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Schedule 13D
Cusip No. 812578102

                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                  SCHEDULE 13D
                                 (Rule 13d-101)

                    Under the Securities Exchange Act of 1934

                             Seattle Genetics, Inc.
--------------------------------------------------------------------------------
                                (Name of Issuer)

                    Common Stock, par value $0.001 per share
                ------------------------------------------------
                         (Title of Class of Securities)

                                   812578102
                ------------------------------------------------
                                 (CUSIP Number)


                               Phillip Isom, Esq.
                              O'Melveny & Myers LLP
                                 7 Times Square
                               New York, NY 10036
                            Telephone: (212) 408-2418


--------------------------------------------------------------------------------
            (Name, Address and Telephone Number of Person Authorized
                     to Receive Notices and Communications)



                                  May 8, 2004
                ------------------------------------------------
             (Date of Event which Requires Filing of this Statement)

         If the filing person has previously filed a statement on Schedule 13G
to report the acquisition that is the subject of this Schedule 13D, and is
filing this schedule because of Rule 13d-l(e), 13d-l(f) or 13d-l(g), check the
following box |_|

         Note: Schedules filed in paper format shall include a signed original
and five copies of the schedule, including all exhibits. See Rule 13d-7 for
other parties to whom copies are to be sent. The remainder of this cover page
shall be filled out for a reporting person's initial filing on this form with
respect to the subject class of securities, and for any subsequent amendment
containing information which would alter disclosures provided in a prior cover
page. The information required on this cover page shall not be deemed to be
"filed" for the purpose of Section 18 of the Securities Exchange Act of 1934
("Exchange Act") or otherwise subject to the liabilities of that section of the
Exchange Act but shall be subject to all other provisions of the Exchange Act
(however, see the Notes)


                                  Page 1 of 37


Schedule 13D
Cusip No. 812578102

--------------------------------------------------------------------------------
1        NAMES OF REPORTING PERSONS
         I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

         J.P. Morgan Partners (BHCA), L.P.
         13-3371826
--------------------------------------------------------------------------------
2        CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

                                                                         (a) |_|
                                                                         (b) |X|
--------------------------------------------------------------------------------
3        SEC USE ONLY

--------------------------------------------------------------------------------
4        SOURCE OF FUNDS
         WC
--------------------------------------------------------------------------------
5        CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
         PURSUANT TO ITEMS 2(d) or 2(e)                                      |_|
--------------------------------------------------------------------------------
6        CITIZENSHIP OR PLACE OF ORGANIZATION
         Delaware
--------------------------------------------------------------------------------
SHARES BENEFICIALLY OWNED         7        SOLE VOTING POWER
 BY EACH REPORTING PERSON                  5,760,349 (includes shares of
           WITH                            Series A Convertible Preferred Stock)
                                  ----------------------------------------------
                                  8        SHARED VOTING POWER
                                           0
                                  ----------------------------------------------
                                  9        SOLE DISPOSITIVE POWER
                                           5,760,349 (includes shares of
                                           Series A Convertible Preferred Stock)
                                  ----------------------------------------------
                                  10       SHARED DISPOSITIVE POWER
                                           0
--------------------------------------------------------------------------------
11       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
         5,760,349 (includes shares of Series A Convertible Preferred Stock)
--------------------------------------------------------------------------------
12       CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
         CERTAIN SHARES(1)                                                   |X|
--------------------------------------------------------------------------------
13       PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)
         12.5 %
--------------------------------------------------------------------------------
14       TYPE OF REPORTING PERSON
         PN
--------------------------------------------------------------------------------

--------
(1) The Reporting Person above is party to a voting agreement contained in the
Investors Rights Agreement described herein. As a result, the parties to the
Investors Rights Agreement may be deemed to constitute a "group" for purposes of
Section 13(d)(3) of the Securities Exchange Act of 1934, as amended (the "Act")
with respect to 16,875,000 shares of Common Stock (defined herein), representing
29.6% of the outstanding voting power of the Issuer. The Reporting Person above
disclaims beneficial ownership of any securities held by any other Reporting
Person and the filing of this Statement on Schedule 13D shall not be deemed an
admission that the Reporting Person above and any other person or persons
constitute a "group" for purposes of Section 13(d)(3) of the Act or Rule 13d-5
thereunder.


                                  Page 2 of 37


Schedule 13D
Cusip No. 812578102

--------------------------------------------------------------------------------
1        NAMES OF REPORTING PERSONS
         I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

         J.P. Morgan Partners Global Investors, L.P.
         13-4197054
--------------------------------------------------------------------------------
2        CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

                                                                         (a) |_|
                                                                         (b) |X|
--------------------------------------------------------------------------------
3        SEC USE ONLY

--------------------------------------------------------------------------------
4        SOURCE OF FUNDS
         WC
--------------------------------------------------------------------------------
5        CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
         PURSUANT TO ITEMS 2(d) or 2(e)                                      |_|
--------------------------------------------------------------------------------
6        CITIZENSHIP OR PLACE OF ORGANIZATION
         Delaware
--------------------------------------------------------------------------------
SHARES BENEFICIALLY OWNED         7        SOLE VOTING POWER
 BY EACH REPORTING PERSON                  912,791 (includes shares of Series A
           WITH                            Convertible Preferred Stock)
                                  ----------------------------------------------
                                  8        SHARED VOTING POWER
                                           0
                                  ----------------------------------------------
                                  9        SOLE DISPOSITIVE POWER
                                           912,791 (includes shares of Series A
                                           Convertible Preferred Stock)
                                  ----------------------------------------------
                                  10       SHARED DISPOSITIVE POWER
                                           0
--------------------------------------------------------------------------------
11       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
         912,791 (includes shares of Series A Convertible Preferred Stock)
--------------------------------------------------------------------------------
12       CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
         CERTAIN SHARES(2)                                                   |X|
--------------------------------------------------------------------------------
13       PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)
         2.2 %
--------------------------------------------------------------------------------
14       TYPE OF REPORTING PERSON
         PN
--------------------------------------------------------------------------------

--------
(2) The Reporting Person above is party to a voting agreement contained in the
Investors Rights Agreement described herein. As a result, the parties to the
Investors Rights Agreement may be deemed to constitute a "group" for purposes of
Section 13(d)(3) of the Securities Exchange Act of 1934, as amended (the "Act")
with respect to 16,875,000 shares of Common Stock (defined herein), representing
29.6% of the outstanding voting power of the Issuer. The Reporting Person above
disclaims beneficial ownership of any securities held by any other Reporting
Person and the filing of this Statement on Schedule 13D shall not be deemed an
admission that the Reporting Person above and any other person or persons
constitute a "group" for purposes of Section 13(d)(3) of the Act or Rule 13d-5
thereunder.


                                  Page 3 of 37


Schedule 13D
Cusip No. 812578102

--------------------------------------------------------------------------------
1        NAMES OF REPORTING PERSONS
         I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

         J.P. Morgan Partners Global Investors A, L.P.
         26-0032493
--------------------------------------------------------------------------------
2        CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

                                                                         (a) |_|
                                                                         (b) |X|
--------------------------------------------------------------------------------
3        SEC USE ONLY

--------------------------------------------------------------------------------
4        SOURCE OF FUNDS
         WC
--------------------------------------------------------------------------------
5        CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
         PURSUANT TO ITEMS 2(d) or 2(e)                                      |_|
--------------------------------------------------------------------------------
6        CITIZENSHIP OR PLACE OF ORGANIZATION
         Delaware
--------------------------------------------------------------------------------
SHARES BENEFICIALLY OWNED         7        SOLE VOTING POWER
 BY EACH REPORTING PERSON                  124,436 (includes shares of Series A
           WITH                            Convertible Preferred Stock)
                                  ----------------------------------------------
                                  8        SHARED VOTING POWER
                                           0
                                  ----------------------------------------------
                                  9        SOLE DISPOSITIVE POWER
                                           124,436 (includes shares of Series A
                                           Convertible Preferred Stock)
                                  ----------------------------------------------
                                  10       SHARED DISPOSITIVE POWER
                                           0
--------------------------------------------------------------------------------
11       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
         124,436 (includes shares of Series A Convertible Preferred Stock)
--------------------------------------------------------------------------------
12       CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
         CERTAIN SHARES(3)                                                   |X|
--------------------------------------------------------------------------------
13       PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)
         0.3 %
--------------------------------------------------------------------------------
14       TYPE OF REPORTING PERSON
         PN
--------------------------------------------------------------------------------

--------
(3) The Reporting Person above is party to a voting agreement contained in the
Investors Rights Agreement described herein. As a result, the parties to the
Investors Rights Agreement may be deemed to constitute a "group" for purposes of
Section 13(d)(3) of the Securities Exchange Act of 1934, as amended (the "Act")
with respect to 16,875,000 shares of Common Stock (defined herein), representing
29.6% of the outstanding voting power of the Issuer. The Reporting Person above
disclaims beneficial ownership of any securities held by any other Reporting
Person and the filing of this Statement on Schedule 13D shall not be deemed an
admission that the Reporting Person above and any other person or persons
constitute a "group" for purposes of Section 13(d)(3) of the Act or Rule 13d-5
thereunder.


                                  Page 4 of 37


Schedule 13D
Cusip No. 812578102

--------------------------------------------------------------------------------
1        NAMES OF REPORTING PERSONS
         I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

         J.P. Morgan Partners Global Investors (Cayman), L.P.
         13-4197057
--------------------------------------------------------------------------------
2        CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

                                                                         (a) |_|
                                                                         (b) |X|
--------------------------------------------------------------------------------
3        SEC USE ONLY

--------------------------------------------------------------------------------
4        SOURCE OF FUNDS
         WC
--------------------------------------------------------------------------------
5        CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
         PURSUANT TO ITEMS 2(d) or 2(e)                                      |_|
--------------------------------------------------------------------------------
6        CITIZENSHIP OR PLACE OF ORGANIZATION
         Cayman Islands
--------------------------------------------------------------------------------
SHARES BENEFICIALLY OWNED         7        SOLE VOTING POWER
 BY EACH REPORTING PERSON                  463,298 (includes shares of Series A
           WITH                            Convertible Preferred Stock)
                                  ----------------------------------------------
                                  8        SHARED VOTING POWER
                                           0
                                  ----------------------------------------------
                                  9        SOLE DISPOSITIVE POWER
                                           463,298 (includes shares of Series A
                                           Convertible Preferred Stock)
                                  ----------------------------------------------
                                  10       SHARED DISPOSITIVE POWER
                                           0
--------------------------------------------------------------------------------
11       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
         463,298 (includes shares of Series A Convertible Preferred Stock)
--------------------------------------------------------------------------------
12       CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
         CERTAIN SHARES(4)                                                   |X|
--------------------------------------------------------------------------------
13       PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)
         1.1 %
--------------------------------------------------------------------------------
14       TYPE OF REPORTING PERSON
         PN
--------------------------------------------------------------------------------

--------
(4) The Reporting Person above is party to a voting agreement contained in the
Investors Rights Agreement described herein. As a result, the parties to the
Investors Rights Agreement may be deemed to constitute a "group" for purposes of
Section 13(d)(3) of the Securities Exchange Act of 1934, as amended (the "Act")
with respect to 16,875,000 shares of Common Stock (defined herein), representing
29.6% of the outstanding voting power of the Issuer. The Reporting Person above
disclaims beneficial ownership of any securities held by any other Reporting
Person and the filing of this Statement on Schedule 13D shall not be deemed an
admission that the Reporting Person above and any other person or persons
constitute a "group" for purposes of Section 13(d)(3) of the Act or Rule 13d-5
thereunder.


                                  Page 5 of 37


Schedule 13D
Cusip No. 812578102

--------------------------------------------------------------------------------
1        NAMES OF REPORTING PERSONS
         I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

         J.P. Morgan Partners Global Investors (Cayman) II, L.P.
         26-0005546
--------------------------------------------------------------------------------
2        CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

                                                                         (a) |_|
                                                                         (b) |X|
--------------------------------------------------------------------------------
3        SEC USE ONLY

--------------------------------------------------------------------------------
4        SOURCE OF FUNDS
         WC
--------------------------------------------------------------------------------
5        CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
         PURSUANT TO ITEMS 2(d) or 2(e)                                      |_|
--------------------------------------------------------------------------------
6        CITIZENSHIP OR PLACE OF ORGANIZATION
         Cayman Islands
--------------------------------------------------------------------------------
SHARES BENEFICIALLY OWNED         7        SOLE VOTING POWER
 BY EACH REPORTING PERSON                  51,626 (includes shares of Series A
           WITH                            Convertible Preferred Stock)
                                  ----------------------------------------------
                                  8        SHARED VOTING POWER
                                           0
                                  ----------------------------------------------
                                  9        SOLE DISPOSITIVE POWER
                                           51,626 (includes shares of Series A
                                           Convertible Preferred Stock)
                                  ----------------------------------------------
                                  10       SHARED DISPOSITIVE POWER
                                           0
--------------------------------------------------------------------------------
11       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
         51,626 (includes shares of Series A Convertible Preferred Stock)
--------------------------------------------------------------------------------
12       CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
         CERTAIN SHARES(5)                                                   |X|
--------------------------------------------------------------------------------
13       PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)
         0.1 %
--------------------------------------------------------------------------------
14       TYPE OF REPORTING PERSON
         PN
--------------------------------------------------------------------------------

--------
(5) The Reporting Person above is party to a voting agreement contained in the
Investors Rights Agreement described herein. As a result, the parties to the
Investors Rights Agreement may be deemed to constitute a "group" for purposes of
Section 13(d)(3) of the Securities Exchange Act of 1934, as amended (the "Act")
with respect to 16,875,000 shares of Common Stock (defined herein), representing
29.6% of the outstanding voting power of the Issuer. The Reporting Person above
disclaims beneficial ownership of any securities held by any other Reporting
Person and the filing of this Statement on Schedule 13D shall not be deemed an
admission that the Reporting Person above and any other person or persons
constitute a "group" for purposes of Section 13(d)(3) of the Act or Rule 13d-5
thereunder.


                                  Page 6 of 37


Schedule 13D
Cusip No. 812578102

--------------------------------------------------------------------------------
1        NAMES OF REPORTING PERSONS
         I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS

         Julian C. Baker
--------------------------------------------------------------------------------
2        CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions)

                                                                         (a) |_|
                                                                         (b) |X|
--------------------------------------------------------------------------------
3        SEC USE ONLY

--------------------------------------------------------------------------------
4        SOURCE OF FUNDS
         WC
--------------------------------------------------------------------------------
5        CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
         PURSUANT TO ITEMS 2(d) or 2(e)                                      |_|
--------------------------------------------------------------------------------
6        CITIZENSHIP OR PLACE OF ORGANIZATION
         United States
--------------------------------------------------------------------------------
SHARES BENEFICIALLY OWNED         7        SOLE VOTING POWER
 BY EACH REPORTING PERSON                  -0-
           WITH                   ----------------------------------------------
                                  8        SHARED VOTING POWER
                                           7,312,500
                                  ----------------------------------------------
                                  9        SOLE DISPOSITIVE POWER
                                           -0-
                                  ----------------------------------------------
                                  10       SHARED DISPOSITIVE POWER
                                           7,312,500
--------------------------------------------------------------------------------
11       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
         7,312,500
--------------------------------------------------------------------------------
12       CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
         CERTAIN SHARES (See Instructions)                                   |X|
--------------------------------------------------------------------------------
13       PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)
         15.4%
--------------------------------------------------------------------------------
14       TYPE OF REPORTING PERSON
         IN
--------------------------------------------------------------------------------


                                  Page 7 of 37


Schedule 13D
Cusip No. 812578102

--------------------------------------------------------------------------------
1        NAMES OF REPORTING PERSONS
         I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS

         Felix J. Baker
--------------------------------------------------------------------------------
2        CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions)

                                                                         (a) |_|
                                                                         (b) |X|
--------------------------------------------------------------------------------
3        SEC USE ONLY

--------------------------------------------------------------------------------
4        SOURCE OF FUNDS
         WC
--------------------------------------------------------------------------------
5        CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
         PURSUANT TO ITEMS 2(d) or 2(e)                                      |_|
--------------------------------------------------------------------------------
6        CITIZENSHIP OR PLACE OF ORGANIZATION
         United States
--------------------------------------------------------------------------------
SHARES BENEFICIALLY OWNED         7        SOLE VOTING POWER
 BY EACH REPORTING PERSON                  -0-
           WITH                   ----------------------------------------------
                                  8        SHARED VOTING POWER
                                           7,312,500
                                  ----------------------------------------------
                                  9        SOLE DISPOSITIVE POWER
                                           -0-
                                  ----------------------------------------------
                                  10       SHARED DISPOSITIVE POWER
                                           7,312,500
--------------------------------------------------------------------------------
11       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
         7,312,500
--------------------------------------------------------------------------------
12       CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
         CERTAIN SHARES (See Instructions)                                   |X|
--------------------------------------------------------------------------------
13       PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)
         15.4%
--------------------------------------------------------------------------------
14       TYPE OF REPORTING PERSON
         IN
--------------------------------------------------------------------------------


                                  Page 8 of 37


Schedule 13D
Cusip No. 812578102

--------------------------------------------------------------------------------
1        NAMES OF REPORTING PERSONS
         I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

         Delphi Ventures VI, L.P.
         42-1561726
--------------------------------------------------------------------------------
2        CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

                                                                         (a) |_|
                                                                         (b) |X|
--------------------------------------------------------------------------------
3        SEC USE ONLY

--------------------------------------------------------------------------------
4        SOURCE OF FUNDS
         WC
--------------------------------------------------------------------------------
5        CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
         PURSUANT TO ITEMS 2(d) or 2(e)                                      |_|
--------------------------------------------------------------------------------
6        CITIZENSHIP OR PLACE OF ORGANIZATION
         Delaware
--------------------------------------------------------------------------------
SHARES BENEFICIALLY OWNED         7        SOLE VOTING POWER
 BY EACH REPORTING PERSON                  0
           WITH                   ----------------------------------------------
                                  8        SHARED VOTING POWER
                                           2,227,725 (includes 1,980,200 shares
                                           of Common Stock issuable upon
                                           conversion of the Series A
                                           Convertible Preferred Stock and
                                           247,525 shares of Common Stock
                                           issuable upon exercise of the
                                           Warrants)
                                  ----------------------------------------------
                                  9        SOLE DISPOSITIVE POWER
                                           0
                                  ----------------------------------------------
                                  10       SHARED DISPOSITIVE POWER
                                           2,227,725 (includes 1,980,200 shares
                                           of Common Stock issuable upon
                                           conversion of the Series A
                                           Convertible Preferred Stock and
                                           247,525 shares of Common Stock
                                           issuable upon exercise of the
                                           Warrants)
--------------------------------------------------------------------------------
11       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
         2,227,725 (includes 1,980,200 shares of Common Stock issuable upon
         conversion of the Series A Convertible Preferred Stock and 247,525
         shares of Common Stock issuable upon exercise of the Warrants)
--------------------------------------------------------------------------------
12       CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
         CERTAIN SHARES(6)                                                   |X|
--------------------------------------------------------------------------------
13       PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)
         5.3 %
--------------------------------------------------------------------------------
14       TYPE OF REPORTING PERSON
         PN
--------------------------------------------------------------------------------

--------
(6) The Reporting Person above is party to a voting agreement contained in the
Investors Rights Agreement described herein. As a result, the parties to the
Investors Rights Agreement may be deemed to constitute a "group" for purposes of
Section 13(d)(3) of the Securities Exchange Act of 1934, as amended (the "Act")
with respect to 16,875,000 shares of Common Stock (defined herein), representing
29.6% of the outstanding voting power of the Issuer. The Reporting Person above
disclaims beneficial ownership of any securities held by any other Reporting
Person and the filing of this Statement on Schedule 13D shall not be deemed an
admission that the Reporting Person above and any other person or persons
constitute a "group" for purposes of Section 13(d)(3) of the Act or Rule 13d-5
thereunder.


                                  Page 9 of 37


Schedule 13D
Cusip No. 812578102

--------------------------------------------------------------------------------
1        NAMES OF REPORTING PERSONS
         I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

         Delphi BioInvestments VI, L.P.
         04-3760672
--------------------------------------------------------------------------------
2        CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

                                                                         (a) |_|
                                                                         (b) |X|
--------------------------------------------------------------------------------
3        SEC USE ONLY

--------------------------------------------------------------------------------
4        SOURCE OF FUNDS
         WC
--------------------------------------------------------------------------------
5        CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
         PURSUANT TO ITEMS 2(d) or 2(e)                                      |_|
--------------------------------------------------------------------------------
6        CITIZENSHIP OR PLACE OF ORGANIZATION
         Delaware
--------------------------------------------------------------------------------
SHARES BENEFICIALLY OWNED         7        SOLE VOTING POWER
 BY EACH REPORTING PERSON                  0
           WITH                   ----------------------------------------------
                                  8        SHARED VOTING POWER
                                           22,275 (includes 19,800 shares of
                                           Common Stock issuable upon
                                           conversion of the Series A
                                           Convertible Preferred Stock and
                                           2,475 shares of Common Stock
                                           issuable upon exercise of the
                                           Warrants)
                                  ----------------------------------------------
                                  9        SOLE DISPOSITIVE POWER
                                           0
                                  ----------------------------------------------
                                  10       SHARED DISPOSITIVE POWER
                                           22,275 (includes 19,800 shares of
                                           Common Stock issuable upon
                                           conversion of the Series A
                                           Convertible Preferred Stock and
                                           2,475 shares of Common Stock
                                           issuable upon exercise of the
                                           Warrants)
--------------------------------------------------------------------------------
11       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
         22,275 (includes 19,800 shares of Common Stock issuable upon conversion
         of the Series A Convertible Preferred Stock and 2,475 shares of Common
         Stock issuable upon exercise of the Warrants)
--------------------------------------------------------------------------------
12       CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
         CERTAIN SHARES(7)                                                   |X|
--------------------------------------------------------------------------------
13       PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)
         0 %
--------------------------------------------------------------------------------
14       TYPE OF REPORTING PERSON
         PN
--------------------------------------------------------------------------------

--------
(7) The Reporting Person above is party to a voting agreement contained in the
Investors Rights Agreement described herein. As a result, the parties to the
Investors Rights Agreement may be deemed to constitute a "group" for purposes of
Section 13(d)(3) of the Securities Exchange Act of 1934, as amended (the "Act")
with respect to 16,875,000 shares of Common Stock (defined herein), representing
29.6% of the outstanding voting power of the Issuer. The Reporting Person above
disclaims beneficial ownership of any securities held by any other Reporting
Person and the filing of this Statement on Schedule 13D shall not be deemed an
admission that the Reporting Person above and any other person or persons
constitute a "group" for purposes of Section 13(d)(3) of the Act or Rule 13d-5
thereunder.


                                 Page 10 of 37


Schedule 13D
Cusip No. 812578102

--------------------------------------------------------------------------------
1        NAMES OF REPORTING PERSONS
         I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

         Delphi Management Partners VI, L.L.C.
--------------------------------------------------------------------------------
2        CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

                                                                         (a) |_|
                                                                         (b) |X|
--------------------------------------------------------------------------------
3        SEC USE ONLY

--------------------------------------------------------------------------------
4        SOURCE OF FUNDS
         WC
--------------------------------------------------------------------------------
5        CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
         PURSUANT TO ITEMS 2(d) or 2(e)                                      |_|
--------------------------------------------------------------------------------
6        CITIZENSHIP OR PLACE OF ORGANIZATION
         Delaware
--------------------------------------------------------------------------------
SHARES BENEFICIALLY OWNED         7        SOLE VOTING POWER
 BY EACH REPORTING PERSON                  0
           WITH                   ----------------------------------------------
                                  8        SHARED VOTING POWER
                                           2,250,000 (includes 2,000,000 shares
                                           of Common Stock issuable upon
                                           conversion of the Series A
                                           Convertible Preferred Stock and
                                           250,000 shares of Common Stock
                                           issuable upon exercise of the
                                           Warrants)
                                  ----------------------------------------------
                                  9        SOLE DISPOSITIVE POWER
                                           0
                                  ----------------------------------------------
                                  10       SHARED DISPOSITIVE POWER
                                           2,250,000 (includes 2,000,000 shares
                                           of Common Stock issuable upon
                                           conversion of the Series A
                                           Convertible Preferred Stock and
                                           250,000 shares of Common Stock
                                           issuable upon exercise of the
                                           Warrants)
--------------------------------------------------------------------------------
11       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
         2,250,000 (includes 2,000,000 shares of Common Stock issuable upon
         conversion of the Series A Convertible Preferred Stock and 250,000
         shares of Common Stock issuable upon exercise of the Warrants)
--------------------------------------------------------------------------------
12       CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
         CERTAIN SHARES(8)                                                   |X|
--------------------------------------------------------------------------------
13       PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)
         5.3%
--------------------------------------------------------------------------------
14       TYPE OF REPORTING PERSON
         OO
--------------------------------------------------------------------------------

--------
(8) The Reporting Person above is party to a voting agreement contained in the
Investors Rights Agreement described herein. As a result, the parties to the
Investors Rights Agreement may be deemed to constitute a "group" for purposes of
Section 13(d)(3) of the Securities Exchange Act of 1934, as amended (the "Act")
with respect to 16,875,000 shares of Common Stock (defined herein), representing
29.6% of the outstanding voting power of the Issuer. The Reporting Person above
disclaims beneficial ownership of any securities held by any other Reporting
Person and the filing of this Statement on Schedule 13D shall not be deemed an
admission that the Reporting Person above and any other person or persons
constitute a "group" for purposes of Section 13(d)(3) of the Act or Rule 13d-5
thereunder.


                                 Page 11 of 37


Schedule 13D
Cusip No. 812578102

Item 1.  Security and Issuer.

         The class of equity securities to which this statement (this
         "Statement") relates is the Common Stock, par value $0.001 per share
         (the "Common Stock") of Seattle Genetics, Inc., a Delaware corporation
         (the "Issuer" or "Company"). The Issuer's principal executive offices
         are located at 21823 -- 30th Drive S.E., Bothell, WA 98021.

Item 2.  Identity and Background.

         JPMP Reporting Persons

         This Statement is being filed by: (i) J.P. Morgan Partners (BHCA),
         L.P., a limited partnership organized under the laws of Delaware ("JPMP
         (BHCA)"), whose principal office is located at 1221 Avenue of the
         Americas, New York, NY 10020, (ii) J.P. Morgan Partners Global
         Investors, L.P., a limited partnership organized under the laws of
         Delaware ("JPMP Global"), whose principal office is located at the same
         address as JPMP (BHCA), (iii) J.P. Morgan Partners Global Investors A,
         L.P., a limited partnership organized under the laws of Delaware ("JPMP
         Global A"), whose principal office is located at the same address as
         JPMP (BHCA), (iv) J.P. Morgan Partners Global Investors (Cayman), L.P.,
         a limited partnership organized under the laws of the Cayman Islands
         ("JPMP Cayman"), whose principal office is located at the same address
         as JPMP (BHCA), and (v) J.P. Morgan Partners Global Investors (Cayman)
         II, L.P. a limited partnership organized under the laws of the Cayman
         Islands ("JPMP Cayman II" and collectively with JPMP (BHCA), JPMP
         Global, JPMP Global A and JPMP Cayman, the "JPMP Reporting Persons"),
         whose principal office is located at the same address as JPMP (BHCA).

         JPMP (BHCA) is engaged in the venture capital, private equity and
         leveraged buyout business. The general partner of JPMP (BHCA) is JPMP
         Master Fund Manager, L.P., a Delaware limited partnership ("JPMP Master
         Fund"), whose principal business office is located at the same address
         as JPMP (BHCA), and is also engaged directly and indirectly (through
         affiliates) in the venture capital, private equity and leveraged buyout
         business.

         JPMP Global, JPMP Global A, JPMP Cayman and JPMP Cayman II
         (collectively, the "Global Fund Entities") are also engaged in the
         venture capital, private equity and leveraged buyout business. The
         general partner of each of the Global Fund Entities is JPMP Global
         Investors, L.P., a Delaware limited partnership ("JPMP Investors"),
         whose principal place of business is located at the same address as
         JPMP (BHCA). JPMP Investors is engaged indirectly in the venture
         capital, private equity and leveraged buyout business as general
         partner of each of the Global Fund Entities.


                                 Page 12 of 37


         The general partner of each of JPMP Master Fund and JPMP Investors is
         JPMP Capital Corp., a New York corporation ("JPMP Capital Corp."),
         whose principal business office is located at the same address as JPMP
         (BHCA), and is also engaged directly and indirectly (through
         affiliates) in the venture capital, private equity and leveraged buyout
         business. Set forth in Schedule A hereto and incorporated herein by
         reference are the names, business addresses, principal occupations and
         employments of each executive officer and director of JPMP Capital
         Corp.

         JPMP Capital Corp. is a wholly owned subsidiary of J.P. Morgan Chase &
         Co., a Delaware Corporation ("JP Morgan Chase") which is engaged
         (primarily through subsidiaries) in the commercial banking business
         with its principal office located at 270 Park Avenue, New York, NY
         10018. Set forth in Schedule B hereto and incorporated herein by
         reference are the names, business addresses, principal occupations and
         employments of each executive officer and director of JP Morgan Chase.

         Baker Reporting Persons

         This Statement is also being filed by: (i) Julian C. Baker and (ii)
         Felix J. Baker, each of whom is a United States citizen whose principal
         office is located at 667 Madison Avenue, New York, NY 10021
         (collectively, the "Baker Reporting Persons"). Set forth below is
         certain information with respect to the Baker Reporting Persons:

         Name              Present Principal Occupation
         ----              ----------------------------

         Julian C. Baker   Managing Member, Baker Bros. Advisors, LLC (an entity
                           engaged in investment activities)

         Felix J. Baker    Managing Member, Baker Bros. Advisors, LLC (an entity
                           engaged in investment activities)

         Delphi Reporting Persons

         This Statement is also being filed by: (i) Delphi Ventures VI, L.P., a
         limited partnership organized under the laws of Delaware ("Delphi
         Ventures"), whose principal office is located at 3000 Sand Hill Road,
         Building 1, Suite 135, Menlo Park, CA 94025, (ii) Delphi BioInvestments
         VI, L.P., a limited partnership organized under the laws of Delaware
         ("Delphi BioInvestments"), whose principal office is located at the
         same address as Delphi Ventures, and (iii) Delphi Management Partners
         VI, L.L.C., a Delaware limited liability company ("Delphi Management",
         and together with Delphi Ventures and Delphi BioInvestments, the
         "Delphi Reporting Persons") whose principal office is located at the
         same address as Delphi Ventures.

         The Delphi Reporting Persons are engaged in the venture capital
         business. The general partner of each of Delphi Ventures and Delphi
         BioInvestments is Delphi Management. Delphi Management is also engaged
         indirectly (through affiliates) in the venture capital business. Set
         forth in Schedule C hereto and incorporated herein by reference are the
         names, business addresses, principal occupations and employments of
         each managing member of Delphi Management.


                                 Page 13 of 37


         The Delphi Reporting Persons, the JPMP Reporting Persons and the Baker
         Reporting Persons are collectively referred to herein as the "Reporting
         Persons".

         During the last five years, none of the Reporting Persons have been
         convicted in any criminal proceeding (excluding traffic violations or
         similar misdemeanors) or have been a party to a civil proceeding of a
         judicial or administrative body of competent jurisdiction resulting in
         their being subject to a judgment, decree or final order enjoining
         future violations of, or prohibiting or mandating activities subject
         to, federal or state securities laws, or finding any violations with
         respect to such laws.

Item 3.  Source and Amount of Funds or Other Consideration.

         JPMP Reporting Persons:

         The funds provided by JPMP (BHCA) and the Global Fund Entities for the
         purchase of the securities reported in Item 5 below were obtained from
         the contributed capital and available working capital of JPMP (BHCA)
         and the Global Fund Entities, which includes funds that are held
         available for such purpose.

         Baker Reporting Persons:

         The funds used by the limited partnerships controlled by Julian C.
         Baker and Felix J. Baker to purchase the securities reported in Item 5
         below were provided from the available working capital of such limited
         partnerships.

         Delphi Reporting Persons:

         The funds provided by Delphi Ventures and Delphi BioInvestments for the
         purchase of the securities reported in Item 5 below were obtained from
         the contributed capital and available working capital of Delphi
         Ventures and Delphi BioInvestments respectively, which includes funds
         that are held available for such purpose.

Item 4.  Purpose of Transactions.

         The securities referred to in Item 5 below were acquired pursuant to
         the Securities Purchase Agreement referred to in Item 6 below solely
         for investment purposes.

         The transactions described in Item 6 below are incorporated in their
         entirety herein by reference.


                                 Page 14 of 37


         Subject to the rights of the Reporting Persons set forth in the
         Securities Purchase Agreement and the Investors Rights Agreement
         referred to in Item 6 below, except as set forth in this Item 4, none
         of the JPMP Reporting Persons, the Baker Reporting Persons, or the
         Delphi Reporting Persons have a present plan or proposal that relates
         to or would result in any of the actions specified in clauses (a)
         through (j) of Item 4 of Schedule 13D. However, each of the JPMP
         Reporting Persons, the Baker Reporting Persons and the Delphi Reporting
         Persons reserves the right to propose or participate in future
         transactions which may result in one or more of such actions, including
         but not limited to, an extraordinary corporate transaction, such as a
         merger, reorganization or liquidation, sale of a material amount of
         assets of the Issuer or its subsidiaries, or other transactions which
         might have the effect of causing the Issuer's Common Stock to cease to
         be listed on the NASDAQ National Market System or causing the Common
         Stock to become eligible for termination of registration, under section
         12(g) of the Securities Exchange Act of 1934, as amended (the "Act").

Item 5.  Interest in Securities of the Issuer.

         The percentages of outstanding shares of the Issuer reported in this
         Item 5 are based on 40,196,299 shares of Common Stock outstanding as of
         March 22, 2004 as reported by the Issuer in its most recent Schedule
         14A as filed on April 16, 2004 with the Securities and Exchange
         Commission.

         JPMP Reporting Persons

         JPMP (BHCA) beneficially owns 5,760,349 shares of the Issuer's Common
         Stock, which represents 12.5% of the Issuer's Common Stock. JPMP Global
         beneficially owns 912,791 shares of the Issuer's Common Stock, which
         represents 2.2% of the Issuer's Common Stock. JPMP Global A
         beneficially owns 124,436 shares of the Issuer's Common Stock, which
         represents 0.3% of the Issuer's Common Stock. JPMP Cayman beneficially
         owns 463,298 shares of the Issuer's Common Stock, which represents 1.1%
         of the Issuer's Common Stock. JPMP Cayman II beneficially owns 51,626
         shares of the Issuer's Common Stock, which represents 0.1% of the
         Issuer's Common Stock.

         JPMP Master Fund, as the General Partner of JPMP (BHCA), may be deemed
         to beneficially own the shares beneficially owned by JPMP (BHCA).

         JPMP Investors, as the General Partner of each of the Global Fund
         Entities, may be deemed to beneficially own the shares beneficially
         owned by each of the Global Fund Entities.

         JPMP Capital Corp., as the General Partner of each of JPMP Master Fund
         and JPMP Investors, may be deemed to beneficially own the shares
         beneficially owned by JPMP (BHCA) and each of the Global Fund Entities.


                                 Page 15 of 37


         JPMP Capital Corp. is a wholly owned subsidiary of JP Morgan Chase and
         therefore JP Morgan Chase may be deemed to beneficially own the shares
         beneficially owned by JPMP (BHCA) and each of the Global Fund Entities.

         The foregoing shall not be an admission that JPMP Master Fund, JPMP
         Investors, JPMP Capital Corp. or JP Morgan Chase are the beneficial
         owners of the shares held by JPMP (BHCA) and/or the Global Fund
         Entities.

         Baker Reporting Persons:

         Set forth in the table below is the aggregate number of shares of
         Common Stock beneficially owned as of the date hereof by each of the
         limited partnerships controlled by the Baker Reporting Persons,
         together with the percentage of outstanding shares of Common Stock that
         such ownership represents based upon 40,196,299 shares of Common Stock
         outstanding as of March 22, 2004, as reported by the Issuer in its most
         recent Schedule 14A filed on April 16, 2004, in each case taking into
         account the shares of Common Stock that can be acquired upon conversion
         of Series A Convertible Preferred Stock and exercise of the Warrants to
         purchase shares of Common Stock:

                                                Number of      Percent of Class
                       Name                      Shares           Outstanding
         --------------------------------       ---------      ----------------
         Baker/Tisch Investments, L.P.            446,063            0.9%
         Baker Bros. Investments, L.P.            301,275            0.6%
         Baker Bros. Investments II, L.P.         310,781            0.7%
         Baker Biotech Fund I, L.P.             3,058,088            6.4%
         Baker Biotech Fund II, L.P.            2,809,462            5.9%
         Baker Biotech Fund II (Z), L.P.          386,831            0.8%
                                                ---------           ----
         Total                                  7,312,500           15.4%

         By virtue of their ownership of entities that have the power to control
         the investment decisions of the limited partnerships listed in the
         table above (collectively, the "Baker Entities"), Julian C. Baker and
         Felix J. Baker may each be deemed to be beneficial owners of securities
         owned by the Baker Entities and may be deemed to have shared power to
         vote or direct the vote and to dispose or direct the disposition of
         such securities, although such entities have the sole right to receive
         and power to direct the receipt of dividends from, and the proceeds
         from the sale of, securities owned by them.

         Additionally, Felix J. Baker is a director of the Issuer.


                                 Page 16 of 37


         Delphi Reporting Persons

         Delphi Ventures beneficially owns 2,227,725 shares of the Issuer's
         Common Stock, which represents 5.3% of the Issuer's Common Stock.
         Delphi BioInvestments beneficially owns 22,275 shares of the Issuer's
         Common Stock, which represents 0.01% of the Issuer's Common Stock.

         As the general partner of Delphi Ventures and Delphi BioInvestments,
         Delphi Management may be deemed to beneficially own the shares
         beneficially owned by each of Delphi Ventures and Delphi
         BioInvestments.

         The foregoing shall not be an admission that Delphi Management is the
         beneficial owner of the shares held by Delphi Ventures and/or Delphi
         BioInvestments.

         The Reporting Persons are party to a voting agreement contained in the
         Investors Rights Agreement referred to in Item 6 below. The JPMP
         Reporting Persons, the Baker Reporting Persons, and the Delphi
         Reporting Persons together may be deemed to constitute a "group" for
         purposes of Section 13(d)(3) of the Act, with respect to 16,875,000
         shares of Common Stock, representing 29.6% of the outstanding voting
         power of the Issuer.

         Each of the Reporting Persons, however, disclaims beneficial ownership
         of any of the securities owned by any other Reporting Person and
         disclaims that it is a member of a "group" with any other persons
         either for purposes of Section 13(d)(3) of the Act or Rule 13d-5
         thereunder or this Statement or for any other purpose related to its
         beneficial ownership of the Issuer's securities. The filing of this
         Statement shall not be construed as an admission that the Reporting
         Person is the beneficial owner of such shares or that the Reporting
         Person and any of such other stockholders' constitute for purposes of
         Section 13(d) of the Act, a "group." Each Reporting Person is not
         responsible for the accuracy of any information filed in this Statement
         relating to any Reporting Person other than itself and its related
         persons or entities.

         There have been no transactions involving the Issuer's Common Stock
         during the past sixty days which are required to be reported in this
         Statement.

         No person other than the JPMP Reporting Persons, the Baker Reporting
         Persons and the Delphi Reporting Persons has the right to receive or
         the power to direct the receipt of dividends from or the proceeds from
         the sale of the Issuer's Common Stock owned beneficially by the JPMP
         Reporting Persons, the Baker Reporting Persons and the Delphi Reporting
         Persons.

Item 6.  Contracts, Arrangements, Understandings or Relationships With Respect
         to Securities of the Issuer.

         On May 12, 2003 the Company entered into the Securities Purchase
         Agreement (as amended by Amendment No. 1 dated as of May 14, 2003 and
         Amendment No. 2 dated as of June 2, 2003) (the "SPA"), with JPMP
         (BHCA), the Global Fund Entities, the Baker Entities, Delphi Ventures,
         Delphi BioInvestments, entities affiliated with BA Venture Partners and
         T. Rowe Price Health Sciences Fund, Inc. (collectively, the "Series A
         Investors"). Both the SPA and all exhibits thereto are attached as
         Exhibit A hereto and are incorporated herein in their entirety by
         reference.


                                 Page 17 of 37


         Pursuant to the SPA, the Issuer issued in a private placement (a)
         1,640,000 shares of the Company's Series A Convertible Preferred Stock
         (the "Preferred Stock") to the Series A Investors, as well as the
         reservation for issuance of 16,400,000 shares of the Company's Common
         Stock upon conversion of the Preferred Stock, and (b) warrants (the
         "Warrants") to purchase 2,050,000 shares of the Company's Common Stock
         and the reservation for issuance of 2,050,000 shares of the Company's
         Common Stock upon the exercise of such Warrants (together, the
         "Preferred Stock Financing"). The Preferred Stock has the rights,
         preferences and privileges set forth in the Certificate of Designations
         of Series A Convertible Preferred Stock as filed with the Secretary of
         State of the State of Delaware. The purchase price for the Preferred
         Stock was $25.00 per share. Each share of Preferred Stock is initially
         convertible into 10 shares of Common Stock at a fixed conversion price
         of $2.50 per share (subject to adjustment upon the occurrence of
         certain events including stock subdivisions, combinations, splits,
         stock dividends, capital reorganizations, or capital reclassifications
         of the Common Stock), at such holder's option at any time after the
         first anniversary of the closing of the Investors Rights Agreement
         among the Company, the Reporting Persons and the other investors named
         therein, dated as of July 8, 2003, a copy of which is attached hereto
         as Exhibit B and is incorporated herein in its entirety by reference
         (the "Investors Rights Agreement").

         The Warrants are immediately exercisable at a fixed purchase price of
         $6.25 per share of Common Stock and expire on December 31, 2011.

         Pursuant to the Certificate of Designations and the Investors Rights
         Agreement, the Series A Investors, voting together as a separate class,
         have the right to designate two members of the Company's Board of
         Directors so long as at least 37.5% of the shares of Preferred Stock
         issued at the closing of the Preferred Stock Financing remain
         outstanding. If between 18.75% and 37.5% of the shares of Preferred
         Stock issued at the closing of the Preferred Stock Financing are
         outstanding, the Series A Investors, voting together as a separate
         class, have the right to designate one member of the Company's Board of
         Directors. If less than 18.75% of the shares of Preferred Stock issued
         at the closing of the Preferred Stock Financing are outstanding, the
         rights of the Series A Investors to vote separately for the election of
         directors shall terminate.


                                 Page 18 of 37


         Pursuant to the terms of the Investors Rights Agreement, one director
         will be designated by the JPMP Reporting Persons and one director will
         be designated by the Baker Entities. The right of the JPMP Reporting
         Persons and the Baker Entities, as applicable, to designate a director
         terminates if the JPMP Reporting Persons or the Baker Entities, as
         applicable, hold less than 50% of the Preferred Stock (or Common Stock
         issued upon conversion thereof) purchased by it at the closing of the
         Preferred Stock Financing. Pursuant to these rights, the JPMP Reporting
         Persons designated Srinivas Akkaraju, M.D., Ph.D. as its representative
         on the Company's Board of Directors and the Baker Entities designated
         Felix Baker, Ph.D. as its representative on the Company's Board of
         Directors upon the closing of the Preferred Stock Financing. The Series
         A Investors do not have the right to vote on members of the Company's
         Board of Directors other than the nominees they designate.

         Each of JPMP (BHCA) and the Global Fund Entities is a party to the
         Regulatory Sideletter, dated as of July 8, 2003, by and among the
         Company, JPMP (BHCA) and each of the Global Fund Entities, a copy of
         which is attached as Exhibit C hereto and is incorporated herein in its
         entirety by reference.

Item 7.  Material to be Filed as Exhibits.

         SCHEDULE A

         Item 2 information for executive officers and directors of JPMP Capital
         Corp.

         SCHEDULE B

         Item 2 information for executive officers and directors of J.P. Morgan
         Chase.

         SCHEDULE C

         Item 2 information for managing members of Delphi Management.

         EXHIBIT A

         Securities Purchase Agreement dated as of May 12, 2003, by and among
         the Issuer and the Series A Investors incorporated by reference to
         Exhibit 10.1 of the Form 8-K filed with the Commission on May 15, 2003.

         EXHIBIT B

         Investors Rights Agreement dated as of July 8, 2003, by and among the
         Company and the Investors named therein incorporated by reference to
         Exhibit 4.2 of the Form 8-K filed with the Commission on May 15, 2003.

         EXHIBIT C

         Regulatory Sideletter dated as of July 8, 2003, by and among the
         Company, JPMP (BHCA) and each of the Global Fund Entities.

         EXHIBIT D

         Joint Filing Agreement dated as of May 17th, 2004 among the JPMP
         Entities, the Bakers and the Delphi Entities.


                                 Page 19 of 37


                                   SIGNATURE

         After reasonable inquiry and to the best of our knowledge and belief,
we certify that the information set forth in this Statement is true, complete
and correct.

Dated: May 17, 2004


                                        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/ Jeffrey  C. Walker
                                                 -------------------------------
                                                 Name:  Jeffrey C. Walker
                                                 Title: President

                                        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/ Jeffrey  C. Walker
                                                 -------------------------------
                                                 Name:  Jeffrey C. Walker
                                                 Title: President

                                        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/ Jeffrey  C. Walker
                                                 -------------------------------
                                                 Name:  Jeffrey C. Walker
                                                 Title: President


                                 Page 20 of 37


                                        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/ Jeffrey  C. Walker
                                                 -------------------------------
                                                 Name:  Jeffrey C. Walker
                                                 Title: President

                                        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/ Jeffrey  C. Walker
                                                 -------------------------------
                                                 Name:  Jeffrey C. Walker
                                                 Title: President


                                        JULIAN C. BAKER

                                        By:      /s/ Julian C. Baker
                                                 -------------------------------
                                                 Julian C. Baker

                                        FELIX J. BAKER

                                        By:      /s/ Felix J. Baker
                                                 -------------------------------
                                                 Felix J. Baker


                                        DELPHI VENTURES VI, L.P.

                                        By:      Delphi Management Partners VI,
                                                 L.L.C., its general partner


                                        By:      /s/ Deepika R. Pakianathan
                                                 -------------------------------
                                                 Deepika R. Pakianathan
                                                 Managing Member


                                 Page 21 of 37


                                        DELPHI BIOINVESTMENTS VI, L.P.

                                        By:      Delphi Management Partners VI,
                                                 L.L.C., its general partner


                                        By:      /s/ Deepika R. Pakianathan
                                                 -------------------------------
                                                 Deepika R. Pakianathan
                                                 Managing Member


                                        DELPHI MANAGEMENT PARTNERS VI, L.L.C.

                                        By:      /s/ Deepika R. Pakianathan
                                                 -------------------------------
                                                 Deepika R. Pakianathan
                                                 Managing Member


                                 Page 22 of 37


                                                                      SCHEDULE A


                               JPMP CAPITAL CORP.


                             Executive Officers(1)

Jeffrey C. Walker*                                      President
Arnold L. Chavkin*                                      Executive Vice President
Dr. Dana Beth Ardi*                                     Managing Director
Christopher C. Behrens*                                 Managing Director
Julie Casella-Esposito*                                 Managing Director
Rodney A. Ferguson*                                     Managing Director
Cornell Buck French*                                    Managing Director
David J. Gilbert*                                       Managing Director
Michael R. Hannon*                                      Managing Director
Jonathan R. Lynch*                                      Managing Director
Stephen P. Murray*                                      Managing Director
Timothy Purcell*                                        Managing Director
John Reardon*                                           Managing Director
Faith Rosenfeld*                                        Managing Director
Robert R. Ruggiero, Jr.*                                Managing Director
Shahan D. Soghikian*                                    Managing Director
William Stuek*                                          Managing Director
Patrick J. Sullivan*                                    Managing Director
Timothy J. Walsh*                                       Managing Director
Richard D. Waters, Jr.*                                 Managing Director
Damion E. Wicker, M.D.*                                 Managing Director


                                  Directors(1)

                             William B. Harrison**
                               Jeffrey C. Walker*

--------
(1)      Each of whom is a United States citizen.
*        Principal occupation is employee and/or officer of J.P. Morgan
         Partners, LLC. Business address is c/o J.P. Morgan Partners, LLC, 1221
         Avenue of the Americas, New York, New York 10020.
**       Principal occupation is employee or officer of J.P. Morgan Chase & Co.
         Business address is c/o J.P. Morgan Chase & Co., 270 Park Avenue, New
         York, New York 10017.


                                 Page 23 of 37


                                                                      SCHEDULE B


                            J.P. MORGAN CHASE & CO.

                             Executive Officers(1)

Chairman of the Board and Chief Executive Officer       William B. Harrison Jr.*
Head of Investment Bank and Investment Management
and Private Banking                                     David A. Coulter*
Head of Chase Financial Services, Treasury,
Security Services, and Technology                       Donald H. Layton*
Head of JPMorgan Partners                               Jeffrey C. Walker**
Chief Risk Officer and Chairman, Risk Management
Committee                                               Don M. Wilson III*
Executive Vice President; Chief Financial Officer       Dina Dublon*
General Counsel                                         William H. McDavid*
Director of Human Resources                             John J. Farrell*
Director of Corporate Marketing and Communications      Frederick W. Hill*
Chairman of Technology Council                          John W. Schmidlin*
Executive Vice President and Controller                 Joseph L. Sclafani*
Vice Chairman                                           James B. Lee Jr.*
Vice Chairman,                                          Walter A. Gubert*
Chairman, Investment Bank

--------
(1)      Each of whom is a United States citizen.
*        Principal occupation is employee or officer of J.P. Morgan Chase & Co.
         Business address is c/o J.P. Morgan Chase & Co., 270 Park Avenue, New
         York, New York 10017.
**       Principal occupation is employee and/or officer of J.P. Morgan
         Partners, LLC. Business address is c/o J.P. Morgan Partners, LLC, 1221
         Avenue of the Americas, New York New York 10020.


                                 Page 24 of 37


                                  DIRECTORS(1)



                                   Principal Occupation or Employment;
Name                               Business or Residence Address
----------------------------------------------------------------------------------------------------------
                               
Hans W. Becherer                   Retired Chairman of the Board and Chief Executive Officer
                                   Deere & Company
                                   One John Deere Place
                                   Moline, IL 61265
----------------------------------------------------------------------------------------------------------
Riley P. Bechtel                   Chairman and Chief Executive Officer
                                   Bechtel Group, Inc.
                                   P.O. Box 193965
                                   San Francisco, CA 94119-3965
----------------------------------------------------------------------------------------------------------
Frank A. Bennack, Jr.              Chairman of the Executive Committee and Vice Chairman of the Board
                                   The Hearst Corporation
                                   1345 Avenue of the Americas, 42nd Floor
                                   New York, New York 10105
----------------------------------------------------------------------------------------------------------
John H. Biggs                      Former Chairman and Chief Executive Officer
                                   TIAA-CREF
                                   730 Third Avenue
                                   25th Floor
                                   New York, NY 10017
----------------------------------------------------------------------------------------------------------
Lawrence A. Bossidy                Retired Chairman of the Board
                                   Honeywell International, Inc.
                                   104 West Mountain Road,
                                   Ridgefield, CT 06877-3638
----------------------------------------------------------------------------------------------------------
M. Anthony Burns                   Chairman of the Board Emeritus
                                   Ryder System, Inc.
                                   3600 N.W. 82nd Avenue
                                   Miami, Florida 33166
----------------------------------------------------------------------------------------------------------
Ellen V. Futter                    President and Trustee
                                   American Museum of Natural History
                                   Central Park West at 79th Street
                                   New York, NY 10024
----------------------------------------------------------------------------------------------------------
William H. Gray, III               Retired President and Chief Executive Officer
                                   The College Fund/UNCF
                                   8260 Willow Oaks Corporate Drive
                                   P.O. Box 10444
                                   Fairfax, Virginia 22031
----------------------------------------------------------------------------------------------------------
William B. Harrison, Jr.*          Chairman of the Board and Chief Executive Officer
                                   J.P. Morgan Chase & Co.
                                   270 Park Avenue, 8th Floor
                                   New York, New York  10017-2070
----------------------------------------------------------------------------------------------------------
Helene L. Kaplan                   Of Counsel
                                   Skadden, Arps, Slate, Meagher & Flom LLP
                                   Four Times Square, Floor 44, Room 416
                                   New York, New York 10036
----------------------------------------------------------------------------------------------------------
Lee R. Raymond                     Chairman of the Board and Chief Executive Officer
                                   Exxon Mobil Corporation
                                   5959 Las Colinas Boulevard
                                   Irving, TX 75039-2298
----------------------------------------------------------------------------------------------------------
John R. Stafford                   Retired Chairman of the Board
                                   Wyeth
                                   5 Giralda Farms
                                   Madison, New Jersey 07940
----------------------------------------------------------------------------------------------------------


----------
(1)      Each of whom is a United States citizen.
*        Principal occupation is employee or officer of J.P. Morgan Chase & Co.
         Business address is c/o J.P. Morgan Chase & Co., 270 Park Avenue, New
         York, New York 10017.
**       Principal occupation is employee and/or officer of J.P. Morgan
         Partners, LLC. Business address is c/o J.P. Morgan Partners, LLC, 1221
         Avenue of the Americas, New York New York 10020.


                                 Page 25 of 37


                                                                      SCHEDULE C


                     DELPHI MANAGEMENT PARTNERS VI, L.L.C.



                              Managing Members(1)



         Managing Member            James J. Bochnowski*
         Managing Member            David L. Douglass*
         Managing Member            Douglas A. Roeder*
         Managing Member            Deepika R. Pakianathan*
         Managing Member            John F. Maroney*











----------
(1)      Each of whom is a United States citizen except for Ms. Pakianathan.
*        Principal occupation is Managing Member of Delphi Management Partners
         VI, L.L.C. Business address is 3000 Sand Hill Road, Building 1, Suite
         135, Menlo Park, California 94025.


                                 Page 26 of 37


                                                                       EXHIBIT C

                             REGULATORY SIDELETTER

         AGREEMENT dated as of [___________], 2003 by and among J.P. MORGAN
PARTNERS (BHCA), L.P., a Delaware limited partnership ("JPMP BHCA"), J.P. MORGAN
PARTNERS GLOBAL INVESTORS, L.P., a Delaware limited partnership (the "Global
Domestic Fund"), J.P. MORGAN PARTNERS GLOBAL INVESTORS (CAYMAN), L.P., a Cayman
Islands limited partnership (the "Global Cayman Fund"), J.P.MORGAN PARTNERS
GLOBAL INVESTORS A, L.P., a Delaware limited partnership (the "Paul Capital
Fund") and J.P. MORGAN PARTNERS GLOBAL INVESTORS (CAYMAN) II, L.P., a Cayman
Islands limited partnership (the "Swiss Fund" and together with JPMP BHCA, the
Global Domestic Fund, the Global Cayman Fund and the Paul Capital Fund,
collectively, the "JP Morgan Investors" and singularly, a "JP Morgan Investor")
and SEATTLE GENETICS, INC., a Delaware corporation (the "Company").

         WHEREAS, each JP Morgan Investor is a regulated entity and an indirect
subsidiary of J.P. Morgan Chase & Co. and in connection therewith each JP Morgan
Investor is subject to various regulations that may impose restrictions on the
type and terms of each JP Morgan Investor's investment in the Company;

         NOW THEREFORE, in connection with the foregoing, the parties hereby
agree as follows:


                                 Page 27 of 37


         Section 1.        Regulatory Matters Generally.

                  (a)      Regulatory Cooperation.

                           (i)      In the event that any JP Morgan Investor
         reasonably determines that it has a Regulatory Problem, the Company
         agrees to take such actions as are reasonably requested by such JP
         Morgan Investor in order (A) to effectuate and facilitate any transfer
         by such JP Morgan Investor of any securities of the Company then held
         by such JP Morgan Investor to any Affiliate of such JP Morgan Investor;
         provided, however, that any such transfer must be made in accordance
         with applicable United States federal and state securities laws and all
         regulatory requirements to which the Company is then subject, including
         without limitation, the rules of the National Association of Securities
         Dealers, Inc. ("NASD") and The Nasdaq Stock Market ("Nasdaq"), and (B)
         to permit such JP Morgan Investor (or any of its Affiliates) to
         exchange all or any portion of the voting securities then held by such
         Person on a share-for-share basis for shares of a class or series of
         non-voting securities of the Company, which non-voting securities shall
         be identical in all material respects to such voting securities
         (provided that such non-voting securities may be of a different class
         or series of stock than the voting securities then held by the JP
         Morgan Investor) except that such new securities shall be non-voting
         and shall be convertible into voting securities on such terms as are
         requested by such JP Morgan Investor in light of regulatory
         considerations then prevailing and reasonably acceptable to the
         Company. If any JP Morgan Investor elects to transfer securities of the
         Company in order to avoid a Regulatory Problem to an Affiliate subject
         to limitations on its voting or total ownership interest in the
         Company, the Company and such Affiliate shall enter into such mutually
         acceptable agreements as the Company or such Affiliate may reasonably
         request in order to assist such Affiliate in complying with Laws to
         which either of them is then subject.

                           (ii)     In the event that any Affiliate (other than
         an Affiliate referred to in clause (i) of such definition) of the
         Company ever offers to issue any of its securities to any JP Morgan
         Investor, then the Company will cause such Affiliate to enter into an
         agreement with such JP Morgan Investor substantially similar to this
         Agreement.

         Section 2.        Cross Marketing Activities.

         The Company hereby represents and warrants that except as otherwise
previously disclosed to the JP Morgan Investors, neither the Company nor any of
its subsidiaries (i) offers or markets, directly or through any arrangement, any
product or service of any depository institution owned by J.P. Morgan Chase &
Co., or (ii) knowingly permits any of its products or services to be offered or
marketed, directly or through any arrangement, by or through any depository
institution owned by J.P. Morgan Chase & Co.

         Section 3.        Lending Activities.

         The Company hereby represents and warrants that except as otherwise
previously disclosed to the JP Morgan Investors, neither the Company nor any of
its subsidiaries currently has or is expected to have a loan facility, credit
facility, debt financing, line of credit or any other extension of credit from
any depository institution owned by J.P. Morgan Chase & Co.


                                 Page 28 of 37


         Section 4.        Covenants.

                  (a)      The Company shall give each JP Morgan Investor thirty
(30) days prior written notice before taking any affirmative steps which would
cause the representations and warranties contained in Sections 2 or 3 to be
untrue.

                  (b)      The Company shall use its commercially reasonable
efforts to notify each JP Morgan Investor promptly at any time in which the
Company reasonably believes the representations contained in Sections 2 or 3 to
be untrue whether as a result of the Company's affirmative action or otherwise.

                  (c)      The Company shall use commercially reasonable efforts
to obtain stockholder approval for an action under Section 1 of this Agreement
(including, but not limited to, calling a stockholder meeting and preparing,
delivering and disseminating a proxy information statement to the stockholders)
if such action would require the approval of the Company's stockholders under
applicable rules of the NASD or Nasdaq, under any applicable state corporate law
or under the Company's Fundamental Documents; provided, however, that the
Company may, upon prior written notice to the JP Morgan Investors, delay the
filing of any proxy statement for a reasonable period of time (not to exceed 90
days or such shorter period as is reasonably necessary to enable the JP Morgan
Investors to cure such Regulatory Problem within the proscribed time period) if
at the time such approval is required the Company is engaged in a Material
Transaction (as defined in the Investor Rights Agreement).

                  (d)      The JP Morgan Investors shall pay all actual,
out-of-pocket costs and expenses reasonably incurred by the Company in
connection with the Company's compliance with its obligations under Section 1 of
this Agreement, and if applicable, any action to which the Company consents
under Section 4(c), including, without limitation, (i) reasonable fees and
expenses of counsel, accountants, investment bankers and printers, and (ii)
filing fees with the NASD, Nasdaq and state corporate authorities. Such amounts
shall be paid in full by the JP Morgan Investors within 30 days of the date the
JP Morgan Investors are provided with a written invoice detailing the amounts of
such expenses incurred by the Company.

         Section 5.        Definitions.

         "Affiliate" means, with respect to any Person, (i) a director or
executive officer of such Person or of any Person identified in clause (ii)
below, and (ii) any other Person that, directly or indirectly through one or
more intermediaries, Controls, is Controlled by or is under common Control with
such Person. When such term is used in the context of a Regulatory Problem, it
also has the meaning ascribed to it in any Law.

         "Banking Regulations" means all federal, state and foreign Laws
applicable to banks, bank holding companies and their subsidiaries and
Affiliates, including without limitation, the Bank Holding Company Act and the
Federal Reserve Act.

         "Control" means, with respect to any Person, the possession, directly
or indirectly, of the power to direct or cause the direction of the management
or policies of a Person, whether through the ownership of voting securities, by
contract or otherwise.


                                 Page 29 of 37


         "Fundamental Documents" means the documents by which any Person (other
than an individual) establishes its legal existence or which govern its internal
affairs. The Fundamental Documents of the Company are its Certificate of
Incorporation and its By-laws.

         "Investor Rights Agreement" means the Investor Rights Agreement dated
on or about the date hereof among the Company and the investors that are parties
thereto.

         "Law," with respect to any Person, means (i) all provisions of all
laws, statutes, ordinances, rules, regulations, permits, certificates or orders
of any governmental authority applicable to such Person or any of its assets or
property or to which such Person or any of its assets or property is subject,
including, without limitation, Banking Regulations, and (ii) all judgments,
injunctions, orders and decrees of all courts and arbitrators in proceedings or
actions in which such Person is a party or by which it or any of its assets or
properties is or may be bound or subject.

         "Person" shall be construed as broadly as possible and shall include an
individual or natural person, a partnership (including a limited liability
partnership), a corporation, an association, a joint stock company, a limited
liability company, a trust, a joint venture, an unincorporated organization and
a governmental authority.

         "Purchase Agreement" means the Securities Purchase Agreement dated as
of May 12, 2003 among the Company, the JP Morgan Investors and the other parties
thereto.

         "Regulatory Problem" means any set of facts or circumstances in which
any JP Morgan Investor's ownership of securities issued by the Company (i) gives
rise to a material violation of Law by such JP Morgan Investor or any of its
Affiliates, or gives rise to a reasonable belief by such JP Morgan Investor that
such a violation is likely to occur or (ii) gives rise to a limitation in Law
that will impair materially the ability of such JP Morgan Investor or any of its
Affiliates to conduct its business or gives rise to a reasonable belief by such
JP Morgan Investor that such a limitation is likely to arise.

         Section 6.        Amendments; Benefit.

         The terms and provisions of this Agreement may not be modified or
amended, unless pursuant to a written agreement executed by each of the parties
hereto. This Agreement shall be for the benefit of each JP Morgan Investor and
its Affiliates and shall apply to each acquisition of securities issued by the
Company to each JP Morgan Investor or its Affiliates.

         Section 7.        Counterparts; Facsimile Signatures.

         This Agreement may be executed in any number of counterparts, including
by means of facsimile, and each counterpart hereof shall be deemed to be an
original instrument, but all such counterparts together shall constitute but one
agreement.


                                 Page 30 of 37


         Section 8.        Notices.

         All notices, claims, certificates, requests, demands and other
communications to be given to any JP Morgan Investor hereunder or relating to
any JP Morgan Investor's investment in the Company shall be addressed as
follows:

                                    c/o J.P. Morgan Partners, LLC
                                    1221 Avenue of the Americas
                                    New York, New York  10020-1080
                                    Telephone:  (212) 899-3400
                                    Facsimile:  (212) 899-3401
                                    Attention:  Official Notices Clerk
                                                (FBO: Srinivas Akkaraju)

                                    with a copy to:

                                    O'Melveny & Myers LLP
                                    Times Square Tower
                                    7 Times Square
                                    New York, NY  10036
                                    Telephone:  (212) 408-2400
                                    Telecopier: (212) 408-2420
                                    Attention:  Phillip Isom, Esq.

         Section 9.        Governing Law.

         This Agreement shall be governed by and construed in accordance with
the laws of the State of New York (without regard to any choice of law or any
conflicting provision or rule).

                                     *****


                                 Page 31 of 37


Schedule 13D
Cusip No. 812578102

         IN WITNESS WHEREOF, the parties hereto have executed this Agreement as
of the date first written above.



                                        SEATTLE GENETICS, INC.


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


                                        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 32 of 37


                                        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


                                 Page 33 of 37


                                                                       EXHIBIT D


                             JOINT FILING AGREEMENT

         In accordance with Rule 13d-1(k) under the Securities and Exchange Act
of 1934, as amended, the undersigned hereby acknowledge and agree that the
foregoing statement on Schedule 13D is filed on behalf of each of the
undersigned.

         This Joint Filing Agreement may be executed in any number of
counterparts all of which together shall constitute one and the same instrument.

                                   * * * * *


                                 Page 34 of 37


                  IN WITNESS WHEREOF, the undersigned hereby execute this Joint
Filing Agreement.

Dated this 17 day of May, 2004.


                                        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/ Jeffrey  C. Walker
                                                 -------------------------------
                                                 Name:  Jeffrey C. Walker
                                                 Title: President


                                        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/ Jeffrey  C. Walker
                                                 -------------------------------
                                                 Name:  Jeffrey C. Walker
                                                 Title: President

                                        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/ Jeffrey  C. Walker
                                                 -------------------------------
                                                 Name:  Jeffrey C. Walker
                                                 Title: President


                                 Page 35 of 37


                                        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/ Jeffrey  C. Walker
                                                 -------------------------------
                                                 Name:  Jeffrey C. Walker
                                                 Title: President

                                        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/ Jeffrey  C. Walker
                                                 -------------------------------
                                                 Name:  Jeffrey C. Walker
                                                 Title: President


                                 Page 36 of 37


                                        JULIAN C. BAKER

                                        By:      /s/ Julian C. Baker
                                                 -------------------------------
                                                 Julian C. Baker

                                        FELIX J. BAKER

                                        By:      /s/ Felix J. Baker
                                                 -------------------------------
                                                 Felix J. Baker


                                        DELPHI VENTURES VI, L.P.

                                        By:      Delphi Management Partners VI,
                                                 L.L.C., its general partner


                                        By:      /s/ Deepika R. Pakianathan
                                                 -------------------------------
                                                 Deepika R. Pakianathan
                                                 Managing Member



                                        DELPHI BIOINVESTMENTS VI, L.P.

                                        By:      Delphi Management Partners VI,
                                                 L.L.C., its general partner


                                        By:      /s/ Deepika R. Pakianathan
                                                 -------------------------------
                                                 Deepika R. Pakianathan
                                                 Managing Member


                                        DELPHI MANAGEMENT PARTNERS VI, L.L.C.

                                        By:      /s/ Deepika R. Pakianathan
                                                 -------------------------------
                                                 Deepika R. Pakianathan
                                                 Managing Member


                                 Page 37 of 37