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                                                                    Exhibit 10.1

                           EXCLUSIVE LICENSE AGREEMENT

          This Exclusive License Agreement ("Agreement") is made as of this day
of January, 2000 (the "Effective Date") by and between ABBOTT LABORATORIES, a
company organized under the laws of the State of Illinois, with its principal
office at 100 Abbott Park Road, Abbott Park, IL 60064 ("Abbott") and AMERICAN
BIOGENETIC SCIENCES, INC., a company organized under the laws of the State of
Delaware, with its principal office at 1375 Akron Street, Copiague, N.Y. 11726
("ABS").

                                   WITNESSETH

         WHEREAS, ABS is the holder of certain patent applications and patents
("Patents," as more fully defined below) relating to Compound (as defined
below);

         WHEREAS, ABS also possesses proprietary Know-How (as defined below)
relating to the Compound and/or Product (as defined below);

         WHEREAS, Abbott wishes to obtain, and ABS wishes to grant to Abbott and
its Affiliates (as defined below), an exclusive license in the Territory under
the Patents and Know-How for the development and commercialization of Product;

         NOW THEREFORE, in consideration of the mutual obligations and promises
as set forth herein, the parties do hereby agree as follows:

         1. DEFINITIONS. As used in this Agreement, the following terms shall
have the following respective meanings:

         1.1 "ABS'S TECHNOLOGY" means the Patents and Know-How, including all
Improvements developed by ABS.

         1.2 "AFFILIATE" means any corporation, company, partnership, joint
venture and/or firm which controls, is controlled by, or is under common control
of either party hereto. For purposes of this definition, control shall mean
direct or indirect ownership of at least fifty percent (50%) of the stock or
participating shares entitled to vote for the election of directors.

         1.3 "COMBINATION PRODUCT" means a pharmaceutical product that is
comprised in part of Product and in part of one or more other active agents in
any configuration, formulation or combination.

         1.4 "COMPOUND" means ABS-103, (***).

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     ***Denotes confidential information that has been omitted from the exhibit
and filed separately, accompanied by a confidential treatment request, with the
Securities and Exchange Commission pursuant to Rule 24b-2 of the Securities
Exchange Act of 1934, as amended.

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         1.5 "CONFIDENTIAL INFORMATION" means any and all information or data
relating to the Compound and/or Product which a party discloses to the other
party, its employees or representatives, or is conceived or reduced to practice
during the Term by either party or by a third party conducting feasibility and
evaluation studies for Abbott, whether in writing, orally or by observation,
including, without limitation, all scientific, clinical, technical, commercial,
financial and business information and Know-How, and other information or data
considered confidential in nature, except any portion thereof which:

                  (i)      is known to the receiving party at the time of
                           disclosure and documented by written records made
                           prior to the date of this Agreement;

                  (ii)     is subsequently disclosed to the receiving party
                           without any obligations of confidence by an
                           unaffiliated third person who has not obtained it
                           directly or indirectly from the other party and who
                           has the right to make such disclosure;

                  (iii)    becomes patented, published or otherwise part of the
                           public domain as a result of acts by an unaffiliated
                           third person obtaining such information as a matter
                           of right;

                  (iv)     is independently developed by or for the receiving
                           party by person(s) having no knowledge of or access
                           to such information and without breach of any
                           confidentiality obligation as evidenced by its
                           written records; or

                  (v)      is required to be disclosed by legal, regulatory,
                           statutory or governmental process or authorities,
                           provided in each case the party disclosing
                           information promptly informs the other and uses its
                           best efforts to limit the disclosure and to maintain
                           confidentiality to the maximum extent possible and
                           permits the other party to attempt by appropriate
                           legal means to limit such disclosure.

                  The parties agree that the contents of and the Exhibits to
this Agreement shall constitute Confidential Information.

         1.6 "EFFECTIVE DATE" shall have the meaning ascribed to such term in
the opening paragraph of this Agreement.

         1.7 "FDA" means the United States Food and Drug Administration or any
successor entity and its equivalent in other countries of the Territory.

         1.8 "FIRST COMMERCIAL SALE" means the first sale of Product in the
Territory by Abbott, its Affiliates (or their sublicensee) to any unaffiliated
third party as evidenced by the selling party's invoice or other relevant
document to such third party. A sale to an unaffiliated third party shall not
include quantities delivered solely for research purposes, for clinical trials
or quantities distributed as samples or promotions.

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         1.9 "IMPROVEMENTS" means all additions, developments, modifications,
enhancements and adaptations (i) which directly relate to the Compound, the
Product or any formulation thereof, (ii) which come into existence during the
Term, and (iii) which are conceived or reduced to practice during the Term.

         1.10 "IND" means an investigational new drug application filed with the
FDA or an equivalent application in other countries of the Territory, in order
to commence human clinical testing of a drug or biologic. An IND together with
all supplemental filings referencing the initial IND filing shall be deemed one
and the same IND for all purposes of this Agreement.

         1.11 "KNOW-HOW" means any proprietary technology (other than the
Patents) owned by or licensed (with a right of sublicense) to ABS during the
Term relating to the Compound and/or Product, including all trade secrets and
any other technical information relating to design, development, use or sale.

         1.12 "LIABILITIES" shall have the meaning ascribed to such term in
Section 5.2 of this Agreement.

         1.13 "MAJOR MARKET COUNTRY" means (***).

         1.14 "NDA" means an application (whether original, supplementary or
abbreviated) to the FDA, or an equivalent application in other countries of the
Territory, for approval by the FDA or the equivalent governmental agencies in
other countries of the Territory, necessary for the commercial sale of a product
in such country. An NDA, together with all supplemental filings referencing the
initial NDA filing shall be deemed one and the same NDA for all purposes of this
Agreement.

         1.15 "NET SALES" means gross sales of the Product covered by the claims
of a composition of matter, formulation, therapeutic use or process of
manufacture patent, sold by Abbott, its Affiliates and sub-licensees to
unrelated third parties, in arm's length transactions, including but not limited
to, pharmaceutical wholesalers, pharmacies, hospitals or dispensing physicians,
less any of the following charges or expenses that are incurred in connection
with gross sales of the Product during the term of this Agreement:

                  (i)      discounts, including cash discounts, customary trade
                           allowances or rebates actually taken, governmental
                           rebates, charge-backs, and group purchasing
                           management fees for formulary access;

                  (ii)     credits or allowances given or made for retroactive
                           price reductions, rejection, recall or return of
                           previously sold Product actually taken;

                  (iii)    any tax or government charge (including any tax such
                           as a value added or similar tax or government charge)
                           levied on the sale, transportation or

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     ***Denotes confidential information that has been omitted from the exhibit
and filed separately, accompanied by a confidential treatment request, with the
Securities and Exchange Commission pursuant to Rule 24b-2 of the Securities
Exchange Act of 1934, as amended.
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                           delivery of Product when included on the invoice or
                           other written document between the parties;

                  (iv)     freight, postage, transportation, insurance and
                           duties on shipment of Product when included on the
                           invoice or other written document between the
                           parties; and

                  (v)      provisions for uncollectible accounts determined in
                           accordance with generally accepted accounting
                           principles consistently applied to all products sold
                           by the seller of Product.

                  Net Sales shall not include quantities of Product distributed
for research, testing, pre-clinical, clinical, development or as promotional
samples or free goods. With respect to a Combination Product, Net Sales of such
Combination Product shall first be calculated in accordance with Net Sales of
Product above, and then the Net Sales of such Combination Product shall be
determined on a country-by-country basis as follows:

                  (i)      multiply the Net Sales of such Combination Product by
                           the fraction A/(A+B), where A is the total of the
                           average selling price of Product which contains the
                           Compound as its sole active ingredient and B is the
                           total of the average selling prices in such country
                           of pharmaceutical product(s) which contain each of
                           the other active ingredients as their sole active
                           ingredient; or

                  (ii)     if either the average selling price of the Product
                           which contains the Compound as its sole active
                           ingredient or the average selling price of all of the
                           other pharmaceutical products which contain each of
                           the other active ingredients in such Combination
                           Product is not available, multiply the Net Sales of
                           such Combination Product by a percentage, determined
                           by mutual agreement of the parties, which represents
                           the proportionate economic value of the Compound
                           relative to the economic value contributed by all
                           other active ingredients in such Combination Product.
                           If the parties cannot agree, then the alternative
                           dispute resolution procedure set forth on Exhibit C
                           shall be used to determine the matter.


         1.16 "PATENTS" means the patent applications and patents listed in
Exhibit A hereto and any and all other patents and patent applications,
including foreign equivalents, and any and all substitutions, extensions,
additions, reissues, reexaminations, renewals, divisions, continuations,
continuations-in-part or supplementary protection certificates owned by or
licensed to (with the right to sublicense) ABS during the Term relating to the
Compound and/or the Product.

         1.17 "PRODUCT" means any pharmaceutical formulation containing the
Compound as an active ingredient, and any Improvement.


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         1.18 "REGULATORY APPROVAL" means all governmental approvals and
authorizations necessary for the manufacture and commercial sale of the Product
in a country of the Territory, including, but not limited to, marketing
authorization, pricing approval and pricing reimbursement, as applicable.

         1.19 "ROYALTY PERIOD" shall have the meaning ascribed to such term in
Exhibit F of this Agreement.


         1.20 "TERM" means the period commencing on the Effective Date and
terminating as set forth in Article 7 below.

         1.21 "TERRITORY" means the entire world.

         1.22 "TRADEMARK" means any trademark registered, owned and chosen for
Product by Abbott in any country of the Territory.

         2. LICENSE GRANT; DOCUMENTATION; RELATIONSHIP; SUPPLY; EXCLUSIVITY.

         2.1 LICENSE GRANT: ABS hereby grants to Abbott and its Affiliates an
exclusive right and license in the Territory and under ABS's Technology, and for
all indications with the right to grant sublicenses, to: (i) research, develop,
apply for and obtain Regulatory Approvals, all as may be required to manufacture
and commercialize Compound and Product; and (ii) make, have made, register, use,
import/export, market, offer to sell and sell Compound and Product. Such license
shall be exclusive to Abbott, its Affiliates and its sublicensees and shall
operate to exclude all others, including ABS, within the Territory.

         2.2 DOCUMENTATION AND MATERIALS: Within thirty (30) days following the
Effective Date, ABS shall convey to Abbott all existing information under ABS's
and its Affiliates' control involving the Compound including, but not limited
to, all Know-How in the possession of ABS, its Affiliates and agents, involving:

                  (a)      Results of prior sponsored research or research
                           performed by ABS outside of this Agreement.

                  (b)      Patents.

                  (c)      Clinical research and development.

                  (d)      Requirements for Regulatory Approval.

                 Thereafter, and continuing throughout the Term, ABS shall
promptly convey to Abbott all additional Know-How developed and/or acquired by
ABS, its Affiliates and agents,


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and information of a like nature as and when generated by ABS, its Affiliates
and agents in connection with the Compound.

         2.3 NON-DISCLOSURE: ABS, on behalf of itself and its Affiliates, hereby
covenants that it shall not, during the Term, disclose Confidential Information
except in furtherance of this Agreement or enter into any discussions for a
business relationship with any third party regarding ABS's Technology which
would conflict with the license granted to Abbott herein, nor take any action,
or commit any omission, which could have the effect of materially diminishing
the value of ABS's Technology.

         2.4 SUPPLY OF COMPOUND: At the request of Abbott, ABS shall provide
Abbott with a sufficient supply of Compound, having an optical purity (***)
to enable Abbott to conduct its feasibility and evaluation studies. The
initial schedule of required deliveries is set forth on Exhibit B attached
hereto. The price for such Compound supplied by ABS shall be (***). Except with
respect to the quantities set forth in Exhibit B, nothing contained in this
Section 2.4 shall prevent Abbott from purchasing Compound from a third party
manufacturing source or from manufacturing Compound itself.

         2.5 ALTERNATIVE COMPOUNDS: (***).

         2.6 EXCLUSIVITY: During the Term, ABS and its Affiliates shall not
undertake any development or commercialization activities related to the use of
any (***). Abbott shall have the exclusive right to work with ABS and its
Affiliates on development or commercialization of (***) during the Term and any
inquiries that ABS or its Affiliates shall receive during the Term with respect
to these fields shall be referred to Abbott. (***).  As soon as practicable
following the Effective Date, ABS and its Affiliates shall identify any existing
collaborations with respect


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     ***Denotes confidential information that has been omitted from the exhibit
and filed separately, accompanied by a confidential treatment request, with the
Securities and Exchange Commission pursuant to Rule 24b-2 of the Securities
Exchange Act of 1934, as amended.
<PAGE>   7
to the Compound and during the Term, ABS and its Affiliates shall not conduct
any activities with the Compound.

         3. EXECUTION FEE, EQUITY INVESTMENT, MILESTONE PAYMENTS AND ROYALTIES.

         3.1. EXECUTION FEE: Abbott shall pay to ABS Five Hundred Thousand
Dollars ($500,000) within ten (10) days after the Effective Date.

         3.2 EQUITY INVESTMENT: Within ten (10) days after the Effective Date,
Abbott will make an equity investment in ABS of One Million Five Hundred
Thousand Dollars ($1,500,000) by purchasing from ABS unregistered shares of
Class A Common Stock at the average of the closing market prices for the period
measured by the twenty (20) trading days immediately preceding the Effective
Date (but not including the Effective Date itself). Abbott's equity investment
in ABS shall be documented by a Stock Purchase Agreement and a Registration
Rights Agreement executed by the parties of even date herewith and attached to
this Agreement as Exhibits D and E, respectively.

         3.3 (***).

         3.4 ROYALTIES:

                  (a)      Abbott shall make royalty payments to ABS as set
                           forth in Exhibit F.

                  (b)      ROYALTY REPORTS AND PAYMENTS. Beginning with the
                           First Commercial Sale anywhere in the Territory,
                           within forty-five (45) days after the end of each
                           calendar quarter, Abbott shall prepare and deliver to
                           ABS a report detailing the calculation of Net Sales
                           in (***), on a (***), for such just ended quarter
                           along with the calculation of royalties due thereon
                           pursuant to Section 3.4(a) above. Each report shall
                           be accompanied by full payment in US dollars of the
                           royalties shown thereon to be due. In the event that
                           conversion from foreign currency is required in
                           calculating a royalty payment hereunder, the exchange
                           rate used shall be the ratio in effect at the end of
                           the last business day of the applicable quarter for
                           which royalties are calculated, as reported by the
                           Wall Street Journal.


                  (c)      BOOKS AND RECORDS/AUDIT RIGHTS. Abbott shall keep
                           books and records accurately showing all Products
                           manufactured, used or sold under the terms of this
                           Agreement. Such books and records shall be open to
                           inspection by representatives of ABS solely for the
                           purposes of determining the correctness of the
                           royalties paid under this Agreement. Such audit,
                           conducted no more than one time per calendar year,
                           shall be during normal business hours after
                           reasonable advance notice and subject


                                      -7-

-----------
     ***Denotes confidential information that has been omitted from the exhibit
and filed separately, accompanied by a confidential treatment request, with the
Securities and Exchange Commission pursuant to Rule 24b-2 of the Securities
Exchange Act of 1934, as amended.
<PAGE>   8
                           to suitable confidentiality provisions. In the event
                           an audit shows a deficiency to be due, Abbott shall
                           immediately pay such deficiency along with the
                           reasonable costs and expense of the audit if the
                           deficiency is more than ten percent (10%) of the
                           amount due during such audited period. If the audit
                           shows that an excess was paid, Abbott shall be
                           entitled to deduct the amount of such excess from the
                           payment due for the next calendar quarter. Such books
                           and records shall be preserved for a period of at
                           least three (3) years after the date of the royalty
                           payment to which they pertain, and no audit may be
                           conducted with respect to royalties due in any
                           calendar year that is more than two (2) years
                           preceding the calendar year in which the audit is
                           being conducted. Books and records for a given
                           calendar year may only be audited once.

                  (d)      WITHHOLDING TAXES ON ROYALTIES. Where any sum due to
                           be paid to ABS hereunder is subject to any
                           withholding or similar tax, the parties shall use all
                           reasonable efforts to do all such acts and things and
                           to sign all such documents as will enable them to
                           take advantage of any applicable double taxation
                           agreement or treaty. In the event there is no
                           applicable double taxation agreement or treaty, or if
                           an applicable double taxation agreement or treaty
                           reduces but does not eliminate such withholding or
                           similar tax, ABBOTT shall pay such withholding or
                           similar tax to the appropriate government authority,
                           deduct the amount paid from the amount due ABS and
                           secure and send to ABS the best available evidence of
                           such payment sufficient to enable ABS to obtain a
                           deduction for such withheld taxes or obtain a refund
                           thereof.

          3.5 For purposes of this Article 3, Abbott means Abbott, its
Affiliates and sublicensees. Abbott shall advise ABS in writing within 30 days
of the occurrence of each Milestone as it is achieved.


         4. FEASIBILITY/EVALUATION/MANUFACTURING/MARKETING/OTHER.

         4.1 FEASIBILITY/EVALUATION STUDIES: Abbott shall have sole
responsibility for conducting and/or supervising the performance by third
parties of feasibility and evaluation studies on the Compound. Abbott shall
provide ABS with a copy of all such studies related to the Compound and until
the first of the Fourth Milestones is achieved, with semi-annual summary reports
providing a synopsis of any experiments performed and the results obtained
during the 6 months preceding the report and a general description of the
efforts to be undertaken during the following 6 months. ABS and Abbott agree
that Abbott shall, at all times, have the right to undertake feasibility and
evaluation activities relating to compounds similar to the Compound in parallel
with those feasibility and evaluation activities being conducted on the Compound
under this Section 4.1.

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         4.2 TERMINATION: If Abbott determines in its reasonable scientific and
commercial judgment that the Compound does not have an acceptable profile or a
reasonable likelihood of commercial success, Abbott shall have the right to
terminate this Agreement upon thirty (30) days written notice, at the end of
which the termination shall be effective.

         4.3 MANUFACTURING: Except as provided in Section 2.4 hereof, Abbott and
its Affiliates shall have sole responsibility for manufacturing Product or
having Product manufactured for it by a third party manufacturer.

         4.4 MARKETING: Abbott shall have sole responsibility for marketing
Product, including entering into any co-marketing and/or co-promotion
arrangements with third parties, and neither ABS nor its Affiliates shall have
any rights to market and/or co-promote the Product.

         4.5 CLINICAL DEVELOPMENT: Abbott shall have sole responsibility for
the clinical development of Product and have final decision making authority
with regard to all clinical development activities conducted with respect to the
Product.

         4.6 (***).

         5. REPRESENTATIONS/WARRANTY/INDEMNITY.

         5.1 REPRESENTATIONS AND WARRANTIES OF ABS: ABS makes the following
representations and warranties with respect to this Agreement and ABS's
Technology:

                  (a)      CORPORATE POWER AND AUTHORIZATION. ABS represents and
                           warrants that it is duly organized, validly existing
                           and in good standing under the laws of Delaware, that
                           it has full corporate power and authority to enter
                           into this Agreement and to carry out its provisions,
                           and that there are no outstanding agreements,
                           assignments or encumbrances in existence that are
                           inconsistent with the provisions of this Agreement.
                           ABS further represents and warrants that it is duly
                           authorized to execute and deliver this Agreement and
                           to perform its obligations hereunder and that the
                           execution, delivery and performance of this Agreement
                           by it does not require the consent, approval or
                           authorization of or notice, filing or registration
                           with any governmental or regulatory agency.

                  (b)      TITLE AND VALIDITY OF PATENTS; NO THIRD PARTY RIGHTS.
                           ABS represents and warrants to Abbott that (i) ABS
                           either owns and possesses or controls all right,
                           title and interest in and to ABS's Technology and no
                           third party owns, has acquired or possesses any
                           right, title or interest in or to ABS's Technology;
                           (ii) ABS has valid and complete assignments and/or
                           license rights from each inventor listed on Patents,
                           (iii) ABS is the sole and exclusive licensee of all
                           of (***) and its foreign


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-----------
     ***Denotes confidential information that has been omitted from the exhibit
and filed separately, accompanied by a confidential treatment request, with the
Securities and Exchange Commission pursuant to Rule 24b-2 of the Securities
Exchange Act of 1934, as amended.
<PAGE>   10
                           counterparts (included in Patents) pursuant to a
                           (***); (iv) ABS has provided Abbott with a true,
                           correct and complete copy of the aforesaid license
                           agreement; (v) there are no defaults or events which,
                           with the lapse of time or otherwise would constitute
                           defaults under the aforesaid license agreement; (vi)
                           the Patents have not knowingly been obtained through
                           any act, omission or representation that would limit
                           or destroy their validity and ABS has no knowledge or
                           information that would materially impact the validity
                           and/or enforceability of the Patents; (vii) there are
                           no actions, threatened or pending before any court or
                           administrative tribunal or body relating to ABS's
                           Technology; (viii) ABS has not granted any third
                           party any rights or license to ABS's Technology and
                           has no agreement to grant any such rights or license;
                           (ix) Exhibit A lists all the patents issued and
                           patent applications filed on or before the Effective
                           Date that are included in the Patents and all of the
                           inventors named in said patents and applications have
                           assigned or are under an obligation to assign or
                           license all of their right, title and interest
                           thereto to ABS; and (x) none of the Patents, as of
                           the Effective Date, has lapsed by reason of
                           abandonment or non-payment of annuities or other
                           fees.

                  (c)      WARRANTY ON EXISTENCE OF PRE-CLINICAL/CLINICAL DATA:
                           ABS represents and warrants that ABS has no knowledge
                           of the existence of any pre-clinical or clinical data
                           or information concerning Product which suggests that
                           there may exist toxicity, safety and/or efficacy
                           concerns which may materially impair the utility
                           and/or safety of the Product.

                  (d)      WARRANTY OWNERSHIP OR INTEREST IN OTHER RELEVANT
                           PATENTS: ABS represents and warrants that the Patents
                           listed on Exhibit A represent all the patents and
                           patent applications owned or exclusively licensed by
                           ABS as of the Effective Date relating to Compound.
                           ABS also represents and warrants that the Patents
                           listed on Exhibit A represent all the patents and
                           patent applications owned or exclusively licensed by
                           ABS as of the Effective Date in the area of bipolar
                           disorder, epilepsy and migraine, except for ABS-205.


         5.2 INDEMNIFICATION BY ABS: ABS shall indemnify, defend and hold
Abbott, its Affiliates and sublicensees and their directors, officers, employees
and agents harmless from and against any and all liabilities, actions, suits,
claims, demands, prosecutions, damages, costs, expenses or money judgments
(including reasonable legal fees) (the "LIABILITIES") incurred by or instituted
or rendered against Abbott to the extent that such Liabilities result from the
willful misconduct or the negligent acts or omissions of ABS or its Affiliates,
or ABS's breach of the terms of this Agreement; provided, however, that Abbott
shall give ABS notice in writing as


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-----------
     ***Denotes confidential information that has been omitted from the exhibit
and filed separately, accompanied by a confidential treatment request, with the
Securities and Exchange Commission pursuant to Rule 24b-2 of the Securities
Exchange Act of 1934, as amended.
<PAGE>   11
soon as practicable of any such claim or lawsuit and shall permit ABS to
undertake the defense thereof at ABS's expense. In any such claim or lawsuit:

                  (a)      Abbott will cooperate in the defense by providing
                           access to witnesses and evidence available to it.
                           Abbott shall have the right to participate, at its
                           expense, in any defense to the extent that in its
                           judgment Abbott may be prejudiced thereby.

                  (b)      With respect to this Agreement, Abbott shall not
                           settle, offer to settle or admit liability in any
                           claim or suit in which Abbott intends to seek
                           indemnification by ABS without the written consent of
                           a duly authorized officer of ABS, which consent shall
                           not be unreasonably withheld.

         5.3 REPRESENTATIONS AND WARRANTIES OF ABBOTT: Abbott makes the
following representations and warranties with respect to this Agreement:

                  (a)      CORPORATE POWER AND AUTHORIZATION: Abbott represents
                           and warrants that it is duly organized, validly
                           existing and in good standing under the laws of
                           Illinois, that it has full corporate power and
                           authority to enter into this Agreement and to carry
                           out its provisions, and that there are no outstanding
                           agreements, assignments or encumbrances in existence
                           that are inconsistent with the provisions of this
                           Agreement. Abbott further represents and warrants
                           that it is duly authorized to execute and deliver
                           this Agreement and to perform its obligations
                           hereunder, and that the execution, delivery and
                           performance of this Agreement by it does not require
                           the consent, approval or authorization of or notice,
                           filing or registration with any governmental or
                           regulatory agency.

         5.4 INDEMNIFICATION BY ABBOTT: Abbott shall indemnify and hold ABS, its
Affiliates and their directors, officers, employees and agents harmless from and
against Liabilities incurred by or instituted or rendered against ABS to the
extent such Liabilities result from the willful misconduct or the negligent acts
or omissions of Abbott or its Affiliates or Abbott's breach of the terms of this
Agreement; provided, however, that ABS shall give Abbott notice in writing as
soon as practicable of any such claim or lawsuit and shall permit Abbott to
undertake the defense thereof at Abbott's expense. In any such claim or lawsuit:

                  (a)      ABS will cooperate in the defense by providing access
                           to witnesses and evidence available to it. ABS shall
                           have the right to participate, at its expense, in any
                           defense to the extent that in its judgment ABS may be
                           prejudiced thereby.

                  (b)      With respect to this Agreement, ABS shall not settle,
                           offer to settle or admit liability in any claim or
                           suit in which ABS intends to seek indemnification by
                           Abbott without the written consent of a duly


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<PAGE>   12
                           authorized officer of Abbott, which consent shall not
                           be unreasonably withheld.

         5.5 REPORTABLE OCCURRENCES: Each party warrants that it shall advise
the other promptly of any occurrence which is reported or reportable by it to
the regulatory authorities relating in any way to the Compound or the Product.

         5.6 LIMITATION: Except for the express warranties in this Article 5,
neither party makes any warranties, express or implied, in fact or by operation
of law, statutory or otherwise. ABS specifically disclaims any implied warranty
of merchantability or fitness for a particular purpose. NEITHER PARTY SHALL BE
LIABLE TO THE OTHER PARTY HERETO OR TO ANY THIRD PARTY FOR ANY SPECIAL,
CONSEQUENTIAL, EXEMPLARY OR INCIDENTAL DAMAGES (INCLUDING LOST OR ANTICIPATED
PROFITS RELATING TO THE SAME) ARISING FROM ANY CLAIM RELATING TO THIS AGREEMENT,
WHETHER SUCH CLAIM IS BASED ON CONTRACT, TORT (INCLUDING NEGLIGENCE) OR
OTHERWISE, EVEN IF AN AUTHORIZED REPRESENTATIVE OF SUCH PARTY IS ADVISED OF THE
POSSIBILITY OR LIKELIHOOD OF SAME.

         5.7 TERM OF INDEMNIFICATION: The obligations of the parties set forth
in this Article 5 shall apply during the Term and for a period of seven (7)
years thereafter, after which time they shall terminate, except with respect to
claims notified to the other party prior to the expiration of the seven (7) year
period.

         6. CONFIDENTIALITY AND NON-DISCLOSURE.

         6.1. Neither party shall use or disclose any Confidential Information
received by it from the other party pursuant to this Agreement without the prior
written consent of the other during the Term. This obligation will continue for
a period of seven (7) years after termination of this Agreement or expiration of
the Term, whichever is earlier.

         6.2 Each party shall restrict dissemination of Confidential Information
to those of its employees, agents and sublicensees (if any) who have an actual
need to know and have a legal obligation to protect the confidentiality of such
Confidential Information. All Confidential Information disclosed by one party to
the other shall remain the sole property of the disclosing party and neither
party shall obtain any right of any kind to the Confidential Information
disclosed, except as granted under this Agreement.

         6.3 Nothing contained in this Article 6 shall be construed to restrict
the parties from disclosing Confidential Information solely to the extent and
solely as required:

                  (a)      for regulatory, tax or customs reasons;

                  (b)      for audit purposes;

                                      -12-
<PAGE>   13
                  (c)      by court order or other government order or request;
                           or

                  (d)      from using such Confidential Information as is
                           reasonably necessary to perform acts permitted by
                           this Agreement, including disclosure by Abbott to
                           third parties undertaking feasibility and evaluation
                           studies, clinical trials and the like on behalf of
                           Abbott.

         6.4 Neither ABS nor its Affiliates shall publish any information
relating to the Compound or the Product during the Term. Abbott may publish
information relating to the Compound or the Product without obtaining ABS's
consent.

         7. TERM.

         7.1. The term of the license to ABS's Technology shall (***).

         7.2. Either party may terminate this Agreement by giving to the other
party prior written notice of not less than thirty (30) days in the event the
other party shall commit a material breach of this Agreement (ten (10) days, in
the case of any payment default), and such breaching party shall fail to cure
such breach during the thirty (30) day period or ten (10) day period, as
applicable. In the case of a non-monetary breach, the cure period may be
extended for such longer period as may reasonably be necessary if cure is not
reasonably possible within the initial thirty (30) day period, provided the
breaching party continues its diligent efforts to cure. No such cancellation and
termination shall release the breaching party from any obligations hereunder
incurred prior thereto. It is understood that in the event of a dispute whether
a material breach has occurred, the existence of material breach shall be
determined using the alternative dispute resolution procedure agreed upon by the
parties as set forth on Exhibit C, and that a party's right to terminate this
Agreement shall only apply if the breaching party fails to cure such breach in
the manner required by the final judgment of the alternative dispute resolution
hearing. In the event that this Agreement is terminated for Abbott's material
breach, ABS shall be entitled to retain for its own use all funds previously
paid by Abbott, together with all studies and information generated hereunder
and Abbott shall return all unused Compound previously supplied by ABS. In the
event that this Agreement is terminated for ABS's material breach, Abbott shall
not be liable for payments not yet due and payable under Article 3 hereof, and
Abbott shall be entitled to retain for its own use all studies and information
generated hereunder and all Compound previously supplied by ABS.

         7.3 In lieu of Abbott's exercise of its right to terminate this
Agreement for a material breach by ABS as provided in Section 7.2 above, Abbott
shall have the right to withhold all payments payable under Article 3 until ABS
cures such breach. If Abbott elects to exercise said rights to withhold such
payments, Abbott shall give ABS sixty (60) days' prior written notice of


                                      -13-

-----------
     ***Denotes confidential information that has been omitted from the exhibit
and filed separately, accompanied by a confidential treatment request, with the
Securities and Exchange Commission pursuant to Rule 24b-2 of the Securities
Exchange Act of 1934, as amended.
<PAGE>   14
its intention to withhold such payments. The notice shall include a detailed
statement describing the nature of the breach. If the breach is capable of being
remedied within the sixty (60) day notice period or is capable of remedy but
only within an additional sixty (60) day period, then Abbott shall not withhold
payment. If the breach is incapable of remedy, or if ABS does not cure the
breach within the original sixty (60) days given if the breach is capable of
remedy within such time, or cure the breach within the additional sixty (60)
days, if applicable, then the withholding of payments shall take effect at the
end of the sixty (60) day notice period or sixty (60) day extension, if
applicable, and shall continue until the breach by ABS is remedied.

         7.4 Either party may terminate this Agreement on thirty (30) days
notice if the other party passes a resolution or the court makes an order for
its winding up; or has a receiver or administrator appointed over its business
or any of its assets; or is or becomes bankrupt or insolvent; or takes or
suffers any analogous action on account of debt; or ceases or threatens to cease
to carry on business or the equivalent to any of the above in any jurisdiction.
In the event that this Agreement is terminated under this Section 7.4, the
terminating party shall be entitled to retain for its own use all studies and
information generated hereunder and all Compound previously supplied.
Notwithstanding the bankruptcy or insolvency of ABS or the impairment of
performance by ABS of its obligations under this Agreement as a result of
bankruptcy or insolvency of ABS, Abbott shall be entitled to retain the licenses
granted herein, without any further obligation to ABS other than the royalty
obligations under Section 3.4 and the other payment obligations under Article 3.

         7.5 (a) Abbott may terminate this Agreement without cause, (***), upon
three (3) months prior written notice and, upon such termination Abbott shall
pay all payments, milestones or royalties which may have become due prior to the
effective date of such termination. ABS shall be entitled to retain for its own
use (***).

                  (b) Abbott shall use all commercially reasonable efforts to
develop and commercialize the Product on a country-by-country basis using at
least that level of effort it would use with its own similar compounds. If there
is any material disagreement between the parties concerning whether material
efforts towards commercialization have been made, then the matter shall be
submitted to alternative dispute resolution pursuant to Exhibit C where remedies
for failure to expend such efforts could include a requirement to expend
additional efforts to make up for any failures, damages and/or termination of
the license rights in the applicable country unless Abbott chooses to undertake
such activities and expenses as needed to correct the failure. In determining
whether commercially reasonable efforts have been expended, local market and
regulatory issues shall be considered. Nothing contained herein shall require
Abbott to undertake commercialization where the effect would be to create an
adverse financial impact upon the Product or Abbott.

         7.6 Termination of this Agreement shall be without prejudice to any
rights of either party against the other which may have accrued up to the date
such termination becomes effective.



                                      -14-

-----------
     ***Denotes confidential information that has been omitted from the exhibit
and filed separately, accompanied by a confidential treatment request, with the
Securities and Exchange Commission pursuant to Rule 24b-2 of the Securities
Exchange Act of 1934, as amended.
<PAGE>   15

      7.7 All causes of action accruing to either party under this Agreement
shall survive expiration or termination of this Agreement for any reason.

      7.8 Upon any termination or expiration of this Agreement, each party shall
promptly return to the other party all written Confidential Information, and all
copies thereof (retaining one copy of the Confidential Information of the other
in its confidential files for archival purposes only), which is not covered by a
paid-up license or other rights specified herein surviving such termination or
expiration.

      8. INFRINGEMENT OF PATENTS BY THIRD PARTY. In the event of an actual or
suspected infringement of a Patent by a third party, the following shall apply:


      8.1   NOTICE: Each party shall give the other written notice if one of
            them becomes aware of any infringement by a third party of any
            Patent. Upon notice of any such infringement, the parties shall
            promptly consult with one another with a view toward reaching
            agreement on a course of action to be pursued.

      8.2   ABBOTT'S RIGHT TO BRING INFRINGEMENT ACTION:

            (a)   ABBOTT ELECTION: If a third party infringes any patent
                  included in the Patents in the Territory, Abbott shall have
                  the first right but not the obligation to institute and
                  prosecute an action or proceeding to abate such infringement
                  and to resolve such matter by settlement or otherwise.

                  (i)   Abbott shall notify ABS of its intention to bring an
                        action or proceeding prior to filing the same and in
                        sufficient time to allow ABS the opportunity to
                        discuss with Abbott the choice of counsel for such
                        matter.  Abbott shall keep ABS timely informed of
                        material developments in the prosecution or
                        settlement of such action or proceeding.  Abbott
                        shall be responsible for all costs and expenses of
                        any action or proceeding against infringers which
                        Abbott initiates, provided, that, Abbott may decrease
                        the amount of royalties due under Section 3.4 by up
                        to fifty percent (50%) effective as of the date of
                        filing an action against third party infringers to
                        reimburse Abbott for legal expenses and fees of the
                        action.  Notwithstanding the foregoing, Abbott shall
                        withhold only that portion of such royalties as may
                        reasonably be necessary to reimburse amounts incurred
                        in the prosecution of such action in accordance with
                        the terms of this paragraph.  ABS shall cooperate
                        fully at its expense by joining as a party plaintiff
                        if required to do so by law to maintain such action
                        or proceeding and by executing and making available
                        such documents as Abbott may reasonably request.  ABS
                        may be represented by counsel in any such legal

                                     - 15 -
<PAGE>   16
                        proceedings, at ABS's own expense, subject to
                        reimbursement under subparagraph (b) below, acting in
                        an advisory but not controlling capacity.  The
                        prosecution, settlement, including the granting of
                        one or more sublicenses, or abandonment of any
                        infringement action or proceeding brought by Abbott
                        shall be at Abbott's reasonable discretion provided
                        that Abbott shall not otherwise have any right to
                        surrender, limit or adversely affect any of ABS's
                        rights to the Patents.

                  (ii)  If Abbott elects not to exercise such first right,
                        ABS shall have the right, at its discretion, to
                        institute and prosecute an action or proceeding to
                        abate such infringement and to resolve such matter by
                        settlement or otherwise.  Abbott shall cooperate
                        fully by joining as a party plaintiff if required to
                        do so by law to maintain such action and by executing
                        and making available such documents as ABS may
                        reasonably request.  In such case, ABS shall promptly
                        reimburse Abbott for its out-of-pocket fees and
                        expenses incurred in joining the action at ABS's
                        request.  Abbott may be represented by counsel in any
                        such action at its own expense, provided, if the
                        amounts recovered by ABS exceed its reasonable third
                        party out-of-pocket fees and expenses, ABS agrees to
                        pay Abbott for its out-of-pocket fees and expenses
                        incurred as a result of electing to join the action.

            (b)   USE OF PROCEEDS:  Except as provided herein, all amounts of
                  every kind and nature recovered from an action or
                  proceeding of infringement by Abbott shall belong to
                  Abbott.  If the amount recovered by Abbott exceeds Abbott's
                  reasonable out-of-pocket fees and expenses of the action,
                  the excess shall first be applied to reimburse ABS for
                  withheld royalties and second to reimburse ABS for
                  out-of-pocket fees and expenses ABS incurred in joining the
                  action at Abbott's request.  The balance of the amounts
                  recovered by Abbott shall be considered Net Sales under
                  this Agreement and subject to royalty payments under
                  Section 3.4.

      9.    INFRINGEMENT OF THIRD PARTY RIGHTS

      9.1 ABBOTT DEFENSE OF SUIT: If ABS, its Affiliates, Abbott, its
Affiliates, sublicensees, distributors or other customers are sued or threatened
with suit in the Territory by a third party alleging infringement in one or more
countries of the Territory of patents or other intellectual property rights that
are alleged to cover the manufacture, use sale, import, export or distribution
of one or more Products, Abbott or ABS, whichever is relevant, will promptly
notify the other in writing and provide a copy of the lawsuit or claim. Abbott
may elect to control the defense in any such claim or suit and withhold up to
fifty percent (50%) of the royalties payable under Section 3.4 related to the
Product(s) affected. Abbott shall use such withheld royalties to


                                     - 16 -
<PAGE>   17
reimburse the legal defense costs, fees and liability incurred in such
infringement suit. Notwithstanding the foregoing, Abbott shall withhold only
that portion of such royalties as may reasonably be necessary to reimburse
amounts incurred in the defense of such action in accordance with the terms of
this paragraph. If Abbott is required to pay a royalty or other amount to a
third party for the manufacture, use, sale, import, export or distribution of
one or more Products in the Territory as a result of a final judgment or
settlement, such amounts may be deducted by Abbott from the royalties payable
under Section 3.4. ABS shall cooperate with Abbott in the defense of any such
action at ABS's expense. Abbott shall have the sole right to settle any such
suit, including the right to grant one or more sublicenses, provided that Abbott
shall not otherwise have the right to surrender, limit or adversely affect any
rights to the Patents. If the royalties deducted by Abbott are sufficient to pay
the costs and fees for the defense of the claim or suit, including any appeals,
the excess shall be paid to ABS with the next reporting period for royalties
under Section 3.4(b). If the royalties deducted by Abbott are insufficient to
pay the costs and fees for the defense of the claim or suit, including any
appeals, Abbott may continue to deduct the amount of the insufficiency against
future royalties until the costs and fees are fully paid.

      9.2 INDEMNIFICATION BY ABS: ABS shall indemnify, defend and hold harmless
Abbott, its Affiliates, sublicensees, distributors and customers of the
foregoing and their directors, officers, employees and agents from and against
any and all third party claims, demands, losses, settlement amounts, damages,
penalties, costs and expenses (including fees and costs of attorneys and
witnesses) of any kind or nature, arising from the alleged infringement by
Abbott of (i) patent rights that dominate a claim of the Patent or (ii) patents
or other intellectual property rights that cover the manufacture, use, sale,
import, export or distribution of one or more Products, but only as to the
Compound and not to any other aspect of Product such as delivery vehicle,
stabilizing agents or formulation and further provided, that ABS's liability
under this indemnity shall not exceed the total monies paid to ABS under this
Agreement (including Abbott's equity investment in ABS under Section 3.2
hereof). ABS shall have no obligation to Abbott or its Affiliates, sublicensees,
distributors and other customers with respect to claims, demands, losses,
settlement amounts, damages, penalties, costs and expenses (including fees and
costs of attorneys and witnesses) of any kind or nature, arising out of the
intentional or negligent acts of Abbott or its Affiliates, sublicensees and
distributors or the directors, officers, employees and agents of any of them. If
a claim is made or a suit is brought against Abbott, its Affiliates,
sublicensees, distributors or other customers, Abbott will promptly notify ABS
in writing and provide a copy of the lawsuit or claim. ABS and Abbott shall
promptly meet to discuss the handling of the claim or suit. In the event Abbott
elects not to defend any such claim or suit, ABS shall defend the same in
accordance with its indemnification obligation contained herein. If Abbott
defends the claim or suit, Abbott shall be entitled to withhold that portion of
royalties payable under Section 3.4 with respect to the Product(s) that are the
subject of the claim or suit as may reasonably be necessary to reimburse amounts
incurred by Abbott in the defense of such claim or suit. If ABS defends the
claim or suit, Abbott shall continue to pay royalties for such Product(s) while
defense of the claim or suit is ongoing. The non-defending party agrees to
cooperate with the party defending the claim or suit at the non-defending
party's expense. Upon final resolution of the claim or suit, including any
appeals,


                                     - 17 -
<PAGE>   18
if Abbott defended the claim or suit, Abbott shall resume paying ABS any
royalties payable hereunder, provided that, if Abbott, as a result of the
settlement or final outcome of the claim or suit, becomes obligated to pay
royalties to a third party in order to manufacture, use, sell, import, export or
distribute the Products that were the subject of the claim or suit, one hundred
percent (100%) of such royalties shall be creditable against royalties payable
by Abbott under Section 3.4. In no event shall Abbott be liable for the payment
of royalties previously deducted by Abbott for the defense of the claim or suit
except as to any costs which shall have been reimbursed in connection with the
defense of the claim. If the royalties deducted by Abbott were insufficient to
pay the costs and fees for the defense of the claim or suit, including any
appeals, Abbott may continue to deduct the amount of the insufficiency against
future royalties until the costs and fees are fully paid.

      9.3 ABBOTT ENJOINED: If Abbott is enjoined or otherwise prohibited from
making, having made, importing, exporting, using or selling any Product as a
result of alleged infringement of a third party patent in any country of the
Territory, then (i) the royalties for such Product otherwise due and payable
under Section 3.4 shall not be due and payable and Abbott shall not be liable to
ABS for such royalties for the period of time the injunction is in effect,
including any time the injunction may be stayed pending the outcome of any
appeals; and (ii) Abbott shall have the right to delete such country from the
Territory on ten (10) days prior written notice given any time while the
injunction is in effect, including any time the injunction may be stayed pending
the outcome of any appeals.

      10.   PATENT PROSECUTION AND MAINTENANCE; PATENT COSTS.

      10.1 DISCLOSURE OF PATENTS/APPLICATIONS TO ABBOTT: Within ten (10) days
following the Effective Date, ABS shall disclose to Abbott the complete text (a)
of all patent applications included in the Patents filed anywhere in the
Territory; and (b) of all patents included in the Patents as well as all
information in ABS's, its Affiliates and its patent counsel's possession
concerning the institution or possible institution of any interference,
opposition, re-examination, reissue, revocation, nullification or any official
proceeding involving an issued patent included in the Patents anywhere in the
Territory.

      10.2 PROSECUTION AND MAINTENANCE: Beginning with the Effective Date,
Abbott shall be solely responsible for the preparation, filing, prosecution and
maintenance of the Patents in ABS's name including oppositions and
interferences. Abbott shall pay 100% of the external Patent costs incurred on
and after the Effective Date but shall have the right to apply such external
Patent costs as a credit against future payments due under Sections 3.3 and 3.4
up to $100,000. ABS shall cooperate and shall use reasonable efforts to cause
its Affiliates, employees and agents to cooperate with Abbott in the
preparation, filing, prosecution and maintenance of the Patents by disclosing
such information as may be necessary for the same and by promptly executing such
documents as Abbott may reasonably request in connection therewith. Within 60
days after the Effective Date, Abbott shall cause its patent counsel to provide
ABS with a list of the countries in which it intends to file applications other
than those listed in Exhibit A. Such


                                     - 18 -
<PAGE>   19
list shall be provided to ABS at least sixty (60) days prior to the expiration
of the relevant priority date to allow ABS time to suggest that additional
countries be added to the list. Abbott shall file applications in the additional
countries requested by ABS unless it otherwise notifies ABS in writing in
sufficient time to allow ABS an opportunity to file prior to the relevant
priority date. If ABS so elects to file in any such countries, such patents
shall not be included in the definition of Patents. ABS shall bear its own costs
in connection with its cooperation with Abbott under this Article. Abbott will
provide ABS copies of all material documents received or prepared by Abbott in
the prosecution and maintenance of the Patents. Abbott shall provide copies in a
timely manner to allow ABS an opportunity to review and comment on Abbott's
proposed patent strategy.

      10.3 ABS'S RIGHTS TO PROSECUTE AND MAINTAIN PATENTS: Abbott shall notify
ABS in writing of any country(ies) where it either previously declared its
intention to file under Section 10.2 above and subsequently decided not to file
in such country(ies) or previously filed and decided to abandon the patent
application or issued patent. Such notice shall be given so as to allow ABS a
reasonable time within which to file in countries where Abbott does not now
intend to file or take over the maintenance or prosecution of the relevant
application or patent Abbott intends to abandon. Such patents shall not be
included in the definition of Patents.

      10.4 COVENANT RE: PATENTS LICENSED FROM THIRD PARTIES. ABS shall maintain
in good standing all Patents licensed by ABS from third parties and shall,
during the Term, provide Abbott with any and all default notices or other
correspondence of a material nature received by ABS from the third party
licensor(s) of such Patents. Within two (2) weeks following the Effective Date,
ABS shall provide Abbott with an agreement from all licensors of Patents to
provide written notice to Abbott of any alleged defaults under their applicable
license agreements with ABS, providing Abbott with the right to cure such
default within an acceptable time period. In the event Abbott is required to
expend money to cure any such default by ABS, Abbott shall be entitled to deduct
all such amounts paid to the third party licensor from payments due under
Article 3 hereof.

      11. TRADEMARK. Abbott may select any Trademark or Trademarks for the
Product in the Territory. All costs related to the selection and maintenance of
the Trademark(s) shall be borne by Abbott. The Trademark(s) shall be owned by
Abbott, and ABS shall have no claims or rights in or to the Trademark(s).

      12. IMPROVEMENTS. All Improvements made solely by Abbott and/or its
Affiliates hereunder shall be the sole and exclusive property of Abbott. All
Improvements made solely by ABS and/or its Affiliates shall become part of ABS's
Technology, licensed exclusively to Abbott with all of the rights set forth in
Section 2.1 hereof. All Improvements made jointly by Abbott and ABS (or by their
Affiliates) hereunder shall be the sole and exclusive property of Abbott.

      13.   MISCELLANEOUS.


                                     - 19 -
<PAGE>   20
      13.1 FORCE MAJEURE: If the performance by either party of any of its
obligations under this Agreement shall be prevented by circumstances beyond its
reasonable control which could not have been avoided by the exercise of
reasonable diligence, then such party shall be excused from the performance of
that obligation for the duration of the event. The affected party shall promptly
notify the other party in writing should such circumstances arise, give an
indication of the likely extent and duration thereof, and shall use all
commercially reasonable efforts to resume performance of its obligations as soon
as practicable.

      13.2 NOTICES: Any notice required to be given or made under this Agreement
by one of the parties hereto to the other shall be in writing, by personal
delivery, registered U.S. mail or overnight courier, 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 shall be effective
upon the date of receipt.

      If to ABS:        American Biogenetic Sciences, Inc.
                        1375 Akron Street, Copiague
                        Copiague, NY 11726
                        Attn: Chairman

      With a copy to:   Brown, Rudnick, Freed & Gesmer
                        One Financial Square
                        Boston, MA  02111
                        Attn:  Mark A. Hofer, Esq.

      If to Abbott:     Abbott Laboratories
                        100 Abbott Park Road
                        Dept. 309; Bldg. AP30
                        Abbott Park, IL 60064-3537
                        Attn: Senior Vice President,
                              Pharmaceutical Operations

      With a copy to:   Abbott Laboratories
                        100 Abbott Park Road
                        Dept. 364; Bldg. AP6D
                        Abbott Park, IL 60064-6032
                        Attn: Senior Vice President,
                              General Counsel and Secretary

      13.3 APPLICABLE LAW/COMPLIANCE: This Agreement shall be governed by and
construed in accordance with the laws of the State of New York, excluding its
conflict of laws provision. Each party hereto shall comply with all applicable
laws, rules, ordinances, guidelines, consent decrees and regulations of any
federal, state or other governmental authority.


                                     - 20 -
<PAGE>   21
      13.4 ENTIRE AGREEMENT: Except for the Stock Purchase Agreement and the
Registration Rights Agreement entered into between the parties of even date
herewith, this Agreement and the attachments contain the entire understanding of
the parties with respect to the subject matter hereof. All express or implied
agreements and understandings, either oral or written, heretofore made are
expressly merged in and made a part of this Agreement. This Agreement may be
amended, or any term hereof modified, only by a written instrument duly executed
by both parties hereto.

      13.5 COUNTERPARTS: This Agreement may be executed in two or more
counterparts, each of which shall be deemed an original, but all of which
together shall constitute one and the same instrument.

      13.6 SEVERABILITY: If any provision of this Agreement is deemed
unenforceable, the remainder of the Agreement will not be affected and, if
appropriate, the parties will attempt to replace the unenforceable provision
with a new provision that, to the extent possible, reflects the parties'
original intent.

      13.7 ASSIGNMENT: Neither party may without written approval of the other:

            (a)   assign this Agreement or transfer its interest or any part
                  thereof under this Agreement to any third party except that
                  (i) either party may assign this Agreement to a third party
                  that acquires all or substantially all of the business to
                  which this Agreement pertains, or, (ii) in the case of
                  Abbott, Abbott may assign this Agreement in whole or part
                  to any Affiliate or sublicensee of Abbott, and Abbott
                  hereby guarantees the performance by such Affiliates and
                  sublicensees.

            (b)   designate or cause any third party to perform all or part of
                  its activities hereunder, or to have the benefit of all or
                  part of its non-monetary rights hereunder.

      13.8 MISCELLANEOUS: The parties hereto shall attempt to settle any dispute
arising out of or relating to this Agreement in an amicable way. Any
controversy, claim or right of termination for cause which may arise under, out
of, in connection with, or relating to this Agreement, or any breach thereof,
shall be settled according to the Alternative Dispute Resolution provisions
attached hereto as Exhibit C.

      13.9 INDEPENDENT CONTRACTOR: It is understood that both parties hereto are
independent contractors and engage in the operation of their own respective
businesses and neither party hereto is to be considered the agent of the other
party for any purpose whatsoever and neither party has any authority to enter
into any contract or assume any obligation for the other party or to make any
warranty or representation on behalf of the other party. Each party shall be
fully responsible for its own employees, servants and agents, and the employees,


                                     - 21 -
<PAGE>   22
servants and agents of one party shall not be deemed to be employees, servants
and agents of the other party for any purpose whatsoever.

      13.10 NO IMPLIED OBLIGATIONS OF ABBOTT: Abbott's sole obligation to
exploit the Patents is as set forth in Article 4 and Section 7.5. Nothing in
this Agreement shall be deemed to require Abbott to otherwise exploit the
Patents or prevent Abbott from commercializing products similar to or
competitive with a Product.

      13.11 PUBLICITY: Except as otherwise required by law or regulation,
neither party nor their Affiliates shall make any public announcement concerning
this Agreement nor the subject matter thereof without the prior written consent
of the other party. If either party (or such party's Affiliate) determines that
a public announcement is required by law or regulation, such party shall submit
a copy of the proposed announcement to the other party for review. The other
party shall have three (3) days (or 24 hours if urgent) to review such
announcement and provide comments and suggestions. The party issuing such
announcement, subject to legal requirements, shall use all reasonable efforts to
accommodate the other party's comments and suggestions. Both parties agree that
the names of the other party, its officers, employees and agents will not be
used for purposes of any public commercial activity without their prior written
consent.


      IN WITNESS WHEREOF, the parties hereto have executed this Agreement as of
the Effective Date.

ABBOTT LABORATORIES                 AMERICAN BIOGENETIC
                                          SCIENCES, INC.


By: ____________________________    By: _________________________________

Print Name:  Arthur J. Higgins             Print Name:  Alfred J. Roach

Its:  Senior Vice President,               Its:  Chairman
        Pharmaceutical Operations


                                     - 22 -
<PAGE>   23
                                    EXHIBIT A

                         Patents and Patent Applications

                                     (***)


ISSUED PATENTS:

         A.       (***)


PATENT APPLICATIONS:

         B.       (***)


-----------
     ***Denotes confidential information that has been omitted from the exhibit
and filed separately, accompanied by a confidential treatment request, with the
Securities and Exchange Commission pursuant to Rule 24b-2 of the Securities
Exchange Act of 1934, as amended.
<PAGE>   24
         C.       (***)



         D.       (***)



         E.       (***)



         F.       (***)


                                Page 1 of 2


-----------
     ***Denotes confidential information that has been omitted from the exhibit
and filed separately, accompanied by a confidential treatment request, with the
Securities and Exchange Commission pursuant to Rule 24b-2 of the Securities
Exchange Act of 1934, as amended.
<PAGE>   25
                                    EXHIBIT B

                                 Delivery Dates


      Material                                        Delivery Date

(***) grams of ABS-103 (***)                (***)

                                                (***)

(***) grams of ABS-103 (***)                    (***)

                                                (***)

(***) grams of ABS-103 (***)                    (***)

A (***) sample of each lot(s) of any material sent to (***) shall be sent in
advance to Abbott for confirmation of analysis. If multiple lots are involved,
they shall be split evenly for shipment to Abbott & to (***) so that each of
these parties is working with the same material. All shipments shall be
accompanied by certificates of analysis.


-----------
     ***Denotes confidential information that has been omitted from the exhibit
and filed separately, accompanied by a confidential treatment request, with the
Securities and Exchange Commission pursuant to Rule 24b-2 of the Securities
Exchange Act of 1934, as amended.
<PAGE>   26
                                    EXHIBIT C

                         ALTERNATIVE DISPUTE RESOLUTION

      The parties recognize that a bona fide dispute as to certain matters may
arise from time to time during the term of this Agreement which relates to
either party's rights and/or obligations. To have such a dispute resolved by
this Alternative Dispute Resolution (ADR) provision, a party must send written
notice of the dispute to the other party for attempted resolution by good faith
negotiations between their respective presidents (or their equivalents) of the
affected subsidiaries, divisions, or business units within twenty-eight (28)
days after such notice is received (all references to "days" in this ADR
provision are to calendar days). If the matter has not been resolved within
twenty-eight (28) days of the notice of the dispute, or if the parties fail to
meet within such twenty-eight (28) days, either party may initiate an ADR
proceeding as provided herein. The parties shall have the right to be
represented by counsel in such a proceeding.

      1. To begin an ADR proceeding, a party shall provide written notice to the
other party of the issues to be resolved by ADR. Within fourteen (14) days after
receipt of such notice, the other party may, by written notice to the party
initiating the ADR, add additional issues to be resolved within the same ADR.

      2. Within twenty-one (21) days following receipt of the original ADR
notice, the parties shall select a mutually acceptable neutral to preside in the
resolution of any disputes in this ADR proceeding. If the parties are unable to
agree on a mutually acceptable neutral within such period, either party may
request the President of the CPR Institute for Dispute Resolution (CPR), 366
Madison Avenue, 14th Floor, New York, New York 10017, to select a neutral
pursuant to the following procedures:

            (a) The CPR shall submit to the parties a list of not less than five
(5) candidates within fourteen (14) days after receipt of the request, along
with a Curriculum Vitae for each candidate. No candidate shall be an employee,
director, or shareholder of either party or any of their subsidiaries or
Affiliates.

            (b) Such list shall include a statement of disclosure by each
candidate of any circumstance likely to affect his or her impartiality.

            (c) Each party shall number the candidates in order of preference
(with the number one (1) signifying the greatest preference) and shall deliver
the list to the CPR within seven (7) days following receipt of the list of
candidates. If a party believes a conflict of interest exists regarding any of
the candidates, the party shall provide a written explanation of the conflict to
the CPR along with its list showing its order of preference for the candidates.
Any party failing to return a list of preferences on time shall be deemed to
have no order of preference.

            (d) If the parties collectively have identified fewer than three (3)
candidates deemed to have conflicts, the CPR shall designate as neutral the
candidate for whom the parties
<PAGE>   27
collectively have indicated the greatest preference. If a tie shall result
between two candidates, the CPR may designate either candidate. If the parties
collectively have identified three (3) or more candidates deemed to have
conflicts, the CPR shall review the explanations regarding conflicts, and, in
its sole discretion, may either (i) immediately designate as the neutral the
candidate for whom the parties collectively have indicated the greatest
preference, or (ii) issue a new list of not less than five (5) candidates, in
which case the procedures set forth in subparagraphs 2(a) 2(d) shall be
repeated.

      3. No earlier than twenty-eight (28) days or later than fifty-six (56)
days after the selection, the neutral shall hold a hearing to resolve each of
the issues identified by the parties. The ADR proceeding shall take place at a
location agreed upon by the parties. If the parties cannot agree, the neutral
shall designate a location other than the principle place of business of either
party or any of their subsidiaries or Affiliates.

      4. At least seven (7) days prior to the hearing, each party shall submit
the following to the other party and the neutral:

            (a) a copy of all exhibits on which such party intends to rely in
any oral or written presentation to the neutral;

            (b) a list of any witnesses such party intends to call at the
hearing, and a short summary of the anticipated testimony of each witness;

            (c) a proposed ruling on each issue to be resolved, together with a
request for a specific damage award or other remedy for each issue. The proposed
rulings and remedies shall not contain any recitation of the facts or any legal
arguments and shall not exceed one (1) page per issue.

            (d) a brief in support of each party's proposed rulings and remedies
provided that the brief shall not exceed twenty (20) pages. This page limitation
shall apply regardless of the number of issues raised in the ADR proceeding.

      Except as expressly set forth in subparagraphs 4(a) 4(d), no discovery
shall be required or permitted by any means, including depositions,
interrogatories, requests for admissions, or production of documents.

      5. The hearing shall be conducted on two (2) consecutive days and shall be
governed by the following rules:

            (a) Each party shall be entitled to five (5) hours of hearing time
to present its case. The neutral shall determine whether each party has had the
five (5) hours to which it is entitled.

            (b) Each party shall be entitled, but not required, to make an
opening statement, to present regular and rebuttal testimony, documents or other
evidence, to cross examine witnesses, and to make a closing argument. Cross
examination of witnesses shall occur immediately after their
<PAGE>   28
direct testimony, and cross examination shall be charged against the party
conducting the cross examination.

            (c) The party initiating the ADR shall begin the hearing and, if it
chooses to make an opening statement, shall address not only issues it raised
but also any issues raised by the responding party. The responding party, if it
chooses to make an opening statement, also shall address all issues raised in
the ADR. Thereafter, the presentation of regular and rebuttal testimony and
documents, other evidence, and closing arguments shall proceed in the same
sequence.

            (d) Except when testifying, witnesses shall be excluded from the
hearing until closing arguments.

            (e) Settlement negotiations, including any statements made therein,
shall not be admissible under any circumstances. Affidavits prepared for
purposes of the ADR hearing also shall not be admissible. As to all other
matters, the neutral shall have sole discretion regarding the admissibility of
any evidence.

      6. Within seven (7) days following completion of the hearing, each party
may submit to the other party and the neutral a posthearing brief in support of
its proposed rulings and remedies, provided that such brief shall not contain or
discuss any new evidence and shall not exceed ten (10) pages. This page
limitation shall apply regardless of the number of issues raised in the ADR
proceeding.

      7. The neutral shall rule on each disputed issue within fourteen (14) days
following completion of the hearing. Such ruling shall adopt in its entirety the
proposed ruling and remedy of one of the parties on each disputed issue but may
adopt one parties proposed rulings and remedies on some issues and the other
party's proposed rulings and remedies on other issues. The neutral shall not
issue any written opinion or otherwise explain the basis of the ruling.

      8. The neutral shall be paid a reasonable fee plus expenses. These fees
and expenses, along with the reasonable legal fees and expenses of the
prevailing party (including all expert witness fees and expenses), the fees and
expenses of a court recorder, and any expenses for a hearing room, shall be paid
as follows:

            (a) If the neutral rules in favor of one party on all disputed
issues in the ADR, the losing party shall pay 100% of such fees and expenses.

            (b) If the neutral rules in favor of one party on some issues, and
the other party on other issues, the neutral shall issue with the rulings a
written determination as to how such fees and expenses shall be allocated
between the parties. The neutral shall allocate the fees and expenses in a way
that bears a reasonable relationship to the outcome of the ADR, with the party
prevailing on more issues, or on issues of greater value or gravity, recovering
a relatively larger share of its legal fees and expenses.
<PAGE>   29
      9. The rulings of the neutral and the allocation of fees and expenses
shall be binding, non-reviewable, and non-appealable, and may be entered as a
final judgment in any court having jurisdiction.

      10. Except as provided in paragraph 9 and except as to such disclosure
which is required by applicable law or regulation, the existence of the dispute,
any settlement negotiations, the ADR hearing, any submissions (including
exhibits, testimony, proposed rulings, and briefs), and the rulings shall be
deemed Confidential Information. The neutral shall have the authority to impose
sanctions for unauthorized disclosure of Confidential Information.

                                   EXHIBIT D
                            (Filed as Exhibit 99.1)

                                   EXHIBIT E
                             (Filed as Exhibit 4.1)

                                   EXHIBIT F

                                    PAYMENTS

MILESTONE PAYMENTS

     3.3 Abbott shall make the following milestone payments to ABS within thirty
(30) days after the occurrence of the corresponding named events:

          (a)  FIRST MILESTONE PAYMENT: (***).

          (b)  SECOND MILESTONE PAYMENT: (***).

          (c)  THIRD MILESTONE PAYMENTS: (***).

          (d)  FOURTH MILESTONE PAYMENTS: (***).

Royalty Payments

          (a)  ROYALTY RATE AND ROYALTY PERIOD: Beginning with the First
               Commercial Sale, Abbott will pay a royalty in accordance with the
               following schedule:

               ANNUAL NET SALES                        ROYALTY
               ----------------                        -------
               (***)                                   (***)

               (***)







     ***Denotes confidential information that has been omitted from the exhibit
and filed separately, accompanied by a confidential treatment request, with the
Securities and Exchange Commission pursuant to Rule 24b-2 of the Securities
Exchange Act of 1934, as amended.