SEATTLE GENETICS INC /WA
AMENDMENT NO. 2 TO SECURITIES PURCHASE AGREEMENT
<DOCUMENT>
<TYPE>EX-10.1
<SEQUENCE>4
<FILENAME>dex101.txt
<DESCRIPTION>AMENDMENT NO. 2 TO SECURITIES PURCHASE AGREEMENT
<TEXT>
<PAGE>


                                                                    Exhibit 10.1

                                                                  EXECUTION COPY

                                            AMENDMENT NO. 2, dated as of June 2,
                                 2003 (this "Amendment No. 2"), to the
                                 Securities Purchase Agreement, dated as of May
                                 12, 2003, as amended by Amendment No. 1 dated
                                 May 14, 2003 (as amended, the "Purchase
                                 Agreement"), among SEATTLE GENETICS, INC., a
                                 Delaware corporation (the "Company"), and the
                                 purchasers identified on Schedule I to such
                                 Purchase Agreement (the "Purchasers").

                                    RECITALS

          The Company and the Requisite Purchasers hereby agree to an amendment
to the Purchase Agreement, on the terms and subject to the conditions set forth
herein.

          NOW, THEREFORE, in consideration of the mutual covenants and
agreements contained in this Amendment No. 2, the sufficiency of which is hereby
acknowledged, the parties agree as follows:

     Section 1. Defined Terms. Capitalized terms used but not defined in this
Amendment No. 2 have the meanings ascribed to them in the Purchase Agreement.

     Section 2. Amendment to the Purchase Agreement. Exhibit A to the Purchase
Agreement is hereby amended by deleting said Exhibit in its entirety and
inserting in lieu thereof the new Exhibit A, in substantially the form attached
hereto.

     Section 3. References to the Purchase Agreement. From and after the date
hereof, all references in the Purchase Agreement and each other agreement
entered into pursuant thereto shall be deemed to be references to the Purchase
Agreement after giving effect to this Amendment No. 2.

     Section 4. No Other Amendments. Except as expressly set forth herein, the
Purchase Agreement remains in full force and effect in accordance with its terms
and nothing contained herein shall be deemed (i) a waiver, amendment,
modification or other change of any term, condition or provision of the Purchase
Agreement or any agreement entered into pursuant to the Purchase Agreement (or a
consent to any such waiver, amendment, modification or other change), (ii) a
consent to any transaction or (iii) to prejudice any right or rights which the
Company and each of the Purchasers may have under the Purchase Agreement and/or
any agreement entered into in connection therewith.

     Section 5. Further Assurances. The parties hereto agree to take such
further acts, to do such things, and to execute and deliver such additional
conveyances, assignments, agreements and instruments, as may be reasonably
requested in connection with the administration and enforcement of this
Amendment No. 2 and to permit the exercise thereof in compliance with any
Applicable Laws.

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     Section 6. Headings. The headings used herein are for convenience of
reference only and shall not affect the construction of, nor shall they be taken
into consideration in interpreting, this Amendment No. 2.

     Section 7. Counterparts. This Amendment No. 2 may be executed in any number
of separate counterparts, each of which shall be an original and all of which
taken together shall constitute one and the same instrument.

     Section 8. Applicable Law. This Amendment No. 2 shall be governed by, and
construed and interpreted in accordance with, the laws of the State of New York.

                                    * * * * *


                                       -2-

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          IN WITNESS WHEREOF, the parties hereto have caused this Amendment No.
2 to be duly executed and delivered as of the day and year first above written.

                                      COMPANY:

                                      SEATTLE GENETICS, INC.

                                      By:  /s/ Clay B. Siegall
                                           -------------------------------------
                                           Name:  Clay B. Siegall
                                           Title: President and CEO


                                      REQUISITE PURCHASERS:

                                      J.P. MORGAN PARTNERS (BHCA), L.P.

                                      By:  JPMP Master Fund Manager, L.P.,
                                           its general partner


                                      By:  JPMP Capital Corp.,
                                           Its general partner

                                      By:  /s/ Rodney A. Ferguson
                                           -------------------------------------
                                           Name:  Rodney A. Ferguson
                                           Title: Managing Director

                                      J.P. MORGAN PARTNERS GLOBAL
                                      INVESTORS, L.P.

                                      By:  JPMP Global Investors, L.P.,
                                           its general partner


                                      By:  JPMP Capital Corp.,
                                           Its general partner

                                      By:  /s/ Rodney A. Ferguson
                                           -------------------------------------
                                           Name:  Rodney A. Ferguson
                                           Title: Managing Director

<PAGE>

                                      J.P. MORGAN PARTNERS GLOBAL
                                      INVESTORS (CAYMAN), L.P.

                                      By:  JPMP Global Investors, L.P.,
                                           its general partner


                                      By:  JPMP Capital Corp.,
                                           Its general partner

                                      By:  /s/ Rodney A. Ferguson
                                           -------------------------------------
                                           Name:  Rodney A. Ferguson
                                           Title: Managing Director

                                      J.P. MORGAN PARTNERS GLOBAL
                                      INVESTORS A, L.P.

                                      By:  JPMP Global Investors, L.P.,
                                           its general partner


                                      By:  JPMP Capital Corp.,
                                           Its general partner

                                      By:  /s/ Rodney A. Ferguson
                                           -------------------------------------
                                           Name:  Rodney A. Ferguson
                                           Title: Managing Director

                                      J.P. MORGAN PARTNERS GLOBAL
                                      INVESTORS (CAYMAN) II, L.P.

                                      By:  JPMP Global Investors, L.P.,
                                           its general partner


                                      By:  JPMP Capital Corp.,
                                           Its general partner

                                      By:  /s/ Rodney A. Ferguson
                                           -------------------------------------
                                           Name:  Rodney A. Ferguson
                                           Title: Managing Director

                                       -4-

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                                      BAKER/TISCH INVESTMENTS, L.P.

                                      By:  Baker/Tisch Capital, L.P.,
                                           its general partner


                                      By:  Baker/Tisch Capital (GP), LLC,
                                           its general partner


                                      By:  /s/ Felix Baker
                                           -------------------------------------
                                           Name:  Felix Baker, Ph.D.
                                           Title: Managing Member


                                      BAKER BROS. INVESTMENTS, L.P.

                                      By:  Baker Bros. Capital, L.P.,
                                           its general partner


                                      By:  Baker Bros. Capital (GP), LLC,
                                           its general partner


                                      By:  /s/ Felix Baker
                                           -------------------------------------
                                           Name:  Felix Baker, Ph.D.
                                           Title: Managing Member


                                      BAKER BROS. INVESTMENTS II, L.P.


                                      By:  Baker Bros. Capital, L.P.,
                                           its general partner


                                      By:  Baker Bros. Capital (GP), LLC,
                                           its general partner


                                      By:  /s/ Felix Baker
                                           -------------------------------------
                                           Name:  Felix Baker, Ph.D.
                                           Title: Managing Member



                                       -5-

<PAGE>

                                      BAKER BIOTECH FUND I, L.P.

                                      By:  Baker Biotech Capital, L.P.,
                                           its general partner


                                      By:  Baker Biotech Capital (GP), LLC,
                                           its general partner


                                      By:  /s/ Felix Baker
                                           -------------------------------------
                                           Name:  Felix Baker, Ph.D.
                                           Title: Managing Member


                                      BAKER BIOTECH FUND II, L.P.

                                      By:  Baker Biotech Capital II, L.P.,
                                           its general partner


                                      By:  Baker Biotech Capital II (GP), LLC,
                                           is general partner


                                      By:  /s/ Felix Baker
                                           -------------------------------------
                                           Name:  Felix Baker, Ph.D.
                                           Title: Managing Member


                                      BAKER BIOTECH FUND II (Z), L.P.

                                      By:  Baker Biotech Capital II, L.P.,
                                           its general partner


                                      By:  Baker Biotech Capital II (GP), LLC,
                                           is general partner


                                      By:  /s/ Felix Baker
                                           -------------------------------------
                                           Name:  Felix Baker, Ph.D.
                                           Title: Managing Member

                                       -6-

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