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                                                                   Exhibit 10.24

                       CYPRESS BIOSCIENCE, INC. LETTERHEAD

February 1, 2002

Fresenius HemoCare GmbH
Adsorber Technology Division
Frankfurther Str. 6-8
D-66606 St. Wendel
Germany
Attn:    Mr. Yorck Schmidt

Fresenius HemoCare, Inc.
6675 185/th/ Avenue NE, Suite 100
Redmond, WA  98052
Attn: Linxian Wu

Re:  Amended and Restated License Agreement

Dear Mr. Schmidt Mr. Wu:

This letter agreement (the "Letter Amendment") serves to amend certain
provisions of the Amended and Restated License Agreement (the "Original
Agreement") dated January 19, 2001 among Cypress Bioscience, Inc., a Delaware
corporation (the "Licensor"), Fresenius Hemocare, Inc., a Delaware corporation
(the "Licensee"), and Fresenius Hemocare Gmbh, a company organized under the
laws of the Federal Republic of Germany ("Fresenius GmbH"). Licensor, Licensee
and Fresenius GmbH (collectively referred to herein as the "Parties") agree to
amend and restate the provisions in the Original Agreement as described below.
All other provisions in the Original Agreement shall remain in full force and
effect.

        (1)      The definition of "License Fee Period" shall now read "License
                 Fee Period" means the seven (7) Contract Year period commencing
                 as of the Effective Date.

        (2)      Section 10.2(b) shall now read, "Notwithstanding Section
                 10.2(a), the License Fee shall be deemed to cover all royalties
                 with respect to Unit Sales of the Product during the License
                 Fee Period, and Licensor shall not be entitled to any
                 additional royalties during such License Fee Period,
                 notwithstanding the Final Payment (as defined in Section
                 10.3(a) below)."

        (3)      Section 10.2(c) shall now read, "Licensor shall not be entitled
                 to any royalties or payments with respect to sales of
                 Alternative Products during the License Fee Period."

        (4)      Section 10.3(a) shall now read, "Licensor shall be entitled to
                 one final payment in US dollars (the "Final Payment"), due
                 within ninety (90) days of end of the License Fee Period,
                 calculated as follows:

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                 (i)    If aggregate Unit Sales of the Product over the License
Fee Period are less than 35,000 Units, then no Final Payment shall be due
Licensor.

                 (ii)   If aggregate Unit Sales of the Product over the License
Fee Period are greater than 35,000 Units but less than 50,000 Units, then the
Final Payment due Licensor shall be US$1,000,000.

                 (iii)  If aggregate Unit Sales of the Product over the License
Fee Period are greater than 50,000 Units, then the Final Payment due Licensor
shall be US$2,000,000.

                 Upon receipt by Licensor in full of the Final Payment, Licensor
shall have no right to future revenues or royalties resulting from Unit Sales of
the Product thereafter. The Final Payment, if any such payment is due to
Licensor pursuant to Sections 10.3(a)(i) or 10.3(a)(ii), shall be payable on
January 30, 2008."

        (5)      Sections 10.5(b), 10.5(c) and 10.5(d) shall be deleted.

        (6)      Section 12.2(a) shall now read "Licensee shall provide
                 quarterly statements to Licensor on the 30/th/ day following
                 the conclusion of each calendar quarter during the term of this
                 Agreement. Each such statement shall present, for the quarter
                 to which such statement relates, total Unit Sales by territory
                 for such quarter."

        (7)      Section 16.3(a)(vii) shall now read, "Licensee and Fresenius
                 GmbH shall not be entitled to any refund or repayment of any
                 portion of the License Fee or the Final Payment, if any, under
                 any circumstances."

In addition, in connection with the execution of this Letter Amendment, Licensor
agrees to reimburse Licensee and Fresenius GmbH for legal fees incurred in
connection with the negotiation and execution of this Letter Amendment;
provided, however, that such fees shall not exceed US$5,000.

Sincerely,

CYPRESS BIOSCIENCE, INC.

/s/ John Bonfiglio
----------------------------------
Dr. John Bonfiglio
Chief Operating Officer and
Executive Vice President

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Acknowledged and Agreed to by:

FRESENIUS HEMOCARE GmbH

By: /s/ Yorck Schmidt
   ---------------------------------
Name:   Dr. York Schmidt
        ----------------------------
Its:    President and CFO
        ----------------------------


By: /s/ Wolfgang Hockh
   ---------------------------------
Name:   Dr. Wolfgang Hockh
        ----------------------------
Its:    Vice President
        ----------------------------


FRESENIUS HEMOCARE, INC.

By: /s/ Linxian Wu
    --------------------------------
     Linxian Wu
     President

cc:      Robert Grauman, Esq, O'Melveny & Myers
         Roland Kirsten, Fresenius Aktiengesellschaft
         Dr. Jay Kranzler, Cypress Bioscience, Inc.
         Fred Muto, Esq, Cooley Godward LLP
         Denise Woolard, Esq, Cooley Godward LLP
         Dan Kleeburg, Ernst & Young