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                                                                    EXHIBIT 14.1

                                  EPIMMUNE INC.

                       CODE OF BUSINESS CONDUCT AND ETHICS

           ADOPTED BY THE BOARD OF DIRECTORS ON DECEMBER 9, 2003

INTRODUCTION

      We are committed to maintaining the highest standards of business conduct
and ethics. This Code of Business Conduct and Ethics (this "CODE") reflects the
business practices and principles of behavior behind that commitment. We expect
every employee, officer and director to read and understand this Code and abide
by it in the performance of his or her business responsibilities. Employees are
also expected to ensure that all agents and contractors conform to Code
standards when working for or on behalf of Epimmune Inc. ("EPIMMUNE"). In
addition, any employee who makes an exemplary effort to implement and uphold our
legal and ethical standards will be recognized for that effort in his or her
performance review. In complying with this Code, you should consider not only
your own conduct, but also that of your immediate family members, significant
others and other persons who live in your household.

      Violations of this Code will not be tolerated. Any employee who violates
the standards in the Code may be subject to disciplinary action, as described in
this Code.

1.    HONEST AND ETHICAL CONDUCT

      Epimmune promotes high standards of integrity by conducting our affairs in
an honest and ethical manner. The integrity and reputation of Epimmune depends
on the honesty, fairness and integrity brought to the job by each person
associated with us. Unyielding personal integrity is the foundation of our
corporate integrity.

2.    LEGAL COMPLIANCE

      Disregard of the law will not be tolerated. Violation of domestic or
foreign laws, rules and regulations may subject an individual, as well as
Epimmune, to civil and/or criminal penalties. Your conduct and records,
including emails, are subject to internal and external audits, and to discovery
by third parties in the event of a government investigation or civil litigation.
It is in everyone's best interests to know and comply with our legal and ethical
obligations.

3.    CONFLICTS OF INTEREST

      You must avoid personal interests that conflict with interests of
Epimmune, or that might influence or even appear to influence your judgment or
actions in performing your duties. You should not have any business, financial
or other relationship with collaborators, license partners, suppliers or
competitors that might impair or even appear to impair the independence of
Epimmune. We acknowledge that the non-employee members of our Board of Directors
(the "BOARD") may have various business, financial, scientific or other
relationships with existing or potential collaborators, license partners,
supplier or competitors. Any actual or potential conflicts of interest relating
to any of these relationships of our non-employee directors that have been or
are disclosed


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to our Board shall not be considered violations of this Code and shall not
otherwise require a waiver of any provisions of this Code. Notwithstanding the
foregoing, if the Board affirmatively determines that any such relationship is
inconsistent with the director's responsibilities, it shall so advise the
director and the director shall terminate the relationship as promptly as
practical.

4.    CORPORATE OPPORTUNITIES

      You may not take personal advantage of opportunities that are presented to
you or discovered by you as a result of your position with us or through your
use of corporate property or information, unless authorized by your supervisor,
the Compliance Officer or the Audit Committee.

5.    MAINTENANCE  OF CORPORATE  BOOKS,  RECORDS,  DOCUMENTS  AND  ACCOUNTS;
FINANCIAL INTEGRITY; PUBLIC REPORTING

      Our corporate and business records should be completed accurately and
honestly. Making any false or misleading entries, whether they relate to
financial results or test results, is strictly prohibited. Our records serve as
a basis for managing our business and are important in meeting our obligations
to our collaborators, license partners, suppliers, employees and others with
whom we do business. As a result, it is important that our books, records and
accounts accurately and fairly reflect, in reasonable detail, our assets,
liabilities, revenues, costs and expenses, as well as all transactions and
changes in assets and liabilities. We require that no entry be made in our books
and records that intentionally hides or disguises the nature or any transaction
or of any of our liabilities, or misclassifies any transactions as to accounts
or accounting periods.

      Employees who collect, provide or analyze information for or otherwise
contribute in any way in preparing or verifying our internal reports, reports
filed with the Securities and Exchange Commission or press releases issued by
the Company should strive to ensure that our financial and other disclosure is
timely, accurate and transparent and that our reports and press releases contain
all of the information about Epimmune that would be important to enable
stockholders and potential investors to assess the soundness and risks of our
business and finances and the quality and integrity of our accounting and
disclosures. Any employee who becomes aware of any departure from these
standards has a responsibility to report his or her knowledge promptly to a
supervisor, the Compliance Officer or our Chief Executive Officer.

6.    WAIVERS

      Any waiver of this Code for executive officers (including, where required
by applicable laws, our principal executive officer, principal financial
officer, principal accounting officer or controller (or persons performing
similar functions)) or directors may be authorized only by our Board or a
committee of the Board and will be disclosed to stockholders as required by
applicable laws, rules and regulations.


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7.    COMPLIANCE STANDARDS AND PROCEDURES

      COMPLIANCE RESOURCES. We have established the position of Compliance
Officer to oversee this program and he can address any of your questions or
concerns. The Compliance Officer, our Chief Financial Officer, can be reached at
(858) 860-2553. You may also speak with your supervisor or our Chief Executive
Officer.

      ETHICS HOTLINE. You may call 858-860-2557 (our Ethics Hotline) and leave a
message if you wish to ask questions about Epimmune policy, seek guidance on
specific situations or report violations of this Code. Our Compliance Officer
will retrieve any messages left at least once a week. You may call the number
anonymously if you prefer as it is not equipped with caller identification,
although the Compliance Officer will be unable to obtain follow-up details from
you that may be necessary to investigate the matter. Your telephonic contact
with the Ethics Hotline will be kept strictly confidential to the extent
reasonably possible within the objectives of this Code.

      CLARIFYING QUESTIONS AND CONCERNS; REPORTING POSSIBLE VIOLATIONS. If you
encounter a situation or are considering a course of action and its
appropriateness is unclear, discuss the matter promptly with your supervisor,
the Compliance Officer or our Chief Executive Officer.

      OBLIGATION  TO  REPORT  POSSIBLE  VIOLATIONS.  If you are  aware  of a
suspected  or actual  violation  of Code  standards  by  others,  you have a
responsibility to report it.

      NO  REPRISALS.  We will take prompt  disciplinary  action  against any
employee who  retaliates  against you, up to and  including  termination  of
employment.

      CONFIDENTIALITY.  Supervisors  must promptly  report any complaints or
observations of Code violations to the Compliance Officer.

      DISCIPLINE. If the investigation indicates that a violation of this Code
has probably occurred, we will take such action as we believe to be appropriate
under the circumstances. If we determine that an employee is responsible for a
Code violation, he or she will be subject to disciplinary action up to, and
including, termination of employment and, in appropriate cases, civil action or
referral for criminal prosecution. Appropriate action may also be taken to deter
any future Code violations. Such disciplinary actions may also be taken (A) when
an employee fails to report or withholds relevant information concerning a
violation of such standards, laws or regulation, or (B) when there has been
inadequate supervision or lack of diligence by a supervisor or manager in
connection with a violation of such standards, laws, or regulations.


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