Exhibit
10.13  SUPERGEN, INC.  EMPLOYMENT, CONFIDENTIAL
INFORMATION,
INVENTION ASSIGNMENT, AND ARBITRATION AGREEMENT  This Employment, Confidential Information, Invention Assignment, and
Arbitration Agreement (the Agreement)
is entered into as of December 31, 2003 (the Effective Date), by and between SuperGen, Inc., a Delaware
corporation (the Company), and Joseph Rubinfeld (Employee).  BACKGROUND  A.The
Company and Employee were parties to (i) that certain Employment, Confidential
Information and Invention Assignment Agreement, dated as of January 1,
1994, as amended by Amendment No. 1 dated January 17, 1996, and as
further amended and restated on January 1, 1998, (the First Agreement) and (ii) that certain
Executive Employment, Confidential Information, Invention Assignment and
Arbitration Agreement, dated March 1, 2002 (the Second Agreement), which superseded in its entirety the First
Agreement (collectively, the Prior
Employment Agreements).  B.The
Second Agreement will expire by its terms on December 31, 2003, and the parties
desire to enter into this Agreement, which supersedes in its entirety the Prior
Employment Agreements.  C.Pursuant
to the terms of the Second Agreement, which expires by its terms on December
31, 2003, Employee serves as the Companys President and Chief Executive
Officer.  NOW THEREFORE, in consideration of the respective covenants and
agreements of the parties contained in this Agreement, the Company and Employee
agree as follows:  AGREEMENT  1.TERM.  The Company hereby agrees to employ
Employee, and Employee hereby accepts employment, on the terms and conditions
set forth herein.  The term of this
Agreement shall commence upon the Effective Date and shall continue until and including
December 31, 2004, unless otherwise terminated sooner by the parties (the
Term).  The parties may agree to enter into another at-will employment
agreement, on terms agreeable to both parties, at the end of the Term;
provided, however, that Employees annualized base salary pursuant to such
agreement shall not be less than $595,000, less applicable withholdings.  2.AT-WILL
EMPLOYMENT.  Notwithstanding the
foregoing in Section 1 above, the parties agree that Employees employment with
the Company will be at-will employment and may  1 
   be
terminated for any reason at any time with or without notice.  Employee understands and agrees that neither
his job performance, commendations, bonuses or the like from the Company give
rise to or in any way serve as the basis for modification, amendment or
extension, by implication or otherwise, of his employment with the Company.  3.POSITION
AND DUTIES.  Effective at midnight,
Pacific Standard Time, on December 31, 2003, the Parties agree to Employees
reassignment to the position of Chief Scientist of the Company from that of
President and Chief Executive Officer of the Company (the Reassignment).  As a result of the Reassignment, Employee shall no longer be
employed by the Company as an officer, and Employee hereby expressly consents
to such Reassignment and resigns as President and Chief Executive Officer of
the Company effective as of midnight, Pacific Standard Time, on December 31,
2003.  Employee will render such
business and professional services in the performance of his duties as Chief
Scientist as the Company will reasonably assign to him.  During the Term, Employee agrees to be
available to perform employment services at Employees home office for no more
than twenty (20) hours per week (at the request of the Company), provided that
Employee agrees to be periodically available at the Companys Dublin facilities
upon the reasonable request of the Company.  4.BOARD
MEMBERSHIP.  Notwithstanding the
Reassignment, Employee shall continue to serve as a member on the Companys
board of directors (the Board)
until the next regularly scheduled meeting of the Companys stockholders.  The Company will use reasonable efforts to
nominate him to reelection as a member of the Board at that regularly scheduled
meeting of stockholders and will use reasonable efforts to effect such
reelection.  Employee shall serve on the
Board as Chair Emeritus, with full membership and under the same terms and
conditions to which all directors are subject.  5.CONFIDENTIAL
INFORMATION.  (a)COMPANY
INFORMATION.  Employee agrees at all
times during the Term and thereafter, to hold in strictest confidence, and not
to use, except for the benefit of the Company, or to disclose to any person,
firm or corporation without written authorization of the Board of Directors of
the Company, any Confidential Information of the Company, except under a
non-disclosure agreement duly authorized and executed by the Company.  Employee understands that Confidential Information means any non-public
information that relates to the actual or anticipated business or research and
development of the Company, technical data, trade secrets or know-how,
including, but not limited to, research, product plans or other information
regarding Companys products or services and markets therefor, customer lists
and customers (including, but not limited to, customers of the Company on whom
Employee called or with whom Employee became acquainted during his entire term
of his employment with the Company), software, developments, inventions,
processes, formulas, technology, designs, drawings, engineering, hardware
configuration information, marketing, finances or other business
information.  Employee further
understands that Confidential Information does not include any of the foregoing
items, which have become publicly known and made generally available through no
wrongful act of Employees or of others who were under confidentiality
obligations as to the item or items involved or improvements or new versions
thereof.  The parties agree that
disclosures of Confidential Information may be made by Employee, and that this
paragraph shall not apply, (i) to the extent  2 
   necessary to comply with governmental disclosure requirements
or applicable laws, (ii) pursuant to subpoena or order of any judicial,
legislative, executive, regulatory or administrative body, or for Employee to
lawfully enforce Employees rights under this Agreement and (iii) to employees,
advisors, legal counsel and financial advisors as may be necessary and
appropriate in connection with the proper performance and enforcement of this
Agreement.  (b)FORMER
EMPLOYER INFORMATION.  Employee
agrees that he will not, during his employment with the Company, improperly use
or disclose any proprietary information or trade secrets of any former employer
or other person or entity and that he will not bring onto the premises of the
Company any unpublished document or proprietary information belonging to any
such employer, person or entity unless consented to in writing by such
employer, person or entity.  (c)THIRD
PARTY INFORMATION.  Employee
recognizes that the Company has received and in the future will receive from
third parties their confidential or proprietary information subject to a duty
on the Companys part to maintain the confidentiality of such information and
to use it only for certain limited purposes. 
Employee agrees to hold all such confidential or proprietary information
in the strictest confidence and not to disclose it to any person, firm or
corporation or to use it except as necessary in carrying out Employees work
for the Company consistent with the Companys agreement with such third party.  6.INVENTIONS.  (a)INVENTIONS
RETAINED AND LICENSED.  Employee has
no inventions, original works of authorship, developments, improvements, and
trade secrets which were made by him prior to his employment with the Company
(collectively referred to as Prior
Inventions), which belong to him, which relate to the Companys
proposed business, products or research and development, and which were not
previously assigned to the Company.  If
in the course of Employees employment with the Company, Employee incorporates
into a Company product, process or service Prior Inventions owned by Employee
or in which Employee has an interest, Employee hereby grants to the Company a
nonexclusive, royalty-free, fully paid-up, irrevocable, perpetual, worldwide
license to make, have made, modify, use and sell such Prior Inventions as part
of or in connection with such product, process or service, and to practice any
methods related thereto.  (b)ASSIGNMENT
OF INVENTIONS.  Employee agrees that
he will promptly make full written disclosure to the Company, will hold in
trust for the sole right and benefit of the Company, and hereby assigns to the
Company, or its designee, all of Employees right, title, and interest in and
to any and all inventions, original works of authorship, developments,
concepts, improvements, designs, discoveries, ideas, trademarks or trade
secrets, whether or not patentable or registrable under copyright or similar
laws, which Employee may solely or jointly conceive or develop or reduce to
practice, or cause to be conceived or developed or reduced to practice, as a
result of and within the scope of his duties as an Employee of the Company and
during the period of time Employee is in the employ of the Company
(collectively referred to as Company
Inventions), except as provided
in Section 6(f) below.  Employee further acknowledges that all
original works of authorship which are made by him (solely or jointly with
others) within the scope of and during the period of his employment with the
Company, and which are protectable by  3 
   copyright,
are works made for hire, as that term is defined in the United States
Copyright Act.  Employee understands and
agrees that the decision whether or not to commercialize or market any Company
Inventions developed by Employee solely or jointly with others is within the
Companys sole discretion and for the Companys sole benefit and that no
royalty will be due to Employee as a result of the Companys efforts to
commercialize or market any such Inventions. 
The parties agree that any and all inventions, original works of
authorship, development, concepts, improvements, designs, discoveries, ideas,
trademarks or trade secrets, whether or not patentable or registrable under
copyright or similar laws which are made by Employee (solely or jointly with
others) that are not within the scope of his duties for the Company (i.e., not
during the time that he is actually performing duties for the Company)
(collectively referred to as non-Company
Inventions) shall not be subject to this paragraph and shall be the
sole property of Employee and that he shall have the sole right, title and
interest in any such non-Company Inventions.  (c)INVENTIONS
ASSIGNED TO THE UNITED STATES. 
Employee agrees to assign to the United States government all his right,
title, and interest in and to any and all Company Inventions whenever such full
title is required to be in the United States by a contract between the Company
and the United States or any of its agencies.  (d)MAINTENANCE
OF RECORDS.  Employee agrees to keep
and maintain adequate and current written records of all Inventions made by
Employee (solely or jointly with others) during the period of his employment
with the Company.  The records will be
in the form of dated notes, sketches, drawings, and any other format that may
be specified by the Company.  The
records will be available to and remain the sole property of the Company at all
times.  (e)PATENT
AND COPYRIGHT REGISTRATIONS. 
Employee agrees to cooperate and assist the Company, or its designee, agents,
and representatives, at the Companys expense, in every proper way to secure
and perfect the Companys rights, title and interest in the Company Inventions
and any copyrights, patents, mask work rights or other intellectual property
rights relating thereto in any and all countries, including the disclosure to
the Company of all pertinent information and data with respect thereto, the
preparation and execution of all applications, patent applications,
specifications, oaths, assignments, statements, declarations, petitions,
certificates and petitions for correction and all other instruments which the
Company or any government agency shall deem necessary in order to apply for,
prosecute, correct and obtain such rights and in order to assign and convey to the
Company, its successors, assigns, and nominees the sole and exclusive rights,
title and interest in and to such Company Inventions, and any copyrights,
patents, mask work rights or other intellectual property rights relating
thereto in any and all countries. 
Employee further agrees that his obligation to execute or cause to be
executed, when it is in his power to do so, any such instrument or papers shall
continue after the termination of this Agreement without further
consideration.  In addition, Employee
covenants and agrees to take no action that would impair or interfere with the
Companys quiet enjoyment of its sole and exclusive rights, title and interest
in and to such Company Inventions after termination of this Agreement.  If the Company is unable because of
Employees mental or physical incapacity or for any other reason to secure
Employees signature to apply for or to pursue, prosecute or correct any
application for any United States or foreign patents or copyright registrations
covering Company Inventions or original works of authorship assigned to the
Company as above, then Employee hereby irrevocably designates and appoints the
Company and its duly authorized officers and agents as his agent and attorney
in fact, to  4 
   act for
and in Employees behalf and stead to execute and file any such applications
and to do all other lawfully permitted acts to further the prosecution,
correction, maintenance and issuance of letters patent or copyright registrations
thereon with the same legal force and effect as if executed by Employee.  (f)EXCEPTION
TO ASSIGNMENTS.  Employee
understands that the provisions of this Agreement requiring assignment of
Company Inventions to the Company do not apply to any invention which qualifies
fully under the provisions of California Labor Code Section 2870 (attached
hereto as Exhibit A) or to any non-Company Inventions.  Employee will advise the Company in writing,
within thirty (30) days, of any inventions that Employee believes meet the
criteria in California Labor Code Section 2870.  7.COMPENSATION,
BONUS AND FRINGE BENEFITS.  (a)BASE
SALARY.  During the Term, the
Company will pay Employee as compensation for his services a base salary at the
annualized rate of Five Hundred and Ninety Five Thousand Dollars ($595,000),
less applicable withholdings (the Base
Salary).  The Base Salary
shall be paid in periodic installments in accordance with the Companys regular
payroll practices.  (b)DISCRETIONARY
BONUS.  Employee shall be entitled
to a discretionary bonus payment for 2003 in the amount of Two Hundred and
Fifty Thousand Dollars ($250,000), less applicable withholdings (the Bonus). The Company shall pay Employee the
Bonus within ten (10) business days after Employee executes (and does not
revoke) the Release (as defined below), and the Release becomes effective (the
Release Date).  (c)OTHER
BENEFITS.  Employee shall be
entitled to participate in such group life, pension, disability, accident,
hospital and medical insurance plans, and such other plan or plans which may be
instituted by the Company for the benefit of its employees generally, upon such
terms as may be therein provided of general application to all employees of the
Company and such other benefits as are mutually deemed appropriate to the
position held by Employee and to the discharge of Employees duties.  Employee shall be entitled to not less than
twenty (20) business days vacation per year, with remuneration.  (d)LIFE
INSURANCE.  During the Term, the
Company, at its expense, will maintain life insurance on behalf of Employee
equal to one hundred and fifty percent (150%) of the Base Salary.  Employee will be entitled to select personal
beneficiaries for 100% of the proceeds of the insurance policy.  The Company will provide Employee with
additional cash compensation at the end of each calendar year to fully offset
taxes attributable to Employee as a result of payment of the life insurance
premiums by the Company.  8.EXPENSES.  The Company will reimburse Employee, in
accordance with the Companys established policies, for reasonable business
related expenses incurred by Employee in furtherance of or in connection with
the performance of Employees duties hereunder, including reasonable expenses
incurred in connection with Employees home office (including but not limited
to a computer, telephone, fax and internet charges).  Employee shall furnish the Company with  5 
   evidence
of such expenses within a reasonable period of time from the date such expenses
were incurred.  9.TERMINATION
BENEFITS.  (a)INVOLUNTARILY
TERMINATION.  If, during the Term,
the Company terminates Employees employment with the Company other than for
Cause (as defined herein), death or Disability (as defined herein), and
Employee signs and does not revoke a standard release of claims with the
Company, then Employee will be entitled to receive continuing payments of
severance pay (less applicable withholding taxes) at a rate equal to his Base
Salary rate, as then in effect, until December 31, 2004  (the Payment).  The Payment will be paid in accordance with
the Companys normal payroll practices.  (b)VOLUNTARY
TERMINATION.  In the event the
Employee voluntarily terminates his employment with the Company for any reason
(except as otherwise provided for herein) during the Term, and Employee signs
and does not revoke a standard release of claims with the Company, then
Employee will be entitled to receive continuing payments (less applicable
withholding taxes) at a rate equal to 50% of his Base Salary rate, as then in
effect, until December 31, 2004 (the Continuing
Payment). The Continuing Payment will be paid in accordance with
the Companys normal payroll practices.  (c)TERMINATION
FOR CAUSE, DEATH OR DISABILITY.  In
the event Employees employment with the Company is terminated for Cause, death
or Disability, then Employee shall not be entitled to receive the Payment or
the Continuing Payment, but may be eligible for those benefits (if any) as may
then be established under the Companys then existing severance policies at the
time of such termination.  (d)ACCRUED
WAGES AND VACATION; EXPENSES. 
Without regard to the reason for, or the timing of, Employees
termination of employment:  (i) the
Company shall pay Employee any unpaid base salary due for periods prior to his
termination of employment; (ii) the Company shall pay Employee all of
Employees accrued and unused vacation through his termination of employment;
and (iii) following submission of proper expense reports by the Employee,
the Company shall reimburse Employee for all expenses reasonably and
necessarily incurred by Employee in connection with the business of the Company
prior to his termination of employment. 
These payments shall be made promptly upon Employees termination of
employment and within the period of time mandated by law.  (e)CAUSE.  For the purposes of this Agreement, Cause means (i) any act of personal
dishonesty taken by Employee in connection with his responsibilities which is
intended to result in personal enrichment of Employee, (ii) Employees
conviction of a felony, (iii) any act by Employee that constitutes
material misconduct and is injurious to the Company, or (iv) continued
violations by Employee of his obligations to the Company; provided that, in
each case except (ii), Employee has received written notice of the described
activity, has been afforded a reasonable opportunity to cure or correct the
activity (not to exceed 15 days) as described in the notice, and has failed to
cure, correct or cease the activity, as appropriate.  6 
   (f)DISABILITY.  For purposes of this Agreement, Disability shall mean a disability, due to
illness or injury, which materially limits Employee from performing each of his
material and substantial duties, even with reasonable accommodation, for a
period of six (6) consecutive months. 
The Company shall provide Employee fourteen (14) days written notice of
termination for Disability.  10.STOCK
OPTIONS.  (a)MILESTONE
STOCK OPTIONS.  Employee has
heretofore been granted by the Company options to purchase the Companys common
stock, which vest upon the attainment of certain milestones and triggers (the Milestone Option).  As of the date hereof, approximately 300,000
shares subject to the Milestone Option are unvested.  The Company shall accelerate, on or about the Release Date, the
vesting of 170,000 shares subject to the Milestone Option, in tranches of
100,000 shares and 70,000 shares respectively, as identified by Employee.  The remaining 130,000 shares subject to the
Milestone Option shall continue to vest in accordance with the terms of the
stock option plan under which they were issued and the stock option agreement
between the Company and Employee  (b)OPTION
ACCELERATION IN THE EVENT OF INVOLUNTARY TERMINATION FOLLOWING A CHANGE OF
CONTROL.  If, during the Term,
Employees employment with the Company or a successor corporation is terminated
by the Company or successor corporation as a result of an Involuntary
Termination (as defined below) following a Change of Control (as defined
below), Employee shall be entitled to full acceleration of the vesting of any
then unvested stock options (including all unvested Milestone Options) then
held by Employee, and such accelerated options shall remain subject to and be
exercisable in accordance with the terms of the stock option plan under which
they were issued and the stock option agreement between the Company and
Employee.  (c)CHANGE
OF CONTROL.  For purposes of this
Agreement, Change of Control
means the occurrence of any of the following events:  (i) any person (as such term is used in Sections 13(d) and
14(d) of the Exchange Act) becomes the beneficial owner (as defined in Rule
13d-3 of the Exchange Act), directly or indirectly, of securities of the
Company representing fifty percent (50%) or more of the total voting power
represented by the Companys then outstanding voting securities; (ii) the
consummation of the sale or disposition by the Company of all or substantially
all of the Companys assets; or (iii) the consummation of a merger or
consolidation of the Company with any other corporation, other than a merger or
consolidation which would result in the voting securities of the Company
outstanding immediately prior thereto continuing to represent (either by
remaining outstanding or by being converted into voting securities of the
surviving entity or its parent) at least fifty percent (50%) of the total
voting power represented by the voting securities of the Company or such
surviving entity or its parent outstanding immediately after such merger or
consolidation.  (d)INVOLUNTARY
TERMINATION.  For purposes of this
Agreement, Involuntary Termination
means (i) without Employees express written consent, a significant
reduction of Employees duties, position or responsibilities relative to
Employees duties, position or responsibilities in effect immediately prior to
such reduction; (ii) without Employees express  7 
   written
consent, a substantial reduction, without good business reasons, of the
facilities and perquisites (including office space and location) available to
Employee immediately prior to such reduction; (iii) without Employees
express written consent, a material reduction by the Company of Employees Base
Salary as in effect immediately prior to such reduction; (iv) without
Employees express written consent, a material reduction by the Company in the
kind or level of employee benefits to which Employee is entitled immediately
prior to such reduction with the result that Employees overall benefits
package is significantly reduced; (v) without Employees express written
consent, the relocation of Employee to a facility or a location more than fifty
(50) miles from his current location, or (vi) any purported termination of
Employee other than for Cause (as defined in this Agreement).  11.RELEASE
OF CLAIMS.  In consideration for the
receipt of the Bonus provided for in Section 7(b) hereof, Employee agrees to
execute and not revoke, in the form substantially attached hereto as Exhibit
B, a mutual release of claims covering potential claims by both parties
against the other up to and including the Effective Date (the Release). 
In no event shall the Company be obligated to provide, and Employee
shall have no right to receive, the Bonus in the event (i) Employee fails to
execute the Release or (ii) Employee revokes the Release.  Furthermore, in consideration of the
Termination Benefits provided for in Sections 9(a) and/or 9(b), Employee agrees
to execute and not revoke, in a form substantially similar to Exhibit C,
a mutual release of claims for the time period covering the Term (the Second Release).  The Company will also execute the Release and the Second Release
once, and if, Employee executes each document.  12.LIMITATION
ON PAYMENTS.  In the event that the
severance and other benefits provided for in this Agreement or otherwise
payable to Employee, including but not limited to, the accelerated vesting of
any stock options previously or hereafter granted to Employee,
(i) constitute parachute payments within the meaning of
Section 280G of the Code, and (ii) would be subject to the excise tax
imposed by Section 4999 of the Code (the Excise Tax), then Employees benefits under this Agreement
shall be reduced to the extent necessary in order to avoid such benefits being
subject to the Excise Tax.  Unless the Company and Employee otherwise agree in
writing, any determination required under this Section 12 shall be made in
writing by the Companys independent public accountants (the Accountants), whose determination shall be
conclusive and binding upon Employee and the Company for all purposes.  For purposes of making the calculations
required by this Section 12, the Accountants may make reasonable assumptions
and approximations concerning applicable taxes and may rely on reasonable, good
faith interpretations concerning the application of Section 280G and 4999
of the Code.  The Company and Employee
shall furnish to the Accountants such information and documents as the
Accountants may reasonably request in order to make a determination under this
Section 12.  The Company shall bear all
costs the Accountants may reasonably incur in connection with any calculations
contemplated by this Section 12.  13.NONSOLICITATION.  During the Term and for a period of twelve
(12) months following Employees termination of employment with the Company for
any reason, Employee agrees that he shall not either directly or indirectly
solicit, induce, recruit or encourage any of the Companys employees to leave
their employment, or attempt to solicit, induce, recruit, or encourage  8 
   any of
the Companys employees to leave their employment with the Company, either for
himself or any other person or entity.  14.NON-COOPERATION.  Employee agrees that he will not counsel or
assist any stockholder of the Company, attorneys, their clients or any
individual in the presentation or prosecution of any disputes, differences,
grievances, claims, charges, or complaints by any third party against the
Company and/or any officer, director, employee, agent, representative,
stockholder or attorney of the Company, unless (a) under a subpoena or other
court order to do so or (b) pursuant to a derivative action against the Company
where Employee is in the plaintiff class.  15.NON-DISPARAGEMENT.  Employee agrees to refrain from any
defamation, libel or slander of the Company, any parent or subsidiary of the
Company and/or any officer, director, employee, agent, representative,
stockholder, successor, predecessor or affiliate thereof or to engage in any
tortious interference with the contracts and relationships of the Company, any
parent and/or subsidiary of the Company. 
The Company, any parent or subsidiary of the Company and/or any officer,
director, employee, agent, representative, stockholder, successor, predecessor
or affiliate thereof agrees to refrain from any defamation, libel or slander of
Employee.  16.RIGHT
OF FIRST REFUSAL.  Subject to the
terms and conditions herein, Employee shall be free to seek other employment
with third parties (each, an Other Employer);
provided that during the Term the Company shall have a right of first refusal
with respect to the development, registration and/or commercialization of all
Anti-Cancer Compounds (as defined below) developed by Other Employers during
the Term.  Employee shall ensure that
its written employment agreements with Other Employers contain provisions
expressly granting such right of first refusal to the Company as provided in
this Section 16.  For purposes of the
foregoing, Anti-Cancer Compounds
shall mean pharmaceutical compounds for treatment, diagnosis, palliation,
and/or prevention of cancer, including without limitation, hematology-oncology,
immunology and related fields.  17.SURVIVAL
OF CERTAIN PROVISIONS.  For the
avoidance of doubt, the parties expressly agree and understand that Sections 5,
6, 14 and 15 of this Agreement shall remain in full force and effect in
perpetuity.  18.ARBITRATION
AND EQUITABLE RELIEF.  (a)ARBITRATION.  In consideration of Employees employment
with the Company, the Companys promise to arbitrate all employment-related
disputes and Employees receipt of the compensation and other benefits paid to
Employee by the Company, at present and in the future, Employee agrees that any
and all controversies, claims or disputes with anyone (including the Company
and any employee, officer, director, stockholder or benefit plan of the Company
in their capacity as such or otherwise) arising out of, relating to, or
resulting from Employees employment with the Company, or the termination of
Employees employment with the Company, including any breach of this Agreement,
shall be subject to binding arbitration rules set forth in California Code of
Civil Procedure Section 1280 through 1294.2, including Section 1283.05
(the Rules) and pursuant to
California law.  Disputes which Employee
agrees to arbitrate, and thereby agrees to waive any right to a trial by jury,
include any statutory claims under the state or federal  9 
   law,
including, but not limited to, claims under title VII of the Civil Rights Act
of 1964, the Americans with Disabilities Act of 1990, the Age Discrimination in
Employment Act of 1967, the Older Workers Benefit Protection Act, the
California Fair Employment and Housing Act, the California Labor Code, claims
of harassment, discrimination or wrongful termination and any statutory
claims.  Employee further understands
that this Agreement to arbitrate also applies to any disputes that the Company
may have with Employee.  (b)PROCEDURE.  Employee agrees that any arbitration will be
administered by the American Arbitration Association (AAA) and that the neutral arbitrator will
be selected in a manner consistent with its National Rules for the Resolution
of Employment Disputes.  Employee agrees
that the arbitrator shall have the power to decide any motions brought to any
party to the arbitration, including motions for summary judgment and/or
adjudication and motions to dismiss and demurrers, prior to any arbitration
hearing.  Employee also agrees that the
arbitrator shall have the power to award any remedies, including attorneys
fees and costs, available under applicable law.  Employee understands the Company will pay for any administrative
or hearing fees charged by the arbitrator or AAA except that Employee shall pay
the first $200.00 of any filing fees associated with any arbitration
initiated.  Employee agrees that the
arbitrator shall administer and conduct any arbitration in a manner consistent
with the rules and that to the extent that the AAAs National Rules for the
Resolution of Employment Disputes conflict with the Rules, the Rules shall take
precedence.  Employee agrees that the
decision of the arbitrator shall be in writing.  (c)REMEDY.  Except as provided by the Rules and this Agreement, arbitration
shall be the sole, exclusive and final remedy for any dispute between Employee
and the Company.  Accordingly, except as
provided for and by the Rules and this Agreement, neither Employee nor the
Company will be permitted to pursue court action regarding claims that are subject
to arbitration.  Notwithstanding, the
arbitrator will not have the authority to disregard or refuse to enforce any
lawful Company policy, and the arbitrator shall not order or require the
Company to adopt a policy not otherwise required by law which the Company has
not adopted.  (d)AVAILABILITY
OF INJUNCTIVE RELIEF.  In addition
to the right under the Rules to petition to the court for provisional relief,
Employee agrees that any party may also petition the court for preliminary
injunctive relief where either party alleges or claims a violation of this
Agreement or any other agreement regarding trade secrets, confidential
information, nonsolicitation or Labor Code §2870, upon the same basis and
showing as would other litigants, together with a showing that any potential
arbitration award would be rendered ineffectual without such preliminary
injunctive relief.  Employee understands
that any breach or threatened breach of such an agreement will cause
irreparable injury and that money damages will not provide an adequate remedy
therefor and both parties hereby consent to the issuance of an injunction.  In the event either party seeks injunctive
relief, the prevailing party shall be entitled to recover reasonable costs and
attorney fees.  (e)ADMINISTRATIVE
RELIEF.  Employee understands that
this Agreement does not prohibit Employee from pursuing an administrative claim
with a local, state or federal administrative body such as the Department of
Fair Employment and Housing, the Equal Employment Opportunity Commission or the
Workers Compensation Board.  This
Agreement does, however, preclude Employee from pursuing court action regarding
any such claim.  10 
   (f)VOLUNTARY
NATURE OF THIS AGREEMENT.  Employee
acknowledges and agrees that Employee is executing this Agreement voluntarily
and without any duress or undue influence by the Company or anyone else.  Employee further acknowledges and agrees
that Employee has carefully read this Agreement and has asked any questions
needed for Employee to understand the terms, consequences and binding effect of
this Agreement and fully understand it, including that Employee is waiving his right to a
jury trial.  Finally,
Employee agrees that he has been provided an opportunity to seek the advice of
an attorney of his choice before signing this Agreement.  19.ASSIGNMENT.  This Agreement shall be binding upon and
inure to the benefit of (a) the heirs, executors and legal representatives
of Employee upon Employees death or disability and (b) any successor of
the Company.  Any such successor of the
Company shall be deemed substituted for the Company under the terms of this
Agreement for all purposes.  As used
herein, successor shall include any person, firm, corporation or other
business entity which at any time, whether by purchase, merger or otherwise,
directly or indirectly acquires all or substantially all of the assets or
business of the Company.  None of the
rights of Employee to receive any form of compensation payable pursuant to this
Agreement shall be assignable or transferable except through a testamentary
disposition or by the laws of descent and distribution upon the death of
Employee.  Any attempted assignment,
transfer, conveyance or other disposition (other than as aforesaid) of any
interest in the rights of Employee to receive any form of compensation
hereunder shall be null and void.  20.NOTICES.  All notices, requests, demands and other
communications called for hereunder shall be in writing and shall be deemed
given if delivered personally or three (3) days after being mailed by
registered or certified mail, return receipt requested, prepaid and addressed
to the parties or their successors in interest at the following addresses, or
at such other addresses as the parties may designate by written notice in the
manner aforesaid:  If to the
  Company:
  SuperGen, Inc.4140 Dublin
  Blvd., Suite 200Dublin, CA 94568Attn:  Chief Financial OfficerIf to Employee:
  Joseph Rubinfeld5304 Blackhawk DriveDanville, CA 
  94506  21.SEVERABILITY.  In the event that any provision hereof
becomes or is declared by a court of competent jurisdiction to be illegal,
unenforceable or void, this Agreement shall continue in full force and effect
without said provision.  22.ENTIRE
AGREEMENT.  This Agreement and the
Release represents the entire agreement and understanding between the Company
and Employee concerning Employees employment relationship with the Company,
and supersedes and replaces any and all prior agreements and understandings,
whether oral or written, concerning Employees employment relationship with the
Company.  11 
   23.NO
ORAL MODIFICATION, CANCELLATION OR DISCHARGE.  This Agreement may only be amended, canceled or discharged in
writing signed by Employee and the Company.  24.GOVERNING
LAW.  This Agreement shall be
governed by the internal substantive laws, but not the choice of law rules, of
the State of California.  25.ACKNOWLEDGMENT.  Employee acknowledges that he has had the
opportunity to discuss this matter with and obtain advice from his private
attorney, has had sufficient time to, and has carefully read and fully
understands all the provisions of this Agreement, and is knowingly and
voluntarily entering into this Agreement.   [Signature
Page Follows]  12 
   IN WITNESS WHEREOF, the
parties have executed this Agreement as of the date first above written.   SUPERGEN,
  INC.
  JOSEPH
  RUBINFELDBy:
  /s/ Walter Lack
  
  /s/ Joseph RubinfeldIts:
  ChairmanCompensation
  Committee  13 
   EXHIBIT A  CALIFORNIA LABOR CODE
SECTION 2870
INVENTION ON OWN TIME-EXEMPTION FROM AGREEMENT  (a)Any
provision in an employment agreement which provides that an employee shall
assign, or offer to assign, any of his or her rights in an invention to his or
her employer shall not apply to an invention that the employee developed
entirely on his or her own time without using the employers equipment,
supplies, facilities, or trade secret information except for those inventions
that either:  (1)Relate
at the time of conception or reduction to practice of the invention to the
employers business, or actual or demonstrably anticipated research or
development of the employer; or  (2)Result
from any work performed by the employee for the employer.  (b)To
the extent a provision in an employment agreement purports to require an
employee to assign an invention otherwise excluded from being required to be
assigned under subdivision (a), the provision is against the public policy
of this state and is unenforceable.


EXHIBIT B  AGREEMENT AND RELEASE  RECITALS  This Agreement and Release (the Release) is made by
and between Joseph Rubinfeld (Employee) and SuperGen, Inc. (the Company),
collectively referred to as the Parties.  WHEREAS, the Parties are mutually agreeing to a
reassignment of Employees position as President and Chief Executive Officer of
the Company to that of Chief Scientist of the Company, effective December 31,
2003;  WHEREAS, in connection with such reassignment, the
Parties are entering into that certain Employment, Confidential Information,
Invention and Assignment Agreement, dated December 31, 2003 (the Employment
Agreement), which is incorporated herein by reference, pursuant to which
Employee will be entitled to receive, upon execution and nonrevocation of this
Release, good and valuable benefits;  WHEREAS,
Employee wishes to release the Company from any and all claims arising from or
related to his employment relationship with the Company up to and including
December 31, 2003;  WHEREAS, the Parties, and each of them, wish to
resolve any and all disputes, claims, complaints, grievances, charges, actions,
petitions and demands that the Employee may have against the Company as defined
herein, including, but not limited to, any and all claims arising or in any way
related to Employees employment with the Company up to and including December
31, 2003;  NOW THEREFORE, in consideration of the benefits
provided for in the Employment Agreement and the promises made herein, the
Parties hereby agree as follows:  COVENANTS  1.Consideration.  (a) The Company agrees to
provide the benefits as provided for in Sections 7(b) and 10(a) and (b) of the
Employment Agreement.  (b) Payment.  The Company will tender the benefits
provided for in Sections 7(b) and 10(a) and (b) of the Employment Agreement
within the dates specified in the Employment Agreement.  2.Confidential Information.  Employee shall continue to maintain the
confidentiality of all confidential and proprietary information of the Company
and shall continue to comply with all such applicable provisions as set forth
in the Employment Agreement, including, without limitation, Sections 5 and 6 of
the Employment Agreement.  
   3.Release of Claims.  Employee agrees that the foregoing
consideration represents settlement in full of all outstanding obligations owed
to Employee by the Company up to and including December 31, 2003.  Employee, on his own behalf, and on behalf
of his respective heirs, family members, executors, and assigns, hereby fully
and forever releases the Company covering the period of his employment with the
Company up to and including December 31, 2003 and its officers, directors,
employees, investors, shareholders, administrators, affiliates, divisions,
subsidiaries, predecessor and successor corporations, and assigns, from, and
agree not to sue concerning, any claim, duty, obligation or cause of action
relating to any matters of any kind, whether presently known or unknown,
suspected or unsuspected, that Employee may possess arising from any omissions,
acts or facts that have occurred up until and including the Effective Date of
this Release including, without limitation:  (a) any and all claims
relating to or arising from Employees employment relationship with the Company
and the termination of that relationship;  (b) any and all claims
relating to, or arising from, Employees right to purchase, or actual purchase
of shares of stock of the Company, including, without limitation, any claims
for fraud, misrepresentation, breach of fiduciary duty, breach of duty under
applicable state corporate law, and securities fraud under any state or federal
law;  (c) any and all claims
under the law of any jurisdiction including, but not limited to, wrongful
discharge of employment; constructive discharge from employment; termination in
violation of public policy; discrimination; breach of contract, both express
and implied; breach of a covenant of good faith and fair dealing, both express
and implied; promissory estoppel; fraud; fraudulent inducement; negligent or
intentional infliction of emotional distress; negligent or intentional
misrepresentation; negligent or intentional interference with contract or
prospective economic advantage; unfair business practices; defamation; libel;
slander; negligence; personal injury; assault; battery; invasion of privacy;
false imprisonment; and conversion;  (d) any and all claims
for violation of any federal, state or municipal statute, including, but not
limited to, Title VII of the Civil Rights Act of 1964, the Civil Rights Act of
1991, the Age Discrimination in Employment Act of 1967, the Americans with
Disabilities Act of 1990, the Fair Labor Standards Act, the Employee Retirement
Income Security Act of 1974, The Worker Adjustment and Retraining Notification
Act, Older Workers Benefit Protection Act; the California Fair Employment and
Housing Act, and California Labor Code section 201, et seq. and section 970, et seq.;  (e) any and all claims
for violation of the federal, or any state, constitution;  (f) any and all claims
arising out of any other laws and regulations relating to employment or
employment discrimination;  (g) any claim for any
loss, cost, damage, or expense arising out of any dispute over the
non-withholding or other tax treatment of any of the proceeds received by
Employee as a result of this Release; and  2 
   (h)any and all claims for attorneys fees and costs.  The Company and Employee
agree that the release set forth in this section shall be and remain in effect
in all respects as a complete general release as to the matters released.  This release does not extend to any
obligations incurred under this Release or to obligations provided for in the
Employment Agreement.  Employee
acknowledges and agrees that any breach of any provision of this Release shall
constitute a material breach of this Release and shall entitle the Company
immediately to recover the benefits provided to Employee pursuant to Section
1(a) of this Release.  Employee shall
also be responsible to the Company for all costs, attorneys fees and any and
all damages incurred by the Company (a) enforcing the obligation, including the
bringing of any suit to recover the monetary consideration, and (b) defending
against a claim or suit brought or pursued by Employee in violation of this
provision.  4.Acknowledgement of Waiver of
Claims Under ADEA.  Employee
acknowledges that he is waiving and releasing any rights he may have under the
Age Discrimination in Employment Act of 1967 (ADEA) for the period of time
during his employment with the Company up to and including December 31, 2003
and that this Release is knowing and voluntary.  Employee and the Company agree that this waiver and release does not
apply to any rights or claims that may arise under ADEA after the Effective
Date of this Release.  Employee
acknowledges that the consideration given for Release is in addition to
anything of value to which Employee was already entitled.  Employee further acknowledges that he has
been advised by this writing that  (a) he should consult
with an attorney prior to executing this Release;  (b) he has up to
twenty-one (21) days within which to consider this Release;  (c) he has seven (7) days
following his execution of this Release to revoke the Release; and  (d) this Release shall
not be effective until the revocation period has expired.  (e) nothing in this
Release prevents or precludes Employee from challenging or seeking a
determination in good faith of the validity of this waiver under the ADEA, nor
does it impose any condition precedent, penalties or costs for doing so, unless
specifically authorized by federal law.  5.Civil Code Section 1542.  The Parties represent that they are not
aware of any claim by either of them other than the claims that are released by
this Release.  Employee acknowledges
that he has been advised by legal counsel and is familiar with the provisions
of California Civil Code Section 1542, which provides as follows:  3 
   A GENERAL RELEASE DOES
NOT EXTEND TO CLAIMS WHICH THE CREDITOR DOES NOT KNOW OR SUSPECT TO EXIST IN
HIS FAVOR AT THE TIME OF EXECUTING THE RELEASE, WHICH IF KNOWN BY HIM MUST HAVE
MATERIALLY AFFECTED HIS SETTLEMENT WITH THE DEBTOR.  Employee, being aware of said
code section, agrees to expressly waive any rights he may have thereunder, as
well as under any other statute or common law principles of similar effect.  6.No Pending or Future Lawsuits.  Employee represents that he has no lawsuits,
claims, or actions pending in his name, or on behalf of any other person or
entity, against the Company or any other person or entity referred to
herein.  Employee also represents that
he does not intend to bring any claims on his own behalf or on behalf of any
other person or entity against the Company or any other person or entity
referred to herein.  7.No Admission of Liability.  No action taken by the Parties hereto, or
either of them, either previously or in connection with this Release shall be
deemed or construed to be:  (a) an admission of the
truth or falsity of any claims heretofore made or  (b) an acknowledgment or
admission by either party of any fault or liability whatsoever to the other
party or to any third party.  8.No Knowledge of
Wrongdoing.  Employee represents
that he has no knowledge of any wrongdoing involving improper or false claims
against a federal or state governmental agency, or any other wrongdoing that
involves Employee or other present or former Company employees.  9.Costs.  The Parties shall each bear their own costs,
expert fees, attorneys fees and other fees incurred in connection with this
Release.  10.Indemnification.  Employee agrees to indemnify and hold
harmless the Company from and against any and all loss, costs, damages or
expenses, including, without limitation, attorneys fees or expenses incurred
by the Company arising out of the breach of this Release by Employee, or from
any false representation made herein by Employee, or from any action or
proceeding which may be commenced, prosecuted or threatened by Employee or for
Employees benefit, upon Employees initiative, or with Employees aid or
approval, contrary to the provisions of this Release.  Employee further agrees that in any such action or proceeding,
this Release may be pled by the Company as a complete defense, or may be
asserted by way of counterclaim or cross-claim.  11.Arbitration.  The Parties agree that any and all disputes
arising out of the terms of this Release, their interpretation, and any of the
matters herein released, shall be subject to binding arbitration as provided
for in the Employment Agreement.  12.Authority.  The Company represents and warrants that the
undersigned has the authority to act on behalf of the Company and to bind the
Company and all who may claim through it to the terms and conditions of this
Release.  Employee represents and
warrants that he has the capacity to  4 
   act
on his own behalf and on behalf of all who might claim through him to bind them
to the terms and conditions of this Release. 
Each party warrants and represents that there are no liens or claims of
lien or assignments in law or equity or otherwise of or against any of the
claims or causes of action released herein.  13.No Representations.  Each party represents that it has had the
opportunity to consult with an attorney, and has carefully read and understands
the scope and effect of the provisions of this Release.  Neither party has relied upon any
representations or statements made by the other party hereto which are not
specifically set forth in this Release.  14.Severability.  In the event that any provision hereof
becomes or is declared by a court of competent jurisdiction to be illegal,
unenforceable or void, this Release shall continue in full force and effect
without said provision so long as the remaining provisions remain intelligible
and continue to reflect the original intent of the Parties.  15.Entire Agreement.  This Release and the Employment Agreement
constitutes the entire agreement and understanding between the Parties
concerning the subject matter of this Release and all prior representations,
understandings, and agreements concerning the subject matter of this Release
have been superseded and replaced by the terms of this Release.  16.No Waiver.  The failure of any party to insist upon the
performance of any of the terms and conditions in this Release, or the failure
to prosecute any breach of any of the terms and conditions of this Release,
shall not be construed thereafter as a waiver of any such terms or
conditions.  This entire Release shall
remain in full force and effect as if no such forbearance or failure of
performance had occurred.  17.No Oral Modification.  Any modification or amendment of this Release,
or additional obligation assumed by either party in connection with this
Release, shall be effective only if placed in writing and signed by both
Parties or by authorized representatives of each party.  No provision of this Release can be changed,
altered, modified, or waived except by an executed writing by the Parties.  18.Governing Law.  This Release shall be deemed to have been
executed and delivered within the State of California, and it shall be
construed, interpreted, governed, and enforced in accordance with the laws of
the State of California, without regard to choice of law principles.  19.Attorneys Fees.  In the event that either Party brings an
action to enforce or effect its rights under this Release, the prevailing party
shall be entitled to recover its costs and expenses, including the costs of
mediation, arbitration, litigation, court fees, plus reasonable attorneys
fees, incurred in connection with such an action.  20.Effective Date.  This Release is effective after it has been signed
by both parties and after eight (8) days have passed since Employee has signed
the Release (the Effective Date), unless revoked by Employee within seven (7)
days after the date the Release was signed by Employee.  5 
   21.Counterparts.  This Release may be executed in
counterparts, and each counterpart shall have the same force and effect as an
original and shall constitute an effective, binding agreement on the part of
each of the undersigned.  22.Voluntary Execution of Agreement.  This Release is executed voluntarily and
without any duress or undue influence on the part or behalf of the Parties
hereto, with the full intent of releasing all claims.  The Parties acknowledge that:  (a) They have read this
Release;  (b) They have been
represented in the preparation, negotiation, and execution of this Release by
legal counsel of their own choice or that they have voluntarily declined to
seek such counsel  (c) They understand the
terms and consequences of this Release and of the releases it contains; and  (d) They are fully aware
of the legal and binding effect of this Release.  IN WITNESS WHEREOF, the
Parties have executed this Release on the respective dates set forth below.  SuperGen, Inc.Dated:
  
  
  By
  /s/ Walter LackIts:
  ChairmanCompensation CommitteeJoseph Rubinfeld, an individualDated:
  
  
  /s/ Joseph RubinfeldJoseph Rubinfeld  6


EXHIBIT C  MUTUAL RELEASE AGREEMENT  This Mutual Release Agreement  (the Mutual Release) is made by and
between Joseph Rubinfeld (Employee) and SuperGen, Inc. (the Company),
collectively referred to as the Parties.  1.     Mutual Release of Claims.  The Parties hereby release and forever
discharge each other from all claims, demands, obligations, losses, causes of
action, costs, expenses, attorneys fees and liabilities of any nature
whatsoever, whether known or unknown, and whether based on contract, tort,
statutory or other legal or equitable theory of recovery, which the Parties
have, had, or claim to have against each other prior to and including the
Effective Date of this Agreement (the Released Claims); provided, however,
that the foregoing release shall not apply to (a) any claims relating to
Employees service as a member of the Companys board of directors and (b) any
stockholder derivative claims that Employee may bring against the Company. The
foregoing mutual releases of the Released Claims shall be binding upon, and
shall inure to the benefit of, not only the Parties, but also, as applicable,
the Parties past and present officers, directors, principals, general
partners, limited partners, employees, shareholders, agents, attorneys,
accountants, insurers, representatives, licensees and licensors, servants,
affiliates, subsidiaries, parent companies, successors, heirs, and
assigns.  These mutual releases shall
have no effect upon the rights and obligations of the Parties under the
Employment, Confidential Information, and Invention Assignment Agreement,
entered into as of December 31, 2003 (the Employment Agreement), or upon any
rights Employee may have to indemnification by the Company in his capacity as
an officer or director of the Company pursuant to the Companys Amended and
Restated Certificate of Incorporation, Bylaws (as amended), insurance policies
or laws, as applicable.  2.     Waiver & Release of Unknown
Claims:  California Civil Code Section 1542.  The Parties expressly waive and relinquish
any and all rights and benefits they now have or may have in the future that
are related to the Released Claims under the terms of Section 1542 of the
Civil Code of the State of California:  A GENERAL RELEASE DOES
NOT EXTEND TO CLAIMS WHICH THE CREDITOR DOES NOT KNOW OR SUSPECT TO EXIST IN
HIS FAVOR AT THE TIME OF EXECUTING THE RELEASE, WHICH IF KNOWN BY HIM MUST HAVE
MATERIALLY AFFECTED HIS SETTLEMENT WITH THE DEBTOR.  The Parties acknowledge that they are aware that,
after executing this Agreement, they or their attorneys or agents may discover
claims or facts in addition to or different from those which they now know or
believe to exist with respect to the subject matter of this Agreement, the
Released Claims described in Paragraph 1 above, or the Parties hereto, but that
it is the Parties intention to fully, finally and forever settle and release
all of the Released Claims, claims, matters, disputes and differences known or
unknown, suspected or unsuspected, which now exist, may exist, or heretofore
may have existed against each other relating to the Released Claims.  
   3.     Acknowledgement of Waiver of Claims
Under ADEA.  Employee acknowledges
that he is waiving and releasing any rights he may have under the Age
Discrimination in Employment Act of 1967 (ADEA) for the period of time during
his employment with the Company up to and including December 31, 2003 and that
this Release is knowing and voluntary. 
Employee and the Company agree that this waiver and release does not
apply to any rights or claims that may arise under ADEA after the Effective
Date of this Release.  Employee
acknowledges that the consideration given for Release is in addition to
anything of value to which Employee was already entitled.  Employee further acknowledges that he has been
advised by this writing that  (a) he should consult
with an attorney prior to executing this Release;  (b) he has up to
twenty-one (21) days within which to consider this Release;  (c) he has seven (7) days
following his execution of this Release to revoke the Release; and  (d) this Release shall
not be effective until the revocation period has expired.  (e) nothing in this
Release prevents or precludes Employee from challenging or seeking a
determination in good faith of the validity of this waiver under the ADEA, nor
does it impose any condition precedent, penalties or costs for doing so, unless
specifically authorized by federal law.  4.     No Pending or Future Lawsuits.  The parties represent that they have no
lawsuits, claims, or actions pending against each other and that they do not
intend to bring any such lawsuits, claims or actions.  5.     No Knowledge of Wrongdoing.  The parties represent that they  have no knowledge of any wrongdoing
involving improper or false claims against a federal or state governmental
agency, or any other wrongdoing that involves Employee or other present or
former Company employees.  6.     Costs.  The Parties shall each bear their own costs, expert fees,
attorneys fees and other fees incurred in connection with this Release.  7.     Arbitration.  The Parties agree that any and all disputes
arising out of the terms of this Release, their interpretation, and any of the
matters herein released, shall be subject to binding arbitration as provided
for in the Employment Agreement.  8.     Authority.  The Company represents and warrants that the undersigned has the
authority to act on behalf of the Company and to bind the Company and all who
may claim through it to the terms and conditions of this Mutual Release.  Employee represents and warrants that he has
the capacity to act on his own behalf and on behalf of all who might claim
through him to bind them to the terms and conditions of this Mutual
Release.  Each party warrants and
represents that there are  2 
   no liens or claims
of lien or assignments in law or equity or otherwise of or against any of the
claims or causes of action released herein.  9.     No Representations.  Each party represents that it has had the
opportunity to consult with an attorney, and has carefully read and understands
the scope and effect of the provisions of this Mutual Release.  Neither party has relied upon any
representations or statements made by the other party hereto which are not
specifically set forth in this Mutual Release.  10.   Severability.  In the event that any provision hereof
becomes or is declared by a court of competent jurisdiction to be illegal,
unenforceable or void, this Mutual Release shall continue in full force and
effect without said provision so long as the remaining provisions remain
intelligible and continue to reflect the original intent of the Parties.  11.   Entire Agreement.  This Mutual Release constitutes the entire
agreement and understanding between the Parties concerning its subject matter.  12.   No Waiver.  The failure of any party to insist upon the performance of any of
the terms and conditions in this Mutual Release, or the failure to prosecute
any breach of any of the terms and conditions of this Mutual Release, shall not
be construed thereafter as a waiver of any such terms or conditions.  This entire 
Mutual Release shall remain in full force and effect as if no such
forbearance or failure of performance had occurred.  13.   No Oral Modification.  Any modification or amendment of this Mutual
Release, or additional obligation assumed by either party in connection with
this Mutual Release, shall be effective only if placed in writing and signed by
both Parties or by authorized representatives of each party.  No provision of this Mutual Release can be
changed, altered, modified, or waived except by an executed writing by the
Parties.  14.   Governing Law.  This Mutual Release shall be deemed to have
been executed and delivered within the State of California, and it shall be
construed, interpreted, governed, and enforced in accordance with the laws of
the State of California, without regard to choice of law principles.  15.   Attorneys Fees.  In the event that either Party brings an
action to enforce or effect its rights under this Mutual Release, the
prevailing party shall be entitled to recover its costs and expenses, including
the costs of mediation, arbitration, litigation, court fees, plus reasonable
attorneys fees, incurred in connection with such an action.  16.   Effective Date.  This Mutual Release is effective after it
has been signed by both parties and after eight (8) days have passed since
Employee has signed the Mutual Release (the Effective Date), unless revoked
by Employee within seven (7) days after the date the Mutual Release was signed
by Employee.  17.   Counterparts.  This Mutual Release may be executed in
counterparts, and each counterpart shall have the same force and effect as an
original and shall constitute an effective, binding agreement on the part of
each of the undersigned.  3 
   18.   Voluntary Execution of Agreement.  This Mutual Release is executed voluntarily
and without any duress or undue influence on the part or behalf of the Parties
hereto, with the full intent of releasing all claims.  The Parties acknowledge that:  (a) They have read this
Mutual Release;  (b) They have been
represented in the preparation, negotiation, and execution of this Mutual
Release by legal counsel of their own choice or that they have voluntarily
declined to seek such counsel  (c) They understand the
terms and consequences of this Mutual Release and of the releases it contains;
and  (d) They are fully aware
of the legal and binding effect of this Mutual Release.  IN WITNESS WHEREOF, the
Parties have executed this Mutual Release on the respective dates set forth
below.  SuperGen, Inc.Dated:
  
  
  ByIts:Joseph Rubinfeld, an individualDated:Joseph Rubinfeld  4