<PAGE>   1
                                                                   EXHIBIT 10.32

                                 [CONFIDENTIAL]

                              PUBLIC HEALTH SERVICE

                      PATENT LICENSE AGREEMENT-NONEXCLUSIVE

                                   COVER PAGE

For Office of Technology Transfer/NIH internal use only:
Patent License Number: L-052-98/0

Serial Numbers of Licensed Patents: 60/024,386

Licensee: Introgen Therapeutics, Inc., 301 Congress Avenue, Suite 1850, Austin,
TX 78701

CRADA Number (if applicable): None

Additional Remarks:

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

This Patent License Agreement, hereinafter referred to as the "AGREEMENT,"
consists of this Cover Page, an attached agreement, a Signature Page, Appendix A
(Patent or Patent Application), Appendix B (Fields of Use and Territory),
Appendix C (Royalties), and Appendix D (Modifications). This Cover Page serves
to identify the Parties to this AGREEMENT as follows:

1.   The National Institutes of Health ("NIH") or the Centers for Disease
     Control ("CDC"), hereinafter singly or collectively referred to as "PHS,"
     agencies of the United States Public Health Service within the Department
     of Health and Human Services ("DHHS"); and

2.   The person, corporation, or institution identified above and/or on the
     Signature Page, having offices at the address indicated on the Signature
     Page, hereinafter referred to as "LICENSEE."



NIH Office of Technology Transfer
PHS PATENT LICENSE AGREEMENT-NONEXCLUSIVE
L-052-98/0 Final Introgen Therapeutics Inc. 07/22/98 - Page 1 of 17

<PAGE>   2

                 PHS PATENT LICENSE AGREEMENT-NONEXCLUSIVE

PHS and LICENSEE agree as follows:

1.  BACKGROUND

    1.01   In the course of conducting biomedical and behavioral research, PHS
           investigators made inventions that may have commercial applicability.

    1.02   By assignment of rights from PHS employees and other inventors, DHHS,
           on behalf of the United States Government, owns intellectual property
           rights claimed in any United States and foreign patent applications
           or patents corresponding to the assigned inventions. DHHS also owns
           any tangible embodiments of these inventions actually reduced to
           practice by PHS.

    1.03   The Assistant Secretary for Health of DHHS has delegated to PHS the
           authority to enter into this AGREEMENT for the licensing of the
           rights to these inventions under 35 U.S.C. Sections 200-212, the
           Federal Technology Transfer Act of 1986, 15 U.S.C. Section 3710a,
           and/or the regulations governing the licensing of Government-owned
           inventions, 37 CFR Part 404.

    1.04   PHS desires to transfer these inventions to the private sector
           through commercialization licenses to facilitate the commercial
           development of products and processes for public use and benefit.

    1.05   LICENSEE desires to acquire commercialization rights to certain of
           these inventions in order to develop processes, methods, or
           marketable products for public use and benefit.

2.  DEFINITIONS

    2.01   "LICENSED PATENT RIGHTS" shall mean:

            a)  U.S. patent applications and patents listed in Appendix A, all
                divisions and continuations of these applications, all patents
                issuing from such applications, divisions, and continuations,
                and any reissues, reexaminations, and extensions of all such
                patents;

            b)  to the extent that the following contain one or more claims
                directed to the invention or inventions claimed in a) above: i)
                continuations-in-part of a) above; ii) all divisions and
                continuations of these continuations-in-part; iii) all patents
                issuing from such continuations-in-part, divisions, and
                continuations; and iv) any reissues, reexaminations, and
                extensions of all such patents;

            c)  to the extent that the following contain one or more claims
                directed to the invention or inventions claimed in a) above: all
                counterpart foreign applications and patents to a) and b) above,
                including those listed in Appendix A.

                LICENSED PATENT RIGHTS shall not include b) or c) above to the
                extent that they contain one or more claims directed to new
                matter which is not the subject matter of a claim in a) above.

    2.02   "LICENSED PRODUCT(S)" means tangible materials which, in the
           course of manufacture,



NIH Office of Technology Transfer
PHS PATENT LICENSE AGREEMENT-NONEXCLUSIVE
L-052-98/0 Final Introgen Therapeutics Inc. 07/22/98 - Page 2 of 17

<PAGE>   3

           use, or sale would, in the absence of this AGREEMENT, infringe one or
           more claims of the LICENSED PATENT RIGHTS that have not been held
           invalid or unenforceable by an unappealed or unappealable judgement
           of a court of competent jurisdiction.

    2.03   "LICENSED PROCESS(ES)" means processes which, in the course of being
           practiced would, in the absence of this AGREEMENT, infringe one or
           more claims of the LICENSED PATENT RIGHTS that have not been held
           invalid or unenforceable by an unappealed or unappealable judgment of
           a court of competent jurisdiction.

    2.04   "LICENSED TERRITORY" means the geographical area identified in
           Appendix B.

    2.05   "NET SALES" means the total gross receipts for sales of LICENSED
           PRODUCTS or practice of Licensed Processes by or on behalf of
           LICENSEE and from leasing, renting, or otherwise making LICENSED
           PRODUCTS available to others without sale or other dispositions,
           whether invoiced or not, less returns and allowances actually
           granted, packing costs, insurance costs, freight out, taxes or excise
           duties imposed on the transaction (if separately invoiced), and
           wholesaler and cash discounts in amounts customary in the trade. No
           deductions shall be made for commissions paid to individuals, whether
           they be with independent sales agencies or regularly employed by
           LICENSEE and on its payroll, or for the cost of collections.

    2.06   "FIRST COMMERCIAL SALE" means the initial transfer by or on behalf of
           LICENSEE of LICENSED PRODUCTS or the initial practice of a LICENSED
           PROCESS in exchange for cash or some equivalent to which value can be
           assigned for the purpose of determining NET SALES.

    2.07   "GOVERNMENT" means the government of the United States of America.

    2.08   "LICENSED FIELDS OF USE" means the fields of use identified in
           Appendix B.

3.  GRANT OF RIGHTS

    3.01   PHS hereby grants and LICENSEE accepts, subject to the terms and
           conditions of this AGREEMENT, a nonexclusive license to LICENSEE
           under the LICENSED PATENT RIGHTS in the LICENSED TERRITORY to make
           and have made, to use and have used, and to sell and have sold any
           LICENSED PRODUCTS in the LICENSED FIELDS OF USE and to practice and
           have practiced any LICENSED PROCESSES in the LICENSED FIELDS OF USE.

    3.02   LICENSEE has no right to grant sublicenses.

    3.03   This AGREEMENT confers no license or rights by implication, estoppel,
           or otherwise under any patent applications or patents of PHS other
           than the LICENSED PATENT RIGHTS regardless of whether such patents
           are dominant or subordinate to LICENSED PATENT RIGHTS.

4.  STATUTORY AND PHS REQUIREMENTS AND RESERVED GOVERNMENT RIGHTS

    4.01   LICENSEE agrees that products used or sold in the United States
           embodying LICENSED PRODUCTS or produced through use of LICENSED
           PROCESSES shall be manufactured substantially in the United States,
           unless a written waiver is obtained in advance from PHS.


NIH Office of Technology Transfer
PHS PATENT LICENSE AGREEMENT-NONEXCLUSIVE
L-052-98/0 Final Introgen Therapeutics Inc. 07/22/98 - Page 3 of 17

<PAGE>   4
5.  ROYALTIES AND REIMBURSEMENT

    5.01   LICENSEE agrees to pay to PHS a noncreditable, nonrefundable license
           issue royalty as set forth in Appendix C within thirty (30) days from
           the date that this AGREEMENT becomes effective.

    5.02   LICENSEE agrees to pay to PHS a nonrefundable minimum annual royalty
           as set forth in Appendix C. The minimum annual royalty is due and
           payable on January 1 of each calendar year [*]. The minimum annual
           royalty for the first calendar year of this AGREEMENT is due and
           payable within thirty (30) days from the effective date of this
           AGREEMENT and will be prorated according to the fraction of the
           calendar year remaining between the effective date of this AGREEMENT
           and the next subsequent January 1.

    5.03   LICENSEE agrees to pay PHS benchmark royalties as set forth in
           Appendix C.

    5.04   LICENSEE agrees to pay PHS earned royalties as set forth in Appendix
           C.

    5.05   A claim of a patent licensed under this AGREEMENT shall cease to fall
           within the LICENSED PATENT RIGHTS for the purpose of computing the
           minimum annual royalty and earned royalty payments in any given
           country on the earliest of the dates that a) the claim has been
           abandoned but not continued, b) the patent expires, c) the patent is
           no longer maintained by the Government, or d) all claims of the
           LICENSED PATENT RIGHTS have been held to be invalid or unenforceable
           by an unappealed or unappealable decision of a court of competent
           jurisdiction or administrative agency.

    5.06   No multiple royalties shall be payable because any LICENSED PRODUCTS
           or LICENSED PROCESSES are covered by more than one of the LICENSED
           PATENT RIGHTS.

    5.07   On sales of LICENSED PRODUCTS by LICENSEE in other than an
           arm's-length transaction, the value of the NET SALES attributed under
           this Article 5 to such a transaction shall be that which would have
           been received in an arm's-length transaction, based on sales of like
           quantity and quality products on or about the time of such
           transaction.

    5.08   As an additional royalty, LICENSEE agrees to pay PHS within (60) days
           of PHS's submission of a statement and request for payment, an amount
           equivalent to all patent expenses previously incurred by PHS in the
           preparation, filing, prosecution, and maintenance of LICENSED PATENT
           RIGHTS, to be divided equally among all nonexclusive
           commercialization licensees of record as of the date the statement
           and request for payment is sent by PHS to LICENSEE. LICENSEE further
           agrees to pay PHS annually, within sixty (60) days of PHS's
           submission of a statement and request for payment, a royalty amount
           equivalent to all such future patent expenses incurred during the
           previous calendar year divided equally among all nonexclusive
           commercialization licensees of record as of the date the statement
           and request for payment are sent by PHS to LICENSEE. [*] of the
           cumulative amount of the payments due under this Paragraph 5.07 may
           be credited against royalties due under Paragraph 5.03; however, the
           net royalty payment in any calendar year may not be lower than the
           minimum annual royalty specified in Appendix C. LICENSEE may elect to
           surrender its rights in any country of the LICENSED TERRITORY under
           any LICENSED PATENT RIGHTS upon sixty (60) days' written notice to
           PHS and owe no payment obligation under this Paragraph for subsequent
           patent-related expenses incurred in that country.


NIH Office of Technology Transfer
PHS PATENT LICENSE AGREEMENT-NONEXCLUSIVE
L-052-98/0 Final Introgen Therapeutics Inc. 07/22/98 - Page 4 of 17



         [*]    Certain information on this page has been omitted and filed
                separately with the Commission. Confidential treatment has been
                requested with respect to the omitted portions.


<PAGE>   5

6.  RECORD KEEPING

    6.01   LICENSEE agrees to keep accurate and correct records of LICENSED
           PRODUCTS made, used, or sold and LICENSED PROCESSES practiced under
           this AGREEMENT appropriate to determine the amount of royalties due
           PHS. Such records shall be retained for at least five (5) years
           following a given reporting period. They shall be available during
           normal business hours for inspection at the expense of PHS by an
           accountant or other designated auditor selected by PHS for the sole
           purpose of verifying reports and payments hereunder. The accountant
           or auditor shall only disclose to PHS information relating to the
           accuracy of reports and payments made under this AGREEMENT. If an
           inspection shows an underreporting or underpayment in excess of five
           percent (5%) for any twelve (12) month period, then LICENSEE shall
           reimburse PHS for the cost of the inspection at the time LICENSEE
           pays the unreported royalties, including any late charges as required
           by Paragraph 7.06 of this AGREEMENT. All payments required under this
           Paragraph shall be due within thirty (30) days of the date PHS
           provides LICENSEE notice of the payment due.

7.  REPORTS ON PROGRESS, SALES, AND PAYMENTS

    7.01   Prior to signing this AGREEMENT, LICENSEE has provided to PHS a
           written commercialization plan ("COMMERCIAL DEVELOPMENT PLAN") under
           which LICENSEE intends to bring the subject matter of the LICENSED
           PATENT RIGHTS into commercial use. The COMMERCIAL DEVELOPMENT PLAN is
           hereby incorporated by reference into this AGREEMENT.

    7.02   LICENSEE shall provide written annual reports on its product
           development progress or efforts to commercialize under the COMMERCIAL
           DEVELOPMENT PLAN for each of the LICENSED FIELDS OF USE within sixty
           (60) days after December 31 of each calendar year. These progress
           reports shall include, but not be limited to: progress on research
           and development, status of applications for regulatory approvals,
           manufacturing, marketing, and sales during the preceding calendar
           year, as well as plans for the present calendar year. LICENSEE agrees
           to provide any additional data reasonably required by PHS to evaluate
           LICENSEE's performance.

    7.03   LICENSEE shall report to PHS the date of the FIRST COMMERCIAL SALE in
           each country in the LICENSED TERRITORY within thirty (30) days of
           such occurrence.

    7.04   LICENSEE shall submit to PHS within sixty (60) days after each
           calendar half-year ending June 30 and December 31 a royalty report
           setting forth for the preceding half-year period the amount of the
           LICENSED PRODUCTS sold or LICENSED PROCESSES practiced by or on
           behalf of LICENSEE in each country within the LICENSED TERRITORY, the
           NET SALES, and the amount of royalty accordingly due. With each such
           royalty report, LICENSEE shall submit payment of the earned royalties
           due. If no earned royalties are due to PHS for any reporting period,
           the written report shall so state. The royalty report shall be
           certified as correct by an authorized officer of LICENSEE and shall
           include a detailed listing of all deductions made under Paragraph
           2.05 to determine NET SALES made under Article 5 to determine
           royalties due.

    7.05   Royalties due under Article 5 shall be paid in U.S. dollars. For
           conversion of foreign currency to U.S. dollars, the conversion rate
           shall be the rate quoted in The Wall Street Journal on the day that
           the payment is due. All checks and bank drafts shall be drawn on
           United States banks and shall be payable to NIH/Patent Licensing at
           the address shown


NIH Office of Technology Transfer
PHS PATENT LICENSE AGREEMENT-NONEXCLUSIVE
L-052-98/0 Final Introgen Therapeutics Inc. 07/22/98 - Page 5 of 17

<PAGE>   6

           on the Signature Page below. Any loss of exchange, value, taxes, or
           other expenses incurred in the transfer or conversion to U.S. dollars
           shall be paid entirely by LICENSEE. All royalty payments due under
           this AGREEMENT shall be mailed to the following address: NIH
           P.O. Box 360120, Pittsburgh, Pennsylvania 15251-6120. The royalty
           report required by paragraph 7.04 of this AGREEMENT shall accompany
           each such payment and a copy of such report shall also be mailed to
           PHS at its address for notices indicated on the Signature Page of
           this AGREEMENT.

    7.06   Late charges will be applied to any overdue payments as required by
           the U.S. Department of Treasury in the Treasury Fiscal Requirements
           Manual, Section 8025.40. The payment of such late charges shall not
           prevent PHS from exercising any other rights it may have as a
           consequence of the lateness of any payment.

    7.07   All plans and reports required by this Article 7 and marked
           "confidential" by LICENSEE shall be treated by PHS as commercial and
           financial information obtained from a person, and as privileged and
           confidential and, to the extent permitted by law, shall not be
           subject to disclosure under the Freedom of Information Act, 5 U.S.C.
           Section 552.

8.  PERFORMANCE

    8.01   LICENSEE shall use its reasonable best efforts to introduce the
           LICENSED PRODUCTS into the commercial market or apply the LICENSED
           PROCESSES to commercial use as soon as practicable. "Reasonable best
           efforts" for the purpose of this provision shall include, but not be
           limited to, adherence to the COMMERCIAL DEVELOPMENT PLAN.

    8.02   Upon the FIRST COMMERCIAL SALE, until the expiration of this
           AGREEMENT, LICENSEE shall use its reasonable best efforts to keep
           LICENSED PRODUCTS and LICENSED PROCESSES reasonably accessible to the
           public.

9.  INFRINGEMENT AND PATENT ENFORCEMENT

    9.01   PHS and LICENSEE agree to notify each other promptly of each
           infringement or possible infringement, as well as any facts which may
           affect the validity, scope, or enforceability of the LICENSED PATENT
           RIGHTS of which either Party becomes aware.

    9.02   If PHS has been unable to eliminate a substantial infringement within
           one (1) year of written notification to the Office of Technology
           Transfer from LICENSEE of the existence of a substantial infringement
           and has not instituted infringement litigation, LICENSEE shall be
           excused from [*]. Thereafter, when the substantial infringement has
           ceased or an infringement suit has been initiated, PHS shall so
           notify the LICENSEE in writing, at which time [*] shall resume as
           of the date of such notification.

    9.03   In the event that a declaratory judgment action alleging invalidity
           of any of the LICENSED PATENT RIGHTS shall be brought against PHS,
           PHS agrees to notify LICENSEE that an action alleging invalidity has
           been brought. PHS does not represent that it will commence legal
           action to defend against a declaratory action alleging invalidity.
           LICENSEE shall take no action to compel the GOVERNMENT either to
           initiate or to join in any such declaratory judgment action. Should
           the GOVERNMENT be made a party to any such suit by motion or


NIH Office of Technology Transfer
PHS PATENT LICENSE AGREEMENT-NONEXCLUSIVE
L-052-98/0 Final Introgen Therapeutics Inc. 07/22/98 - Page 6 of 17





         [*]    Certain information on this page has been omitted and filed
                separately with the Commission. Confidential treatment has been
                requested with respect to the omitted portions.

<PAGE>   7


           any other action of LICENSEE, LICENSEE shall reimburse the GOVERNMENT
           for any costs, expenses, or fees which the GOVERNMENT incurs as a
           result of its defending against such motion or other action taken in
           response to the motion. Upon LICENSEE's payment of all costs incurred
           by the GOVERNMENT as a result of LICENSEE's joinder motion or other
           action, these actions by LICENSEE will not be considered a default in
           the performance of any material obligation under this AGREEMENT.

10. NEGATION OF WARRANTIES AND INDEMNIFICATION

    10.01  PHS offers no warranties other than those specified in Article 1.

    10.02  PHS does not warrant the validity of the LICENSED PATENT RIGHTS and
           makes no representations whatsoever with regard to the scope of the
           LICENSED PATENT RIGHTS, or that the LICENSED PATENT RIGHTS may be
           exploited without infringing other patents or other intellectual
           property rights of third parties.

    10.03  PHS MAKES NO WARRANTIES, EXPRESSED OR IMPLIED, OF MERCHANTABILITY OR
           FITNESS FOR A PARTICULAR PURPOSE OF ANY SUBJECT MATTER DEFINED BY THE
           CLAIMS OF THE LICENSED PATENT RIGHTS.

    10.04  PHS does not represent that it will commence legal actions against
           third parties infringing the LICENSED PATENT RIGHTS.

    10.05  LICENSEE shall indemnify and hold PHS, its employees, students,
           fellows, agents, and consultants harmless from and against all
           liability, demands, damages, expenses, and losses, including but not
           limited to death, personal injury, illness, or property damage in
           connection with or arising out of a) the use by or on behalf of
           LICENSEE, ALSO sublicensees or its directors, employees, or third
           parties of any LICENSED PATENT RIGHTS, or b) the design, manufacture,
           distribution, or use of any LICENSED PRODUCTS, LICENSED PROCESSES, or
           other products or processes developed in connection with or arising
           out of the LICENSED PATENT RIGHTS. LICENSEE agrees to maintain a
           liability insurance program consistent with sound business practice.

11. TERMINATION AND MODIFICATION OF RIGHTS

    11.01  This AGREEMENT is effective when signed by all parties and shall
           extend to the expiration of the last to expire of the LICENSED PATENT
           RIGHTS unless sooner terminated as provided in this Article 11.

    11.02  In the event that LICENSEE is in default in the performance of any
           material obligations under this AGREEMENT, and if the default has not
           been remedied within ninety (90) days after the date of notice in
           writing of such default, PHS may terminate this AGREEMENT by written
           notice.

    11.03  At least thirty (30) days prior to filing a petition in bankruptcy,
           LICENSEE must inform PHS in writing of its intention to file the
           petition in bankruptcy or of a third party's intention to file an
           involuntary petition in bankruptcy.

    11.04  In the event that LICENSEE becomes insolvent, files a petition in
           bankruptcy, has such a petition filed against it, determines to file
           a petition in bankruptcy, or receives notice of a


NIH Office of Technology Transfer
PHS PATENT LICENSE AGREEMENT-NONEXCLUSIVE
L-052-98/0 Final Introgen Therapeutics Inc. 07/22/98 - Page 7 of 17

<PAGE>   8

           third party's intention to file an involuntary petition in
           bankruptcy, LICENSEE shall immediately notify PHS in writing.
           Furthermore, PHS shall have the right to terminate this AGREEMENT by
           giving LICENSEE written notice. Termination of this AGREEMENT is
           effective upon LICENSEE's receipt of the written notice.

    11.05  LICENSEE shall have a unilateral right to terminate this AGREEMENT
           and/or its rights in any country by giving PHS sixty (60) days'
           written notice to that effect.

    11.06  PHS shall specifically have the right to terminate or modify, at its
           option, this AGREEMENT, if PHS determines that the LICENSEE: 1) is
           not executing the COMMERCIAL DEVELOPMENT PLAN submitted with its
           request for a license and the LICENSEE cannot otherwise demonstrate
           to PHS's satisfaction that the LICENSEE has taken, or can be expected
           to take within a reasonable time, effective steps to achieve
           practical application of the LICENSED PRODUCTS or LICENSED PROCESSES;
           2) has willfully made a false statement of, or willfully omitted, a
           material fact in the license application or in any report required by
           the license agreement; 3) has committed a substantial breach of a
           covenant or agreement contained in the license; 4) is not keeping
           LICENSED PRODUCTS or LICENSED PROCESSES reasonably available to the
           public after commercial use commences; 5) cannot reasonably satisfy
           unmet health and safety needs; or 6) cannot reasonably justify a
           failure to comply with the domestic production requirement of
           Paragraph 4.01 unless waived. In making this determination, PHS will
           take into account the normal course of such commercial development
           programs conducted with sound and reasonable business practices and
           judgment and the annual reports submitted by LICENSEE under Paragraph
           7.02. Prior to invoking this right, PHS shall give written notice to
           LICENSEE providing LICENSEE specific notice of, and a ninety (90) day
           opportunity to respond to, PHS's concerns as to the previous items 1)
           to 6). If LICENSEE fails to alleviate PHS's concerns as to the
           previous items 1) to 6) or fails to initiate corrective action to
           PHS's satisfaction, PHS may terminate this AGREEMENT.

    11.07  PHS reserves the right according to 35 U.S.C. Section 209(f)(4) to
           terminate or modify this AGREEMENT if it is determined that such
           action is necessary to meet requirements for public use specified by
           Federal regulations issued after the date of the license and such
           requirements are not reasonably satisfied by LICENSEE.

    11.08  Within thirty (30) days of receipt of written notice of PHS's
           unilateral decision to terminate this AGREEMENT, LICENSEE may,
           consistent with the provisions of 37 CFR Section 404.11, appeal the
           decision by written submission to the Director of NIH or designee.
           The decision of the NIH Director or designee shall be the final
           agency decision. LICENSEE may thereafter exercise any and all
           administrative or judicial remedies that may be available.

    11.09  Within ninety (90) days of termination of this AGREEMENT under this
           Article 11 or expiration under Paragraph 11.01, a final report shall
           be submitted by LICENSEE. Any royalty payments and unreimbursed
           patent expenses due to PHS become immediately due and payable upon
           termination or expiration of this AGREEMENT, and LICENSEE shall
           return all LICENSED PRODUCTS or other materials included within the
           LICENSED PATENT RIGHTS to PHS or provide PHS with certification of
           their destruction.

    11.10  Paragraphs 6.01, 7.05-7.07, 10.01, 10.03, 10.05, and 11.08 of this
           AGREEMENT shall survive termination of this AGREEMENT.


NIH Office of Technology Transfer
PHS PATENT LICENSE AGREEMENT-NONEXCLUSIVE
L-052-98/0 Final Introgen Therapeutics Inc. 07/22/98 - Page 8 of 17
<PAGE>   9

12. GENERAL PROVISIONS

    12.01  Neither Party may waive or release any of its rights or interests in
           this AGREEMENT except in writing. The failure of the GOVERNMENT to
           assert a right hereunder or to insist upon compliance with any term
           or condition of this AGREEMENT shall not constitute a waiver of that
           right by the GOVERNMENT or excuse a similar subsequent failure to
           perform any such term or condition by LICENSEE.

    12.02  This AGREEMENT constitutes the entire agreement between the Parties
           relating to the subject matter of the LICENSED PATENT RIGHTS, and all
           prior negotiations, representations, agreements, and understandings
           are merged into, extinguished by, and completely expressed by this
           AGREEMENT.

    12.03  The provisions of this AGREEMENT are severable, and in the event that
           any provision of this AGREEMENT shall be determined to be invalid or
           unenforceable under any controlling body of law, such determination
           shall not in any way affect the validity or enforceability of the
           remaining provisions of this AGREEMENT.

    12.04  If either Party desires a modification to this AGREEMENT, the Parties
           shall, upon reasonable notice of the proposed modification by the
           Party desiring the change, confer in good faith to determine the
           desirability of such modification. No modification will be effective
           until a written amendment is signed by the signatories to this
           AGREEMENT or their designees.

    12.05  The construction, validity, performance, and effect of this AGREEMENT
           shall be governed by Federal law as applied by the Federal courts in
           the District of Columbia.

    12.06  All notices required or permitted by this AGREEMENT shall be given by
           prepaid, first class, registered or certified mail properly addressed
           to the other Party at the address designated on the following
           Signature Page, or to such other address as may be designated in
           writing by such other Party, and shall be effective as of the date of
           the postmark of such notice.

    12.07  This AGREEMENT shall not be assigned by LICENSEE except a) with the
           prior written consent of PHS; or b) as part of a sale or transfer of
           substantially the entire business of LICENSEE relating to operations
           which concern this AGREEMENT. LICENSEE shall notify PHS within ten
           (10) days of any assignment of this AGREEMENT by LICENSEE.

    12.08  LICENSEE agrees in its use of any PHS-supplied materials to comply
           with all applicable statutes, regulations, and guidelines, including
           Public Health Service and National Institutes of Health regulations
           and guidelines. LICENSEE agrees not to use the materials for research
           involving human subjects or clinical trials in the United States
           without complying with 21 CFR Part 50 and 45 CFR Part 46. LICENSEE
           agrees not to use the materials for research involving human subjects
           or clinical trials outside of the United States without notifying
           PHS, in writing, of such research or trials and complying with the
           applicable regulations of the appropriate national control
           authorities. Written notification to PHS of research involving human
           subjects or clinical trials outside of the United States shall be
           given no later than sixty (60) days prior to commencement of such
           research or trials.

    12.09  LICENSEE acknowledges that it is subject to and agrees to abide by
           the United States laws and regulations (including the Export
           Administration Act of 1979 and Arms Export Control Act) controlling
           the export of technical data, computer software, laboratory



NIH Office of Technology Transfer
PHS PATENT LICENSE AGREEMENT-NONEXCLUSIVE
L-052-98/0 Final Introgen Therapeutics Inc. 07/22/98 - Page 9 of 17

<PAGE>   10

           prototypes, biological material, and other commodities. The transfer
           of such items may require a license from the cognizant agency of the
           U.S. GOVERNMENT or written assurances by LICENSEE that it shall not
           export such items to certain foreign countries without prior approval
           of such agency. PHS neither represents that a license is or is not
           required or that, if required, it shall be issued.

    12.10  LICENSEE agrees to mark the LICENSED PRODUCTS or their packaging sold
           in the United States with all applicable U.S. patent numbers and
           similarly to indicate "Patent Pending" status. All LICENSED PRODUCTS
           manufactured in, shipped to, or sold in other countries shall be
           marked in such a manner as to preserve PHS patent rights in such
           countries.

    12.11  By entering into this AGREEMENT, PHS does not directly or indirectly
           endorse any product or service provided, or to be provided, by
           LICENSEE whether directly or indirectly related to this AGREEMENT.
           LICENSEE shall not state or imply that this AGREEMENT is an
           endorsement by the GOVERNMENT, PHS any other GOVERNMENT
           organizational unit, or any GOVERNMENT employee. Additionally,
           LICENSEE shall not use the names of PHS, NIH, or CDC or their
           employees in any advertising, promotional, or sales literature
           without the prior written consent of PHS.

    12.12  The Parties agree to attempt to settle amicably any controversy or
           claim arising under this AGREEMENT or a breach of this AGREEMENT,
           except for appeals of modification or termination decisions provided
           for in Article 11. LICENSEE agrees first to appeal any such unsettled
           claims or controversies to the Director of NIH, or designee, whose
           decision shall be considered the final agency decision. Thereafter,
           LICENSEE may exercise any administrative or judicial remedies that
           may be available.

    12.13  Nothing relating to the grant of a license, nor the grant itself,
           shall be construed to confer upon any person any immunity from or
           defenses under the antitrust laws or from a charge of patent misuse,
           and the acquisition and use of rights pursuant to 37 CFR Part 404
           shall not be immunized from the operation of state or Federal law by
           reason of the source of the grant.

                          SIGNATURES BEGIN ON NEXT PAGE


NIH Office of Technology Transfer
PHS PATENT LICENSE AGREEMENT-NONEXCLUSIVE
L-052-98/0 Final Introgen Therapeutics Inc. 07/22/98 - Page 10 of 17

<PAGE>   11

                    PHS PATENT LICENSE AGREEMENT-NONEXCLUSIVE

                                 SIGNATURE PAGE

FOR PHS


by:     /s/ JACK SPIEGEL                                8/17/98
    ------------------------------------            ------------------
Jack Spiegel, Ph.D.                           Date
Director, Division of Technology Development and Transfer
National Institutes of Health

Mailing Address for Notices:

Office of Technology Transfer
National Institutes of Health
6011 Executive Boulevard, Suite 325
Rockville, Maryland 20852

FOR LICENSEE (Upon information and belief, the undersigned expressly certifies
or affirms that the contents of any statements of LICENSEE made or referred to
in this document are truthful and accurate.):


INTROGEN THERAPEUTICS, INC.
----------------------------------------
LICENSEE

by: /s/ MAHENDRA G. SHAH                                7/27/98
   -------------------------------------            ------------------
Signature of Authorized Official              Date

MAHENDRA G. SHAH
----------------------------------------
Printed Name

V.P.
----------------------------------------
Title

Mailing Address for Notices:


301 Congress Avenue
----------------------------------------

Suite - 1850
----------------------------------------

Austin, Texas 78701
----------------------------------------


NIH Office of Technology Transfer
PHS PATENT LICENSE AGREEMENT-NONEXCLUSIVE
L-052-98/0 Final Introgen Therapeutics Inc. 07/22/98 - Page 11 of 17

<PAGE>   12

                     APPENDIX A-PATENT OR PATENT APPLICATION

PATENT OR PATENT APPLICATION:

U.S. Patent Application No. [*] entitled [*]

NIH Office of Technology Transfer
PHS PATENT LICENSE AGREEMENT-NONEXCLUSIVE
L-052-98/0 Final Introgen Therapeutics Inc. 07/22/98 - Page 12 of 17








         [*]    Certain information on this page has been omitted and filed
                separately with the Commission. Confidential treatment has been
                requested with respect to the omitted portions.
<PAGE>   13

                 APPENDIX B-LICENSED FIELDS OF USE AND TERRITORY

LICENSED TERRITORY:

Worldwide

LICENSED FIELDS OF USE:

[*]


NIH Office of Technology Transfer
PHS PATENT LICENSE AGREEMENT-NONEXCLUSIVE
L-052-98/0 Final Introgen Therapeutics Inc. 07/22/98 - Page 13 of 17






         [*]    Certain information on this page has been omitted and filed
                separately with the Commission. Confidential treatment has been
                requested with respect to the omitted portions.
<PAGE>   14

                              APPENDIX C-ROYALTIES

ROYALTIES:

LICENSEE agrees to pay to PHS a noncreditable, nonrefundable license issue
royalty in the amount of [*].

LICENSEE agrees to pay to PHS a nonrefundable minimum annual royalty in the
amount of [*].

LICENSEE agrees to pay PHS earned royalties on NET SALES:

[*] on NET SALES of LICENSED PRODUCTS in LICENSED TERRITORY.

LICENSEE agrees to pay PHS Benchmark Royalties for each LICENSED PRODUCT as
follows:

[*] for a LICENSED PRODUCT: [*]

Initiation of the first [*] Clinical Trials for a LICENSED PRODUCT:
[*]

Initiation of the first [*] Clinical Trials for a LICENSED PRODUCT:
[*]

Initiation of the first [*] Clinical Trials for a LICENSED PRODUCT:
[*]

Approval of the first [*] for a LICENSED PRODUCT:
[*]

The benchmark royalty amounts shall be reduced by [*] with respect to [*] to
meet such milestone. [*] For purposes of the foregoing benchmark payments,
a LICENSED PRODUCT shall be deemed to include all LICENSED PRODUCTS (as
defined in Paragraph 2.02) which incorporate the same gene.

LICENSEE agrees to pay PHS benchmark royalties for EACH SUBLICENSED PRODUCT as
follows:

In the event that LICENSEE grants a SUBLICENSE, which includes intellectual
property other than LICENSED PATENT RIGHTS, LICENSEE shall pay the following
percentage of SUBLICENSING payments based on the phase of development of all
LICENSED PRODUCTS:

[*] of the total SUBLICENSING FEE prior to [*].



NIH Office of Technology Transfer
PHS PATENT LICENSE AGREEMENT-NONEXCLUSIVE
L-052-98/0 Final Introgen Therapeutics Inc. 07/22/98 - Page 14 of 17





         [*]    Certain information on this page has been omitted and filed
                separately with the Commission. Confidential treatment has been
                requested with respect to the omitted portions.
<PAGE>   15
[*] of the total SUBLICENSING FEE in the event the LICENSEE has initiated at
least one [*] study with respect to any LICENSED PRODUCT subject to the
SUBLICENSE arrangement.

[*] of the total SUBLICENSING FEE in the event the LICENSEE has initiated at
least one [*] study with respect to any LICENSED PRODUCT subject to the
SUBLICENSE arrangement.

[*] of the total SUBLICENSING FEE in the event the LICENSEE has initiated at
least one [*] study with respect to any LICENSED PRODUCT subject to the
SUBLICENSE arrangement.

For purposes of the foregoing payments, "SUBLICENSING FEE" shall mean all
up-front cash payments received by LICENSEE from a SUBLICENSEE for rights to the
LICENSED PATENTS, but excluding (i) amounts received in reimbursement for
research or development related to the LICENSED PATENTS, (ii) amounts received
as payment for marketing services, equity, or goods or products, and (iii)
amounts received in consideration for the sale of all or substantially all of
the business or assets of LICENSEE relating to this Agreement.



NIH Office of Technology Transfer
PHS PATENT LICENSE AGREEMENT-NONEXCLUSIVE
L-052-98/0 Final Introgen Therapeutics Inc. 07/22/98 - Page 15 of 17






         [*]    Certain information on this page has been omitted and filed
                separately with the Commission. Confidential treatment has been
                requested with respect to the omitted portions.
<PAGE>   16

                            APPENDIX D-MODIFICATIONS

PHS and LICENSEE agree to the following modifications to the Articles and
Paragraphs of this AGREEMENT:

2.05 "NET SALES" means the total gross receipts for sales of LICENSED PRODUCTS
or practice of LICENSED PROCESSES by or on behalf of LICENSEE or its
Sublicensees and from leasing, renting, or otherwise making LICENSED PRODUCTS
available to others without sale or other dispositions, whether invoiced or not,
less returns and allowances actually granted, packing costs, insurance costs,
freight out, taxes or excise duties imposed on the transaction (if separately
invoiced), and wholesaler and cash discounts in amounts customary in the trade.
No deductions shall be made for commissions paid to individuals, whether they be
with independent sales agencies or regularly employed by LICENSEE or its
Sublicensees and on its payroll, or for the cost of collections.

2.09 "Sublicensee" means any non-affiliate third party to whom LICENSEE has
granted the right to make and sell a LICENSED PRODUCT and/or practice a LICENSED
PROCESS, with respect to the LICENSED PRODUCTS made and sold or the LICENSED
PROCESSES practiced by such third party.

3.02 Upon written approval by PHS, which approval will not be unreasonably
withheld or delayed, Licensee has the right to grant sublicenses to the LICENSED
PATENT Rights to third parties. LICENSEE shall forward a copy of the executed
sublicense agreement within (60) days of its execution.

3.04 LICENSEE agrees that any sublicenses granted by it hereunder shall provide
that the obligations to PHS of Paragraphs 4.01, 6.01, 7.01, 7.03, 8.01, 8.02,
9.01, 9.02, 9.03, 10.05, and 11.06-11.08 of this Agreement shall be binding upon
the Sublicensee as if it were a party to this Agreement. LICENSEE further agrees
to attach copies of these Paragraphs to all such sublicense agreements.

3.05 Any sublicenses granted by LICENSEE shall provide for the termination of
the sublicense or the conversion to a license directly between such Sublicensees
and PHS on the applicable terms and conditions herein, at the option of the
Sublicensee, upon termination of this Agreement under Article 11. Such
conversion is subject and contingent upon acceptance by the Sublicensee of the
applicable provisions of this Agreement.

5.08 As an additional royalty, LICENSEE agrees to pay PHS within (60) days of
PHS's submission of a statement and request for payment, an amount equivalent to
all patent expenses previously incurred by PHS in the preparation, filing,
prosecution, and maintenance of LICENSED PATENT RIGHTS, to be divided equally
among all nonexclusive commercialization LICENSEES of record as of the date the
statement and request for payment is sent by PHS to LICENSEE. LICENSEE further
agrees to pay PHS annually, within sixty (60) days of PHS's submission of a
statement and request for payment, a royalty amount equivalent to all such
future patent expenses incurred during the previous calendar year divided
equally among all nonexclusive commercialization LICENSEES of record as of the
date the statement and request for payment are sent by PHS to LICENSEE. [*] of
the cumulative amount of the payments due under this Paragraph 5.08 may be
credited against royalties due under Paragraph 5.03; however, the net royalty
payment in any calendar year may not be lower than the minimum annual royalty
specified in Appendix C. LICENSEE may elect to surrender its rights in any
country of the LICENSED TERRITORY under any LICENSED PATENT RIGHTS upon sixty
(60) days' written notice to PHS and owe [*] under this Paragraph for subsequent
patent-related expenses incurred in that country.

5.09 LICENSEE agrees to pay PHS the sublicensing royalties as set forth in
Appendix C.



NIH Office of Technology Transfer
PHS PATENT LICENSE AGREEMENT-NONEXCLUSIVE
L-052-98/0 Final Introgen Therapeutics Inc. 07/22/98 - Page 16 of 17





         [*]    Certain information on this page has been omitted and filed
                separately with the Commission. Confidential treatment has been
                requested with respect to the omitted portions.
<PAGE>   17


10.05 LICENSEE shall indemnify and hold PHS, its employees, students, fellows,
agents, and consultants harmless from and against all liability, demands,
damages, expenses, and losses, including but not limited to death, personal
injury, illness, or property damage in connection with or arising out of a) the
use by or on behalf of LICENSEE its Sublicensees and their officers, directors,
employees, or third parties acting on their behalf of any LICENSED PATENT
RIGHTS, or b) the design, manufacture, distribution, or use of any LICENSED
PRODUCTS, LICENSED PROCESSES, or other products or processes developed in
connection with or arising out of the LICENSED PATENT RIGHTS hereunder; provided
that any party seeking indemnification under this Paragraph 10.5 shall: (i)
promptly notify LICENSEE in writing of any claim, suit or other proceeding with
respect to which the party intends to claim such indemnification: (ii) provide
LICENSEE the opportunity as is afforded by applicable laws, rules or regulations
to jointly control the defense and/or settlement of such claim suit or
proceeding: (iii) provide LICENSEE, at LICENSEE's request and expense, with
reasonable assistance and full information with respect to such claim, suit or
proceeding. LICENSEE agrees to maintain a liability insurance program consistent
with sound business practice.

11.03 [Delete]

11.04 PHS may terminate this Agreement on written notice to LICENSEE, if the
LICENSEE becomes the subject of a voluntary: Petition in bankruptcy, or any
proceeding relating to insolvency, receivership, liquidation, or composition for
the benefit of creditors, if that petition or proceeding is not dismissed with
prejudice within sixty (60) days after filing. Without limiting the foregoing,
LICENSEE shall promptly notify PHS upon the filing of any of the foregoing
petitions or proceedings.

12.07 This Agreement shall not be assigned by LICENSEE except a) with the prior
written consent of PHS, or b) as part of a sale or transfer of substantially the
entire business of LICENSEE relating to operations which concern this Agreement
or to a party that is an affiliate or subsidiary of LICENSEE at the time of the
assignment. LICENSEE shall notify PHS within ten (10) days of any assignment of
this Agreement by LICENSEE.


NIH Office of Technology Transfer
PHS PATENT LICENSE AGREEMENT-NONEXCLUSIVE
L-052-98/0 Final Introgen Therapeutics Inc. 07/22/98 - Page 17 of 17