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                AGREEMENT TO TERMINATE AND RELEASE OF COLLATERAL

         This Agreement to Terminate and Release of Collateral ("Release") dated
this 30th day of September, 1999 is made by and between SuperGen, Inc., a
Delaware corporation ("SuperGen") and TAKO Ventures, LLC, a California limited
liability company ("TAKO") concerning a Secured Promissory Note dated March 25,
1999 ("Note"), pursuant to which TAKO agreed to make available a loan facility
to SuperGen subject to the terms and conditions contained therein. To secure the
obligations of SuperGen under the Note, SuperGen granted to TAKO a security
interest in the Collateral. (Capitalized terms which are not defined herein
shall have the meanings ascribed thereto in the Note.)

         WHEREAS, SuperGen has not borrowed under the facility and there is no
loan outstanding between the parties, and the parties have agreed to terminate
the Note as of the date of this Release.

         NOW THIS RELEASE WITNESSETH that:

         1.    The Note shall be terminated as of the date of this Release.

         2.    As of the date of this Release, TAKO hereby unconditionally
               and irrevocably RELEASES the security interest in the
               Collateral, including any Intellectual Property Collateral,
               and DISCHARGES SuperGen from all its past, present and future
               (actual or contingent) liabilities to TAKO under the Note,
               including any liability with respect to the Collateral. Upon
               the execution of this Release, the Collateral shall be
               absolutely freed and discharged of and from TAKO's security
               interest as provided in the Note.

         3.    Nothing in this Release shall adversely effect, in any manner
               whatsoever, the warrants to purchase 500,000 shares of common
               stock of SuperGen (including without limitation the existence,
               availability or exercisability thereof) issued to TAKO in
               connection with the original issuance of the Note, which
               warrants shall remain in full force and effect.

         4.    TAKO further undertakes and agrees to do all acts and things
               and/or execute any further documents as SuperGen may
               reasonably request to carry into effect or to give legal
               effect to the provisions of this Release.

         5.    This Release may not be changed except in a writing signed by
               the party against whose interest such change shall operate.
               This Release shall be governed by and construed under the laws
               of the State of California without regard to principles of
               conflicts of law.

IN WITNESS WHEREOF, this Release had been duly executed as of the day and year
first above written.

SUPERGEN, INC.                             TAKO VENTURES, LLC.

By:  /s/ Joseph Rubinfeld                  By:  Cephalopod Corporation, Member
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Title:   President/CEO                     By:  /s/ Philip B. Simon
                                                -----------------------
                                           Title:  President,
                                                   Cephalopod Corporation