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. 4) *

                        Dynavax Technologies Corporation
--------------------------------------------------------------------------------
                                (Name of Issuer)

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

                                    268158102
--------------------------------------------------------------------------------
                                 (CUSIP Number)

                                 October 4, 2006
--------------------------------------------------------------------------------
             (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)

----------
* 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. 268158102                    13G
--------------------------------------------------------------------------------
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
--------------------------------------------------------------------------------
               5.    SOLE VOTING POWER

                     0
               -----------------------------------------------------------------
  NUMBER OF    6.    SHARED VOTING POWER
   SHARES
 BENEFICIALLY        1,949,990
  OWNED BY     -----------------------------------------------------------------
    EACH       7.    SOLE DISPOSITIVE POWER
  REPORTING
   PERSON            0
    WITH       -----------------------------------------------------------------
               8.    SHARED DISPOSITIVE POWER

                     1,949,990
--------------------------------------------------------------------------------
9.    AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

      1,949,990
--------------------------------------------------------------------------------
10.   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*  [_]


--------------------------------------------------------------------------------
11.   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

      6.38%
--------------------------------------------------------------------------------
12.   TYPE OF REPORTING PERSON*

      PN
--------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!


                                                                    Page 2 of 16


CUSIP No. 268158102                    13G
--------------------------------------------------------------------------------
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

      Delaware
--------------------------------------------------------------------------------
               5.    SOLE VOTING POWER

                     0
               -----------------------------------------------------------------
  NUMBER OF    6.    SHARED VOTING POWER
   SHARES
 BENEFICIALLY        1,516,401
  OWNED BY     -----------------------------------------------------------------
    EACH       7.    SOLE DISPOSITIVE POWER
  REPORTING
   PERSON            0
    WITH       -----------------------------------------------------------------
               8.    SHARED DISPOSITIVE POWER

                     1,516,401
--------------------------------------------------------------------------------
9.    AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

      1,516,401
--------------------------------------------------------------------------------
10.   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*  [_]


--------------------------------------------------------------------------------
11.   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

      4.96%
--------------------------------------------------------------------------------
12.   TYPE OF REPORTING PERSON*

      PN
--------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!


                                                                    Page 3 of 16


CUSIP No. 268158102                    13G
--------------------------------------------------------------------------------
1.    NAME OF REPORTING PERSONS
      I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

      Deerfield Special Situations Fund, 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
--------------------------------------------------------------------------------
               5.    SOLE VOTING POWER

                     0
               -----------------------------------------------------------------
  NUMBER OF    6.    SHARED VOTING POWER
   SHARES
 BENEFICIALLY        433,589
  OWNED BY     -----------------------------------------------------------------
    EACH       7.    SOLE DISPOSITIVE POWER
  REPORTING
   PERSON            0
    WITH       -----------------------------------------------------------------
               8.    SHARED DISPOSITIVE POWER

                     433,589
--------------------------------------------------------------------------------
9.    AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

      433,589
--------------------------------------------------------------------------------
10.   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*  [_]


--------------------------------------------------------------------------------
11.   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

      1.42%
--------------------------------------------------------------------------------
12.   TYPE OF REPORTING PERSON*

      PN
--------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!


                                                                    Page 4 of 16


CUSIP No. 268158102                    13G
--------------------------------------------------------------------------------
1.    NAME OF REPORTING PERSONS
      I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

      Deerfield Management Company, 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
--------------------------------------------------------------------------------
               5.    SOLE VOTING POWER

                     0
               -----------------------------------------------------------------
  NUMBER OF    6.    SHARED VOTING POWER
   SHARES
 BENEFICIALLY        2,901,548
  OWNED BY     -----------------------------------------------------------------
    EACH       7.    SOLE DISPOSITIVE POWER
  REPORTING
   PERSON            0
    WITH       -----------------------------------------------------------------
               8.    SHARED DISPOSITIVE POWER

                     2,901,548
--------------------------------------------------------------------------------
9.    AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

      2,901,548
--------------------------------------------------------------------------------
10.   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*  [_]


--------------------------------------------------------------------------------
11.   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

      9.49%
--------------------------------------------------------------------------------
12.   TYPE OF REPORTING PERSON*

      PN
--------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!


                                                                    Page 5 of 16


CUSIP No. 268158102                    13G
--------------------------------------------------------------------------------
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
--------------------------------------------------------------------------------
               5.    SOLE VOTING POWER

                     0
               -----------------------------------------------------------------
  NUMBER OF    6.    SHARED VOTING POWER
   SHARES
 BENEFICIALLY        2,035,137
  OWNED BY     -----------------------------------------------------------------
    EACH       7.    SOLE DISPOSITIVE POWER
  REPORTING
   PERSON            0
    WITH       -----------------------------------------------------------------
               8.    SHARED DISPOSITIVE POWER

                     2,035,137
--------------------------------------------------------------------------------
9.    AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

      2,035,137
--------------------------------------------------------------------------------
10.   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*  [_]


--------------------------------------------------------------------------------
11.   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

      6.65%
--------------------------------------------------------------------------------
12.   TYPE OF REPORTING PERSON*

      CO
--------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!


                                                                    Page 6 of 16


CUSIP No. 268158102                    13G
--------------------------------------------------------------------------------
1.    NAME OF REPORTING PERSONS
      I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

      Deerfield Special Situations Fund 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
--------------------------------------------------------------------------------
               5.    SOLE VOTING POWER

                     0
               -----------------------------------------------------------------
  NUMBER OF    6.    SHARED VOTING POWER
   SHARES
 BENEFICIALLY        866,411
  OWNED BY     -----------------------------------------------------------------
    EACH       7.    SOLE DISPOSITIVE POWER
  REPORTING
   PERSON            0
    WITH       -----------------------------------------------------------------
               8.    SHARED DISPOSITIVE POWER

                     866,411
--------------------------------------------------------------------------------
9.    AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

      866,411
--------------------------------------------------------------------------------
10.   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*  [_]

      2.83%
--------------------------------------------------------------------------------
11.   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

      CO
--------------------------------------------------------------------------------
12.   TYPE OF REPORTING PERSON*


--------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!


                                                                    Page 7 of 16


CUSIP No. 268158102                    13G
--------------------------------------------------------------------------------
1.    NAME OF REPORTING PERSONS
      I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

      James E. Flynn
--------------------------------------------------------------------------------
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
--------------------------------------------------------------------------------
               5.    SOLE VOTING POWER

                     0
               -----------------------------------------------------------------
  NUMBER OF    6.    SHARED VOTING POWER
   SHARES
 BENEFICIALLY        4,851,558
  OWNED BY     -----------------------------------------------------------------
    EACH       7.    SOLE DISPOSITIVE POWER
  REPORTING
   PERSON            0
    WITH       -----------------------------------------------------------------
               8.    SHARED DISPOSITIVE POWER

                     4,851,558
--------------------------------------------------------------------------------
9.    AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

      4,851,558
--------------------------------------------------------------------------------
10.   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*  [_]


--------------------------------------------------------------------------------
11.   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

      15.86%
--------------------------------------------------------------------------------
12.   TYPE OF REPORTING PERSON*

      IN
--------------------------------------------------------------------------------
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!


                                                                    Page 8 of 16


CUSIP No.   268158102
            ---------------------

Item 1(a).  Name of Issuer:

            Dynavax Technologies Corporation
            --------------------------------------------------------------------

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

            717 Potter Street
            Suite 100
            Berkeley, California 94710
            --------------------------------------------------------------------

Item 2(a).  Name of Person Filing:

            James E. Flynn, Deerfield Capital, L.P., Deerfield Partners, L.P.,
            Deerfield Special Situations Fund, L.P., Deerfield Management
            Company, L.P., Deerfield International Limited, Deerfield Special
            Situations Fund International Limited
            --------------------------------------------------------------------

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

            James E. Flynn, Deerfield Capital, L.P., Deerfield Partners, L.P.
            Deerfield Special Situations Fund, L.P., Deerfield Management
            Company, L.P., 780 Third Avenue, 37th Floor, New York, NY 10017
            Deerfield International Limited, Deerfield Special Situations
            International Limited c/o Bisys Management, Bison Court,
            Columbus Centre, P.O. Box 3460, Road Town, Tortola, British Virgin
            Islands
            --------------------------------------------------------------------

Item 2(c).  Citizenship:

            Mr. Flynn - United States citizen
            Deerfield Capital, L.P., Deerfield Partners, L.P. and Deerfield
            Special Situations Fund, L.P. - Delaware limited partnerships
            Deerfield Management Company, L.P. - New York limited partnership
            Deerfield International Limited and Deerfield Special Situations
            International Limited - British Virgin Islands corporations
            --------------------------------------------------------------------

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

            Common Stock
            --------------------------------------------------------------------

Item 2(e).  CUSIP Number:

            268158102
            --------------------------------------------------------------------

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);


                                                                    Page 9 of 16


      (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. - 1,949,990 shares
         Deerfield Partners, L.P. - 1,516,401 shares
         Deerfield Special Situations Fund, L.P. - 433,589 shares
         Deerfield Management Company, L.P. - 2,901,548 shares
         Deerfield International Limited - 2,035,137 shares
         Deerfield Special Situations International Limited - 866,411 shares
         James E. Flynn - 4,851,538 shares
         -----------------------------------------------------------------------

     (b) Percent of class:

         Deerfield Capital, L.P. - 6.38%
         Deerfield Partners, L.P. - 4.96%
         Deerfield Special Situations Fund, L.P. - 1.42%
         Deerfield Management Company, L.P. - 9.49%
         Deerfield International Limited - 6.65%
         Deerfield Special Situations International Limited - 2.83%
         James E. Flynn - 15.86%
         -----------------------------------------------------------------------

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

          (i)   Sole power to vote or to direct the vote     All Reporting
                                                             Persons - 0

                                                             ------------------
          (ii)  Shared power to vote or to direct the vote   Deerfield Capital,
                                                             L.P. - 1,949,990
                                                             Deerfield Partners,
                                                             L.P. - 1,516,401
                                                             Deerfield Special
                                                             Situations Fund,
                                                             L.P. - 433,589
                                                             Deerfield
                                                             Management Company,
                                                             L.P. - 2,901,548
                                                             Deerfield
                                                             International
                                                             Limited - 2,035,137
                                                             Deerfield Special
                                                             Situations Fund
                                                             International
                                                             Limited - 866,411
                                                             James E. Flynn -
                                                             4,851,538
                                                             ------------------


                                                                   Page 10 of 16


          (iii) Sole power to dispose or to direct the
                disposition of                               All Reporting
                                                             Persons - 0
                                                             ------------------

          (ii)  Shared power to vote or to direct the vote   Deerfield Capital,
                                                             L.P. - 1,949,990
                                                             Deerfield Partners,
                                                             L.P. - 1,516,401
                                                             Deerfield Special
                                                             Situations Fund,
                                                             L.P. - 433,589
                                                             Deerfield
                                                             Management Company,
                                                             L.P. - 2,901,548
                                                             Deerfield
                                                             International
                                                             Limited - 2,035,137
                                                             Deerfield Special
                                                             Situations Fund
                                                             International
                                                             Limited - 866,411
                                                             James E. Flynn -
                                                             4,851,538
                                                             ------------------

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 [ ].

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

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


                                                                   Page 11 of 16


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.

         See Exhibit B
         -----------------------------------------------------------------------

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."


                                                                   Page 12 of 16


                                    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: J.E. Flynn Capital LLC,
    General Partner


By: /s/ James E. Flynn
    -----------------------------------
    James E. Flynn, Managing Member


DEERFIELD PARTNERS, L.P.

By: Deerfield Capital, L.P.

By: J.E. Flynn Capital LLC,
    General Partner


By: /s/ James E. Flynn
    -----------------------------------
    James E. Flynn, Managing Member


DEERFIELD SPECIAL SITUATIONS FUND, L.P.

By: Deerfield Capital, L.P.

By: J.E. Flynn Capital LLC,
    General Partner


By: /s/ James E. Flynn
    -----------------------------------
    James E. Flynn, Managing Member


DEERFIELD MANAGEMENT COMPANY, L.P.

By: Flynn Management LLC
    General Partner


By: /s/ James E. Flynn
    -----------------------------------
    James E. Flynn, Managing Member


DEERFIELD INTERNATIONAL LIMITED

By: Deerfield Management Company

By: Flynn Management LLC,
    General Partner


By: /s/ James E. Flynn
    -----------------------------------
    James E. Flynn, Managing Member


DEERFIELD SPECIAL SITUATIONS FUND INTERNATIONAL LIMITED

By: Deerfield Management Company

By: Flynn Management LLC,
    General Partner


By: /s/ James E. Flynn
    -----------------------------------
    James E. Flynn, Managing Member


JAMES E. FLYNN


/s/ James E. Flynn
---------------------------------------

Date: October 6, 2006


                                                                   Page 13 of 16


                                    Exhibit A

                                    Agreement

      The undersigned agree that this Schedule 13G Amendment, and all further
amendments thereto, relating to the Common Stock of Dynavax Technologies
Corporation shall be filed on behalf of the undersigned.

DEERFIELD CAPITAL, L.P.

By: J.E. Flynn Capital LLC,
    General Partner


By: /s/ James E. Flynn
    -----------------------------------
    James E. Flynn, Managing Member


DEERFIELD PARTNERS, L.P.

By: Deerfield Capital, L.P.

By: J.E. Flynn Capital LLC,
    General Partner


By: /s/ James E. Flynn
    -----------------------------------
    James E. Flynn, Managing Member


DEERFIELD SPECIAL SITUATIONS FUND, L.P.

By: Deerfield Capital, L.P.

By: J.E. Flynn Capital LLC,
    General Partner


By: /s/ James E. Flynn
    -----------------------------------
    James E. Flynn, Managing Member


DEERFIELD MANAGEMENT COMPANY

By: Flynn Management LLC
    General Partner


By: /s/ James E. Flynn
    -----------------------------------
    James E. Flynn, Managing Member


DEERFIELD INTERNATIONAL LIMITED

By: Deerfield Management Company

By: Flynn Management LLC,
    General Partner


By: /s/ James E. Flynn
    -----------------------------------
    James E. Flynn, Managing Member


                                                                   Page 14 of 16


DEERFIELD SPECIAL SITUATIONS FUND INTERNATIONAL LIMITED

By: Deerfield Management Company

By: Flynn Management LLC,
    General Partner


By: /s/ James E. Flynn
    -----------------------------------
    James E. Flynn, Managing Member


JAMES E. FLYNN


/s/ James E. Flynn
---------------------------------------


                                                                   Page 15 of 16


                                    Exhibit B

      Due to the relationships between them, the reporting persons hereunder may
be deemed to constitute a "group" with one another for purposes of Section
13(d)(3) of the Securities Exchange Act of 1934.


                                                                   Page 16 of 16