<PAGE>   1
*** CONFIDENTIAL TREATMENT REQUESTED. CONFIDENTIAL PORTIONS OF THIS DOCUMENT
HAVE BEEN REDACTED AND HAVE BEEN FILED SEPARATELY WITH THE SECURITIES AND
EXCHANGE COMMISSION.



                                                                    EXHIBIT 10.7


                                LICENSE AGREEMENT

                                 by and between

                        THE SCRIPPS RESEARCH INSTITUTE,
                             a California nonprofit
                           public benefit corporation

                                       and

                                   IXSYS, INC.
                             a Delaware corporation

<PAGE>   2

                                LICENSE AGREEMENT


        This License Agreement is entered into and made effective as of this
20th day of May, 1994, by and between THE SCRIPPS RESEARCH INSTITUTE, a
California nonprofit public benefit corporation ("Scripps") located at 10666
North Torrey Pines Road, La Jolla, California 92037, and IXSYS, INC., a Delaware
corporation ("Licensee") located at 3550 Dunhill Street, San Diego, California
92121, with respect to the facts set forth below.


                                    RECITALS

        A. Scripps is engaged in fundamental scientific biomedical and
biochemical research including research relating to cell adhesion, angiogenesis
and tumor biology.

        B. Licensee is engaged in research, development and commercialization of
certain products for the diagnosis, prevention and treatment of certain
diseases, states and conditions.

        C. Scripps has disclosed to Licensee certain technology relating to the
murine monoclonal antibody *** and the use of antibodies as inhibitors of
angiogenesis (collectively, the "Technology").

        D. Licensee desires to develop derivatives of the monoclonal antibody
*** and possibly other antibodies, as inhibitors of angiogenesis.

        E. Scripps has the exclusive right to grant a license to the Technology
subject to certain rights of the U.S. Government to use such technology for its
own purposes, resulting from the receipt by Scripps of certain funding from the
U. S. Government.

        F. Scripps desires to grant to Licensee, and Licensee wishes to acquire,
an exclusive worldwide right and license under Scripps' rights in the Technology
subject to the terms and conditions set forth herein.


                                    AGREEMENT

        NOW, THEREFORE, in consideration of the mutual covenants and conditions
set forth herein, Scripps and Licensee hereby agree as follows:

        1. Definitions. Capitalized terms shall have the meaning set forth
below.



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                1.1 Affiliate. The term "Affiliate" shall mean any entity which
directly or indirectly controls, is controlled by or is under common control
with Licensee. The term "control" as used herein means the possession of the
power to direct or cause the direction of the management and the policies of an
entity, whether through the ownership of not less than forty percent (40%) of
the outstanding voting securities or by contract or otherwise.

                1.2 Confidential Information. The term "Confidential
Information" shall mean any and all proprietary or confidential information of
Scripps or Licensee which may be exchanged between the parties at any time and
from time to time during the term of this Agreement. Information shall not be
considered confidential to the extent that it:

                a. Is publicly disclosed through no fault of any party hereto,
either before or after it becomes known to the receiving party; or

                b. Was known to the receiving party prior to the date of this
Agreement, which knowledge was acquired independently and not from another party
hereto (or such party's employees); or

                c. Is subsequently disclosed without any obligation of
confidentiality to the receiving party in good faith by a third party who has a
right to make such disclosure; or

                d. Has been published by a third party as a matter of right.

                1.3 Field. The term "Field" shall mean the diagnosis, prevention
and treatment of any disease, states or conditions in humans, by use of any
antibody or antibody fragment, but excluding the use of (a) ***, and (b) any
other non-immunoglobulin molecules except molecules conjugated to any antibody
or antibody fragment, if the molecules conjugated thereto are not themselves
inhibitors of alphaV-beta3 integrins.

                1.4 Hybridoma ***. The term "Hybridoma ***" shall mean the
cell line *** deposited with the American Type Culture Collection.

                1.5 Licensed Product. The term "Licensed Product" shall mean any
product which (a) if made, used or sold absent the license granted hereby would
infringe the valid claim of one or more valid issued patent(s) included within
the Scripps Patent Rights, or (b) cannot be developed, manufactured, used or
sold without utilizing any part of the Scripps Technology.

                1.6 ***. The term "***" shall mean the *** integrin
murine antibody produced by Hybridoma *** and fragments of said murine
antibody.



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                1.7 *** Gene. The term "*** Gene" shall mean a nucleic acid
encoding all or a portion of ***.

                1.8 *** Sequence Information. The term "*** Sequence
Information" shall mean the nucleotide sequence embodied in an *** Gene
isolated from Hybridoma *** and the amino acid residue sequence information
embodied in ***.

                1.9 Major Country. The term "Major Country" shall mean France,
Germany, Italy, Japan, the United Kingdom and the United States.

                1.10 Net Sales. The term "Net Sales" shall mean, with respect to
any Licensed Product, the invoiced sales price of such Licensed Product sold by
Licensee, its Affiliates and sublicensees to independent customers who are not
Affiliates, less (a) credits, allowances, discounts and rebates to, and
chargebacks from the account of, such independent customers for spoiled,
damaged, out-dated, rejected or returned Licensed Product; (b) actual freight
and insurance costs incurred in transporting such Licensed Product in final form
to such customers; (c) cash, quantity and trade discounts; (d) sales, use,
value-added and taxes or governmental charges (excluding what is commonly known
of as income taxes) incurred in connection with the exportation or importation
of such Licensed Product in final form; and (e) the cost to Licensee of the
devices for dispensing or administering such Licensed Product as well as
diluents or similar materials which accompany such Licensed Product as it is
sold. For purposes of determining Net Sales, a sale shall be deemed to have
occurred when an invoice therefor shall be generated or the Licensed Product
shipped for delivery. Sales of Licensed Products by Licensee, or an Affiliate or
sublicensee of Licensee to any Affiliate or sublicensee which is a reseller
thereof shall be excluded, and only the subsequent sale of such Licensed
Products by Affiliates or sublicensees of Licensee to unrelated parties shall be
deemed Net Sales hereunder.

                1. 11 Scripps Angiogenesis Technology. The term "Scripps
Angiogenesis Technology" shall mean so much of the technology as is proprietary
to Scripps disclosed in United States Patent Application Serial No. 08/210,715,
entitled "Methods and Compositions Useful for Inhibition of Angiogenesis" filed
March 14, 1994, a copy of which is attached hereto and incorporated herein by
reference.

                1.12 Scripps LM609 Technology. The terms "Scripps ***
Technology" shall mean, collectively, Hybridoma ***, ***, *** Gene and
*** Sequence information.

                1.13 Scripps Patent Rights. The term "Scripps Patent Rights"
shall mean (a) U.S. Patent Application Serial No. 08/210,715, entitled "Methods
and Compositions Useful for Inhibition of Angiogenesis" filed March 14, 1994,
together with all foreign counterparts thereof; (b) the patents proceeding from



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<PAGE>   5

such applications, and (c) all divisionals, continuations, continuation-in-part,
reissues, renewals, reexaminations, and extensions thereof, so long as said
patents have not been held invalid and/or unenforceable by a court of competent
jurisdiction from which there is no appeal or, if appealable, from which no
appeal has been taken. The foregoing notwithstanding, Scripps Patent Rights
shall not include any claim that covers subject matter not disclosed in said
United States Patent Application Serial No. 08/210,715.

                1.14 Scripps Technology. The term "Scripps Technology" shall
mean the Scripps *** Technology and the Scripps Angiogenesis Technology,
whether or not the same is eligible for protection under the patent laws of the
United States or elsewhere, and whether or not any such technology would be
enforceable as a trade secret or the copying of which would be enjoined or
restrained by a court as constituting unfair competition.

        2. License Terms and Conditions.

                2.1 Grant of License. Scripps hereby grants to Licensee an
exclusive, worldwide license, including the right to sublicense, under the
Scripps Patent Rights and the Scripps Technology to make, to have made, to use,
and to sell Licensed Products in the Field, subject to the terms of this
Agreement. Promptly upon execution of this Agreement, Scripps shall provide
Licensee with all information available to Scripps regarding the Scripps Patent
Rights and the Scripps Technology.

                2.2 Initial License Fee. In partial consideration for the
exclusive license granted pursuant to Section 2.1 hereof, Licensee shall pay to
Scripps a nonrefundable license fee upon execution of this Agreement in the
amount of *** Dollars (***), and *** shares of Ixsys common stock with rights
and restrictions substantially equivalent to other current common stock
shareholders. The license fee described in this Section is consideration for the
grant and continuation of the license hereunder, and Scripps shall have no
obligation to return any portion of such license fee, notwithstanding any
failure by Licensee to develop any Licensed Product or market any Licensed
Product commercially, and notwithstanding the volume of sales of any such
Licensed Product.

                2.3 Milestone Payments. As additional consideration for the
license granted to Licensee under this Agreement, Licensee shall pay Scripps the
following milestone payments upon the first occurrence of each event set forth
below, which shall be creditable against future royalties owing to Scripps under
Section 2.4 below; provided, however, that Licensee shall not be obligated to
pay any milestone payment for more than one Licensed Product.



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                        2.3.1 *** upon commencement of Phase 1 clinical trials
for a Licensed Product in the United States (or their equivalent in any other
Major Country); and

                        2.3.2 *** upon completion of Phase 3 clinical trials
for a Licensed Product in the United States (or their equivalent in any other
Major Country); and

                        2.3.3 *** upon receipt of the required marketing
approval, and pricing approval (if any), from the FDA (or from the governing
health authority of any other Major Country) for a Licensed Product.

                2.4 Royalties. As additional consideration for the exclusive
license granted pursuant to Section 2.1 hereof, Licensee shall pay to Scripps a
continuing royalty on a country-by-country basis in the amount of (a) ***
percent *** of Net Sales of Licensed Products which if sold in such country
would infringe the valid claim of one or more valid issued patent(s) included
within the Scripps Patent Rights, and (b) *** percent *** of Net Sales of
Licensed Products in all other countries.

                2.5 Term of License. Unless terminated sooner in accordance
with the provisions of this Agreement, the term of this license shall expire
when the last of the royalty obligations set forth in Section 2.8 has expired.

                2.6 Quarterly Payments. Royalties shall be payable by Licensee
quarterly, within ninety (90) days after the end of each calendar quarter, based
upon the Net Sales of Licensed Products during such preceding calendar quarter,
commencing with the calendar quarter in which the first commercial sale of any
Licensed product is made.

                2.7 Sublicense. Licensee shall have the sole and exclusive right
to grant sublicenses to any party with respect to the rights conferred upon
Licensee under this Agreement, provided, however, that any such sublicense shall
be subject in all respects to the restrictions, exceptions, royalty obligations,
milestone payments, reports, termination provisions, and other provisions
contained in this Agreement (but not including the payment of a license fee
pursuant to Section 2.2 hereof). Licensee shall pay Scripps, or cause its
Affiliate or sublicensee to pay Scripps, the same royalties on all Net Sales of
such Affiliate or sublicensee the same as if said Net Sales had been made by
Licensee. Each Affiliate and sublicensee shall report its Net Sales to Scripps
through Licensee, which Net Sales shall be aggregated with any Net Sales of
Licensee for purposes of determining the Net Sales upon which royalties are to
be paid to Scripps.



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                2.8 Duration of Royalty Obligations. The royalty obligations of
Licensee as to each Licensed Product shall terminate concurrently with the
expiration of the last to expire of Scripps Patent Rights utilized by or in such
Licensed Product in each such country or, with respect to Licensed Products not
utilizing any Scripps Patent Rights, ten (10) years after the date of first
commercial sale of such Licensed Product in such country.

                2.9 Reports. Licensee shall furnish to Scripps at the same time
as each royalty payment is made by Licensee, a detailed written report of Net
Sales of the Licensed Products and the royalty due and payable thereon,
including a description of any offsets or credits deducted therefrom, on a
product-by-product and country-by-country basis, for the calendar quarter upon
which the royalty payment is based.

                2.10 Records. Licensee shall keep, and cause its Affiliates and
sublicensees to keep, full, complete and proper records and accounts of all
sales of Licensed Products in sufficient detail to enable the royalties payable
on Net Sales of each Licensed Product to be determined. Scripps shall have the
right to appoint an independent certified public accounting firm of
nationally-recognized standing approved by Licensee, which approval shall not be
unreasonably withheld, to audit the records of Licensee and its Affiliates as
necessary to verify the royalties payable pursuant to this Agreement. Such audit
shall be at Scripps's expense; provided, however, that if the audit discloses
that Scripps was underpaid royalties with respect to any Licensed Product by at
least eight percent (8%) for any calendar quarter, then Licensee shall reimburse
Scripps for any such audit costs. Scripps may exercise its right of audit no
more frequently than once in any calendar year. The accounting firm shall
disclose to Scripps only information relating to the accuracy of the royalty
payments. No other information shall be shared. Licensee and its Affiliates
shall preserve and maintain all such records required for audit for a period of
three (3) years after the calendar quarter to which the record applies.

                2.11 Foreign Sales. The remittance of royalties payable on sales
outside the United States shall be payable to Scripps in United States Dollar
equivalents calculated using the average buying rate for such currency quoted in
the continental terms method of quoting exchange rates (local currency per US$1)
as published in the United States in The Wall Street Journal under the caption
"Currency Trading" on each of the last business day of each month in the quarter
for which the royalties are payable. If the transfer of or the conversion into
the United States Dollar equivalents of any such remittance in any such instance
is not lawful or possible, the payment of such part of the royalties as is
necessary shall be made by the deposit thereof, in the currency of the country
where the sale was made on which the royalty was based to the credit and account
of Scripps or its nominee in any commercial bank or trust company of Scripps's
choice located in


                                      -7-
<PAGE>   8

that country, prompt written notice of which shall be given by Licensee to
Scripps.

                2.12 Foreign Taxes. Any tax required to be withheld by Licensee
under the laws of any foreign country for the accounts of Scripps shall be
promptly paid by Licensee for and on behalf of Scripps to the appropriate
governmental authority, and Licensee shall use its best efforts to furnish
Scripps with proof of payment of such tax together with official or other
appropriate evidence issued by the applicable government authority. Any such tax
actually paid on Scripps's behalf shall be deducted from royalty payments due
Scripps.

        3. Obligations Related to Commercialization.

                3.1 Commercial Development obligation. In order to maintain the
license granted hereunder in force, Licensee shall use reasonable efforts and
due diligence to develop the Scripps Patent Rights and the Scripps Technology
which are licensed hereunder into commercially viable Licensed Products, as
promptly as is reasonably and commercially feasible, and thereafter to produce
and sell reasonable quantities of Licensed Products. Licensee shall keep Scripps
generally informed as to Licensee's progress in such development, production and
sale, including its efforts, if any, to sublicense the Scripps Patent Rights and
the Scripps Technology and Licensee shall deliver to Scripps a semiannual
written report. In the event Scripps has a reasonable basis to believe that
Licensee is not using reasonable efforts and due diligence as required
hereunder, upon notice by Scripps to Licensee which specifies the basis for such
belief, Scripps and Licensee shall negotiate in good faith to attempt to
mutually resolve the issue. In the event Scripps and Licensee cannot agree upon
any matter related to Licensee's commercial development obligations, the parties
agree to utilize arbitration pursuant to Section 9.2 hereof in order to resolve
the matter. If the arbitrator determines that Licensee has not complied with its
obligations hereunder, and such default is not fully cured within sixty (60)
days after the arbitrator's decision, Scripps may terminate Licensee's rights
under this Agreement.

                3.2 Governmental Approvals and Marketing of Licensed Products.
Licensee shall be responsible for obtaining all necessary governmental approvals
for the development, production, distribution, sale and use of any Licensed
Product, at Licensee's expense, including, without limitation, any safety
studies. Licensee shall have sole responsibility for any warning labels,
packaging and instructions as to the use of Licensed Products and for the
quality control for any Licensed Product.

                3.3 Indemnity. Licensee hereby agrees to indemnify, defend and
hold harmless Scripps and any parent, subsidiary or other affiliated entity and
their trustees, officers, employees, scientists and agents from and against any
liability or expense arising from any product liability claim asserted by any
third


                                      -8-
<PAGE>   9

party as to any Licensed Product or any third party claims arising from the use
of the Scripps Patent Rights and the Scripps Technology by Licensee, its
Affiliates or sublicensees pursuant to this Agreement. Such indemnity and
defense obligation shall apply to any product liability or other claims,
including without limitation, personal injury, death or property damage, made by
employees, subcontractors, sublicensees, or agents of Licensee, as well as any
member of the general public. Scripps promptly shall notify Licensee of any
claim for which Scripps intends to claim such indemnification, and Licensee
shall have the right to participate in, or to assume, the defense and settlement
thereof, with counsel selected by Licensee. The indemnity agreement in this
Section 3.3 shall not apply to amounts paid in settlement of any loss,
liability, claim or action if such settlement is effected without the consent of
Licensee, which consent shall not be withheld unreasonably. Scripps, its
employees and agents shall cooperate fully with Licensee and its legal
representatives in the investigation and defense of any action, claim or
liability covered by this indemnification. Licensee shall use its reasonable
best efforts to have Scripps and any parent, subsidiary or other affiliated
entity and their trustees, officers, employees, scientists and agents named as
additional insured parties on any product liability insurance policies
maintained by Licensee, its Affiliates and sublicensees applicable to Licensed
Products, to the extent available to Licensee on commercially reasonable terms
and conditions.

                3.4 Patent Marking. To the extent required by applicable law,
Licensee shall mark all Licensed Products or their containers in accordance with
the applicable patent marking laws.

                3.5 No Use of Name. The use of the name "The Scripps Research
Institute", "Scripps", or any variation thereof in connection with the
advertising or sale of Licensed Products, except as required by applicable law,
regulation or judicial order, is expressly prohibited.

                3.6 U.S. Manufacture. To the extent required by applicable
United States laws, if at all, Licensee agrees that Licensed Products will be
manufactured in the United States, or its territories, subject to such waivers
as may be required, or obtained, if at all, from the United States Department of
Health and Human Services, or its designee.

                3.7 Foreign Registration. Licensee agrees to register this
Agreement with any foreign governmental agency which requires such registration,
and Licensee shall pay all costs and legal fees in connection therewith. In
addition, Licensee shall assure that all foreign laws affecting this Agreement
or the sale of Licensed Products are satisfied in all material respects.

        4. Limited Warranty. Scripps hereby represents and warrants that it has
full right and power to enter into this Agreement, it is the sole owner of the
Scripps Patent Rights and


                                      -9-
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the Scripps Technology, and it has not granted any license or other right
therein or thereto in favor of any third party, except (a) a license granted in
favor of E. Merck, a German general partnership, for use outside the Field, and
(b) those rights required by law to be granted in favor of the United States
Government. SCRIPPS MAKES NO OTHER WARRANTIES CONCERNING THE SCRIPPS PATENT
RIGHTS AND THE SCRIPPS TECHNOLOGY COVERED BY THIS AGREEMENT, INCLUDING WITHOUT
LIMITATION, ANY EXPRESS OR IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A
PARTICULAR PURPOSE AS TO THE SCRIPPS PATENT RIGHTS AND THE SCRIPPS TECHNOLOGY
OR ANY LICENSED PRODUCT. SCRIPPS MAKES NO WARRANTY OR REPRESENTATION THAT ANY
LICENSED PRODUCT WILL BE FREE FROM AN INFRINGEMENT ON PATENTS OR OTHER
INTELLECTUAL PROPERTY RIGHTS OF THIRD PARTIES, OR THAT NO THIRD PARTIES ARE IN
ANY WAY INFRINGING THE SCRIPPS PATENT RIGHTS AND THE SCRIPPS TECHNOLOGY. SCRIPPS
MAKES NO WARRANTY OR REPRESENTATION AS TO THE VALIDITY OR SCOPE OF SCRIPPS
PATENT RIGHTS.

        5. Interests in Intellectual Property Rights.

                5.1 Preservation of Title. Scripps shall retain full ownership
and title to the Scripps Patent Rights and the Scripps Technology and shall use
its reasonable best efforts to preserve and maintain such full ownership and
title, subject to Licensee fully performing all of its obligations under this
Agreement.

                5.2 Governmental Interest. Licensee and Scripps acknowledge that
Scripps has received, and expects to continue to receive, funding from the
United States Government in support of Scripps's research activities. Licensee
and Scripps acknowledge and agree that their respective rights and obligations
pursuant to this Agreement shall be subject to Scripps's obligations and the
rights of the United States Government, if any, which arise or result from
Scripps's receipt of research support from the United States Government,
including without limitation, the grant by Scripps to the United States of a
non-exclusive, irrevocable, royalty-free license to the Scripps Patent Rights
and the Scripps Technology licensed hereunder for governmental purposes.

                5.3 Reservation of Rights. Scripps reserves the right to use for
any non-commercial research purposes and the right to allow other nonprofit
institutions to use for any non-commercial research purposes any Scripps
Technology and Scripps Patent Rights licensed hereunder, without Scripps or such
other institutions being obligated to pay Licensee any royalties or other
compensation, provided that each such other institution shall be bound by
Scripps then existing standard Materials Transfer Agreement and/or
Confidentiality Agreement.

                5.4 Patent Prosecution and Maintenance. Scripps shall be
responsible for and shall control the preparation, filing, prosecution
(including, but not limited to, interference, opposition, reissue and reexam
proceedings) and maintenance of all patents and patent applications (the "Patent
Matters") included


                                      -10-
<PAGE>   11

within the Scripps Patent Rights. Licensee acknowledges and agrees that the
license granted hereunder is in part consideration for Licensee's assumption of
the past and future costs and expenses associated with the Patent Matters as
described herein. Licensee shall reimburse Scripps (a) fifty percent (50%) of
its reasonable past and future costs and expenses incurred in performance of
Patent Matters related to patents and patent applications (i) that are within
Scripps Patent Rights, and (ii) under which E. Merck holds a license for use
outside the Field, and (b) one hundred (100%) of, its past and future reasonable
costs and expenses incurred in performance of Patent Matters related to patents
and patent application that are within Scripps Patent Rights but which are not
licensed to a third party for use outside the Field. Such reimbursement shall be
due and payable within sixty (60) days after Licensee receives a reasonably
detailed statement describing the costs and expenses. In the event Licensee
elects to discontinue payment for the filing, prosecution and/or maintenance of
any patent application and/or patent within Scripps Patent Rights, any such
patent application or patent shall be excluded from the definition of Scripps
Patent Rights and from the scope of the license granted under this Agreement,
and all rights relating thereto shall revert to Scripps and may be freely
licensed by Scripps. Licensee shall give Scripps at least sixty (60) days prior
written notice of such election. No such notice shall have any effect on
Licensee's obligations to pay expenses incurred up to the effective date of such
election. Scripps shall give Licensee an opportunity to review and comment on
the text of each patent application subject to this Section 5.4 before filing,
and shall consider all reasonable requests of Licensee made in good faith
regarding the claims thereof and the foreign countries in which to file and
prosecute patent applications and maintain patents. Scripps shall supply
Licensee with a copy of each such patent application as filed, together with
notice of its filing date and serial number, and with copies of all other
filings, submissions or correspondence to or with the applicable governmental
authorities. In the event that Scripps intends to abandon any patent application
without filing a continuation of same within Scripps Patent Rights, Scripps
shall provide IXSYS with the opportunity to prosecute such patent on Scripps'
behalf.

                5.5 Notification of infringement. Each party shall notify the
other party of any infringement known to such party of the Scripps Patent Rights
and shall provide the other party with the available evidence, if any, of such
infringement.

                5.6 Enforcement of Patent Rights. With respect to any
infringement in the Field, Licensee, at its sole expense, shall have the right
to determine the appropriate course of action to enforce the Scripps Patent
Rights or otherwise abate the infringement thereof, to take (or refrain from
taking) appropriate action to enforce the Scripps Patent Rights, to control any
litigation or other enforcement action and to enter into, or permit, the
settlement of any such litigation or other enforcement action with respect to
the Scripps Patent Rights, and shall


                                      -11-
<PAGE>   12

consider, in good faith, the interests of Scripps in so doing. If Licensee does
not, within one hundred twenty (120) days of receipt of notice from Scripps,
abate the infringement or file suit to enforce the Scripps Patent Rights against
at least one infringing party in the Field, Scripps shall have the right to take
whatever action it deems appropriate to enforce the Scripps Patent Rights in the
Field; provided, however, that, within thirty (30) days after receipt of notice
of Scripps' intent to file such suit, Licensee shall have the right to jointly
prosecute such suit and to fund up to one-half (1/2) the costs of such suit. The
party controlling any such enforcement action shall not settle the action or
otherwise consent to an adverse judgment in such action that diminishes the
rights or interests of the non-controlling party without the prior written
consent of the other party. All monies recovered upon the final judgment or
settlement of any such suit to enforce the Scripps Patent Rights in the Field
shall be shared, after reimbursement of expenses, by Scripps and Licensee with
Scripps receiving the higher of a pro rata share based on the respective
percentages of costs borne by each in such suit or four percent (4%) of said
recovered monies. Notwithstanding the foregoing, Scripps and Licensee shall
fully cooperate with each other in the planning and execution of any action to
enforce the Scripps Patent Rights.

                5.7 Ownership, The patent applications filed and the patents
obtained by Scripps pursuant to Section 5.4 hereof shall be owned solely by
Scripps, assigned to Scripps and deemed a part of Scripps Patent Rights.

                5.8 Scripps Right to Pursue Patent. If at any time during the
term of this Agreement, Licensee's rights with respect to Scripps Patent Rights
are terminated, Scripps shall have the right to take whatever action Scripps
deems appropriate to obtain or maintain the corresponding patent protection as
its own expense.

        6. Confidentiality and Publication.

                6.1 Treatment of Confidential information. The parties agree
that during the term of this Agreement, and for a period of five (5) years after
this Agreement terminates, a party receiving Confidential Information of the
other party will (i) maintain in confidence such Confidential Information, (ii)
not disclose such Confidential Information to any third party without prior
written consent of the other party and (iii) not use such Confidential
Information for any purpose except those permitted by this Agreement.

                The confidentiality obligations contained in this Section 6.1
shall not apply to the extent that the receiving party (the "Recipient") is
required (i) to disclose Confidential Information by law, order or regulation of
a governmental agency or a court of competent jurisdiction, or (ii) to disclose
Confidential Information to any governmental agency for purposes


                                      -12-
<PAGE>   13

of obtaining approval to test or market a product, provided in either case that
the Recipient shall provide written notice thereof to the other party and
sufficient opportunity to object to any such disclosure or to request
confidential treatment thereof. Notwithstanding any other provision of this
Agreement, Licensee may disclose Confidential Information of Scripps to any
person or entity with whom Licensee has, or is proposing to enter into, a
business relationship, as long as such person or entity has entered into a
confidentiality agreement with Licensee.

                Scripps shall treat all financial and other reports provided by
Licensee and all financial information subject to review under this Agreement as
confidential, and shall cause its accounting firm to retain all such financial
information in confidence.

                6.2 Publications. Nothing in this Agreement shall prohibit a
party from publishing its own Confidential Information.


                6.3 Publicity. Except as otherwise provided herein or required
by law, no party shall originate any publication, news release or other public
announcement, written or oral, whether in the public press, stockholders'
reports, or otherwise, regarding the terms of this Agreement, without the prior
written approval of the other party, which approval shall not be unreasonably
withheld.

        7. Term and Termination.

                7.1 Term. Unless terminated sooner in accordance with the terms
set forth herein, this Agreement, and the license granted hereunder, shall
expire on the expiration of Licensee's obligations to pay royalties to Scripps
as provided in Section 2.8 hereof. Nothwithstanding the foregoing, if applicable
government regulations require a shorter term and/or a shorter term of
exclusivity than provided for herein, then the term of this License Agreement
shall be so shortened or this License Agreement shall be amended to provide for
a non-exclusive license, and, in such event, the parties shall negotiate in good
faith to reduce approximately the royalties payable as set forth under the
section heading "Royalties" hereof.

                7.2 Termination Upon Default. Any one or more of the following
events shall constitute an event of default hereunder: (i) the failure of a
party to pay any amounts when due hereunder and the expiration of thirty (30)
days after receipt of a written notice requesting the payment of such amount;
and (ii) the failure of a party to perform any obligation required of its to be
performed hereunder, and the failure to cure within ninety (90) days after
receipt of notice from the other party specifying in reasonable detail the
nature of such default. Upon the occurrence of any event of default, the
non-defaulting party may deliver to the defaulting party written notice of
intent to terminate, such


                                      -13-
<PAGE>   14

termination to be effective upon the date set forth in such notice.

                Such termination rights shall be in addition to and not in
substitution for any other remedies that may be available to the non-defaulting
party. Termination pursuant to this Section 7.2 shall not relieve the defaulting
party from liability and damages to the other party for breach of this
Agreement. Waiver by either party of a single default or a succession of
defaults shall not deprive such party of any right to terminate this Agreement
arising by reason of any subsequent default.

                7.3 Termination Upon Bankruptcy or Insolvency. This Agreement
may be terminated by Scripps giving written notice of termination to Licensee
upon (a) the voluntary filing of bankruptcy of Licensee or appointment of a
receiver of all or substantially all of Licensee's assets, or making by Licensee
of any assignment for the benefit of creditors, or (b) the institution of any
proceedings against Licensee under any bankruptcy law which continues
undismissed or unstated for a period of ninety (90) days. Termination shall be
effective upon the date specified in such notice.

                7.4 Rights Upon Expiration. Neither party shall have any further
rights or obligations upon the expiration of this Agreement upon its regularly
scheduled expiration date with respect to this Agreement, other than the
obligation of Licensee to make any and all reports and payments for the final
quarter period. Provided, however, that upon such expiration, (a) each party
shall be required to continue to abide by its non-disclosure and non-use
obligations as described in Section 6.1, (b) Licensee shall have a fully-paid
non-exclusive irrevocable worldwide license under the Scripps Technology
hereunder, and (c) Licensee shall continue to abide by its obligation to
indemnify Scripps as described in Section 3.3 and by its obligations under
Section 5.2 hereof.

                7.5 Rights Upon Termination. Notwithstanding any other provision
of this Agreement, upon any termination of this Agreement prior to the regularly
scheduled expiration date of this Agreement, the license granted hereunder shall
terminate. Except as otherwise provided in Section 7.6 of this Agreement with
respect to work-in-progress, upon such termination, Licensee shall have no
further right to develop, manufacture or market any Licensed Product, or to
otherwise use the Scripps Patent Rights or any Scripps Technology not otherwise
includable therein. Any such termination shall not relieve either party from any
obligations accrued to the date of such termination. Upon such termination, each
party shall be required to abide by its nondisclosure and non use obligations as
described in Section 6.1, and Licensee shall continue to abide by its
obligations to indemnify Scripps as described in Section 3.3. Upon any such
termination, Licensee shall promptly return all materials, samples, documents
and information which constitute or disclose Scripps Patent Rights or


                                      -14-
<PAGE>   15

Scripps Technology; provided, however, that Licensee shall not be obligated to
provide Scripps with proprietary information of Licensee.

                7.6 Work-in-Progress. Upon any such early termination of the
license granted hereunder in accordance with this Agreement, Licensee shall be
entitled to finish any work-in-progress and to sell any completed inventory of a
Licensed Product covered by such license which remain on hand as of the date of
the termination, so long as Licensee pays to Scripps the royalties applicable to
said subsequent sales in accordance with the terms and conditions as set forth
in this Agreement, provided that no such sales shall be permitted after the
expiration of six (6) months after the date of termination.

        8. Assignment; Successors.

                8.1 Assignment. Neither this Agreement nor any rights granted
hereunder may be assigned or transferred by Licensee except to an Affiliate of
Licensee, without the prior written consent of Scripps; provided, however, that
Licensee may, without such consent, assign this Agreement and its rights and
obligations hereunder in connection with the transfer or sale of all or
substantially all of its business, or in the event of its merger or
consolidation or change in control or similar transaction.

                8.2 Binding Upon Successors and Assigns. Subject to the
limitations on assignment herein, this Agreement shall be binding upon and inure
to the benefit of any successors in interest and assigns of Scripps and
Licensee. Any such successor or assignee of Licensee's interest shall expressly
assume in writing the performance of all the terms and conditions of this
Agreement to be performed by Licensee.

        9. General Provisions.

                9.1 Independent Contractors. The relationship between Scripps
and Licensee is that of independent contractors. Scripps and Licensee are not
joint ventures, partners, principal and agent, master and servant, employer or
employee, and have no other relationship other than independent contracting
parties. Scripps and Licensee shall have no power to bind or obligate each other
in any manner, other than as is expressly set forth in this Agreement.

                9.2 Arbitration. Any controversy or claim originated by either
party and arising out of or relating to this Agreement, or the breach thereof,
shall be settled by binding arbitration in accordance with the Commercial
Arbitration Rules of the American Arbitration Association ("AAA"), and the
procedures set forth below. In the event of any inconsistency between the Rules
of AAA and the procedures set forth below, the procedures set forth below


                                      -15-
<PAGE>   16

shall control. Judgment upon the award rendered by the arbitrators may be
enforced in any court having jurisdiction thereof.

                        9.2.1 Location. The location of the arbitration shall be
in the County of San Diego.

                        9.2.2 Selection of Arbitrators. The arbitration shall be
conducted by a panel of three neutral arbitrators who are independent and
disinterested with respect to the parties, this Agreement, and the outcome of
the arbitration. Each party shall appoint one neutral arbitrator, and these two
arbitrators so selected by the parties shall then select the third arbitrator.
If one party has given written notice to the other party as to the identity of
the arbitrator appointed by the party, and the party thereafter makes a written
demand on the other party to appoint its designated arbitrator within the next
ten days, and the other party fails to appoint its designated arbitrator within
ten days after receiving said written demand, then the arbitrator who has
already been designated shall appoint the other two arbitrators.

                        9.2.3 Discovery. Unless the parties mutually agree in
writing to some additional and specific pre-hearing discovery, the only
pre-hearing discovery shall be (a) reasonably limited production of relevant
documents, and (b) the identification of witnesses to be called at the hearing,
which identification shall give the witness's name, general qualifications and
position, and a brief statement as to the general scope of the testimony to be
given by the witness. The arbitrators shall decide any disputes and shall
control the process concerning these pre-hearing discovery matters. Pursuant to
the Rules of AAA, the parties may subpoena witnesses and documents for
presentation at the hearing.

                        9.2.4 Case Management. Prompt resolution of any dispute
is important to both parties; and the parties agree that the arbitration of any
dispute shall be conducted expeditiously. The arbitrators are instructed and
directed to assume case management initiative and control over the arbitration
process (including scheduling of events, pre-hearing discovery and activities,
and the conduct of the hearing), in order to complete the arbitration as
expeditiously as is reasonably practical for obtaining a just resolution of the
dispute.

                        9.2.5 Remedies. The arbitrators may grant any legal or
equitable remedy or relief that the arbitrators deem just and equitable, to the
same extent that remedies or relief could be granted by a state or federal
court, provided however, that no punitive damages may be awarded. No action may
be maintained seeking punitive damages. The decision of any two of the three
arbitrators appointed shall be binding upon the parties.

                        9.2.6 Expenses. The expenses of the arbitration,
including the arbitrators' fees, expert witness fees, and attorney's fees, may
be awarded to the prevailing party, in the


                                      -16-
<PAGE>   17

discretion of the arbitrators, or may be apportioned between the parties in any
manner deemed appropriate by the arbitrators. Unless and until the arbitrators
decide that one party is to pay for all (or a share) of such expenses, both
parties shall share equally in the payment of the arbitrators' fees as and when
billed by the arbitrators.

                9.3 Entire Agreement; Modification. This Agreement sets forth
the entire agreement and understanding between the parties as to the subject
matter hereof. There shall be no amendments or modifications to this Agreement,
except by a written document which is signed by both parties.

                9.4 California Law. This Agreement shall be construed and
enforced in accordance with the laws of the State of California.

                9.5 Headings. The headings for each article and section in this
Agreement have been inserted for convenience of reference only and are not
intended to limit or expand on the meaning of the language contained in the
particular article or section.

                9.6 Severability. Should any one or more of the provisions of
this Agreement be held invalid or unenforceable by a court of competent
jurisdiction, it shall be considered severed from this Agreement and shall not
serve to invalidate the remaining provisions thereof. The parties shall make a
good faith effort to replace any invalid or unenforceable provision with a valid
and enforceable one such that the objectives contemplated by them when entering
this Agreement may be realized.

                9.7 No Waiver. Any delay in enforcing a party's rights under
this Agreement or any waiver as to a particular default or other matter shall
not constitute a waiver of such party's rights to the future enforcement of its
rights under this Agreement, excepting only as to an express written and signed
waiver as to a particular matter for a particular period of time.

                9.8 Name. Whenever there has been an assignment or a sublicense
by Licensee as permitted by this Agreement, the term "Licensee" as used in this
Agreement shall also include and refer to, if appropriate, such assignee or
sublicensee.


                                      -17-
<PAGE>   18

                9.9 Notices. Any consent, notice or report required or permitted
to be given or made under this Agreement by one of the parties hereto to the
other party shall be in writing, delivered personally or by facsimile (and
promptly confirmed by personal delivery, U.S. first class mail or courier), U.S.
first class mail or courier, postage prepaid (where applicable), addressed to
such other party at its address indicated below, or to such other address as the
addressee shall have last furnished in writing to the addressor and (except as
otherwise provided in this Agreement) shall be effective upon receipt by the
addressee.

         For Scripps:       The Scripps Research Institute
                            10666 North Torrey Pines Road
                            La Jolla, California 92037
                            Attention: Industrial Liaison officer
                            Fax No.: (619) 554-9910

         For Licensee:      Ixsys, Inc.
                            3550 Dunhill Street
                            San Diego, California 92121
                            Attention: Michael Hanifin
                            Fax No.: (619) 597-4950

         with a copy to:    Pillsbury Madison & Sutro
                            235 Montgomery Street, 15th Floor
                            San Francisco, California 94104
                            Attention: Thomas E. Sparks, Jr.
                            Fax: (415) 983-7396


                9.10 Compliance with U.S. Laws. Nothing contained in this
Agreement shall require or permit Scripps or Licensee to do any act inconsistent
with the requirements of any United States law, regulation or executive order as
the same may be in effect from time to time.

        IN WITNESS WHEREOF, the parties have executed this Agreement by their
duly authorized representatives as of the date set forth above.


SCRIPPS:                                    LICENSEE:

THE SCRIPPS RESEARCH INSTITUTE              IXSYS, INC.




By: /s/ Arnie LaGuardia                     By: /s/ Bob Littlewood
   --------------------------------            ---------------------------------

Title: SR. Vice President                   Title: President & CEO


                                      -18-
<PAGE>   19

                                    EXHIBIT A

                        DISCLOSURE OF SCRIPPS TECHNOLOGY


***  TECHNOLOGY

        Collectively Hybridoma ***, *** Gene,
        *** and *** Sequence Information


SCRIPPS ANGIOGENESIS TECHNOLOGY


        Disclosed in U.S. Patent Application Serial
        Number 08/210,715, entitled "Methods and
        Compositions Useful for Inhibition of Angiogenesis"

        Together with all foreign counterparts,
        Thereof; The Patent Proceeding from,
        such applications and all divisionals,
        reexaminations and extensions Thereof




*** CONFIDENTIAL MATERIAL REDACTED AND FILED SEPARATELY WITH THE COMMISSION.

                                      -19-