*
</DIV>
<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>6.4 </B>Sections &#091;***&#093;* shall survive the expiration or termination of this Agreement for any reason,
in accordance with their respective terms and conditions, and for the duration stated, and where no
duration is stated, shall survive indefinitely (except to the extent otherwise stated herein).
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>6.5 </B>Promptly after termination of this Agreement pursuant to Section&nbsp;6.2, 6.3 or 6.8, each Party
will at the request of the other Party return or destroy any Confidential Information or Sirna
Know-How or GSK Know-How provided or disclosed by a Party to the other Party, respectively, in the
accordance with that Party&#146;s instructions, except that one copy may be retained for archival
purposes.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>6.6 </B>The termination or expiration of this Agreement, in whole or in part, will be without prejudice
to (a)&nbsp;the right of the Sirna (or the right of GSK, as applicable) to receive all amounts due and
accrued hereunder under Article&nbsp;5 prior to the effective date of such termination or expiration and
(b)&nbsp;any other remedies as may now or hereafter be available to any Party, whether under this
Agreement or otherwise.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>6.7 </B>(a)&nbsp;If this Agreement &#091;***&#093;* GSK (or Sirna, &#091;***&#093;*), its Affiliates and Third Party Licensees
will (A) &#091;***&#093;* the relevant Lead Compounds, Backup Compounds, Target Compounds and Licensed
Products (provided, however, if &#091;***&#093;* pursuant to Section &#091;***&#093;* for &#091;***&#093;* GSK) is not in
material breach of any undisputed payment obligation hereunder, &#091;***&#093;* as applicable pursuant to
Section &#091;***&#093;* GSK), its Affiliates and Third Party Licensees will have the right to &#091;***&#093;* not to
exceed &#091;***&#093;* any and all Licensed Products in their &#091;***&#093;* under Section &#091;***&#093;* in
</DIV>



<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">31
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">connection therewith (subject to the payment of royalties and other consideration to &#091;***&#093;*
pursuant to Article&nbsp;5 as if this Agreement &#091;***&#093;<B>*</B>, (B)&nbsp;immediately (i) &#091;***&#093;* as applicable
pursuant to Section&nbsp;3.5 for a &#091;***&#093;* Confidential Information in connection with the manufacture,
use and sale of the relevant Lead Compounds, Backup Compounds, Target Compounds and Licensed
Products and (ii) &#091;***&#093;* in connection with the manufacture, use and sale of the relevant Lead
Compounds, Backup Compounds, Target Compounds and Licensed Products, except to the extent
reasonably necessary to exercise the rights in clause (A)&nbsp;above, and (C)&nbsp;assign or transfer to
&#091;***&#093;* pursuant to Section&nbsp;3.5) all marketing and other approvals relating to the relevant Target
Compounds, Lead Compounds, Backup Compounds and Licensed Products, and all of &#091;***&#093;* as applicable
pursuant to Section&nbsp;3.5) right, title and interest in and to such approvals.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b)&nbsp;In the case of any &#091;***&#093;* then (1)&nbsp;any license granted &#091;***&#093;* pertaining to the relevant
Collaboration Targets, Leads, Target Compounds, Lead Compounds and Licensed Products shall &#091;***&#093;*
(2)&nbsp;GSK shall &#091;***&#093;*with respect to the affected Collaboration Targets (but only for a termination
of one or more Programs), Leads, Target Compounds, Lead Compounds and Licensed Products, (3)&nbsp;Sirna
shall &#091;***&#093;* Leads, Target Compounds, Lead Compounds and Licensed Products Target Compounds &#091;***&#093;*
in accordance with the provisions of Section&nbsp;3.5 hereof, and (4)&nbsp;Sirna shall &#091;***&#093;* develop and
commercialize in the &#091;***&#093;* relevant Target Compounds, Lead Compounds and Licensed Products,
subject to &#091;***&#093;* described in Section &#091;***&#093;* Sirna, its Affiliate or Third Party sublicensee of
any Target Compounds, Lead Compounds or Licensed Products in the &#091;***&#093;* Sirna shall &#091;***&#093;* (x)&nbsp;if
the &#091;***&#093;* pursuant to Section &#091;***&#093;* or (y)&nbsp;in the event the &#091;***&#093;* pursuant to Section &#091;***&#093;* or
&#091;***&#093;* pursuant to Section &#091;***&#093;* occurs at any time prior to the commencement of the &#091;***&#093;*
involving a Lead Compound, Target Compound or Licensed Product under the applicable Program.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>6.8 </B>&#091;***&#093;*
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(a) &#091;***&#093;* In the event that &#091;***&#093;* as required hereunder (which &#091;***&#093;* provided in Section
&#091;***&#093;* hereof) for a particular Program prior to the &#091;***&#093;* Program, as mutually agreed by the
Parties or as finally determined &#091;***&#093;* in accordance with Section &#091;***&#093;* hereof, then the
exclusive, worldwide, fully sublicenseable, license granted &#091;***&#093;* as provided in Section &#091;***&#093;*
and the exclusive (or non-exclusive) sublicenseable license granted under &#091;***&#093;* all the relevant
&#091;***&#093;* Program shall automatically become &#091;***&#093;* Target Compounds, Backup Compounds and Licensed
Products and for use with the relevant Collaboration Target for development and commercialization
into Licensed Products &#091;***&#093;*. For all cases wherein &#091;***&#093;* Collaboration Target prior to such
&#091;***&#093;*<B>: </B>(i)&nbsp;such &#091;***&#093;* subject to Section &#091;***&#093;*<B>; </B>(ii) &#091;***&#093;* or (iii) &#091;***&#093;*<B>. </B>In the
alternative, &#091;***&#093;* at its sole discretion, to &#091;***&#093;* have such rights and remedies as may be
provided herein or under applicable law. During the pendency of any &#091;***&#093;* relating to any such
&#091;***&#093;* otherwise required to be &#091;***&#093;* hereunder shall be &#091;***&#093;* in accordance with the &#091;***&#093;* as
may be mutually agreed by the Parties. If the &#091;***&#093;* under this Section&nbsp;6.8(a) occurs prior to the
&#091;***&#093;* Collaboration Compounds identified under such Program as of the date of &#091;***&#093;*to provide
&#091;***&#093;* chemical samples of such Collaboration Compounds. If &#091;***&#093;* this Section&nbsp;6.8(a) occurs
after the identification of a &#091;***&#093;* for such Program, then the &#091;***&#093;* license described in this
paragraph shall apply to all Target Compounds generated under such Program, and &#091;***&#093;*
</DIV>



<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">32
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">obligated to promptly transfer and provide to &#091;***&#093;* chemical samples of all such Target
Compounds, provided that &#091;***&#093;<B>*</B>.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b) &#091;***&#093;* In the event that &#091;***&#093;* as required hereunder (which &#091;***&#093;* provided in Section
6.2(b) hereof) for a particular Program, as mutually agreed by the Parties or as finally determined
&#091;***&#093;* in accordance with Section &#091;***&#093;* hereof, then subject to the terms and conditions set forth
below, the &#091;***&#093;* provided in Article &#091;***&#093;* under such Program shall automatically &#091;***&#093;*to any
&#091;***&#093;* necessary for &#091;***&#093;* develop and commercialize &#091;***&#093;* such Leads, Target Compounds, Lead
Compound and/or Licensed Products and for use with the relevant Collaboration Target for
development and commercialization into Licensed Products &#091;***&#093;*, and only for the &#091;***&#093;* the time
of such &#091;***&#093;*, or, in the alternative, &#091;***&#093;* the Program and thereupon &#091;***&#093;* as may be provided
herein or under applicable law. During the pendency of any &#091;***&#093;*hereunder shall be held &#091;***&#093;* in
accordance with the &#091;***&#093;* mutually agreed upon by the Parties. In the event that such a &#091;***&#093;*
occurs after the initiation of the &#091;***&#093;* involving a Lead Compound under the Program, then &#091;***&#093;*
Licensed Products (as set forth in Section&nbsp;5.5) for all sales by
&#091;***&#093;*. <B>&#091;***&#093;*</B>.
</DIV>


<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="left"><B>7.</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD><U><B>Maintenance, Reporting, and Ownership of Data</B></U></TD>
</TR>

</TABLE>
</DIV>
<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>7.1 </B>At least once &#091;***&#093;*, or as frequently as the JSC may otherwise reasonably determine, each
Party will provide to the other Party written reports setting forth a summary and interpretation of
all data and results arising during and pursuant to the Research Collaboration. The report will
contain such other information as reasonably determined by the JSC.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>7.2 </B>On the request of one Party, the other Party will provide within &#091;***&#093;* of termination of the
Agreement a final written report setting forth a summary and interpretation of all data and results
arising during and pursuant to all the Programs under this Agreement.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>7.3 </B>The Parties will create and maintain complete and accurate written records of all data and
results arising under this Agreement. Each Party will make such records available to the other
Party for inspection and copying &#091;***&#093;* during regular business hours on reasonable advance notice.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>7.4 </B>Representatives of each Party may, on reasonable notice and at times reasonably acceptable to
the other Party, visit for any purpose determined by the JSC the other Party&#146;s facilities where the
activities under this Agreement are being conducted.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>7.5 </B>GSK has a secure information technology exchange system for the electronic exchange of data and
results between GSK and its research partners. The Parties will implement and use the GSK secure
information technology exchange system during the Research Collaboration in accordance with a
procedure to be determined by the Joint Steering Committee. Each Party will bear its own costs and
expenses with respect to the setting up, use and maintenance of the system.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>7.6 </B>Sirna will own solely and exclusively all data, results and know-how that Sirna generates alone
or which is generated jointly with GSK by the Parties pursuant to this Agreement pertaining
</DIV>



<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">33
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">specifically to the synthesis, discovery, or manufacture of siRNAs in connection with the use of
Sirna&#146;s proprietary technology and methodology (&#147;RNAi Data&#148;) and will grant to GSK a non-exclusive,
sublicenseable right to use such RNAi Data in the Respiratory Field &#091;***&#093;<B>* </B>during the Term of this
Agreement. Sirna will have the right to use the RNAi Data in support of regulatory filings and
filing patent applications and for other purposes. In addition, Sirna will have the right to
&#091;***&#093;* under this Agreement in connection with the exercise of rights and licenses granted to Sirna
under this Agreement. Subject always to the licenses and other rights granted to GSK and the
covenants and other applicable restrictions under this Agreement, (i)&nbsp;with respect to &#091;***&#093;*, Sirna
shall have the right to &#091;***&#093;* to process development, analytical development, manufacturing, and
safety (and any other regulatory purposes with the prior consent of GSK, such consent not to be
unreasonably withheld) and in connection with filing and prosecuting Sirna Patents, and (ii)&nbsp;with
respect to any data and results generated solely hereunder by Sirna &#091;***&#093;*<B>, </B>Sirna shall have the
right to use such data and results in connection with the filing and prosecution of patent
applications or patents Controlled by Sirna.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>7.7 </B>GSK will own solely and exclusively all data, results and know-how that GSK generates alone or
which is generated jointly with Sirna pertaining specifically to &#091;***&#093;* and will grant to Sirna a
non-exclusive, sublicenseable right to use such GSK Know-How and Joint Know-How &#091;***&#093;*. Sirna will
have a right to use, for the purpose of conducting research pursuant to this Agreement, any GSK
Know-How or Joint Know-How relating to &#091;***&#093;*. GSK will have the right to use such GSK Know-How
and Joint Know-How for any purpose, including, without limitation, in support of regulatory filings
and filing patent applications and for other purposes.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>7.8 </B>GSK will have the exclusive right to submit to and prosecute before Regulatory Authorities any
matter with respect to Lead Compounds, Target Compounds or Licensed Products in the Field, except
in cases where Sirna acquires the exclusive rights to pursue the development and commercialization
thereof in accordance with Section&nbsp;3.5 hereof, in which cases Sirna will have such exclusive right.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>7.9 </B><U>Regulatory Data Protection</U>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">(a)&nbsp;To the extent required by law or permitted by law, the Parties will use commercially
reasonable efforts to promptly, accurately and completely list, with the applicable Regulatory
Authorities during the Term of this Agreement all applicable Sirna Patents or GSK Patents for any
Licensed Product that the Parties intend to, or have begun to commercialize, and that have become
the subject of a marketing application submitted to FDA, such listings to include all so called
&#147;Orange Book&#148; listings required under the Hatch-Waxman Act (regardless of which Party is the
sponsor of record of the NDA at such time) and all so called &#147;Patent Register&#148; listings as required
in Canada.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">(b)&nbsp;In connection with such listings, the Parties will evaluate and identify all applicable Sirna
Patents and GSK Patents. Where GSK has initiated Development for a Target Compound that has or
will become the subject of a marketing application submitted to FDA, GSK will retain final
</DIV>



<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">34
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">decision-making authority as to the listing of all applicable patents for any Licensed Product,
regardless of which Party owns such patent.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>7.10 </B>Each Party will make its employees and others working on its behalf reasonably available to
consult with the other Party and with any Regulatory Authority on any issue arising under this
Agreement at the expense of the requesting Party.
</DIV>


<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="left"><B>8.</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD><U><B>Manufacturing </B></U></TD>
</TR>

</TABLE>
</DIV>
<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>8.1 </B>Sirna or one of its Affiliates shall have the obligation to manufacture and supply all
requirements for research grade siRNA supply without additional charge to GSK, as set forth in
Section&nbsp;3.3(c) during the Research Term and as specified in the Program of Work and Research Plan.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>8.2 </B>Sirna or one of its Affiliates shall have the obligation to manufacture and supply all Lead
Compounds, Back-Up Compounds, and other Target Compounds, arising hereunder, for all requirements
for IND enabling studies and Phase I and Phase II trials, in accordance with the terms and
conditions set forth in a separate Manufacturing and Supply Agreement including a Quality Agreement
to be negotiated by the Parties, &#091;***&#093;<B>* </B>by GSK for Development, with respect to the quantity,
quality, capacity, and delivery timelines for any such Target Compound. In the Manufacturing and
Supply Agreement, GSK will be obligated to pay COGS plus &#091;***&#093;* for any active pharmaceutical
ingredient.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>8.3 </B>In the event that &#091;***&#093;* manufacture all of GSK&#146;s requirements for IND enabling studies and
Phase I and Phase II trials, to all of GSK&#146;s specifications, criteria and delivery timelines for
the siRNA component &#091;***&#093;*. If (a)&nbsp;Sirna and its Affiliates &#091;***&#093;* any siRNA component of the Lead
Compound, or Backup Compounds in accordance with this Article&nbsp;8, &#091;***&#093;* or (b)&nbsp;Sirna notifies GSK
that &#091;***&#093;* such siRNA component hereunder, &#091;***&#093;* manufacture the siRNA component &#091;***&#093;* under
this Article&nbsp;8. Sirna will make reasonable diligent efforts to cooperate with GSK at GSK&#146;s expense
as reasonably necessary to enable &#091;***&#093;* manufacture the siRNA component. On GSK&#146;s request, &#091;***&#093;*
that is reasonably necessary for &#091;***&#093;* manufacture the siRNA component and, if not already
conveyed &#091;***&#093;* such rights as are required solely for the purpose of enabling &#091;***&#093;* manufacture
or have manufactured the siRNA component.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>8.4 </B>&#091;***&#093;* manufacturing rights for Phase III and commercial manufacturing. &#091;***&#093;* capabilities
and expertise and infrastructure, and shall offer &#091;***&#093;* manufacture and supply to GSK (or its
designee) all active pharmaceutical ingredient (that is, all siRNA component(s), as distinct from
finished product) of all Lead Compounds and Backup Compounds for all Phase III Development needs
and beyond, under the terms of a separate Manufacturing and Supply Agreement including a Quality
Agreement (such Supply Agreement to be distinct from the Supply Agreement referenced in Section
8.1) to be negotiated in good faith between the Parties on commercially-reasonable terms prior to
the start of the first Phase III clinical trial of any Lead Compound or Backup Compounds, and
containing usual and customary terms in manufacturing and supply agreements. &#091;***&#093;* Sirna or its
Affiliate &#091;***&#093;* to provide Phase III Lead Compound
</DIV>



<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">35
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">requirements, the Parties will meet no later than &#091;***&#093;* prior to the start of any manufacture of
Phase III trial materials to discuss the terms of an additional Manufacturing and Supply Agreement.
In the Manufacturing and Supply Agreement, GSK will be obligated to pay COGS plus &#091;***&#093;* for any
active pharmaceutical ingredient.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>8.5 </B>&#091;***&#093;* requirements for Phase III and commercial manufacturing of the Lead Compound, Backup
Compounds or Licensed Product. Sirna agrees to provide &#091;***&#093;* manufacturing of the Target
Compound, Such &#091;***&#093;<B>* </B>shall include but not be limited to (i) &#091;***&#093;* (ii)&nbsp;providing consulting or
engineering assistance, on a full-time-equivalent basis to be negotiated, &#091;***&#093;* acceptable process
yield and quality on a similar scale and/or (iii)&nbsp;at GSK&#146;s request, entering into a &#091;***&#093;* mutually
agreed by the Parties to facilitate manufacture of the Target Compounds &#091;***&#093;*.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>8.6 </B>As a condition of any disclosure of &#091;***&#093;* relating to manufacture of Target Compound &#091;***&#093;*
must agree to be bound by an agreement obligating it to maintain the know how in confidence under
substantially the same terms as those set forth in Article&nbsp;10, and Sirna must have the ability to
review and give consent to the disclosure, such consent not to be unreasonably withheld.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>8.7 </B>For any supply of Target Compounds &#091;***&#093;* agrees to use only suppliers which have been approved
by &#091;***&#093;* and to utilize &#091;***&#093;* where such use would improve quality and/or reduce costs for the
Target Compounds development, manufacture or supply.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>8.8 </B>Sirna agrees to supply GSK with small-scale research reagent grade Target Compounds at COGS
plus &#091;***&#093;* for GSK&#146;s &#091;***&#093;* activities (outside the Program of Work) in accordance with the terms
and condition of this Agreement, based on a written request from GSK.
</DIV>


<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="left"><B>9.</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD><FONT style="font-variant: SMALL-CAPS"><B>INTELLECTUAL PROPERTY</B></FONT></TD>
</TR>

</TABLE>
</DIV>
<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>9.1 </B>Ownership of inventions made under this Agreement, whether or not patentable, will be
determined by inventorship according to U.S. patent law For the avoidance of doubt, inventions
conceived by Sirna employees will be owned by Sirna and inventions conceived by GSK employees will
be owned by GSK, subject to all the applicable license provisions under Article&nbsp;4 and all other
applicable provisions of this Agreement, and inventions conceived jointly by employees of both
Parties will be owned jointly by the Parties, subject to the applicable provisions of Article&nbsp;7 of
this Agreement. Notwithstanding the foregoing, Sirna will own solely and exclusively all
inventions Sirna conceives alone or jointly with GSK specifically relating to the synthesis,
discovery, or manufacture of siRNAs in connection with Sirna&#146;s proprietary technology platform
(&#147;RNAi Inventions&#148;) and will grant to GSK a non-exclusive, sublicenseable license in the Territory
to use such RNAi Inventions in the &#091;***&#093;* during the Term of this Agreement.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>9.2 </B>Sirna will be responsible for filing, prosecuting and maintaining (for the purposes of this
Article&nbsp;9, all these activities will be referred to as &#147;Prosecuting&#148;) the Sirna Patents, any other
patent or application it owns that Cover Collaboration Compounds, Leads, Lead Compounds, Licensed
Products, or methods of use or methods of manufacturing the same, and the Joint Patents,
</DIV>



<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">36
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">until such time as GSK progresses a Lead Compound or other Target Compound hereunder into &#091;***&#093;* shall
assume from that point forward the responsibility &#091;***&#093;<B>* </B>for Prosecuting all such patents and
applications, to the extent such patents Cover a Lead Compound being progressed into Development by
GSK. The Parties shall consider filing &#091;***&#093;* wherever possible, to enable &#091;***&#093;* the Prosecution
of Sirna Patent claims which Cover Lead Compounds being progressed into Development by GSK.
Notwithstanding the foregoing, if such patents or patent applications Cover subject matter &#091;***&#093;*
under this Agreement then, Sirna &#091;***&#093;* Prosecuting all such patents under the same terms set forth
under this Section&nbsp;9.2 of the Agreement. If any such patent or patent application is amended so as
to cease to Cover Leads, Lead Compounds, Licensed Products, or methods of use or methods of
manufacturing the same then &#091;***&#093;*.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>9.3 </B>While Sirna is responsible for Prosecuting the Sirna Patents, Sirna will consult with GSK prior
to filing any document, including for the avoidance of doubt, any new application or specification
for a Sirna Patent or a Joint Patent arising during and pursuant to the Research Collaboration, or
any office action response or making any payment in connection with the Prosecution sufficiently in
advance to enable GSK to comment on the document or payment. Sirna will consult with GSK prior to
filing any foreign patent applications claiming priority to a Sirna Patent or Joint Patent that
Covers Leads, Lead Compounds, Licensed Products, or methods of use or methods of manufacturing the
same, in relation to the countries in which such foreign patent applications will be filed. &#091;***&#093;*
Sirna will provide to GSK copies of any documents it receives in connection with the Prosecution,
and will inform GSK of its progress &#091;***&#093;*. The Parties will cooperate fully in the Prosecution,
particularly as to executing all papers relevant to it.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>9.4 </B>In the event that Sirna elects not to prosecute in any country any Joint Patent or any Sirna
Patent that Covers Leads, Lead Compounds, Licensed Products, or methods of manufacturing the same,
Sirna will give GSK where possible &#091;***&#093;* notice before any relevant deadline and provide to GSK
all information reasonably relating to such patent or application. GSK will have the right to
prosecute such patent or application at its own expense.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>9.5 </B>In the event that GSK elects not to prosecute in any country any patent or application for
which GSK has assumed from Sirna the responsibility for Prosecuting under Section&nbsp;9.2, then Sirna
will have the right to prosecute such patent or application at its own expense.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>9.6</B>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;a.&nbsp;Sirna will have the first right, but not the obligation, to defend &#091;***&#093;* Leads, Lead
Compounds, Licensed Products or methods of use or methods of manufacturing the same, against any
allegations of invalidity, unenforceability or any allegations in relation to incorrect
inventorship or ownership including, without limitation, any oppositions, revocation actions or
interferences brought in relation to such patents or patent applications &#091;***&#093;*. Sirna will consult
with GSK prior to filing any document, or any response or making any payment in connection with the
defense of such patents or patent applications sufficiently in advance to enable GSK to comment on
the document or payment. &#091;***&#093;* Sirna will provide to GSK copies of any documents it receives in
connection with the defense of such patents or patent applications, and will inform
</DIV>


<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">37
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">GSK of its progress. GSK shall reimburse Sirna for 50% of all costs in relation to the defense
of such patents incurred after the Effective Date of this Agreement. The Parties will cooperate
fully in the defense of such patents or patent applications, particularly as to executing all
papers relevant to it.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b)&nbsp;From such time as GSK progresses a Lead Compound hereunder into Development, GSK shall
assume the responsibility (including 100% of all relevant costs) for defending all patents and
applications for which GSK has assumed responsibility for Prosecution under Section&nbsp;9.2 above.
</DIV>
<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>9.7 </B>In the event that a Party elects not to defend in any country any Joint Patent or any Sirna
Patent that Covers Leads, Lead Compounds, Licensed Products, or methods of manufacturing the same,
such Party shall provide the other Party, where possible at least &#091;***&#093;<B>* </B>notice before any relevant
deadline and provide to the other Party all information reasonably relating to such patent or
application and the defense thereof. The other Party will have the right to prosecute and defend
such patent or application at its own expense, and should it do so the declining party shall grant
to the Party assuming such responsibility an exclusive license in such country to make, use, sell,
and offer for sale the invention claimed therein for the term of this Agreement with no
restrictions as to sub-licensing, subject to any royalty or other financial obligations applicable
under Article&nbsp;5. Such a license will be in the Field as to any patent that Sirna solely owns and
without any Field limitation as to any patent that the Parties jointly own.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>Infringement by Third Parties</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>9.8 </B>The Parties will promptly notify each other of any actual or threatened infringement of any
patents that the Parties jointly own or any patents that Cover Licensed Products, Lead Compounds,
or their use or manufacture, and will provide to each other any evidence of such infringement.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>9.9 </B>GSK will have the first right to bring and control, at its expense, any proceeding before any
government or private tribunal (&#147;Infringement Action&#148;) to remedy the infringement of and to defend
against any counterclaim for invalidity of a) any patent which Covers Licensed Products or Lead
Compounds; and b) any patent which GSK owns jointly with Sirna. Sirna will have the right, at its
own expense and by counsel of its choice, to be represented in any such action.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>9.10 </B>Sirna will have the first right to bring and control, at its expense, any Infringement Action
to remedy the infringement of and to defend against any counterclaim for invalidity of any patent
that GSK does not have the first right to enforce under Section&nbsp;9.9. GSK will have the right, at
its own expense and by counsel of its choice, to be represented in any such action.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>9.11 </B>If, within six (6)&nbsp;months following the notice of infringement pursuant to Section&nbsp;9.8 or ten
(10)&nbsp;days before the time limit for filing of an Infringement Action, whichever comes first, a
Party has not reached an agreement with or filed an Infringement Action against the infringer, the
other Party will have the right to bring and control, at its expense, any such action.
</DIV>



<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">38
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>9.12 </B>The Parties will first deduct their expenses from any recovery realized as a result of an
Infringement Action and then pay to Sirna an amount equal to the royalties that would be due to
Sirna had infringing sales been Net Sales. The Parties will share the remainder of the recovery
such that the Party bringing the Infringement Action receives &#091;***&#093;* of the remainder of the
recovery and the other Party receives &#091;***&#093;<B>* </B>of the remainder of the recovery. In event that the
Parties jointly bring an Infringement Action, they will share any recovery according to a formula
they will develop by mutual agreement.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>Infringement of Third-Party Rights</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>9.13 </B>The Parties will promptly notify each other of any allegation of a Third Party that any
activity pursuant to this Agreement infringes or may infringe or misappropriates or may
misappropriate the intellectual property rights of any Third Party.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>9.14 </B>In any allegation that the Development, manufacture, or sale of Licensed Products by GSK or
its Affiliate or Third Party Licensee would infringe or misappropriate an intellectual property
right of a Third Party, GSK will have the first right to control, at its expense, the defense of
any claim involving such allegation. As to all other allegations, Sirna will have the first right
to control, at its expense, the defense of any claim involving such allegations. In each case, the
other Party will have the right, at its own expense and by counsel of its own choice, to be
represented in connection with the defense of any such claim.<U> </U>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>9.15 </B>To the extent such allegations of infringement involve a patent that allegedly Covers a Lead,
Lead Compound, Backup Compounds, Lead Compound, or Licensed Product, or the use of any such
Compound, or a misappropriation by Sirna of any technology relating to such Compounds or any
technology used or practiced by Sirna under the Research Plan in order to design, generate, or
optimize any siRNA Leads or other Compounds, Sirna and GSK shall be jointly responsible for (a)
satisfying all resulting claims, demands and payments required by a final court order or settlement
agreement or other legal or administrative proceeding to be paid by GSK or Sirna resulting from a
Third Party claim of infringement or misappropriation of intellectual property rights; and (b)&nbsp;all
reasonable expenses incurred by GSK and Sirna, including reasonable attorneys fees, in defending
against the claim.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>9.16 </B>The Parties will cooperate in all respects with one another in prosecuting or defending any
action pursuant to this section.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>9.17 </B>Neither Party may settle any action under this Article&nbsp;9 without the consent of the other
Party, such consent not to be unreasonably withheld.
</DIV>



<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">39
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>10. </B><FONT style="font-variant: SMALL-CAPS"><B>Confidentiality and Publication</B></FONT>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>10.1 </B>During the Term and for the five (5)&nbsp;years thereafter each Party will not disclose or use any
Confidential Information unless allowed to do so under this Agreement. Each Party will promptly
notify the other on discovering any unauthorized disclosure or use of Confidential Information.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>10.2 </B>The obligations of non-disclosure and non-use contained in this section will not apply to the
extent that the Party receiving the Confidential Information can establish that
</DIV>


<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>a)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>the information is in the public domain, or after the Effective Date enters
into the public domain through no breach of this Agreement;</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>b)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>the Party knew the information before receiving it from the disclosing Party;</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>c)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>the Party received the information from a Third Party not bound to the
disclosing Party by any obligation of non-disclosure;</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>d)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>the Party independently develops the information without reference to or use of
any Confidential Information disclosed hereunder by the other Party; and</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>e)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>the Party is required to disclose the information by law, court order, or
applicable regulations, provided that Party i) as soon as practical before the
disclosure, notifies the other Party; and ii) identifies the Confidential Information
so required thereby, so that the disclosing Party may seek an appropriate protective
order or other remedy with respect to narrowing the scope of such requirement and/or
waive receiving Party&#146;s compliance with the provisions of this Agreement.</TD>
</TR>

</TABLE>
</DIV>
<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>10.3 </B>This Agreement and its terms will be considered Confidential Information, provided however,
Parties and their Affiliates will each be permitted to disclose such Confidential Information to
the extent reasonably necessary (a)&nbsp;to such Party&#146;s or Affiliate&#146;s attorneys, accountants and other
professional advisors under an obligation of confidentiality to such Party or Affiliate, (b)&nbsp;to
such Party&#146;s or Affiliate&#146;s current or prospective banks or other financial institutions or
investors for the purpose of raising capital or borrowing money or maintaining compliance with
agreements, arrangements and understandings relating thereto and (c)&nbsp;to any person who proposes to
be a sublicensee or to purchase or otherwise succeed (by merger, operation of law or otherwise) to
all of such Party&#146;s or Affiliate&#146;s right, title and interest in, to and under this Agreement, if
such person agrees to maintain the confidentiality of such Confidential Information pursuant to a
written agreement at least as protective of such Confidential Information as the terms set forth in
this Section. The standard of care required to be observed hereunder will be not less than the
degree of care which each Party or Affiliate thereof uses to protect its own information of a
confidential nature, and each Party will use commercially reasonable efforts to ensure that persons
to whom it discloses Confidential Information in accordance herewith do not disclose or make any
unauthorized use of such Confidential Information. Sirna shall also have the right to share a
mutually-agreed redacted version of this Agreement with a Third Party under confidentiality
(pursuant to a written agreement at least as protective of such Confidential Information as the
terms set forth in this Section) for the purposes of establishing a collaboration.
</DIV>

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">40
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>10.4 </B>Should a Party wish to publish (including in a scientific journal or in a press release other
than as set forth in Section&nbsp;10.6), or to publicly announce (including, without limitation, at any
&#147;R&#038;D update&#148;, scientific or investor&#146;s conference, or the like), any research, data, know how or
results arising under this Agreement or the progress of any Program hereunder, or any other
material that contains any such data, know how or results, or the Confidential Information of the
other Party, the Party seeking to make such disclosure will submit a copy of the proposed
publication, press release (other than as set forth under Section&nbsp;10.6) or public announcement to
the JSC and the other Party at least forty-five (45)&nbsp;days before submitting the publication, press
release (other than those set forth in 10.6) or public announcement to a journal or other forum or
otherwise disclosing it. The JSC and the reviewing Party may require modifications to the
publication (including the deletion of the Confidential Information of the reviewing Party) or a
delay for a reasonable duration as necessary to file patent applications or take other necessary
measures, prior to any such disclosure.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>10.5 </B>Each of GSK and Sirna shall have the right to publish summaries of results and data from any
human clinical trials conducted by such Party or conducted by the other Party pursuant to this
Agreement, without obtaining the consent of the other Party. The Parties shall discuss and
reasonably cooperate in order to facilitate the process to be employed in order to ensure the
publication of any such summaries as required on the clinical trial registry of each respective
Party, and shall provide the other Party via submission to the IP Subcommittee established under
Article&nbsp;2, wherever possible at least forty-five (45)&nbsp;days, but in no event less than thirty (30)
days prior notice to review the clinical trials results and data to be published, for the purposes
of preparing any necessary patent filings.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>10.6 </B>The Parties shall each have the right to issue the press release attached hereto as Exhibit&nbsp;G.
Unless required by law, no Party will make any other public announcement relating to the existence
of this Agreement or its terms, without at least forty-eight hours prior written notice to the
other Party, and the express prior written consent of the other Party, such consent not to be
unreasonably withheld.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>10.7 </B>Neither Party may use the name or mark of the other Party without prior written consent of the
other Party, unless otherwise required by law or governmental authority.
</DIV>


<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="left"><B>11.</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD><FONT style="font-variant: SMALL-CAPS"><B>Representations, Warranties and Indemnification </B></FONT></TD>
</TR>

</TABLE>
</DIV>
<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>11.1 </B>Each Party represents to the other that as of the Effective Date:
</DIV>


<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>a)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>it is duly organized and validly existing under the laws of its state of
incorporation and has full authority to enter into this Agreement;</TD>
</TR>

</TABLE>
</DIV>

<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>b)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>the execution and performance of this Agreement does not conflict with
any other agreement, oral or written, to which it is a party;</TD>
</TR>

</TABLE>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>11.2 </B>Sirna represents that as of the Effective Date:
</DIV>
<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">41
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>


<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>a)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>it is the &#091;***&#093;<B>* </B>Sirna Patents and has sufficient rights to grant the
licenses granted to GSK under Article&nbsp;4;</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>b)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>no Third Party has any interest in the Sirna Patents and Sirna Know-How
that would impair or conflict with the rights and licenses granted hereunder to
GSK&#146;s for the use of such Sirna Patents and Sirna Know-How and Joint Patents and
Joint Know-How as provided herein;</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>c)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>&#091;***&#093;* that Sirna&#146;s manufacture, use, sale, offer for sale, or import of
any Target Compound or Collaboration Compound as contemplated hereunder &#091;***&#093;*
patents or other intellectual property right;</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>d)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>neither Sirna nor any of its Affiliates is in material breach or default
of any provision or obligation under any of the Third Party License Agreements;</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>e)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>neither Sirna nor any of its Affiliates is &#091;***&#093;* as of the Effective
Date which is not included under the Third Party License Agreements and licensed to
GSK either exclusively (wherever possible) or non-exclusively (where an exclusive
license is contractually prevented) under Article&nbsp;4, which Sirna or its Affiliate
&#091;***&#093;* for the Parties to conduct the Research Collaboration and for the Development
of Licensed Products as contemplated hereunder; and</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="2%" style="background: transparent">&nbsp;</TD>
    <TD width="3%" nowrap align="left"><B>f)</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD>the Sirna Patents are valid and in full force, and are not the subject of
any pending or to Sirna&#146;s knowledge threatened interference or opposition proceeding
or any infringement or enforcement or other litigation.</TD>
</TR>

</TABLE>
</DIV>
<DIV align="left" style="font-size: 10pt; margin-top: 6pt">In the event that at any time after the Effective Date, Sirna becomes aware that any representation
made under this Section&nbsp;11.2 is no longer accurate, Sirna shall immediately notify GSK in writing
and provide the facts and details with respect to such change in status.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">In the event of any bankruptcy or insolvency of Sirna, or in the event of any default or material
breach by Sirna of the terms of any of the Third Party License Agreements, in any such case as a
result of which Sirna would reasonably be expected to no longer have the right to grant to GSK any
of the licenses granted under any of the Third Party Agreements, then, in order to preserve GSK&#146;s
rights to practice the licenses granted to GSK under Section&nbsp;4 of this Agreement, Sirna hereby
agrees to provide reasonable assistance in the event that GSK and/or its Affiliate desires to
obtain contractual privity directly with any party to one of the Third Party License Agreements to
establish GSK and/or its Affiliate as a stand-in licensee under any of the Third Party License
Agreements such that GSK and/or its Affiliate may continue to practice as a licensee under any of
the Third Party License Agreements.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>11.3 </B>EXCEPT AS OTHERWISE EXPRESSLY STATED IN THIS AGREEMENT, NO PARTY MAKES ANY REPRESENTATIONS OR
WARRANTIES AS TO ANY MATTER WHATSOEVER. ACCORDINGLY, EXCEPT AS EXPRESSLY STATED IN THIS AGREEMENT,
EACH PARTY HEREBY EXPRESSLY DISCLAIMS ALL
</DIV>



<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">42
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">REPRESENTATIONS AND WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, INCLUDING WITHOUT LIMITATION ANY
IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AGAINST NON-INFRINGEMENT
OR THE LIKE, INCLUDING (a)&nbsp;THAT ANY SIRNA PATENT OR TECHNOLOGY OR THE PRACTICE THEREOF OR ANY
LICENSED PRODUCTS WILL IN THE FUTURE BE FREE FROM CLAIMS OF PATENT INFRINGEMENT, INTERFERENCE OR
UNLAWFUL USE OF PROPRIETARY INFORMATION OF ANY PERSON AND (b)&nbsp;OF THE RELIABILITY, TECHNOLOGICAL OR
COMMERCIAL VALUE OR MERCHANTABILITY OF THE SIRNA PATENTS OR ANY LICENSED PRODUCTS, OR THEIR
FITNESS THEREOF FOR ANY PARTICULAR PURPOSE.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>11.4 </B>EXCEPT FOR THOSE CLAIMS OF A THIRD PARTY AS MAY BE PAYABLE PURSUANT TO THIS AGREEMENT, TO THE
MAXIMUM EXTENT PERMITTED BY LAW AND NOTWITHSTANDING ANY PROVISION IN THIS AGREEMENT TO THE
CONTRARY, NEITHER SIRNA, ON THE ONE HAND, NOR GSK, ON THE OTHER HAND, NOR ANY OF THEIR AFFILIATES,
THIRD PARTY LICENSEES OR REPRESENTATIVES WILL BE LIABLE TO THE OTHER PARTY, ITS AFFILIATES OR ANY
OF THEIR THIRD PARTY LICENSEES OR REPRESENTATIVES FOR ANY INDIRECT, INCIDENTAL, CONSEQUENTIAL,
SPECIAL, RELIANCE OR PUNITIVE DAMAGES OR LOST OR IMPUTED PROFITS OR ROYALTIES, LOST DATA OR COST OF
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, WHETHER LIABILITY IS ASSERTED IN CONTRACT, TORT
(INCLUDING NEGLIGENCE AND STRICT PRODUCT LIABILITY), INDEMNITY OR CONTRIBUTION, AND IRRESPECTIVE OF
WHETHER THAT PARTY OR ANY REPRESENTATIVE OF THAT PARTY HAS BEEN ADVISED OF, OR OTHERWISE MIGHT HAVE
ANTICIPATED THE POSSIBILITY OF, ANY SUCH LOSS OR DAMAGE. IN ADDITION, THE LIABILITY OF SIRNA TO
GSK WITH RESPECT TO THE SUBJECT MATTER OF ARTICLE 8 FOR ANY PRE-CLINICAL RESEARCH SUPPLY (NOT FOR
USE IN HUMANS) HEREUNDER (REGARDLESS OF THE FORM OF ACTION, WHETHER IN CONTRACT, IN TORT, OR
OTHERWISE) WILL BE LIMITED TO THE AGGREGATE AMOUNT PAID BY GSK TO SIRNA FOR THE MANUFACTURE AND
SUPPLY BY SIRNA TO GSK OF LEADS, LEAD COMPOUNDS, BACKUP COMPOUNDS, AND COMPOUNDS.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>11.5 </B>GSK hereby agrees to indemnify, defend and hold Sirna, its Affiliates, and their respective
directors, officers, employees, agents and their respective successors, heirs and assigns (the
&#147;Sirna Indemnitees&#148;) harmless from and against any losses, costs, claims, damages, liabilities or
expenses (including reasonable attorneys&#146; and professional fees and other expenses of litigation)
(collectively, &#147;Liabilities&#148;) arising out of claims, suits, actions or demands, in each case
brought by a third party or judgments arising therefrom (including those arising out of personal
injury claims) (each a &#147;Claim&#148;) as a result of (a)&nbsp;activities of GSK, its Affiliates or Third Party
Licensees, or any Third Party acting on behalf of or under authorization by GSK in connection with
GSK&#146;s Development, manufacture (to the extent GSK or any Third Party acting on behalf of GSK
manufactures Target Compounds, Lead Compounds, Backup Compounds or Licensed Products),
commercialization, or other use or handling of Target Compounds, Lead Compounds, Backup Compounds
and Licensed Products, or (b)&nbsp;a breach of the terms and conditions of this Agreement by GSK or
representations and warranties made by GSK in this Agreement; <I>provided, however</I>, that GSK&#146;s
obligations pursuant to this Section&nbsp;11.5 will not apply to the extent such Claims result
</DIV>

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">43
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">from (i)&nbsp;the negligence, recklessness, bad faith, intentional wrongful acts or omissions of any of
the Sirna Indemnitees or (ii)&nbsp;material breach of the terms and conditions of this Agreement by any
of the Sirna Indemnitees.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>11.6 </B>Sirna hereby agrees to indemnify, defend and hold GSK, its Affiliates, and their respective
directors, officers, employees, agents and their respective successors, heirs and assigns (the &#147;GSK
Indemnitees&#148;) harmless from and against any Liabilities arising out of Claims, as a result of (a)
activities of Sirna, its Affiliates, or any Third Party acting on behalf of or under authorization
by Sirna in connection with Sirna&#146;s performance of its responsibilities and activities under the
Research Plan, or the development (where permitted hereunder), manufacture (to the extent Sirna or
a Third Party acting on behalf of Sirna manufactures Target Compounds, Lead Compounds, Backup
Compounds or Licensed Products hereunder), commercialization (where permitted hereunder), or other
use or handling of any Leads, Target Compounds, Lead Compounds, Backup Compounds, or Licensed
Products, or (b)&nbsp;a breach of the terms and conditions of this Agreement by Sirna or a breach of any
of the representations and warranties made by Sirna in this Agreement; <I>provided, however</I>, that
Sirna&#146;s obligations pursuant to this Section&nbsp;11.6 will not apply to the extent such Claims result
from (i)&nbsp;the negligence, recklessness, bad faith, intentional wrongful acts or omissions of any of
the GSK Indemnitees or (ii)&nbsp;material breach of the terms and conditions of this Agreement by any of
the GSK Indemnitees.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>11.7 </B>In the event a Claim is made against a Sirna Indemnitee or GSK Indemnitee, as applicable
(each, an &#147;Indemnified Party&#148;) with respect to which it is entitled to indemnification under this
Article&nbsp;11, such Indemnified Party will promptly notify the Party having such indemnification
obligation (the &#147;Indemnifying Party&#148;) of such Claim and the facts constituting the basis for the
Claim and the Indemnifying Party may, at its option, elect to assume control of the defense of such
Claim with counsel reasonably acceptable to such Indemnified Party; <I>provided, however</I>, that (a)&nbsp;the
Indemnified Party will be entitled to participate therein (through counsel of its own choosing) at
the Indemnified Party&#146;s sole cost and expense, and provided, further, that, if the litigants in any
such action include both the Indemnified Party and the Indemnifying Party and reputable legal
counsel for the Indemnified Party will have reasonably concluded in a written legal opinion
delivered to the Indemnifying Party that, by reason of certain bona fide defenses available to the
Indemnified Party which are different from or additional to those available to the Indemnifying
Party, the interests of the Indemnified Party materially conflict with the interests of the
Indemnifying Party such that it would be unethical under applicable rules relating to attorney
conflicts of interest for the Indemnifying Party and such Indemnified Party to be represented by
the same counsel with respect to such defense, the Indemnified Party will have the right to select
a separate counsel and to assume such legal defenses, with the reasonable expenses and fees of such
separate counsel and other expenses related to such participation to be reimbursed by the
Indemnifying Party as and when incurred and (b)&nbsp;the Indemnifying Party will not settle or
compromise any such Claim without the prior written consent of the Indemnified Parties, unless such
settlement or compromise consists solely of the payment of money by the Indemnifying Party and
includes a general release of the Indemnified Parties from any and all liability with respect
thereto. The Indemnified Parties will reasonably cooperate with and provide full information with
respect to any Claim for which the Indemnified Parties seek indemnification hereunder.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>11.8 </B>Nothing in this Article&nbsp;11 relieves Sirna of its obligations under Article&nbsp;9 of this
Agreement.
</DIV>

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">44
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>


<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="left"><B>12.</B></TD>
    <TD width="1%">&nbsp;</TD>
    <TD><B>GENERAL</B></TD>
</TR>

</TABLE>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>12.1 </B><U><B>Insurance. </B></U>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>b. </B><U> Sirna&#146;s Insurance Obligations</U>. Sirna shall maintain, at its cost, with effect
from prior to the date of first administration of any Licensed Product for testing in humans by
Sirna hereunder and during the Term thereafter, adequate insurance against liability and other
risks associated with its activities contemplated by this Agreement, in such amounts and on such
terms as are customary for reasonably prudent practices in the pharmaceutical industry, for
companies of similar size and nature as Sirna, relating to the activities to be conducted by it
under this Agreement. &#091;***&#093;<B>*</B>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;c. <U>GSK&#146;s Insurance Obligations</U>. GSK hereby represents and warrants to Sirna that it is
self-insured against liability and other risks associated with its activities and obligations under
this Agreement in such amounts and on such terms as are customary for prudent practices for large
pharmaceutical companies in the pharmaceutical industry for the activities to be conducted by it
under this Agreement.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>12.2 </B><U><B>Governing Law</B></U>. This Agreement will be governed by the laws of the State of Delaware.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>12.3 </B><U><B>Notices</B></U>. Any notice made pursuant to this Agreement will be effective only if made in
writing and delivered to all of the addresses below:
</DIV>

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="40%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="55%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD align="center" valign="top"><DIV style="margin-left:0px; text-indent:-0px"><B><I>If to Sirna:</I></B></DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="center" valign="top"><DIV style="margin-left:0px; text-indent:-0px"><B>1.</B> &nbsp;&nbsp;&#091;***&#093;*
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top"><B>2.</B> &nbsp;&nbsp;&#091;***&#093;*</TD>
</TR>
<TR valign="bottom">
    <TD align="center" valign="top"><DIV style="margin-left:0px; text-indent:-0px"><B>3.</B> &nbsp;&nbsp;&#091;***&#093;*</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD align="center" valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="center" valign="top"><DIV style="margin-left:0px; text-indent:-0px"><B><I>If to GSK:</I></B></DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="center" valign="top"><DIV style="margin-left:0px; text-indent:-0px"><B>1.</B> &nbsp;&nbsp;&#091;***&#093;*
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top"><B>2.</B> &nbsp;&nbsp;&#091;***&#093;*</TD>
</TR>
<TR valign="bottom">
    <TD align="center" valign="top"><DIV style="margin-left:0px; text-indent:-0px"><B>3.</B> &nbsp;&nbsp;&#091;***&#093;*</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">The notice will be effective on the first business day it is delivered, if delivered to the
addresses of each Party by hand, electronic facsimile, or overnight courier, or five days after
sending if delivered in any other way. A Party may change the delivery addresses by notice to the
other Party.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>12.4 </B><U><B>Entirety of Agreement</B></U>. This Agreement embodies the entire agreement between the
parties and supersedes any prior agreements between them. This Agreement may be modified in
writing only.
</DIV>



<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">45
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>12.5 </B><U><B>Counterparts</B></U>. This Agreement may be signed in counterparts, each and every one of
which shall be deemed an original, notwithstanding variations in format or file designation which
may result from the electronic transmission, storage and printing of copies of this Agreement from
separate computers or printers. Facsimile signatures shall be treated as original signatures.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>12.6 </B><U><B>Non-Waiver</B></U>. The failure of a Party in any one or more instances to insist upon strict
performance of any terms of this Agreement will not constitute a waiver of the right to assert such
terms on any future occasion.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>12.7 </B><U><B>Disclaimer of Agency</B></U>. Neither Party is the representative of the other, and neither
Party has the authority to bind the other Party to any obligation to any third party.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>12.8 </B><U><B>Severability</B></U>. If a court or government agency of competent jurisdiction holds that
any provision of this Agreement is invalid or unenforceable, then that provision will be severed
and the remainder of the Agreement will continue in full force and effect. To the extent possible,
the Parties will revise such severed provision in a manner that will render it valid.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>12.9 </B><U><B>Assignment; Binding Agreement</B></U>. This Agreement shall not be assignable by either Party
to any Third Party without the written consent of the other Party hereto. Notwithstanding the
foregoing, either Party may assign this Agreement, or any of its rights and obligations hereunder,
without the consent of the other Party, to an Affiliate or to an entity that acquires all or
substantially all of the business or assets of such Party to which this Agreement pertains (whether
by merger, reorganization, acquisition, sale or otherwise), and agrees in writing to be bound by
the terms and conditions of this Agreement. This Agreement and the terms and conditions hereof
shall be binding upon, and shall inure to the benefit of, the successors, heirs and permitted
assigns of the respective Parties.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>12.10 </B><U><B>Bankruptcy</B></U>. All rights granted under this Agreement will be considered for purposes
of Section 365(n) of 11 U.S.C. (&#147;the Bankruptcy Code&#148;) licenses of rights to &#147;intellectual
property&#148; as defined under Section&nbsp;101(56) of the Bankruptcy Code. The Parties agree that each
Party will retain and may fully exercise all of its rights and elections under the Bankruptcy Code.
In the event that either Party seeks or is involuntarily placed under the protection of the
Bankruptcy Code, and the trustee in bankruptcy rejects this Agreement, the other Party hereby
elects, pursuant to Section&nbsp;365(n), to retain all rights granted to it under this Agreement to the
extent permitted by law.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>12.11 </B><U><B>Stock Purchase Agreement</B></U>. GSK shall purchase Sirna common stock in the total amount
of Six Million US Dollars ($6,000,000) at a 25% premium, in accordance with the terms and
conditions of the Stock Purchase Agreement to be effective on the Effective Date of this Agreement.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt"><B>12.12 </B><U><B>Dispute Resolution</B></U>.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">(a)&nbsp;Any dispute, controversy or claim (&#147;<U>Dispute</U>&#148;) arising out of or in relation to this
Agreement, or the breach, termination or invalidity thereof, that cannot be settled amicably by the
Parties after a good faith discussion to resolve the Dispute by the appropriate officers of the
Parties, shall be submitted by either Party to arbitration conducted in accordance with the rules
then in effect of JAMS/Endispute. The arbitration shall take place in San Francisco, California if
initiated by GSK
</DIV>

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">46
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">and in Philadelphia, Pennsylvania if initiated by Sirna and shall be conducted by three (3)
arbitrators, one of whom shall be designated by each Party, and the third selected by the other two
(2)&nbsp;arbitrators, all within the time limits established by the then existing rules of the
JAMS/Endispute. If the two (2)&nbsp;designated arbitrators are unable to agree upon a third arbitrator
within two (2)&nbsp;months after submission of the matter to arbitration, then JAMS/Endispute shall
select such third arbitrator within three (3)&nbsp;months of such original submission. The written
decision of the arbitrators shall be final and binding on the Parties and may be enforced in any
court having jurisdiction over the Parties or their current assets. The award rendered by the
arbitrators shall include the filing fees and arbitrators&#146; fees in connection with the
arbitration. The Parties shall be entitled to discovery as determined by the arbitrators. If the
issues in dispute involve scientific or technical matters, at least one of the arbitrators chosen
hereunder shall have educational training and/or experience sufficient to demonstrate a reasonable
level of knowledge in the Field and pharmaceutical drug development. Notwithstanding the preceding
provisions of this Section&nbsp;12.12, with respect to any breach or threatened breach of this Agreement
of Article&nbsp;9 or 10 hereof, or any other provision where a Party would not be appropriately
compensated by the payment of money, a Party has a right to seek injunctive relief from any court
of competent jurisdiction to enjoin such breach or threatened breach and/or to seek specific
performance, prior to the empaneling of the arbitrators; and after such time, such relief may be
granted by the arbitrators, at their discretion.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">(b) &#091;***&#093;<B>*.</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">(c)&nbsp;Notwithstanding the foregoing, any matter which is subject to the decision-making authority of
the JSC under Article&nbsp;2 or Article&nbsp;3 shall not be subject to review and adjudication by dispute
resolution by arbitration under this Section&nbsp;12.12, except only as expressly stated under Section
3.4(c) or for a Dispute pertaining to the achievement of any milestone event under Section&nbsp;5.3.
</DIV>



<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">47
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">The Parties hereby execute this Agreement by entering the signatures below of their
respective duly authorized officers:
</DIV>

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="2%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="43%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="6%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="43%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD colspan="3" valign="top" align="left"><FONT style="font-variant: SMALL-CAPS"><B>Glaxo Group Limited</B></FONT></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD colspan="3" valign="top" align="left"><FONT style="font-variant: SMALL-CAPS"><B>Sirna Therapeutics, Inc.</B></FONT></TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">By:
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">/s/ Richard Stephens
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">By:
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">/s/ Howard W. Robin</TD>
</TR>
<TR style="font-size: 1px">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top" style="border-top: 1px solid #000000">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top" style="border-top: 1px solid #000000">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Name:
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Richard Stephens
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Name:
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Howard W. Robin</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Title:
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Assistant Company Secretary
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Title:
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">President &#038; CEO</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD colspan="3" valign="top" align="left"><FONT style="font-variant: SMALL-CAPS"><B>SmithKline Beecham Corporation,</B></FONT></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD colspan="3" valign="top" align="left"><FONT style="font-variant: SMALL-CAPS"><B>doing business as GlaxoSmithKline</B></FONT></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">By:
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">/s/ Donald F. Parman</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR style="font-size: 1px">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top" style="border-top: 1px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Name:
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Donald F. Parman</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Title:
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Vice President and Secretary</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">48
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>


<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><FONT style="font-variant: SMALL-CAPS"><B>Exhibit&nbsp;A</B></FONT>
</DIV>


<DIV align="Center" style="font-size: 10pt; margin-top: 6pt"><B>Model Program of Work for<BR>
a Single Collaboration Target</B>

</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 12pt">&#091;***&#093;<B>*</B>
</DIV>



<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">A-1
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>


<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><FONT style="font-variant: SMALL-CAPS"><B>SCHEDULE 1</B></FONT>
</DIV>


<DIV align="Center" style="font-size: 10pt; margin-top: 6pt">&#091;***&#093;<B>*</B>

</DIV>


<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">A-2
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>


<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><B>EXHIBIT B-1</B>
</DIV>


<DIV align="Center" style="font-size: 10pt; margin-top: 6pt"><B>Lead Compound Criteria</B>

</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 12pt">&#091;***&#093;<B>*</B>
</DIV>



<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">B-1
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>


<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><B>EXHIBIT B-2</B>
</DIV>


<DIV align="Center" style="font-size: 10pt; margin-top: 6pt"><B>Lead Criteria</B>

</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 12pt">&#091;***&#093;<B>*</B>
</DIV>



<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">B-2
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>


<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><B>EXHIBIT </B><FONT style="font-variant: SMALL-CAPS"><B>C</B></FONT><BR>
<FONT style="font-variant: SMALL-CAPS"><B>Sirna Patents</B></FONT>
</DIV>


<DIV align="Center" style="font-size: 10pt; margin-top: 6pt"><B>Select Sirna Patents and Patent Applications</B>

</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><FONT style="font-variant: SMALL-CAPS">&#091;***&#093;</FONT><B>*</B>
</DIV>



<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">C-1
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>


<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><FONT style="font-variant: SMALL-CAPS"><B>Exhibit&nbsp;D</B></FONT><BR>
<B>Third Party License Agreements</B>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 12pt">&#091;***&#093;<B>*</B>
</DIV>



<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">D-1
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>


<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><FONT style="font-variant: SMALL-CAPS"><B>Exhibit&nbsp;E</B></FONT><BR>
<B>Target Selection Form</B>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 12pt">&#091;***&#093;<B>*</B>
</DIV>



<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">E-1
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>


<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><FONT style="font-variant: SMALL-CAPS"><B>Exhibit&nbsp;F</B></FONT>
</DIV>


<DIV align="Center" style="font-size: 10pt; margin-top: 6pt"><B>Internal Sirna Committed Targets</B>

</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><FONT style="font-variant: SMALL-CAPS">&#091;***&#093;</FONT><B>*</B>
</DIV>



<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="1%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left"><SUP style="font-size: 85%; vertical-align: text-top">*</SUP></TD>
    <TD>&nbsp;</TD>
    <TD> Indicates that certain information contained
herein has been omitted and filed separately with the Securities and Exchange
Commission. Confidential treatment has been requested with respect to the
omitted portions.</TD>
</TR>

</TABLE>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
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    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">F-1
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>


<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><FONT style="font-variant: SMALL-CAPS"><B>Exhibit&nbsp;G</B></FONT><BR>
<B>PRESS RELEASE</B>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>Issued &#150; April 3</B><SUP style="font-size: 85%; vertical-align: text-top"><B>rd</B></SUP> <B>2006, London, UK, Philadelphia, US and San Francisco, CA.</B>
</DIV>

<DIV align="center" style="font-size: 10pt; margin-top: 6pt"><FONT style="font-variant: SMALL-CAPS"><B>GlaxoSmithKline and Sirna Therapeutics Announce Major Alliance in
RNA</B></FONT><B>i &#151;
</B><FONT style="font-variant: SMALL-CAPS"><B>Based <BR>
Therapeutics for Respiratory Disease</B></FONT>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">GlaxoSmithKline (NYSE: GSK) and Sirna Therapeutics, Inc. (Nasdaq: RNAi) today announced that
they are forming an exclusive multi-year strategic alliance focused on discovery, development and
commercialization of novel RNA interference (RNAi)-based therapeutics for respiratory diseases. The
alliance combines Sirna&#146;s extensive expertise in short interfering RNA (siRNA) chemistry and
biology with GSK&#146;s industry leading capabilities in the development and commercialisation of novel
therapies for respiratory diseases.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">Sirna will receive an initial payment of $12&nbsp;million, made up as cash and purchase of Sirna common
stock, priced at $ 8.36 per share. Under the agreement, Sirna may also receive milestone payments
in excess of $700&nbsp;million for collaboration and clinical development events, as well as royalties
on worldwide sales of products which successfully result from the alliance. In addition, Sirna
will be eligible to receive contract manufacturing revenues.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&#147;By combining GSK&#146;s pulmonary drug delivery expertise with Sirna&#146;s advanced application of RNAi
technology, this alliance will expedite the development of novel therapeutics with potential use in
a number of respiratory diseases such as asthma and COPD,&#148; said Dr.&nbsp;Garth Rapeport, Senior Vice
President, Respiratory &#038; Inflammation CEDD, at GSK. &#147;We recognise Sirna&#146;s leadership in the area of
RNAi-based therapeutics and hope for the potential benefits this research will bring to patients.&#148;
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">Under the terms of the agreement, Sirna will provide GSK optimised and formulated siRNAs against
Sirna and GSK targets. GSK will assume all responsibility for the further preclinical and clinical
development of these compounds as well as worldwide commercialisation of products resulting from
the alliance.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&#147;This collaboration is an extraordinary opportunity for us to work with GSK, the world&#146;s
second largest pharmaceutical company, to develop important new medicines to treat patients with
serious respiratory diseases,&#148; stated Howard W. Robin, President and CEO of Sirna Therapeutics.
&#147;With this collaboration, Sirna continues to successfully execute our strategy to ally selected
therapeutic programmes or drug targets with pharmaceutical companies that lead the industry in
their respective markets.&#148;
</DIV>

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
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<TR valign="bottom">
    <TD width="30%"></TD>
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</TR>
<!-- End Table Head -->
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<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">G-1
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">Sirna will conduct a live audio webcast conference call to discuss this alliance on April&nbsp;3,
2006 at 8:30 am ET. To participate over the Internet, go to www.sirna.com. Participants are urged
to log on to the web site 15 minutes prior to the scheduled start time to download and install any
necessary audio software. To access the live telephonic broadcast, domestic callers should dial
(877)&nbsp;502-9272; international callers may dial (913)&nbsp;981-5581.
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">An audio webcast replay will be available on Sirna&#146;s web site, www.sirna.com, for 30&nbsp;days.
Additionally, a telephonic replay of the call will be maintained through midnight, Monday, April
17, 2006. To access the replay, please dial (888)&nbsp;203-1112 from the U.S. or (719)&nbsp;457-0820 when
calling internationally, using confirmation code 8943556.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>About GSK</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">GlaxoSmithKline &#150; one of the world&#146;s leading research-based pharmaceutical and healthcare companies
&#150; is committed to improving the quality of human life by enabling people to do more, feel better
and live longer.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>About Sirna Therapeutics</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">Sirna Therapeutics is a clinical-stage biotechnology company developing RNAi-based therapies for
serious diseases and conditions, including age-related macular degeneration (AMD), hepatitis B and
C, dermatology, asthma, Huntington&#146;s disease, diabetes and oncology. Sirna Therapeutics completed
its Phase 1 clinical trial for Sirna-027 in AMD in 2005 and with its strategic partner, Allergan,
Inc., will move Sirna-027 into Phase 2 clinical trials in 2006. Sirna has selected a clinical
compound for hepatitis C virus, Sirna-034, which the Company plans to bring into Phase 1 clinical
trials by the end of 2006. Sirna has established an exclusive multi-year strategic alliance with
GlaxoSmithKline for the development of siRNA compounds for the treatment of respiratory diseases.
Sirna has a leading intellectual property portfolio in RNAi covering over 250 mammalian gene and
viral targets and over 175 issued or pending patents covering other major aspects of RNAi
technology. More information on Sirna Therapeutics is available on the Company&#146;s web site at
http://www.sirna.com.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>About RNA interference</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">RNA interference (RNAi) is a natural, selective process for turning off genes. RNAi is triggered by
short interfering RNA (siRNA) molecules that engage a group of cellular proteins, known as RISC
(RNA induced silencing complex). The RISC guides the siRNA to its target messenger RNA (mRNA, the
messenger between DNA and proteins) by complementary base pairing for the targeted break-up of the
mRNA thus halting protein expression or viral replication. The RISC-siRNA-complex binds and cleaves
multiple mRNA molecules in a catalytic fashion.
</DIV>

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
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    <TD width="5%"></TD>
    <TD width="30%"></TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">G-2
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always">&nbsp;</H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>GSK Enquiries:</B>
</DIV>

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom" style="font-size: 1pt">
    <TD width="38%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="38%">&nbsp;</TD>
    <TD width="2%">&nbsp;</TD>
    <TD width="20%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">UK Media enquiries:
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Philip Thomson
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">(020) 8047 5502</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Chris Hunter-Ward
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">(020) 8047 5502</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Alice Hunt
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">(020) 8047 5502</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">US Media enquiries:
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Nancy Pekarek
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">(215) 751 7709</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Mary Anne Rhyne
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">(919) 483 2839</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Patricia Seif
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">(215) 751 7709</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">European Analyst/Investor enquiries:
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Duncan Learmouth
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">(020) 8047 5540</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Anita Kidgell
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">(020) 8047 5542</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Jen Hill
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">(020) 8047 5543</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">David Mawdsley
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">(020) 8047 5564</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">US Analyst/ Investor enquiries:
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Frank Murdolo
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">(215) 751 7002</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Tom Curry
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">(215) 751 5419</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px"><B>Sirna Therapeutics Inc:</B></DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Media enquiries:
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Rebecca Galler Robison
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">(303) 449 6500</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px"><B>McKinney Chicago</B></DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">Media enquiries:
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Alan Zachary
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">(312) 944 6784 x316</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>GSK Cautionary statement regarding forward-looking statements</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">Under the safe harbor provisions of the US Private Securities Litigation Reform Act of 1995, the
company cautions investors that any forward-looking statements or projections made by the company,
including those made in this &#091;Announcement&#093;, are subject to risks and uncertainties that may cause
actual results to differ materially from those projected. Factors that may affect the Group&#146;s
operations are described under &#145;Risk Factors&#146; in the Operating and Financial Review and Prospects
in the company&#146;s Annual Report on Form 20-F for 2005.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>SIRNA Safe Harbor Statement</B>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">Statements in this press release which are not strictly historical are &#147;forward-looking&#148; statements
which should be considered as subject to many risks and uncertainties. For example, most drug
candidates do not become approved drugs. Sirna currently does not have any clinical drug
candidates for the treatment of respiratory diseases. Sirna&#146;s ability to obtain milestone and
royalty payments in its partnerships requires advancing programs that are still at a relatively
early stage, are highly contingent upon future successes, and are subject to significant risks and
unknowns. Additional risks and uncertainties include Sirna&#146;s early
</DIV>

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%"></TD>
    <TD width="5%"></TD>
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    <TD align="right" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">G-3
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
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<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="right" style="font-size: 10pt; margin-top: 12pt"><I>Execution Version</I>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">stage of development and short operating history, Sirna&#146;s history and expectation of losses and
need to raise capital, the rate at which Sirna uses cash, the timing of receipt of development
milestone payments from collaborating partners, Sirna&#146;s need to obtain clinical validation and
regulatory approval for products, Sirna&#146;s need to obtain and protect intellectual property, risk of
third-party patent infringement claims, Sirna&#146;s need to attract and retain qualified personnel,
Sirna&#146;s need to engage collaborators, availability of materials for product manufacturing, the
highly competitive nature of the pharmaceutical market, the limited trading volume and history of
volatility of Sirna&#146;s common stock, Sirna&#146;s concentration of stock ownership, and risks from
relocating Sirna headquarters. These and additional risk factors are identified in Sirna&#146;s
Securities and Exchange Commission filings, including the Forms 10-K and 10-Q and in other SEC
filings. Sirna undertakes no obligation to revise or update any forward-looking statements in order
to reflect events or circumstances that may arise after the date of this release.
</DIV>

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</TR>
<TR valign="bottom">
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">G-4
</TD>
    <TD>&nbsp;</TD>
    <TD align="right" valign="top">CONFIDENTIAL</TD>
</TR>
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</DIV>



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