MSD ACQUISITION CORP. / NEW
LETTER AGREEMENT, DATED MARCH 14, 2022, BY AND BETWEEN MSD ACQUISITION CORP. AND
<DOCUMENT>
<TYPE>EX-10.1
<SEQUENCE>2
<FILENAME>ea156830ex10-1_msdacq.htm
<DESCRIPTION>LETTER AGREEMENT, DATED MARCH 14, 2022, BY AND BETWEEN MSD ACQUISITION CORP. AND ALLEN SHIM
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<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: right"><B>Exhibit 10.1</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: right">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: right">March 14, 2022</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">MSD Acquisition Corp.<BR>
One Vanderbilt Avenue, 26th Floor</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">New York, New York 10017</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0 0pt 0.5in; text-align: left">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0 0pt 0.5in; text-align: left">Re: <U>Insider Agreement</U></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left">Ladies and Gentlemen:</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left; text-indent: 0.5in">This letter (this &ldquo;<B><I>Letter
Agreement</I></B>&rdquo;) is being delivered to you in connection with the appointment of the undersigned, Allen Shim (the &ldquo;<B><I>Insider</I></B>&rdquo;),
as a director of MSD Acquisition Corp., a Cayman Islands exempted company (the &ldquo;<B><I>Company</I></B>&rdquo;). The Insider acknowledges
that the Company has consummated its initial public offering on March 29, 2021 (the &ldquo;<B><I>Public Offering</I></B>&rdquo;) of 57,500,000
units (including 7,500,000 units purchased pursuant to the Underwriters&rsquo; option to purchase additional units, the &ldquo;<B><I>Units</I></B>&rdquo;),
each comprised of one Class A ordinary share, par value $0.0001 per share (the &ldquo;<B><I>Ordinary Shares</I></B>&rdquo;), of the Company,
and one-fifth of one redeemable warrant (each whole warrant, a &ldquo;<B><I>Warrant</I></B>&rdquo;) of the Company. Each Warrant entitles
the holder thereof to purchase one Ordinary Share at a price of $11.50 per share, subject to adjustment. Certain capitalized terms used
herein are defined in <U>paragraph 1</U> hereof.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left; text-indent: 0.5in">For good and valuable consideration,
the receipt and sufficiency of which are hereby acknowledged, the Insider hereby agrees with the Company as follows:</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left; text-indent: 0.5in">1. <U>Definitions</U>. As
used herein, (i) &ldquo;<B><I>Business Combination</I></B>&rdquo; shall mean a merger, share exchange, asset acquisition, share purchase,
reorganization or similar business combination with one or more businesses or entities; (ii) &ldquo;<B><I>Founder Shares</I></B>&rdquo;
shall mean the 14,375,000 Class B ordinary shares of the Company, par value $0.0001 per share, outstanding prior to the consummation of
the Public Offering; (iii) &ldquo;<B><I>Private Placement Warrants</I></B>&rdquo; shall mean the warrants to purchase Ordinary Shares
of the Company that were acquired by the Sponsor (as defined below) for an aggregate purchase price of $14,000,000, or $1.50 per Private
Placement Warrant, in a private placement that closed simultaneously with the consummation of the Public Offering (including the Ordinary
Shares issuable upon exercise thereof); (iv) &ldquo;<B><I>Public Shareholders</I></B>&rdquo; shall mean the holders of Ordinary Shares
included in the Units issued in the Public Offering; (v)&nbsp;&ldquo;<B><I>Public Shares</I></B>&rdquo; shall mean the Ordinary Shares
included in the Units issued in the Public Offering; (vi) &ldquo;<B><I>Trust Account</I></B>&rdquo; shall mean the trust account into
which a portion of the net proceeds of the Public Offering and the sale of the Private Placement Warrants were deposited; (vii) &ldquo;<B><I>Transfer</I></B>&rdquo;
shall mean the (a) sale of, offer to sell, contract or agreement to sell, hypothecate, pledge, grant of any option to purchase or otherwise
dispose of or agreement to dispose of, directly or indirectly, or establishment or increase of a put equivalent position or liquidation
with respect to or decrease of a call equivalent position within the meaning of Section 16 of the Securities Exchange Act of 1934, as
amended, and the rules and regulations of the Commission promulgated thereunder with respect to, any security, (b) entry into any swap
or other arrangement that transfers to another, in whole or in part, any of the economic consequences of ownership of any security, whether
any such transaction is to be settled by delivery of such securities, in cash or otherwise, or (c) public announcement of any intention
to effect any transaction specified in clause (a) or (b); (viii) &ldquo;<B><I>Charter</I></B>&rdquo; shall mean the Company&rsquo;s Amended
and Restated Memorandum and Articles of Association, as the same may be amended from time to time; (ix) &ldquo;<B><I>Underwriters</I></B>&rdquo;
shall mean the underwriters of the Public Offering; and (x) &ldquo;<B><I>Sponsor</I></B>&rdquo; shall mean MSD Sponsor Holdings, LLC,
a Delaware limited liability company.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left; text-indent: 0.5in">2. <U>Representations and
Warranties.</U></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0 0pt 0.5in; text-align: left; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0 0pt 0.5in; text-align: left; text-indent: 0.5in">(a) The Insider
represents and warrants to the Company that he has the full right and power, without violating any agreement to which he is bound (including,
without limitation, any non-competition or non-solicitation agreement with any employer or former employer), to enter into this Letter
Agreement, and to serve as a director on the Company&rsquo;s Board of Directors (the &ldquo;<B><I>Board</I></B>&rdquo;).</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0 0pt 0.5in; text-align: left; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0 0pt 0.5in; text-align: left; text-indent: 0.5in"></P>

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<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0 0pt 0.5in; text-align: left; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0 0pt 0.5in; text-align: left; text-indent: 0.5in">(b) The Insider
represents and warrants that such Insider&rsquo;s biographical information furnished to the Company (including any such information included
in the Current Report on Form 8-K relating to the Insider&rsquo;s appointment and to be filed by the Company with the Securities and Exchange
Commission (the &ldquo;<B><I>Commission</I></B>&rdquo;)) is true and accurate in all material respects and does not omit any material
information with respect to such Insider&rsquo;s background. The Insider&rsquo;s questionnaire furnished to the Company is true and accurate
in all material respects. The Insider represents and warrants that such Insider is not subject to or a respondent in any legal action
for, any injunction, cease-and-desist order or order or stipulation to desist or refrain from any act or practice relating to the offering
of securities in any jurisdiction; such Insider has never been convicted of, or pleaded guilty to, any crime (i) involving fraud, (ii)
relating to any financial transaction or handling of funds of another person, or (iii) pertaining to any dealings in any securities and
such Insider is not currently a defendant in any such criminal proceeding; and such Insider has never been suspended or expelled from
membership in any securities or commodities exchange or association or had a securities or commodities license or registration denied,
suspended or revoked.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left; text-indent: 0.5in">3. <U>Business Combination
Vote</U>. The Insider agrees that if the Company seeks shareholder approval of a proposed initial Business Combination, then in connection
with such proposed initial Business Combination, he shall vote all Founder Shares and any Public Shares held by him in favor of such proposed
initial Business Combination (including any proposals recommended by the Board in connection with such Business Combination) and not redeem
any Public Shares held by him in connection with such shareholder approval.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left; text-indent: 0.5in">4. <U>Failure to Consummate
a Business Combination; Trust Account Waiver</U>.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0 0pt 0.5in; text-align: left; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0 0pt 0.5in; text-align: left; text-indent: 0.5in">(a) The Insider
hereby agrees that in the event that the Company fails to consummate its initial Business Combination within the time period set forth
in the Charter the Insider shall take all reasonable steps to cause the Company to (i) cease all operations except for the purpose of
winding up; (ii) as promptly as reasonably possible but not more than 10 business days thereafter, redeem 100% of the Public Shares, at
a per-share price, payable in cash, equal to the aggregate amount then on deposit in the Trust Account, including interest earned on the
funds held in the Trust Account and not previously released to the Company to pay income taxes (less up to $100,000 of interest to pay
dissolution expenses), divided by the number of then outstanding Public Shares, which redemption will completely extinguish Public Shareholders&rsquo;
rights as shareholders (including the right to receive further liquidation distributions, if any); and (iii) as promptly as reasonably
possible following such redemption, subject to the approval of the Company&rsquo;s remaining shareholders and the Board, liquidate and
dissolve, subject in the case of clauses (ii) and (iii) to the Company&rsquo;s obligations under Cayman Islands law to provide for claims
of creditors and in all cases subject to the other requirements of applicable law. The Insider agrees not to propose any amendment to
the Charter (A) that would modify the substance or timing of the Company&rsquo;s obligation to provide holders of the Public Shares the
right to have their shares redeemed in connection with an initial Business Combination or to redeem 100% of the Public Shares if the Company
does not complete an initial Business Combination within the required time period set forth in the Charter or (B) with respect to any
provision relating to the rights of holders of Public Shares or pre-initial Business Combination activity unless the Company provides
its Public Shareholders with the opportunity to redeem their Public Shares upon approval of any such amendment at a per-share price, payable
in cash, equal to the aggregate amount then on deposit in the Trust Account, including interest earned on the funds held in the Trust
Account and not previously released to the Company to pay income taxes, if any, divided by the number of then-outstanding Public Shares.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0 0pt 0.5in; text-align: left; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0 0pt 0.5in; text-align: left; text-indent: 0.5in">(b) The Insider
acknowledges that he has no right, title, interest or claim of any kind in or to any monies held in the Trust Account or any other asset
of the Company as a result of any liquidation of the Company with respect to the Founder Shares held by him, if any. The Insider hereby
further waives, with respect to any Founder Shares and Public Shares held by him, as applicable, any redemption rights he may have in
connection with (x) the completion of the Company&rsquo;s initial Business Combination, and (y) a shareholder vote to approve an amendment
to the Charter (i) that would modify the substance or timing of the Company&rsquo;s obligation to provide holders of the Public Shares
the right to have their shares redeemed in connection with an initial Business Combination or to redeem 100% of the Public Shares if the
Company has not consummated an initial Business Combination within the time period set forth in the Charter or (ii) with respect to any
provision relating to the rights of holders of Public Shares or pre-initial Business Combination activity (although the Insider shall
be entitled to liquidation rights with respect to any Public Shares he holds if the Company fails to consummate a Business Combination
within the required time period set forth in the Charter).</P>

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<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left; text-indent: 0.5in">5. <U>Lock-up; Transfer Restrictions</U>.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0 0pt 0.5in; text-align: left; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0 0pt 0.5in; text-align: left; text-indent: 0.5in">(a) The Insider
agrees that he shall not Transfer any Founder Shares held, if any (the &ldquo;<B><I>Founder Shares Lock-up</I></B>&rdquo;), until the
earliest of (A) one year after the completion of the Company&rsquo;s initial Business Combination and (B) following the completion of
an initial Business Combination, the date on which the Company completes a liquidation, merger, share exchange, reorganization or other
similar transaction that results in all of the Public Shareholders having the right to exchange their Ordinary Shares for cash, securities
or other property (the &ldquo;<B><I>Founder Shares Lock-up Period</I></B>&rdquo;). Notwithstanding the foregoing, if, subsequent to a
Business Combination, the closing price of the Ordinary Shares equals or exceeds $12.00 per share (as adjusted for share splits, share
capitalizations, reorganizations, recapitalizations and the like) for any 20 trading days within any 30-trading day period commencing
at least 150 days after the Company&rsquo;s initial Business Combination, the Founder Shares shall be released from the Founder Shares
Lock-up.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0 0pt 0.5in; text-align: left; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0 0pt 0.5in; text-align: left; text-indent: 0.5in">(b) Subject to the
provisions set forth in <U>para</U>g<U>raph 5(c)</U>, the Insider agrees that he shall not effectuate any Transfer of Private Placement
Warrants or the Ordinary Shares underlying such Private Placement Warrants until 30 days after the completion of an initial Business Combination.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0 0pt 0.5in; text-align: left; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0 0pt 0.5in; text-align: left; text-indent: 0.5in">(c) Notwithstanding
the provisions set forth in <U>para</U>g<U>raphs 5(a)</U> and <U>(b)</U>, Transfers of the Founder Shares, Private Placement Warrants
and the Ordinary Shares underlying the Private Placement Warrants and the conversion of the Founder Shares are permitted (i) to the Company&rsquo;s
officers or directors, any affiliates or family member of any of the Company&rsquo;s officers or directors, any members or partners of
the Sponsor or their affiliates, any affiliates of the Sponsor, or any employees of the Sponsor or any of its affiliates; (ii) in the
case of an individual, by gift to a member of one of such individual&rsquo;s immediate family or to a trust, the beneficiary of which
is a member of such individual&rsquo;s immediate family, an affiliate of such individual or to a charitable organization; (iii) in the
case of an individual, by virtue of the laws of descent and distribution upon death of such individual; (iv) in the case of an individual,
pursuant to a qualified domestic relations order; (v) by private sales or transfers made in connection with the consummation of a Business
Combination at prices no greater than the price at which the Founder Shares or Private Placement Warrants, as applicable, were originally
purchased; (vi) by virtue of the Sponsor&rsquo;s organizational documents upon liquidation or dissolution of the Sponsor; (vii) to the
Company for no value for cancellation in connection with the consummation of its initial Business Combination, (viii) in the event of
the Company&rsquo;s liquidation prior to the completion of its initial Business Combination; or (ix) in the event of completion of a liquidation,
merger, share exchange or other similar transaction which results in all of the Company&rsquo;s Public Shareholders having the right to
exchange their Ordinary Shares for cash, securities or other property subsequent to the completion of an initial Business Combination;
<U>provided</U>, <U>however</U>, that in the case of clauses (i) through (vi), these permitted transferees must enter into a written agreement
agreeing to be bound by these transfer restrictions.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left; text-indent: 0.5in">6. <U>Remedies</U>. The Insider
hereby agrees and acknowledges that (i) each of the Underwriters and the Company would be irreparably injured in the event of a breach
by the Insider of his obligations, as applicable under <U>paragraphs 3</U>, <U>4</U>, and <U>5</U>, of this Letter Agreement, (ii) monetary
damages may not be an adequate remedy for such breach and (iii) the non-breaching party shall be entitled to injunctive relief, in addition
to any other remedy that such party may have in law or in equity, in the event of such breach.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left; text-indent: 0.5in">7. <U>Termination</U>. This
Letter Agreement shall terminate on the earlier of (i) the expiration of the Founder Shares Lock-up Period and (ii) the liquidation of
the Company.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left; text-indent: 0.5in">8. <U>Entire A</U>g<U>reement</U>.
This Letter Agreement constitutes the entire agreement and understanding of the parties hereto in respect of the subject matter hereof
and supersedes all prior understandings, agreements, or representations by or among the parties hereto, written or oral, to the extent
they relate in any way to the subject matter hereof or the transactions contemplated hereby. This Letter Agreement may not be changed,
amended, modified or waived (other than to correct a typographical error) as to any particular provision, except by a written instrument
executed by each party hereto.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left; text-indent: 0.5in"></P>

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<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left; text-indent: 0.5in">9. <U>Assignment</U>. No party
hereto may assign either this Letter Agreement or any of its rights, interests, or obligations hereunder without the prior written consent
of the other party. Any purported assignment in violation of this paragraph shall be void and ineffectual and shall not operate to transfer
or assign any interest or title to the purported assignee. This Letter Agreement shall be binding on the Insider and each of his successors,
heirs, personal representatives and assigns and permitted transferees.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left; text-indent: 0.5in">10. <U>Counterparts</U>. This
Letter Agreement may be executed in any number of original or facsimile counterparts, and each of such counterparts shall for all purposes
be deemed to be an original, and all such counterparts shall together constitute but one and the same instrument.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left; text-indent: 0.5in">11. <U>Effect of Headin</U>gs.
The paragraph headings herein are for convenience only and are not part of this Letter Agreement and shall not affect the interpretation
thereof.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left; text-indent: 0.5in">12. <U>Severability</U>. This
Letter Agreement shall be deemed severable, and the invalidity or unenforceability of any term or provision hereof shall not affect the
validity or enforceability of this Letter Agreement or of any other term or provision hereof. Furthermore, in lieu of any such invalid
or unenforceable term or provision, the parties hereto intend that there shall be added as a part of this Letter Agreement a provision
as similar in terms to such invalid or unenforceable provision as may be possible and be valid and enforceable.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left; text-indent: 0.5in">13. <U>Governing Law</U>.
This Letter Agreement shall be governed by and construed and enforced in accordance with the laws of the State of New York, without giving
effect to conflicts of law principles that would result in the application of the substantive laws of another jurisdiction. The parties
hereto (i) all agree that any action, proceeding, claim or dispute arising out of, or relating in any way to, this Letter Agreement shall
be brought and enforced in the courts of New York City, in the State of New York, and irrevocably submit to such jurisdiction and venue,
which jurisdiction and venue shall be exclusive, and (ii) waive any objection to such exclusive jurisdiction and venue or that such courts
represent an inconvenient forum.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left; text-indent: 0.5in">14. <U>Notices</U>. Any notice,
consent or request to be given in connection with any of the terms or provisions of this Letter Agreement shall be in writing and shall
be sent by express mail or similar private courier service, by hand delivery or electronic mail.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: left; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: italic 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; text-align: center">[Signature Page Follows]</P>

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<TABLE CELLSPACING="0" CELLPADDING="0" STYLE="font: 10pt Times New Roman, Times, Serif; width: 100%; border-collapse: collapse">
  <TR STYLE="vertical-align: top">
    <TD STYLE="width: 60%">&nbsp;</TD>
    <TD STYLE="width: 40%">Sincerely,</TD></TR>
  <TR STYLE="vertical-align: top">
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD></TR>
  <TR STYLE="vertical-align: top">
    <TD STYLE="padding-bottom: 1.5pt">&nbsp;</TD>
    <TD STYLE="border-bottom: Black 1.5pt solid">/s/ Allen Shim</TD></TR>
  <TR STYLE="vertical-align: top">
    <TD>&nbsp;</TD>
    <TD>Allen Shim</TD></TR>
  </TABLE>
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<TABLE CELLSPACING="0" CELLPADDING="0" STYLE="font: 10pt Times New Roman, Times, Serif; width: 100%; border-collapse: collapse">
  <TR STYLE="vertical-align: top">
    <TD COLSPAN="2">Acknowledged and Agreed:</TD>
    <TD>&nbsp;</TD></TR>
  <TR STYLE="vertical-align: top">
    <TD COLSPAN="2">&nbsp;</TD>
    <TD>&nbsp;</TD></TR>
  <TR STYLE="vertical-align: top">
    <TD COLSPAN="2"><B>MSD ACQUISITION CORP.</B></TD>
    <TD>&nbsp;</TD></TR>
  <TR STYLE="vertical-align: top">
    <TD COLSPAN="2">&nbsp;</TD>
    <TD>&nbsp;</TD></TR>
  <TR STYLE="vertical-align: top">
    <TD STYLE="padding-bottom: 1.5pt; width: 5%">By:</TD>
    <TD STYLE="border-bottom: Black 1.5pt solid; width: 35%">/s/ John Cardoso</TD>
    <TD STYLE="padding-bottom: 1.5pt; width: 60%">&nbsp;</TD></TR>
  <TR STYLE="vertical-align: top">
    <TD>Name:&nbsp;</TD>
    <TD>John Cardoso</TD>
    <TD>&nbsp;</TD></TR>
  <TR STYLE="vertical-align: top">
    <TD>Title:</TD>
    <TD>Chief Financial Officer</TD>
    <TD>&nbsp;</TD></TR>
  </TABLE>
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<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><I>[Signature Page to Insider Letter Agreement]</I></P>

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