SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, DC 20549

                                 SCHEDULE 13G
                                (Rule 13d-102)


            INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT
          TO RULES 13d-1(b)(c), AND (d) AND AMENDMENTS THERETO FILED
                           PURSUANT TO RULE 13d-2(b)

                               (Amendment No. 1)


                               Cerus Corporation
--------------------------------------------------------------------------------
                               (Name of Issuer)


                                 Common Stock
--------------------------------------------------------------------------------
                        (Title of Class of Securities)


                                   157085101
--------------------------------------------------------------------------------
                                (CUSIP Number)


                               December 31, 2002
--------------------------------------------------------------------------------
            (Date of Event Which Requires Filing of this Statement)


     Check the appropriate box to designate the rule pursuant to which this
Schedule is filed:

          [_]  Rule 13d-1(b)

          [X]  Rule 13d-1(c)

          [_]  Rule 13d-1(d)


----------
(1)  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 the disclosures provided in a prior cover page.

     The information required in the remainder of this cover page shall not be
deemed to be "filed" for the purpose of Section 18 of the Securities  Exchange
Act of 1934 or otherwise subject to the liabilities of that section of the Act
but shall be  subject to all other  provisions  of the Act  (however,  see the
Notes).



CUSIP No.   157085101
            ---------------------


1.   NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     Deerfield Capital, L.P.

2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a)  [_]
                                                                 (b)  [X]

3.   SEC USE ONLY



4.   CITIZENSHIP OR PLACE OF ORGANIZATION

     Delaware

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH

5.   SOLE VOTING POWER



6.   SHARED VOTING POWER

     512,176

7.   SOLE DISPOSITIVE POWER



8.   SHARED DISPOSITIVE POWER

     512,176

9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     512,176

10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                          [_]

11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     3.22%

12.  TYPE OF REPORTING PERSON*

     PN





CUSIP No.   157085101
            ---------------------


1.   NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     Deerfield Partners, L.P.

2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a)  [_]
                                                                 (b)  [X]

3.   SEC USE ONLY



4.   CITIZENSHIP OR PLACE OF ORGANIZATION

     New York

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH

5.   SOLE VOTING POWER



6.   SHARED VOTING POWER

     512,176

7.   SOLE DISPOSITIVE POWER



8.   SHARED DISPOSITIVE POWER

     512,176

9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     512,176

10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                          [_]

11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     3.22%

12.  TYPE OF REPORTING PERSON*

     PN





CUSIP No.   157085101
            ---------------------


1.   NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     Deerfield Management Company

2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a)  [_]
                                                                 (b)  [X]

3.   SEC USE ONLY



4.   CITIZENSHIP OR PLACE OF ORGANIZATION

     New York

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH

5.   SOLE VOTING POWER



6.   SHARED VOTING POWER

     402,424

7.   SOLE DISPOSITIVE POWER



8.   SHARED DISPOSITIVE POWER

     402,424

9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     402,424

10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                          [_]

11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     2.53%

12.  TYPE OF REPORTING PERSON*

     PN





CUSIP No.   157085101
            ---------------------


1.   NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     Deerfield International Limited

2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a)  [_]
                                                                 (b)  [X]

3.   SEC USE ONLY



4.   CITIZENSHIP OR PLACE OF ORGANIZATION

     British Virgin Islands

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH

5.   SOLE VOTING POWER



6.   SHARED VOTING POWER

     402,424

7.   SOLE DISPOSITIVE POWER



8.   SHARED DISPOSITIVE POWER

     402,424

9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     402,424

10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                          [_]

11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     2.53%

12.  TYPE OF REPORTING PERSON*

     CO





CUSIP No.   157085101
            ---------------------


1.   NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     Arnold H. Snider

2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a)  [_]
                                                                 (b)  [X]

3.   SEC USE ONLY



4.   CITIZENSHIP OR PLACE OF ORGANIZATION

     United States

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH

5.   SOLE VOTING POWER



6.   SHARED VOTING POWER

     914,600

7.   SOLE DISPOSITIVE POWER



8.   SHARED DISPOSITIVE POWER

     914,600

9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     914,600

10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                          [_]
11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     5.75%

12.  TYPE OF REPORTING PERSON*

     IN





CUSIP No.   157085101
            ---------------------


Item 1(a).  Name of Issuer:


            Cerus Corporation

           --------------------------------------------------------------------

Item 1(b).  Address of Issuer's Principal Executive Offices:


            2411 Stanwell Drive
            Concord, California 94520


           --------------------------------------------------------------------


Item 2(a).  Name of Person Filing:


            Arnold H. Snider, Deerfield Capital, L.P., Deerfield Management
            Company, Deerfield International Limited

           --------------------------------------------------------------------

Item 2(b).  Address of Principal Business Office, or if None, Residence:


            Arnold H. Snider, Deerfield Capital, L.P., Deerfield Management
            Company, 780 Third Avenue, 37th Floor, New York, NY 10017

            Deerfield International Limited, c/o Hemisphere Management
            (B.V.I.)
            Limited, Bison Court, Columbus Centre, P.O. Box 3460, Road Town,
            Tortola, British Virgin Islands

           --------------------------------------------------------------------

Item 2(c).  Citizenship:

            Mr. Snider - United States citizen

            Deerfield Capital, L.P. and Deerfield Partners,
            L.P. - Delaware limited partnerships

            Deerfield Management Company - New York limited
            partnership

            Deerfield International Limited - British Virgin
            Islands corporation



           --------------------------------------------------------------------

Item 2(d).  Title of Class of Securities:


            Common Stock

           --------------------------------------------------------------------

Item 2(e).  CUSIP Number:


            157085101

           --------------------------------------------------------------------


Item 3.  If This Statement is Filed  Pursuant to Rule 13d-1(b),  or 13d-2(b) or
         (c), Check Whether the Person Filing is a:

     (a)  [_] Broker or dealer  registered  under  Section 15 of the  Exchange
              Act.

     (b)  [_] Bank as defined in Section 3(a)(6) of the Exchange Act.

     (c)  [_] Insurance company as defined in Section 3(a)(19) of the Exchange
              Act.

     (d)  [_] Investment  company registered under Section 8 of the Investment
              Company Act.

     (e)  [_] An    investment    adviser    in    accordance    with   Rule
              13d-1(b)(1)(ii)(E);

     (f)  [_] An employee  benefit plan or endowment  fund in accordance  with
              Rule 13d-1(b)(1)(ii)(F);

     (g)  [_] A parent holding  company or control  person in accordance  with
              Rule 13d-1(b)(1)(ii)(G);

     (h)  [_] A savings  association as defined in Section 3(b) of the Federal
              Deposit Insurance Act;

     (i)  [_] A  church  plan  that is  excluded  from  the  definition  of an
              investment  company under Section 3(c)(14) of the Investment
              Company Act;

     (j)  [_] Group, in accordance with Rule 13d-1(b)(1)(ii)(J).

Item 4.  Ownership.

     Provide the following  information  regarding  the  aggregate  number and
percentage of the class of securities of the issuer identified in Item 1.

     (a)  Amount beneficially owned:

          Deerfield Capital, L.P. and Deerfield Partners, L.P. - 512,176
          shares;
          Deerfield Management Company and Deerfield International Limited -
          402,424 shares; Arnold H. Snider - 914,600 shares.

           --------------------------------------------------------------------

     (b)  Percent of class:

          Deerfield Capital, L.P. and Deerfield Partners, L.P. -3.22%;
          Deerfield Management Company and Deerfield International Limited -
          2.53%; Arnold H. Snider - 5.75%

           --------------------------------------------------------------------

     (c)  Number of shares as to which such person has:

          (i)   Sole power to vote or to direct the vote          0
                                                              ----------------,


          (ii)  Shared power to vote or to direct the vote    Deerfield
                                                              Capital,
                                                              L.P. and
                                                              Deerfield
                                                              Partners, L.P. -
                                                              512,176;
                                                              Deerfield
                                                              Management
                                                              Company
                                                              and Deerfield
                                                              International
                                                              Limited -
                                                              402,424;
                                                              Arnold H. Snider -
                                                              914,600.
                                                              ----------------,


          (iii) Sole power to dispose or to direct the            0
                disposition of
                                                              ----------------,


          (iv)  Shared power to dispose or to direct the
                disposition of
                                                              Deerfield Capital,
                                                              L.P. and Deerfield
                                                              Partners, L.P. -
                                                              512,176; Deerfield
                                                              Management Company
                                                              and Deerfield
                                                              International
                                                              Limited  -
                                                              402,424; Arnold H.
                                                              Snider - 914,600.
..
                                                              ----------------.


Item 5.  Ownership of Five Percent or Less of a Class.

     If this statement is being filed to report the fact that as of the date
hereof the reporting person has ceased to be the beneficial owner of more than
five percent of the class of securities check the following [ ].

         N/A

         ----------------------------------------------------------------------


Item 6.  Ownership of More Than Five Percent on Behalf of Another Person.

     If any other person is known to have the right to receive or the power to
direct the receipt of dividends from, or the proceeds from the sale of, such
securities, a statement to that effect should be included in response to this
item and, if such interest relates to more than five percent of the class, such
person should be identified.  A listing of the shareholders of an investment
company registered under the Investment Company Act of 1940 or the
beneficiaries
of employee benefit plan, pension fund or endowment fund is not required.

         N/A

         ----------------------------------------------------------------------


Item 7. Identification and Classification of the Subsidiary Which Acquired the
        Security  Being  Reported  on by the  Parent  Holding  Company or
        Control Person.

     If a parent holding company or Control person has filed this schedule,
pursuant to Rule 13d-1(b)(1)(ii)(G), so indicate under Item 3(g) and attach an
exhibit stating the identity and the Item 3 classification of the relevant
subsidiary.  If a parent holding company or control person has filed this
schedule pursuant to Rule 13d-1(c) or Rule 13d-1(d), attach an exhibit stating
the identification of the relevant subsidiary.

         N/A

         ----------------------------------------------------------------------


Item 8.  Identification  and  Classification  of Members of the Group.

     If a group has filed this schedule pursuant to ss.240.13d-1(b)(1)(ii)(J),
so indicate  under Item 3(j) and attach an exhibit  stating the  identity  and
Item 3  classification  of each member of the group. If a group has filed this
schedule pursuant to  ss.240.13d-1(c)  or  ss.240.13d-1(d),  attach an exhibit
stating the identity of each member of the group.

         N/A

         ----------------------------------------------------------------------


Item 9.  Notice of Dissolution of Group.

     Notice of dissolution  of a group may be furnished as an exhibit  stating
the date of the  dissolution  and that all  further  filings  with  respect to
transactions  in the  security  reported  on will be filed,  if  required,  by
members of the group, in their individual capacity. See Item 5.

          N/A

         ----------------------------------------------------------------------

Item 10.  Certifications.

          "By signing  below I certify  that,  to the best of my knowledge and
          belief,  the securities  referred to above were not acquired and are
          not held  for the  purpose  of or with the  effect  of  changing  or
          influencing the control of the issuer of the securities and were not
          acquired and are not held in connection  with or as a participant in
          any transaction having such purpose or effect."





                                    SIGNATURE

     After  reasonable  inquiry and to the best of my knowledge and belief,  I
certify that the information set forth in this statement is true, complete and
correct.

DEERFIELD CAPITAL, L.P.

By:  Snider Capital Corp.,
     General Partner

By:  /s/ Arnold H. Snider
        -----------------
         Arnold H. Snider, President

DEERFIELD PARTNERS, L.P.

By:  Deerfield Capital, L.P.

By:  Snider Capital Corp.,
     General Partner

By: /s/ Arnold H. Snider
        -----------------
        Arnold H. Snider, President

DEERFIELD MANAGEMENT COMPANY

By:  Snider Management Company,
     General Partner

By:  /s/ Arnold H. Snider
        -----------------
         Arnold H. Snider, President

DEERFIELD INTERNATIONAL LIMITED

By:  Deerfield Management Company

By:  Snider Management Company,
     General Partner

By:  /s/ Arnold H. Snider
        -----------------
         Arnold H. Snider, President

ARNOLD H. SNIDER

     /s/ Arnold H. Snider
        -----------------

Date:  February 11, 2003





                                   Exhibit A

                                   Agreement

     The  undersigned  agree that this  Schedule  13G dated  February 11, 2003
relating to the Common Stock of Cerus  Corporation shall be filed on behalf of
the undersigned.



DEERFIELD CAPITAL, L.P.

By:   Snider Capital Corp.,
      General Partner

By:  /s/ Arnold H. Snider
         -----------------
         Arnold H. Snider, President

DEERFIELD PARTNERS, L.P.

By:   Deerfield Capital, L.P.

By:   Snider Capital Corp.,
      General Partner

By:  /s/ Arnold H. Snider
        -----------------
         Arnold H. Snider, President

DEERFIELD MANAGEMENT COMPANY

By:   Snider Management Company
      General Partner

By:  /s/ Arnold H. Snider
        -----------------
         Arnold H. Snider, President

DEERFIELD INTERNATIONAL LIMITED

By:     Deerfield Management Company

By:     Snider Management Company,
        General Partner

By:  /s/ Arnold H. Snider
     -----------------
         Arnold H. Snider, President

ARNOLD H. SNIDER

        /s/ Arnold H. Snider
        --------------------

00871.0001 #383842