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                                                                    EXHIBIT 10.1

                         SEVERANCE AGREEMENT AND RELEASE

         This Release and Severance Agreement ("Agreement") is being entered
into by David S. Gordon and Aronex Pharmaceuticals, Inc. in order to further the
mutually desired terms and conditions set forth herein:

         For and in consideration for execution of this Agreement, Aronex
                  Pharmaceuticals, Inc. will pay a total payment of $229,000.
                  ("Severance Payment"), less standard deductions. In addition,
                  your Aronex Pharmaceuticals, Inc. vested stock options can be
                  exercised for a period of twenty four (24) months from your
                  termination date. Except as provided in Paragraph 2 below,
                  this sum represents the exclusive amount to be paid by Aronex
                  Pharmaceuticals, Inc., in connection with or arising out of
                  David S. Gordon's termination of employment with Aronex
                  Pharmaceuticals, Inc., and no further amounts shall be
                  required for any items, including, but not limited to,
                  attorneys' fees.

         David S. Gordon on behalf of himself, his heirs, beneficiaries and
                  personal representatives, hereby releases, acquits and forever
                  discharges Aronex Pharmaceuticals, Inc., its officers,
                  employees, former employees, shareholders, directors,
                  partners, agents and assigns, and all other persons, firms,
                  partnerships, or corporations in control of, under the
                  direction of, or in any way presently or formerly associated
                  with Aronex Pharmaceuticals, Inc., of and from all claims,
                  charges, complaints, liabilities, obligations, promises,
                  agreements, contracts, damages, actions, causes of action,
                  suits, accrued benefits or other liabilities of any kind or
                  character, whether known or hereafter discovered, arising from
                  or in any way connected or related with employment with Aronex
                  Pharmaceuticals, Inc. and termination of employment with
                  Aronex Pharmaceuticals, Inc., including, but not limited to,
                  allegations of wrongful termination, breach of contract,
                  intentional infliction of emotional distress, negligent
                  infliction of emotional distress, defamation, invasion of
                  privacy, any action in tort or contract, any violation of any
                  federal, state, or local law, including, but not limited to,
                  any violation of Title VII of the Civil Rights Act of 1964, as
                  amended, 42 U.S.C. Section 2000e et seq., the Equal Pay Act,
                  29 U.S.C. Section 206; the Employee Retirement Income Security
                  Act of 1974, the Americans with Disabilities Act, 42 U.S.C.
                  Section 12101 et seq., the Fair Labor Standards Act, as
                  amended, 29 U.S.C. Section 201 et seq., the Texas Commission
                  on Human Rights Act, Texas Labor Code Section 21.001, et seq.,
                  the Age Discrimination in Employment Act of 1967, as amended
                  ("ADEA"), 29 U.S.C. Section 621 et seq., or any other
                  employment or civil rights act, and any and all claims for
                  severance pay or benefits under any compensation or employee
                  benefit plan, program, policy, contract, agreement or other
                  arrangement of Aronex Pharmaceuticals, Inc., but excluding any
                  benefits which David S. Gordon is entitled to receive under
                  any Aronex Pharmaceuticals, Inc. plan that is a qualified plan
                  under IRC Section 401(a) or is a group health plan subject to
                  COBRA, to the extent David S. Gordon properly elects and pays
                  for such COBRA continuation coverage.

         David S. Gordon agrees not to commence any legal proceeding or lawsuit
                  against Aronex Pharmaceuticals, Inc. arising out of or based
                  upon employment with Aronex Pharmaceuticals, Inc. or the
                  termination of employment with Aronex Pharmaceuticals, Inc.

         The consideration cited above and the promises contained herein are
                  made for the purpose of purchasing the peace of Aronex
                  Pharmaceuticals, Inc. and are not to be construed as an
                  admission of liability or as evidence or unlawful conduct by
                  Aronex Pharmaceuticals, Inc., all liability being expressly
                  denied.


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         5.       David S. Gordon voluntarily accepts the consideration cited
                  herein, as sufficient payment for the full, final and complete
                  release stated herein, and agrees that no other promises or
                  representations have been made to by Aronex Pharmaceuticals,
                  Inc. or any other person purporting to act on behalf of Aronex
                  Pharmaceuticals, Inc., except as expressly stated herein.

         6.       David S. Gordon understands that this is a full, complete, and
                  final release of Aronex Pharmaceuticals, Inc. As evidenced by
                  the signature below, expressly promises and represents to
                  Aronex Pharmaceuticals, Inc. that he has completely read this
                  Agreement and understands its terms, contents, conditions, and
                  effects.

         7.       David S. Gordon understands that he has the right to consult
                  an attorney of his choice and has consulted with an attorney
                  or has knowingly and voluntarily decided not to do so.

         8.       David S. Gordon states that he is not presently effected by
                  any disability which would prevent him from knowingly and
                  voluntarily granting this release, and further states that the
                  promises made herein are not made under duress, coercion or
                  undue influence.

         This Agreement will supersede any and all obligations Aronex
                  Pharmaceuticals, Inc. might otherwise owe to David S. Gordon
                  for any act or omission whatsoever that took place, or should
                  have taken place, on or before the date this Agreement is
                  signed and executed by. This Agreement constitutes the entire
                  understanding and agreement between the parties and it may
                  only be modified or amended in a signed writing by both
                  parties hereto.

         Should any future dispute arise with respect to this Agreement, both
                  parties agree that it should be resolved solely in accordance
                  with the terms and provision of this Agreement and the laws of
                  the State of Texas.

         David S. Gordon hereby waives all rights to recall, reinstatement,
                  employment, reemployment, and past or future wages from Aronex
                  Pharmaceuticals, Inc.

         12.      David S. Gordon understands that he has Twenty-one (21) days
                  within which to consider this Agreement and that this
                  Agreement is revocable by him for a period of seven (7) days
                  following the execution of this Agreement, and if not so
                  revoked, will become effective and enforceable. The
                  consideration cited in Paragraph 1 above to be paid through
                  out normal pay cycle.

         13.      David S. Gordon expressly represents and warrants to Aronex
                  Pharmaceuticals, Inc. that he has completely read this
                  Agreement prior to executing it, has had an opportunity to
                  review it with his counsel, has been offered twenty one (21)
                  days within which to consider this Agreement and to understand
                  its terms, contents, conditions and effects and has entered
                  into this Agreement knowingly and voluntarily.


         14.      David S. Gordon agrees that the terms and conditions of this
                  Agreement, including without limitation of the amount of money
                  and other


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                  consideration, shall be treated as confidential, and shall not
                  be revealed to any other person or entity whatsoever, except
                  as follows:

                       to the extent as may be compelled by legal process; or

                       to the extent necessary to legal or financial advisors.

David S. Gordon agrees that the confidentiality provisions of this Agreement are
a material part of it and are contractual in nature.

Date
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David S. Gordon, M.D.


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Geoffrey F. Cox, Ph.D.