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                                                                 EXHIBIT 10.14



                                LICENSE AGREEMENT

                                 by and between

                         THE SCRIPPS RESEARCH INSTITUTE,
                             a California nonprofit
                           public benefit corporation

                                       and

                              DRUG ABUSE SCIENCES,
                            a California corporation


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                                TABLE OF CONTENTS

<TABLE>
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                                                                                                               PAGE
                                                                                                               ----
<S>    <C>                                                                                                     <C>
1.     Definitions................................................................................................1
       1.1      Affiliate.........................................................................................1
       1.2      Confidential Information..........................................................................2
       1.3      Field.............................................................................................2
       1.4      Licensed Product..................................................................................2
       1.5      Net Sales.........................................................................................2
       1.6      Scripps Patent Rights.............................................................................2
       1.7      Scripps Technology................................................................................3

2.     License Terms and Conditions...............................................................................3
       2.1      Grant of License..................................................................................3
       2.2      Initial License Fee...............................................................................3
       2.3      Milestone Issuances of Stock......................................................................3
       2.4      Royalties.........................................................................................3
                2.4.1    Percentage Royalty.......................................................................3
       2.5      Combination Products..............................................................................4
                2.5.1    Definition of Combination Product........................................................4
                2.5.2    Royalty Payable on Combination Products..................................................4
                2.5.3    Third Party Royalty......................................................................4
       2.6      Quarterly Payments................................................................................4
       2.7      Term of License...................................................................................5
       2.8      Sublicense........................................................................................5
       2.9      Duration of Royalty Obligations...................................................................5
       2.10     Reports...........................................................................................6
       2.11     Records...........................................................................................6
       2.12     Foreign Sales.....................................................................................6
       2.13     Foreign Taxes.....................................................................................6

3.     Patent Matters.............................................................................................6
       3.1      Patent Prosecution and Maintenance................................................................6
       3.2      Information to Licensee...........................................................................7
       3.3      Patent Costs......................................................................................7
       3.4      Ownership.........................................................................................7
       3.5      Scripps Right to Pursue Patent....................................................................7
       3.6      Infringement Actions..............................................................................8
                3.6.1    Prosecution and Defense of Infringements.................................................8
                3.6.2    Allocation of Recovery...................................................................8

4.     Obligations Related to Commercialization...................................................................8
       4.1      Commercial Development Obligation.................................................................8
       4.2      Governmental Approvals and Marketing of Licensed Products.........................................9

                                       i

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       4.3      Indemnity.........................................................................................9
       4.4      Patent Marking....................................................................................9
       4.5      No Use of Name....................................................................................9
       4.6      U.S. Manufacture..................................................................................9
       4.7      Foreign Registration.............................................................................10

5.     Limited Warranty..........................................................................................10

6.     Interests in Intellectual Property Rights.................................................................10
       6.1      Preservation of Title............................................................................10
       6.2      Royalty-free License to Improvements.............................................................10
       6.3      Governmental Interest............................................................................10
       6.4      Reservation of Rights............................................................................10

7.     Confidentiality and Publication...........................................................................11
       7.1      Treatment of Confidential Information............................................................11
       7.2      Publications.....................................................................................11
       7.3      Publicity........................................................................................11

8.     Term and Termination......................................................................................11
       8.1      Term.............................................................................................11
       8.2      Termination Upon Default.........................................................................11
       8.3      Termination Upon Bankruptcy or Insolvency........................................................12
       8.4      Rights Upon Expiration...........................................................................12
       8.5      Rights Upon Termination..........................................................................12
       8.6      Work-in-Progress.................................................................................12

9.     Assignment; Successors....................................................................................12
       9.1      Assignment.......................................................................................12
       9.2      Binding Upon Successors and Assigns..............................................................13

10.    General Provisions........................................................................................13
       10.1     Independent Contractors..........................................................................13
       10.2     Arbitration......................................................................................13
                10.2.1   Location................................................................................13
                10.2.2   Selection of Arbitrators................................................................13
                10.2.3   Discovery...............................................................................13
                10.2.4   Case Management.........................................................................13
                10.2.5.  Remedies................................................................................14
                10.2.6   Expenses................................................................................14
                10.2.7   Confidentiality.........................................................................14
       10.3     Entire Agreement; Modification...................................................................14
       10.4     California Law...................................................................................14
       10.5     Headings.........................................................................................14
       10.6     Severability.....................................................................................14
       10.7     No Waiver........................................................................................15
       10.8     Name.............................................................................................15

                                       ii

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       10.9     Attorneys'Fees...................................................................................15
       10.10    Notices..........................................................................................15
       10.11    Compliance with U.S. Laws........................................................................15
</TABLE>
                                  iii

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          CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED
          AND FILED SEPARATELY WITH THE COMMISSION. CONFIDENTIAL TREATMENT
          HAS BEEN REQUESTED WITH RESPECT TO THE OMITTED PORTIONS.


                                LICENSE AGREEMENT

                  This License Agreement is entered into and made effective
as of this 18th day of June, 1996, by and between THE SCRIPPS RESEARCH
INSTITUTE, nonprofit public benefit corporation ("Scripps") located at 10550
North Torrey Pines Road, La Jolla, California 92037, and Drug Abuse Sciences,
a California corporation ("Licensee") located at 3 O'Dell Place, Atherton,
California 94027, with respect to the facts set forth below.

                                    RECITALS

                  A.       Scripps is engaged in fundamental scientific
biomedical and biochemical research including research relating to
Cocaine-Specific Monoclonal Antibodies: Hapten Design, Synthesis and
Immunization.

                  B.       Licensee is engaged in research and development of
therapeutics and diagnostics for cocaine addiction.

                  C.       Scripps has disclosed to Licensee certain technology
described in TSRI Technology Disclosure #92-05 entitled "Cocaine-Specific
Monoclonal Antibodies: Hapten Design, Synthesis and Immunization," as shell as
the Scripps patent application entitled "Anti-Cocaine Vaccine" (Scripps #507.0),
copies of which are attached hereto as Exhibit A and incorporated herein by
reference (collectively, the "Technology Disclosure").

                  D.       Scripps has the exclusive right to grant a license to
the technology described in the Technology Disclosure, 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.

                  E.       Scripps desires to grant to Licensee, and Licensee
wishes to acquire, an exclusive worldwide right and license to the technology
described in the Technology Disclosure and to certain patent rights and know-how
of Scripps with respect thereto, subject to the terms and conditions set forth
herein, with a view to developing and marketing diagnostic and/or therapeutic
products within the Field (as defined below).

                                    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.

                           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 a majority of the
outstanding voting securities or by contract or otherwise.

[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

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                           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 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
field of the diagnosis and treatment of cocaine addiction and shall specifically
exclude any agricultural applications or products.

                           1.4      LICENSED PRODUCT.  The term
"Licensed Product" shall mean any product which cannot be developed,
manufactured, used or sold without (i) infringing one or more claims under
Scripps Patent Rights or (ii) utilizing any part of Scripps Technology not
otherwise includable within Scripps Patent Rights.

                           1.5      NET SALES.  The term "Net Sales" shall mean
the gross amount invoiced by Licensee, or its Affiliates and sublicensees, or
any of them, on all sales of Licensed Products, less (i) discounts actually
allowed, (ii) credits for claims, allowances, retroactive price reductions or
returned goods, (iii) prepaid freight and (iv) sales taxes or other governmental
charges actually paid in connection with sales of Licensed Products (but
excluding what is commonly known as income taxes). 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.

                           1.6      SCRIPPS PATENT RIGHTS.  The "Scripps Patent
Rights" shall mean rights arising out of or resulting from (i) any and all U.S.
and foreign patent applications and patents covering Scripps Technology, (ii)
the patents proceeding from such applications, (iii) all claims of
continuations-in-part directed solely to subject matter specifically described
in the Technology Disclosure, and (iv) divisionals, continuations, reissues,
reexaminations, and extensions of any patent or application set forth in
(i)-(iii) above, 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.

[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

                                       2

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                           1.7      SCRIPPS TECHNOLOGY.  The term "Scripps
Technology" shall mean so much of the technology as is proprietary to Scripps
disclosed in the Technology Disclosure, together with materials, information and
know-how related thereto 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 processes and technology, or information related thereto, 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, to Scripps Technology and under Scripps Patent Rights, to make,
to have made, to use, and to sell Licensed Products in the Field, subject to
the terms of this Agreement.

                           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 [***]. In addition, pursuant to a Common Stock
Purchase Agreement in substantially the form attached hereto as Exhibit B and
incorporated herein by this reference (a "Common Stock Purchase Agreement"),
promptly after the effective date hereof, Licensee shall issue to Scripps
(subject to the terms and conditions of the Common Stock Purchase Agreement and
conditioned upon such issuance being exempt from any federal or state securities
registration requirements) 110,765 shares of Licensee's Nonvoting Common Stock
(the "Shares"). 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 ISSUANCES OF STOCK.  Pursuant to a
Common Stock Purchase Agreement in substantially the form attached hereto as
Exhibit B, and in addition to the other consideration set forth in this Article
2 for the exclusive license granted pursuant to Section 2.1 hereof, Licensee
shall issue to Scripps (subject to the terms and conditions of the Common Stock
Purchase Agreement and conditioned such issuance being exempt from any federal
or state securities registration requirements) shares of Licensee's Nonvoting
Common Stock (or, if any such issuance shall occur after the closing of an
initial public offering of Licensee's Common Stock pursuant to a Registration
Statement filed under the Securities Act of 1933, shares of such Common Stock)
as follows: (i) 166,148 shares upon the filing of an investigational new drug
application ("IND") for an efficacy clinical trial sponsored by Licensee or its
Sublicensee with the U.S. Food and Drug Administration in respect of a Licensed
Product and (ii) 166,148 shares upon demonstration of human clinical efficacy
for a primary end point in a Phase clinical trial sponsored by Licensee or its
Sublicensee in respect of a Licensed Product.

                           2.4      ROYALTIES.

                                    2.4.1   PERCENTAGE ROYALTY.  As additional
consideration for the exclusive license granted pursuant to Section 2.1 hereof,
Licensee shall pay to Scripps a [***] on

[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

                                       3

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a country-by-country basis in the amount of (i) [***] which cannot be made,
used or sold in such country without utilizing one or more valid claims under
Scripps Patent Rights and (ii) [***].

                           2.5      COMBINATION PRODUCTS.

                                    2.5.1   DEFINITION OF COMBINATION PRODUCT.
As used herein, the term "Combination Product" shall mean a Licensed Product
which cannot be manufactured, used or sold without infringing Scripps Patent
Rights, utilizing Scripps Technology licensed hereunder, infringing or utilizing
one or more patents or proprietary technology or know-how of (i) Licensee, (ii)
a third party licensed pursuant to an agreement between Licensee and such third
party, or (iii) Scripps under a license agreement other than this Agreement
(referred to herein as "other licensed rights").

                                    2.5.2   ROYALTY PAYABLE ON COMBINATION
PRODUCTS. The royalty payable on Combination Products shall be the royalty rate
set forth in Section 2.2.1 above based on a pro rata portion of Net Sales of
Combination Products in accordance with the following formula:

                                          A
                                    X =   -
                                          B, where

                                    X = the pro rata portion of Net Sales
                           attributable to Scripps Patent Rights or other
                           Scripps Technology licensed herein (expressed as a
                           percentage), and

                                    A = the fair market value of the component
                           in the Combination Product utilizing Scripps
                           Technology licensed hereunder, and

                                    B = A plus the fair market value of all
                           other components in the Combination Product using
                           other licensed rights.

                                    2.5.3   THIRD PARTY ROYALTY.  In the event
that Licensee is required to pay a third party a royalty in order to enjoy the
benefits of its license under this Agreement, the parties shall negotiate a
reasonable deduction in the royalties owed under Section 2.4 to offset the third
party royalty, but in no event shall the deduction be greater than [***] of the
applicable royalty set forth in Section 2.4.

The fair market values described above shall be determined by the parties hereto
in good faith. In the absence of agreement as to the fair market value of all of
the components contained in a Combination Product, the fair market value of each
component shall be determined by arbitration in accordance with the provisions
of Section 10.2 hereof.

                           2.6      QUARTERLY PAYMENTS.

                                    2.6.1   SALES BY LICENSEE.  With regard to
Net Sales made by Licensee or its Affiliates, royalties shall be payable by
Licensee [***], based upon the Net Sales

[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

                                       4

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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.

                                    2.6.2   SALES BY SUBLICENSEES.  With regard
to Net Sales made by sublicensees of Licensee or its Affiliates, 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 by such
sublicensee during such preceding calendar quarter, commencing with the calendar
quarter in which the first commercial sale of any Licensed Product is made by
such sublicensee.

                           2.7      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 has expired.
Notwithstanding 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 appropriately the
royalties payable as set forth under the section heading "Royalties" hereof.

                           2.8      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 (i) any
such sublicense shall be subject in all respects to the restrictions,
exceptions, royalty obligations, 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) and (ii) each such sublicensee, and
the form and substance of each such sublicense, shall be subject to the prior
written approval of Scripps, which approval shall not be unreasonably withheld,
provided, however, that any sublicense granted to an Affiliate of Licensee shall
not be subject to Scripps's prior written approval. No approval shall be
required as to any sublicense which utilizes the form of sublicense attached
hereto as Exhibit C. 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.

                  Except as set forth below, any revenues, other than royalties,
due Licensee pursuant to the grant of a sublicense to a party not an Affiliate
shall be reported to Scripps by Licensee. Licensee shall pay to Scripps [***] of
any such revenue, where such license is a bare patent license. As to all fees
other than for a bare patent license, the amount paid Scripps shall be
negotiated, based on the respective contributions of the parties. In no event
shall reasonable fees for performing research by Licensee be included in any
determination of the revenues to be due Scripps.

                           2.9      DURATION OF ROYALTY OBLIGATIONS.  The
royalty obligations of Licensee as to each Licensed Product shall terminate on a
[***] utilized by or in such Licensed Product in each such country or, with
respect to Licensed Products not utilizing any Scripps Patent Rights, the [***].

[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

                                       5

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                           2.10     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.

                           2.11     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 approved by Licensee, which approval shall not be unreasonably
withheld, to audit the records of Licensee, its Affiliates and sublicensees as
necessary to verify the royalties payable pursuant to this Agreement. Licensee,
its Affiliates and sublicensees shall pay to Scripps an amount equal to any
additional royalties to which Scripps is entitled as disclosed by the audit,
[***]. 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 [***] for any calendar quarter, then Licensee, its
Affiliates or sublicensee, as the case may be shall reimburse Scripps for any
such audit costs. Scripps may exercise its right of audit as to each of
Licensee, its Affiliates or sublicensees 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. Licensee, its Affiliates and
sublicensees 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.

                           2.12     FOREIGN SALES.  The remittance of royalties
payable on sales outside the United States shall be payable to Scripps in United
States Dollar equivalents at the official rate of exchange of the currency of
the country from which the royalties are payable, as quoted in the Wall Street
Journal for the last business day of the calendar quarter in 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 county 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
that country, prompt written notice of which shall be given by Licensee to
Scripps.

                           2.13     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.    PATENT MATTERS.

                           3.1      PATENT PROSECUTION AND MAINTENANCE.  From
and after the date of this Agreement, the provisions of this Section 3 shall
control the prosecution and maintenance of any patent included within Scripps
Patent Rights. Subject to the requirements, limitations and

[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

                                      6

<PAGE>

conditions set forth in this Agreement, Scripps shall direct and control (i)
the preparation, filing and prosecution of the United States and foreign
patent applications within Scripps Patent Rights (including any interferences
and foreign oppositions), except that Licensee shall not be liable for
expenses related to foreign patent applications, which foreign patent
applications have not received Licensee's approval for filing and continued
prosecution, and (ii) maintain the patents issuing therefrom. Scripps shall
select the patent attorney, subject to Licensee's written approval, which
approval shall not be unreasonably withheld. Both parties hereto agree that
Scripps may, at its sole discretion, utilize Scripps Office of Patent Counsel
in lieu of outside counsel for patent prosecution and maintenance described
herein, and the fees and expenses incurred by Scripps with respect to work
done by such Office of Patent Counsel shall be paid as set forth below.
Licensee shall have full rights of consultation with the patent attorney so
selected on all matters relating to Scripps Patent Rights. Scripps shall use
its best efforts to implement all reasonable requests made by Licensee with
regard to the preparation, filing, prosecution and/or maintenance of the
patent applications and/or patents within Scripps Patent Rights.

                           3.2      INFORMATION TO LICENSEE.  Scripps shall
keep Licensee informed with regard to the patent application and maintenance
processes. Scripps shall deliver to Licensee copies of all patent
applications, amendments, related correspondence, and other related matters.

                           3.3      PATENT COSTS.  Licensee acknowledges and
agrees that Scripps does not have independent funding to cover patent costs,
and that the license granted hereunder is in part in consideration for
Licensee's assumption of patent costs and expenses as described herein.
Licensee shall pay for all expenses incurred by Scripps pursuant to Section
3.1 hereof. In addition, Licensee agrees to reimburse Scripps for all patent
costs and expenses paid or incurred by Scripps to date in connection with
Scripps Patent Rights licensed hereunder. Licensee agrees to pay all such
past and future patent expenses directly or to reimburse Scripps for the
payment of such expenses within sixty (60) days after Licensee receives an
itemized invoice therefor. 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.

                           3.4      OWNERSHIP.  The patent applications filed
and the patents obtained by Scripps pursuant to Section 3.1 hereof shall be
owned solely by Scripps, assigned to Scripps and deemed a part of Scripps
Patent Rights.

                           3.5      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 at its own expense. If Scripps pursues
patents under this Section 3.5, Licensee agrees to entertain any request by
Scripps to cooperate in the prosecution

[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

                                       7

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of such patents, including by providing, at no charge to Scripps, all
appropriate technical data and executing all necessary legal documents.

                             3.6    INFRINGEMENT ACTIONS.

                                    3.6.1 PROSECUTION AND DEFENSE OF
INFRINGEMENTS. Except as provided herein, in order to maintain the license
granted hereunder in force, Licensee shall prosecute any and all
infringements of any Scripps Patent Rights and shall defend all charges of
infringement arising as a result of the exercise of Scripps Patent Rights by
Licensee, its Affiliates or sublicensees, unless otherwise agreed to between
Scripps and Licensee and Licensee shall hold Scripps harmless from any costs
or expenses of liability respecting all such infringements. Licensee may
enter into settlements, stipulated judgments or other arrangements respecting
such infringement, at its own expense, but only with the prior written
consent of Scripps, which consent shall not be unreasonably withheld. Scripps
shall permit any action to be brought in its name if required by law. Scripps
agrees to provide reasonable assistance of a technical nature which Licensee
may require in any litigation arising in accordance with the provisions of
this Section 3.6.1, for which Licensee shall pay to Scripps a reasonable
hourly rate of compensation. In the event Licensee fails to prosecute any
such infringement, Licensee shall notify Scripps in writing promptly and
Scripps shall have the right to prosecute such infringement on its own
behalf. Failure on the part of Licensee to prosecute any such infringement
shall be grounds for termination of the license granted to Licensee hereunder
(but solely with respect to the patent at issue, which, with respect to the
country in which such infringement occurs, shall thereafter be excluded from
the definition of Scripps Patent Rights) at the option of Scripps, unless
Licensee shall have established to Scripps reasonable satisfaction that such
prosecution would be unwarranted or unreasonable in view of the likelihood of
success, the costs of prosecution, the amount of any anticipated recovery, or
the economic impact of the infringement.

                                    3.6.2   ALLOCATION OF RECOVERY.  Any
damages or other recovery from an infringement action undertaken by Licensee
pursuant to Section 3.6.1 shall first be used to reimburse the parties for
the costs and expenses incurred in such action, and shall thereafter be
allocated between the parties as follows: [***]. If Licensee fails to
prosecute any such action to completion, then any damages or other recovery
net of the parties' costs and expenses incurred in such infringement action
shall be the sole property of Scripps.

                     4.    OBLIGATIONS RELATED TO COMMERCIALIZATION.

                           4.1      COMMERCIAL DEVELOPMENT OBLIGATION.  In
order to maintain the license granted hereunder in force, Licensee shall use
reasonable efforts and due diligence to develop Scripps Technology and
Scripps Patent Rights 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 Scripps Technology and Scripps Patent Rights, and Licensee
shall deliver to Scripps an annual written report and such other reports as
Scripps may reasonably request. The parties hereto acknowledge and agree to
negotiate milestones on an annual basis, beginning with the effective date of
this Agreement, for the proceeding year, and said milestones shall be
incorporated into this Agreement as Exhibit D; however, in this regard,

[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

                                       8

<PAGE>

Scripps hereby acknowledges that Licensee is an early-stage technology
company and Scripps Technology is in an early stage of development and that
milestones will be established accordingly. The achievement of the milestones
described in Exhibit D attached hereto on or before the dates set forth
therein shall be evidence of compliance by Licensee with its commercial
development obligations hereunder for the time periods specified in Exhibit
D. 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 10.2 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.

                           4.2      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.

                           4.3      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 party as to any Licensed Product or any
claims arising from the use of any Scripps Patent Rights or Scripps
Technology 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. Licensee shall use its 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.

                           4.4      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.

                           4.5      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 is expressly
prohibited.

                           4.6      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.

[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

                                        9

<PAGE>

                           4.7      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 fully
satisfied.

                   5.      LIMITED WARRANTY. Scripps hereby represents and
warrants that it has full right and power to enter into this Agreement.
SCRIPPS MAKES NO OTHER WARRANTIES CONCERNING SCRIPPS PATENT RIGHTS OR SCRIPPS
TECHNOLOGY COVERED BY THIS AGREEMENT, INCLUDING WITHOUT LIMITATION, ANY
EXPRESS OR IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR
PURPOSE AS TO SCRIPPS PATENT RIGHTS, SCRIPPS TECHNOLOGY OR ANY LICENSED
PRODUCT. SCRIPPS MAKES NO WARRANTY OR REPRESENTATION AS TO THE VALIDITY OR
SCOPE OF SCRIPPS PATENT RIGHTS, OR 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 SCRIPPS
PATENT RIGHTS OR SCRIPPS TECHNOLOGY COVERED BY THIS AGREEMENT.

                   6.      INTERESTS IN INTELLECTUAL PROPERTY RIGHTS.

                           6.1      PRESERVATION OF TITLE.  Scripps shall
retain full ownership and title to Scripps Technology, and Scripps Patent
Rights licensed hereunder 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.

                           6.2      ROYALTY-FREE LICENSE TO IMPROVEMENTS.
Licensee hereby grants to Scripps a non-exclusive, royalty-free license to
any improvement to Scripps Technology developed by Licensee, to use for its
own non-commercial research purposes or grant to other nonprofit institutions
for their non-commercial research purposes, it being understood that Licensee
has no duty to disclose to Scripps any such improvements and in the event of
an inadvertent disclosure, such disclosure shall be governed by the
restrictions as set forth in Section 7.1 Treatment of Confidential
Information.

                           6.3      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 a non-exclusive, irrevocable, royalty-free
license to Scripps Technology and Scripps Patent Rights licensed hereunder
for governmental purposes.

                           6.4      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

[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

                                       10

<PAGE>

licensed hereunder, without Scripps or such other institutions being
obligated to pay Licensee any royalties or other compensation.

                    7.     CONFIDENTIALITY AND PUBLICATION.

                           7.1      TREATMENT OF CONFIDENTIAL INFORMATION.
The parties agree that during the term of this Agreement, and for a period of
three (3) years after this Agreement terminates, a party receiving
Confidential Information of the other party will (i) maintain in confidence
such Confidential Information to the same extent such party maintains its own
proprietary industrial 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.

                           7.2      PUBLICATIONS.  Licensee agrees that
Scripps shall have a right to publish in accordance with its general
policies, subject to the confidential commitments of Section 7.1 Treatment of
Confidential Information, which shall not be overridden by this Section.

                           7.3      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, relating to this Agreement or to
any sublicense hereunder, or to the performance hereunder or any such
agreements, without the prior written approval of the other party, which
approval shall not be unreasonably withheld. Scientific publications
published in accordance with Section 7.2 of this Agreement shall not be
construed as publicity governed by this Section 7.3.

                    8.     TERM AND TERMINATION.

                           8.1 TERM. Unless terminated sooner in accordance
with the terms set forth herein, this Agreement, and the license granted
hereunder, shall terminate as provided in Section 2.6 hereof.

                           8.2      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 [***] after receipt of a written notice requesting the payment
of such amount; (ii) the failure of a party to perform any obligation
required of its to be performed hereunder, and the failure to cure within
[***] 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 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 8.2 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.

[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

                                       11

<PAGE>

                           8.3      TERMINATION UPON BANKRUPTCY OR
INSOLVENCY. This Agreement may be terminated by Scripps giving written notice
of termination to Licensee upon the filing of bankruptcy or bankruptcy of
Licensee or the appointment of a receiver of any of Licensee's assets, or the
making by Licensee of any assignment for the benefit of creditors, or the
institution of any proceedings against Licensee under any bankruptcy law.
Termination shall be effective upon the date specified in such notice.

                           8.4      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, each party shall be required to continue to abide by its
nondisclosure obligations as described in Section 7.1, and Licensee shall
continue to abide by its obligation to indemnify Scripps as described in
Section 4.3 and by its obligations under Section 6.2 hereof.

                           8.5      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 8.6 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 any Scripps Patent Rights or
any Scripps Technology not otherwise includable therein. Upon any such
termination, Licensee shall promptly return all materials, samples,
documents, information, and other materials which embody or disclose Scripps
Patent Rights or any Scripps Technology not otherwise includable therein;
provided, however, that Licensee shall not be obligated to provide Scripps
with proprietary information which Licensee can show that it independently
developed. Licensee shall be free to keep one copy of all such materials,
samples, documents, information, and other materials for the sole purpose of
monitoring its obligations under this Section 8.5. 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 obligations as described in Section 7.1, and Licensee shall
continue to abide by its obligations to indemnify Scripps as described in
Section 4.3.

                           8.6      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.

                    9.     ASSIGNMENT; SUCCESSORS.

                           9.1      ASSIGNMENT.  Neither this Agreement nor
any rights granted hereunder may be assigned or transferred by Licensee
except (i) to an Affiliate of Licensee or (ii) as expressly permitted
hereunder, without the prior written consent of Scripps, which shall not be
unreasonably withheld.

[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

                                      12

<PAGE>

                           9.2      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.

                   10.     GENERAL PROVISIONS.

                           10.1     INDEPENDENT CONTRACTORS.  The
relationship between Scripps and Licensee is that of independent contractors.
Scripps and Licensee are not joint venturers, 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.

                           10.2     ARBITRATION.  Any controversy or claim
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 shall control.
Judgment upon the award rendered by the arbitrators may be enforced in any
court having jurisdiction thereof.

                                    10.2.1  LOCATION.  The location of the
arbitration shall be in the County of San Diego.

                                    10.2.2  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
patty 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.

                                    10.2.3  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 and non-privileged 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.

                                    10.2.4  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

[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

                                       13

<PAGE>

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.

                                    10.2.5  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 court action may be maintained seeking punitive damages. The
decision of any two of the three arbitrators appointed shall be binding upon
the parties.

                                    10.2.6  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 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.

                                    10.2.7  CONFIDENTIALITY.  Except as set
forth below, the parties shall keep confidential the fact of the arbitration,
the dispute being arbitrated, and the decision of the arbitrators.
Notwithstanding the foregoing, the parties may disclose information about the
arbitration to persons who have a need to know, such as directors, trustees,
management employees, witnesses, experts, investors, attorneys, lenders,
insurers, and others who may be directly affected. Additionally, if a party
has stock which is publicly traded, the party may make such disclosures as
are required by applicable securities laws. Further, if a party is expressly
asked by a third party about the dispute or the arbitration, the party may
disclose and acknowledge in general and limited terms that there is a dispute
with the other party which is being (or has been) arbitrated. Once the
arbitration award has become final, if the arbitration award is not promptly
satisfied, then these confidentiality provisions shall no longer be
applicable.

                           10.3     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.

                           10.4     CALIFORNIA LAW.  This Agreement shall be
construed and enforced in accordance with the laws of the State of California.

                           10.5     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.

                           10.6     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

[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

                                       14

<PAGE>

unenforceable provision with a valid and enforceable one such that the
objectives contemplated by them when entering this Agreement may be realized.

                           10.7     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.

                           10.8     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.

                           10.9     ATTORNEYS' FEES.  In the event of a
dispute between the parties hereto or in the event of any default hereunder,
the party prevailing in the resolution of any such dispute or default shall
be entitled to recover its reasonable attorneys' fees and other costs
incurred in connection with resolving such dispute or default.

                           10.10    NOTICES.  Any notices required by this
Agreement shall be in writing, shall specifically refer to this Agreement and
shall be sent by registered or certified airmail, postage prepaid, or by
telefax, telex or cable, charges prepaid, or by overnight courier, postage
prepaid and shall be forwarded to the respective addresses set forth below
unless subsequently changed by written notice to the other party:

         For Scripps:         The Scripps Research Institute
                              10550 North Torrey Pines Road
                              La Jolla, California 92037
                              Attention: V.P., Technology Development
                              Fax No.: (619) 554-9910

         For Licensee:        Drug Abuse Sciences
                              3 O'Dell Place
                              Atherton, California 94207
                              Attention: President
                              Fax No.: 415-328-8892

Notice shall be deemed delivered upon the earlier of (i) when received, (ii)
three (3) days after deposit into the mail, or (iii) the date notice is sent
via telefax, telex or cable, (iv) the day immediately following delivery to
overnight courier (except Sunday and holidays).

                           10.11    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.

[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

                                        15

<PAGE>

SCRIPPS:                                      LICENSEE:

THE SCRIPPS RESEARCH INSTITUTE                DRUG ABUSE SCIENCES

By:  /s/ Arnold LaGuardia                     By:  /s/ Philippe Pouletty
    ---------------------------------            ------------------------------
Title:  Sr. Vice President                    Title:  Chairman


[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.


                                       16

<PAGE>


                                    EXHIBIT B

                            DRUGABUSE SCIENCES, INC.

                         COMMON STOCK PURCHASE AGREEMENT

                  THIS AGREEMENT is made as of June 18, 1996, between DRUGABUSE
SCIENCES, INC., a California corporation (the "Company"), and The Scripps
Research Institute ("Scripps").

                                    RECITALS

                  A. The Company has entered into and made effective as of the
execution hereof a License Agreement with Scripps (the "License Agreement").

                  B. In connection with the License Agreement, the Company
wishes to issue to Scripps: (i) an aggregate of 110,765 shares of Common Stock
of the Company, which shares, when issued, represent .75% of the outstanding
shares of the Company immediately prior to the execution of this Agreement; (ii)
a warrant to purchase an aggregate of 166,148 shares of Common Stock of the
Company, which shares represent approximately 1.125% of the outstanding shares
of the Company immediately prior to the execution of this Agreement ("Warrant
W-1") and attached hereto as Exhibit 1; and (iii) an additional warrant to
purchase an aggregate of 166,148 shares Common Stock of the Company which shares
represent approximately 1.125% of the outstanding shares of the Company
immediately prior to the execution of this Agreement ("Warrant W-2") and
attached hereto as Exhibit 2.

                  C. The Company wishes to condition the exercise of Warrant W-1
and Warrant W-2 (collectively, the "Warrants") upon the completion of certain
events related to the research and development of new products by the Company
and attached hereto as Exhibit 3 (the "Milestones").

                  D. The authorized capital stock of the Company consists of
120,000,000 shares of Common Stock, 12,515,352 of which are issued and
outstanding and 187,778 shares of Series A Preferred Stock, 187,778 of which are
issued and outstanding and convertible into 2,253,336 shares of Common Stock.
The total number of common stock equivalents as of the date of this Agreement is
14,768,688.

                  E. Scripps wishes to acquire the Common Stock and the Warrants
on the terms and subject to the conditions set forth in this Agreement.

                                    AGREEMENT

                  NOW THEREFORE, in consideration for the willingness to enter
into the License Agreement and for the mutual covenants and representations
herein set forth, the Company and Scripps agree as follows:


[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

<PAGE>

                  F. ISSUANCE OF STOCK. As part of the consideration for the
grant of the licenses set forth in the License Agreement, the Company hereby
issues to Scripps, and Scripps hereby acquires from the Company, 110,765 shares
of the Company's Common Stock (the "Shares") valued at a price of $0.0225 per
share.

                  G. WARRANTS. As further consideration, the Company hereby
issues to Scripps the Warrants, valued at a price of $0.0225 per share subject
to the terms and conditions contained in the Warrants, for the grant of certain
licenses as provided in the License Agreement.

                  H. LEGENDS. The share certificate evidencing the Shares issued
hereunder shall be endorsed with the following legends (in addition to any
legends required under applicable state securities laws):

                  1. "THE SHARES REPRESENTED BY THIS CERTIFICATE HAVE BEEN
         ACQUIRED FOR INVESTMENT AND NOT WITH A VIEW TO, OR IN CONNECTION WITH,
         THE SALE OR DISTRIBUTION THEREOF. NO SUCH SALE OR DISPOSITION MAY BE
         EFFECTED WITHOUT AN EFFECTIVE REGISTRATION STATEMENT RELATED THERETO OR
         AN OPINION OF COUNSEL SATISFACTORY TO THE CORPORATION THAT SUCH
         REGISTRATION IS NOT REQUIRED UNDER THE SECURITIES ACT OF 1933.

                  2. Any legend required to be placed thereon by the California
         Commissioner of Corporations or any other applicable state securities
         laws.

                  I.       INVESTMENT REPRESENTATIONS; RESTRICTION ON TRANSFER.
In connection with the purchase of the Shares, Scripps represents to the Company
the following:

                           (a)      INFORMATION CONCERNING THE COMPANY.  Scripps
is aware of the Company's business affairs and financial condition and has
acquired sufficient information about the Company to reach an informed and
knowledgeable decision to acquire the Shares.

                                    1.      INVESTMENT INTENT.  Scripps is
purchasing these Shares for investment for Scripps' own account only and not
with a view to, or for resale in connection with, any "distribution" thereof
within the meaning of the Securities Act of 1933, as amended (the "Securities
Act").

                                    2.      RESIDENCE.  Scripps' principal
residence is within the State of California and is located at the address
indicated beneath Scripps' signature below.

                                    3.      RISK.   Scripps understands that the
Company is a start-up venture with limited financial and other resources and
that purchase of the Shares will be a highly speculative investment and involves
a high degree of risk, and Scripps is able, without impairing financial
condition, to hold the Shares for an indefinite period of time and to suffer a
complete loss of Scripps' investment.

                                    4.      RESTRICTED SECURITIES.  Scripps
acknowledges and understands that the Shares constitute "restricted securities"
under the Securities Act and must be

[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

                                       2

<PAGE>

held indefinitely unless they are subsequently registered under the
Securities Act or an exemption from such registration is available. Scripps
further acknowledges and understands that the Company is under no obligation
to register the Shares. Scripps understands that the certificate evidencing
the Shares will be imprinted with a legend which prohibits the transfer of
the Shares unless they are registered or such registration is not required in
the opinion of counsel satisfactory to the Company.

                                    5.      RULE 144.  Scripps is familiar
with the provisions of Rule 144, promulgated under the Securities Act, which,
in substance, permits limited public resale of "restricted securities"
acquired, directly or indirectly, from the issuer thereof, in a non-public
offering subject to the satisfaction of certain conditions. Rule 144 requires
among other things: (1) the availability of certain public information about
the Company; (2) the resale occurring not less than two years after the party
has purchased, and made full payment for, within the meaning of Rule 144, the
securities to be sold; and (3) in the case of an affiliate, or of a
non-affiliate who has held the securities less than three years, the sale
being made through a broker in an unsolicited "broker's transaction" or in
transactions directly with a market maker (as said term is defined under the
Securities Exchange Act of 1934) and the amount of securities being sold
during any three-month period not exceeding the specified limitations stated
therein, if applicable. Although the exemption from registration available
under Rule 144 is not necessarily exclusive, Scripps acknowledges that it may
bear a substantial burden of proof in establishing the existence of an
exemption under the Securities Act if the requirements under Rule 144 are not
satisfied.

                                    6.      TAXES.  Scripps understands that
Scripps' investment in the Company may result in personal tax consequences.
Scripps shall rely solely on the determinations of its tax advisors or its
own determinations, and not on any statements or representations by the
Company or any of its agents, with regard to all such tax matters.

                                    7.      NO PUBLIC MARKET.  Scripps
understands that no public market now exists for any securities issued by the
Company and that there is no assurance that a public market will ever exist
for the Shares.

                  J. MARKET STAND-OFF. Scripps agrees, in connection with the
initial public offering of the Company's securities, (i) not to sell, make
short sales of, loan, grant any options for the purchase of, or otherwise
dispose of any securities of the Company held by Scripps (other than those
securities included in the registration) without the prior written consent of
the Company or the underwriters managing such initial underwritten public
offering of the Company's securities for one hundred eighty (180) days from
the effective date of such registration and (ii) further agrees to execute
any agreement reflecting (i) above as may be requested by the underwriters at
the time of the public offering.

                  K. STATE SECURITIES LAW. The sale of the securities which
are the subject of this Agreement has not been qualified with the
Commissioner of Corporations of the State of California and the issuance of
such securities or the payment or receipt of any part of the consideration
therefor prior to such qualification is unlawful, unless the sale of
securities is exempt from the qualification by Section 25100, 25102, or 25105
of the California Corporations

[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

                                       3

<PAGE>

Code. The rights of all parties to this Agreement are expressly conditioned
upon such qualification being obtained, unless the sale is so exempt.

                  L. TRANSFER TO INVENTORS. Subject to applicable state and
federal securities laws, the Company shall permit the transfer of shares of
Common Stock and Warrants issued pursuant to this Agreement to those
inventors whose technology is covered by the License Agreement as directed by
Scripps, provided such inventors acquire such securities on the same terms
and conditions as such securities are acquired by Scripps.

                  M. GENERAL PROVISIONS.

                                    1.      GOVERNING LAW.  This Agreement
shall be governed by the internal laws of the State of California as applied
to agreements made and performed in California by residents of California.

                                    2.      ENTIRE AGREEMENT.  This Agreement
represents the entire agreement between the parties with respect to the
purchase of Common Stock by Scripps and may only be modified or amended in
writing signed by both parties.

                  IN WITNESS WHEREOF, the parties have duly executed this
Common Stock Purchase Agreement as of the day and year first set forth above.

DRUGABUSE SCIENCES, INC,                   THE SCRIPPS RESEARCH INSTITUTE
a California corporation                   a California nonprofit public benefit
                                           corporation

By:  /s/ Philippe Pouletty                 Name:  /s/ Arnold LaGuardia
    ----------------------------------           -----------------------------
Title:  Chairman                           By:   Arnold LaGuardia, Sr. V.P.
    ----------------------------------           -----------------------------
                                           10550 N. Toreey Pines Rd.
                                           -----------------------------------
                                           Address

                                           La Jolla, CA  92037
                                           -----------------------------------


[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

                                        4

<PAGE>

                                    EXHIBIT 1

                                   Warrant W-1










[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.




<PAGE>


THIS WARRANT AND THE SECURITIES ISSUABLE UPON THE EXERCISE HEREOF HAVE NOT BEEN
REGISTERED UNDER THE SECURITIES ACT OF 1933. THEY MAY NOT BE SOLD, OFFERED FOR
SALE, HYPOTHECATED OR OTHERWISE TRANSFERRED EXCEPT PURSUANT TO AN EFFECTIVE
REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933, OR AN OPINION OF
COUNSEL SATISFACTORY TO THE COMPANY THAT REGISTRATION IS NOT REQUIRED UNDER SUCH
ACT OR UNLESS SOLD PURSUANT TO RULE 144 UNDER SUCH ACT.

NO.:  W-1                                                            Void after
                                                                   June 18, 2016

                            DRUGABUSE SCIENCES, INC.

                          COMMON STOCK PURCHASE WARRANT

                              Issued June 18, 1996

                  This Warrant is issued, for good and valuable consideration,
receipt of which is hereby acknowledged, to The Scripps Research Institute, a
California nonprofit public benefit corporation, (the "Holder") by DrueAbuse
Sciences, Inc., a California corporation (the "Company").

                  1. PURCHASE OF SHARES. Subject to the terms and conditions
hereinafter set forth, the Holder is entitled, upon surrender of this Warrant to
the Company, to purchase from the Company fully paid and non-assessable shares
of the Company's Common Stock (as adjusted pursuant to Section 10 hereof, the
"Shares").

                  2. PURCHASE PRICE. The purchase price per share for the Shares
shall be $.0225, (the "Warrant Price"). The number of shares of Common Stock
purchasable upon exercise of this Warrant shall be 166,148 shares.

                  3. EXERCISE PERIOD. This Warrant is exercisable upon the
completion of certain events related to the research and development of new
products by the Company and attached hereto as Schedule 1 (the "Milestones"), at
any time before the close of business on June 18, 2016.

                  4. METHOD OF EXERCISE. While this Warrant remains outstanding,
the Holder may exercise, in whole or in part, the purchase rights evidenced
hereby in accordance with Section 3 above. Such exercise shall be effected by
the surrender of this Warrant to the Chief Financial Officer of the Company at
its principal offices, together with the payment to the Company (i) in cash, by
check or by wire transfer to an account designated by the Company, (ii) by
cancellation by the Holder of any then-outstanding indebtedness of the Company
to the Holder, or (iii) by a combination of (i) and (ii) of an amount equal to
the aggregate purchase price for the number of Shares being purchased.

[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

<PAGE>

                  5. NET ISSUE EXERCISE. In lieu of the payment methods set
forth in Section 4 above, immediately prior to, or at any time after, the
closing of an Initial Public Offering, the Holder may elect to exchange all
or a portion of this Warrant for Shares equal to the value of the amount of
the Warrant being exchanged on the date of exchange. If the Holder elects to
exchange this Warrant as provided in this Section 5, the Holder shall tender
to the Company the Warrant for the amount being exchanged, with written
notice of the Holder's election to exchange some or all of the Warrant, and
the Company shall issue to the Holder the number of Shares computed using the
following formula:

              X = Y (A-B)

                    A

         Where      X     =     the number of Shares to be issued to
                                the Holder.

                    Y     =     the number of Shares purchasable
                                under the amount of the Warrant
                                being exchanged (as adjusted to the
                                date of such calculation).

                    A     =     the Fair Market Value of one Share.

                    B     =     the Purchase Price (as adjusted to
                                the date of such calculation).

                  All references herein to an "exercise" of the Warrant shall
include an exchange pursuant to this Section 5. Upon receipt of a written
notice of the Company's intention to raise capital by selling shares of
Common Stock in an Initial Public Offering (the "IPO NOTICE"), which notice
shall be delivered to the Holder promptly after the date of filing with the
Securities and Exchange Commission of the registration statement associated
with such Initial Public Offering, the Holder shall use its reasonable
efforts to determine whether or not the Holder will exercise this Warrant
pursuant to this Section 5 prior to the completion of the Initial Public
Offering. Notwithstanding whether or not an IPO Notice has been delivered to
the Holder or any other provision of this Warrant to the contrary, if the
Holder decides to exercise this Warrant while a registration statement is on
file with the Securities and Exchange Commission in connection with the
Initial Public Offering, this Warrant shall be deemed exercised on the
closing of the Initial Public Offering and the Fair Market Value of a Share
shall be the price at which one share of Common Stock was sold to the public
in the Initial Public Offering. If the Holder has elected to exercise this
Warrant pursuant to this Section 5 while a registration statement is on file
with the Securities and Exchange Commission in connection with an Initial
Public Offering and the Initial Public Offering is not completed, then the
Holder's exercise of this Warrant shall not be effective.

                  6. EXERCISE NOTICE AND INVESTMENT REPRESENTATIONS. On or
prior to the date of each exercise under this Warrant, Holder shall deliver
an executed copy of (a) the form of Notice of Exercise attached hereto as
EXHIBIT 1 duly executed by the Holder and (b) the form of Investment
Representation Statement attached hereto as EXHIBIT 2.

                  7. CERTIFICATE OF ADJUSTMENT. Whenever the Warrant Price or
number or type of securities issuable upon exercise of this Warrant is adjusted,
as herein provided, the Company

[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

                                       2

<PAGE>

shall promptly deliver to the record holder of this Warrant a certificate of
an officer of the Company setting forth the nature of such adjustment and a
brief statement of the facts requiring such adjustment.

                  8. CERTIFICATES FOR SHARES. Upon the exercise of the
purchase rights evidenced by this Warrant, one or more certificates for the
number of Shares so purchased shall be issued as soon as practicable
thereafter, and in any event within thirty (30) days of the delivery of the
subscription notice.

                  9. RESERVATION OF SHARES. The Company covenants that it
will at all times keep available such number of authorized shares of its
Common Stock, free from all preemptive rights with respect thereto, which
will be sufficient to permit the exercise of this Warrant for the full number
of Shares specified herein. The Company further covenants that such Shares,
when issued pursuant to the exercise of this Warrant, will be duly and
validly issued, fully paid and nonassessable and free from all taxes, liens
and charges with respect to the issuance thereof

                  10. ADJUSTMENT OF WARRANT PRICE AND NUMBER OF SHARES.

                           (a)      SPLITS  AND  COMBINATIONS.  If the
Company at any time subdivides any of its outstanding shares of Common Stock
into a greater number of shares, the Warrant Price in effect immediately
prior to such subdivision shall be proportionately reduced, and, conversely,
if the outstanding shares of Common Stock are combined into a smaller number
of shares, the Warrant Price in effect immediately prior to such combination
shall be proportionately increased. Upon any adjustment of the Warrant Price
under this Section 10(a), the number of shares of Common Stock issuable upon
exercise of this Warrant shall equal the number of shares determined by
dividing (i) the aggregate Warrant Price payable for the purchase of all
shares issuable upon exercise of this Warrant immediately prior to such
adjustment by (ii) the Warrant Price per share in effect immediately after
such adjustment.

                           (b)      RECLASSIFICATIONS  AND EXCHANGES.  If the
Company changes any of the securities as to which purchase rights under this
Warrant exist into the same or a different number of securities of any other
class or classes, this Warrant shall thereafter represent the right to
acquire such number and kind of securities as would have been issuable as the
result of such change with respect to the securities that were subject to the
purchase rights under this Warrant immediately prior to such reclassification
or other change and the Warrant Price therefor shall be appropriately
adjusted. If thirty percent (30%) or more of the Company's outstanding Common
Stock is voluntarily exchanged for a different security issued by the
Company, then the Investor shall have the right to elect to receive such
security rather than the Common Stock on exercise or conversion of this
Warrant.

                           (c)      DIVIDENDS  AND  DISTRIBUTION.  If the
Company declares a non-cash dividend or other distribution on the Common
Stock or if a dividend or other distribution on the Common Stock occurs
pursuant to the Articles of Incorporation (other than a cash dividend or
distribution), then, as part of such dividend or distribution, lawful
provision shall be made so that there shall thereafter be deliverable upon
the exercise of this Warrant or any portion thereof, in addition to the
number of shares of Common Stock receivable thereupon and without payment of
any additional consideration, the amount of the dividend or other
distribution to which the holder

[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

                                       3

<PAGE>

of the number of shares of Common Stock obtained upon exercise hereof would
have been entitled to receive had the exercise occurred as of the record date
for such dividend or distribution.

                  11. NO SHAREHOLDER RIGHTS. Prior to exercise of this
Warrant, the Holder shall not be entitled to any rights of a shareholder
including (without limitation) the right to vote, receive preemptive rights
or be notified of shareholder meetings, and such Holder shall not be entitled
to any notice or other communication concerning the business or affairs or
the Company.

                  12. RESTRICTED SECURITIES. The Holder understands that this
Warrant and the Shares purchasable hereunder constitute "restricted
securities" under the federal securities laws inasmuch as they are being, or
will be, acquired from the Company in transactions not involving a public
offering and accordingly may not, under such laws and applicable regulations,
be resold or transferred without registration under the Securities Act of
1933 or an applicable exemption from registration. In this connection, the
Holder acknowledges that Rule 144 of the Securities and Exchange Commission
is not now, and may not in the future be, available for resales of the Shares
purchased hereunder. The Holder further acknowledges that the Shares and any
other securities issued upon exercise of this Warrant shall bear a legend
substantially in the form of the legend appearing on the face hereof.

                  THE SALE OF THESE SECURITIES HAS NOT BEEN QUALIFIED WITH
THE COMMISSIONER OF CORPORATIONS OF THE STATE OF CALIFORNIA AND THE ISSUANCE
OF SUCH SECURITIES OR THE PAYMENT OR RECEIPT OF ANY PART OF THE CONSIDERATION
THEREFOR PRIOR TO SUCH QUALIFICATION IS UNLAWFUL UNLESS SUCH SALE OR TRANSFER
IS EXEMPT FROM QUALIFICATION BY SECTION 25100, 25102 OR 25105 OF THE
CALIFORNIA CORPORATIONS CODE. THE RIGHTS OF ALL PARTIES TO THESE SECURITIES
ARE EXPRESSLY CONDITIONED UPON SUCH QUALIFICATION BEING OBTAINED UNLESS THE
SALE IS SO EXEMPT.

                  13. CERTIFICATION OF INVESTMENT PURPOSE. Unless a current
registration statement under the Securities Act of 1933 shall be in effect
with respect to the securities to be issued upon exercise of this Warrant,
the Holder, by accepting this Warrant, covenants and agrees that, at the time
of exercise hereof, such Holder will deliver to the Company a written
certification satisfactory to the Company that the securities acquired by the
Holder and acquired for investment purposes only and that such securities are
not acquired with a view to, or for sale in connection with, any distribution
thereof.

                  14. SUCCESSORS AND ASSIGNS. The terms and provisions of
this Warrant shall inure to the benefit of, and be binding upon, the Company
and the Holder hereof and their respective successors and assigns.

                  15. AMENDMENT. This Warrant is one of several warrants (the
"Bridge Warrants") issued by the Company in further consideration of certain
loans made to support the Company's continuing operations prior to the
arrangement of and commitment to close the Next Financing. Any term of this
Warrant may be amended if agreed to by the Company and holders of Bridge
Warrants representing a majority of the shares issuable upon exercise of all
Bridge Warrants then outstanding. Notwithstanding the foregoing, no such
amendment of this Warrant

[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

                                       4

<PAGE>

shall be effective if it would (i) alter the number of shares issuable
hereunder, or (ii) affect this Warrant in a manner different than the other
Bridge Warrants, unless the Holder hereof consents thereto.

                  16. NON-TRANSFERABILITY. The Holder of this note shall not
sell, transfer, pledge, hypothecate or otherwise dispose of any interest in
this note without the prior written consent of the Company, with one
exception: Scripps may transfer any portion of Scripps' interest in this note
to the inventors whose technology is covered by the License Agreement.

                  17. LOCKUP AGREEMENT. In consideration of the Company's
issuance of this Warrant, the Holder agrees in connection with an Initial
Public Offering not to sell, make any short sale of, loan, grant any option
for the purchase of, or otherwise dispose of any Shares issuable hereunder
without the prior written consent of an underwriter or underwriters in such
Initial Public Offering, for such period of time (not to exceed 180 days)
from the effective date of such registration as such underwriter or
underwriters may specify.

                  18. COUNTERPARTS. For the convenience of the parties, any
number of counterparts of this Warrant may be executed by the parties hereto
and each such executed counterpart shall be, and shall be deemed to be, an
original instrument.

                  19. GOVERNING LAW. This Warrant shall be governed by the
laws of the State of California as applied to agreements among California
residents entered into and to be performed entirely within California.

                                      DRUGABUSE SCIENCES, INC.

                                      By:  Chairman
                                          -----------------------------
                                      Title:
                                            ---------------------------


Accepted and Agreed:

By:
   ------------------------------
             Signature

Arnold LaGuardia, Sr. V.P.
-----------------------------------------
    (Print name and, if applicable, title)


[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.


                                       5
<PAGE>

                                    EXHIBIT 1

                               NOTICE OF EXERCISE

                    (To be executed upon exercise of Warrant)

DRUGABUSE SCIENCES, INC.

                  The undersigned hereby irrevocably elects to exercise the
Warrant for shares of capital stock, as provided for therein, and (check the
applicable box):

                  / /      Tenders payment of the purchase price in the form of
                           cash, by check or wire transfer, in the amount of
                           $____________________ for __________ shares of Common
                           Stock.

                  / /      Elects the Net Issue Exercise option pursuant to
                           Section 5 of the Warrant, and requests delivery of a
                           net of __________ shares of Common Stock.

                  The undersigned hereby affirms the statements and covenants in
Section 12 of the Warrant. Please issue a certificate or certificates for such
shares in the name of, and pay any cash for any fractional share to (please
print name, address and social security number)

Name:_______________________________________

Address:____________________________________

Signature:__________________________________

Note:    The above signature should correspond exactly with the name on the
         first page of this Warrant or with the name of the assignee appearing
         in the assignment form below.

                  If said number of shares shall not be all the shares
purchasable under the within Warrant, a new Warrant is to be issued in the name
of the Registered Holder for the balance remaining of the shares purchasable
thereunder together with cash in lieu of any fraction of a share in the amount
of the current Fair Market Value of one whole share as of the date of exercise
multiplied by such fraction.

[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

<PAGE>

                                    EXHIBIT 2

                       INVESTMENT REPRESENTATION STATEMENT

                                           __________ Shares of Common Stock of
                                                        DrugAbuse Sciences, Inc.

                  In connection with the purchase of the above-listed securities
the undersigned hereby represents to DrugAbuse Sciences, Inc. (the "Company") as
follows:

                  RECEIPT OF INFORMATION. The undersigned has received all the
information it considers necessary or appropriate for deciding whether to
purchase the Common Stock issuable upon exercise of the Warrant dated June __,
1996 (the "Warrant") issued by the Company to the undersigned, and it has
examined any information furnished to it by the Company in connection therewith.

                  INVESTMENT REPRESENTATION.

                  (a) The shares of Stock to be received by the undersigned upon
the exercise of the Warrant (the "Securities") will be acquired for investment
for its own account, not as a nominee or agent, and not with a view to the sale
or distribution of any part thereof, except that it is understood that Scripps
may transfer any portion of Scripps' interest in the Warrant and shares of the
Company to the inventors of the technology which is the subject of the License
Agreement and the undersigned has no present intention of selling, granting
participation in or otherwise distributing the same, but subject, nevertheless,
to any requirement of law that the disposition of its property shall at all
times be within its control. By executing this Statement, the undersigned
further represents that it does not have any contract, undertaking, agreement or
arrangement with any person to sell, transfer, or grant participation to such
person or to any third person, with respect to any Securities issuable upon
exercise of the Warrant, except as provided herein.

                  (b) The undersigned understands that the Securities issuable
upon exercise of the Warrant at the time of issuance may not be registered under
the Securities Act of 1933, as amended (the "Act"), and applicable state
securities laws, on the ground that the issuance of such securities is exempt
pursuant to Section 4(2) of the Act and state law exemptions relating to offers
and sales not by means of a public offering, and that the Company's reliance on
such exemptions is predicated on the undersigned's representations set forth
herein.

                  (c) The undersigned agrees that in no event will it make a
disposition of any Securities acquired upon the exercise of the Warrant unless
and until (i) it shall have notified the Company of the proposed disposition and
shall have furnished the Company with a statement of the circumstances
surrounding the proposed disposition, and (ii) it shall have furnished the
Company with an opinion of counsel satisfactory to the Company and the Company's
counsel to the effect that (A) appropriate action necessary for compliance with
the Act and any applicable state securities laws has been taken or an exemption
from the registration requirements of the Act and such laws is available, and
(B) that the proposed transfer will not violate any of said laws.
Notwithstanding the provisions of this paragraph, Scripps may transfer any
portion of the

[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

<PAGE>

Warrant and shares of the Company to Kim Janda and/or Peter Wirshing, the
inventors of the technology which is the subject of the License Agreement
without providing additional notice or advice of counsel.

                  (d) The undersigned represents that it is able to fend for
itself in the transactions contemplated by this Statement, has such knowledge
and experience in financial and business matters as to be capable of evaluating
the merits and risks of its investments, and has the ability to bear the
economic risks (including the risk of a total loss) of its investment. The
undersigned represents that it has had the opportunity to ask questions of the
Company concerning the Company's business and assets and to obtain any
additional information which it considered necessary to verify the accuracy of
or to amplify the Company's disclosures, and has had all questions which have
been asked by it satisfactorily answered by the Company.

                  (e) The undersigned acknowledges that the Securities issuable
upon exercise of the Warrant must be held indefinitely unless subsequently
registered under the Act or an exemption from such registration is available,
except as provided otherwise herein. The undersigned is aware of the provisions
of Rule 144 promulgated under the Act which permit limited resale of shares
purchased in a private placement subject to the satisfaction of certain
conditions, including, among other things, the existence of a public market for
the shares, the availability of certain current public information about the
Company, the resale occurring not less than two years after a party has
purchased and paid for the security to be sold, the sale being through a
"broker's transaction" or in transactions directly with a "market maker" (as
provided by Rule 144(f)) and the number of shares being sold during any
three-month period not exceeding specified limitations. The undersigned is aware
that the conditions for resale set forth in Rule 144 have not been satisfied.

Dated:  __________

                                   _______________________________________
                                   (Signature)

                                   _______________________________________
                                   (Typed or Printed Name)

                                   _______________________________________
                                   (Title)


                                       2

[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

<PAGE>

                                   SCHEDULE 1

                                   MILESTONES

                  1. Warrant W-l is exercisable upon the filing of an
investigational new drug application ("IND") for an efficacy clinical trial
sponsored by Licensee or its Sublicensee with the U.S. Food and Drug
Administration in respect of a Licensed Product.

[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

<PAGE>

                                    EXHIBIT 2

                                   Warrant W-2










[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

<PAGE>

THIS WARRANT AND THE SECURITIES ISSUABLE UPON THE EXERCISE HEREOF HAVE NOT BEEN
REGISTERED UNDER THE SECURITIES ACT OF 1933. THEY MAY NOT BE SOLD, OFFERED FOR
SALE, HYPOTHECATED OR OTHERWISE TRANSFERRED EXCEPT PURSUANT TO AN EFFECTIVE
REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933, OR AN OPINION OF
COUNSEL SATISFACTORY TO THE COMPANY THAT REGISTRATION IS NOT REQUIRED UNDER SUCH
ACT OR UNLESS SOLD PURSUANT TO RULE 144 UNDER SUCH ACT.

NO.:  W-1                                                            Void after
                                                                   June 18, 2016

                            DRUGABUSE SCIENCES, INC.

                          COMMON STOCK PURCHASE WARRANT
                              Issued June 18, 1996

                  This Warrant is issued, for good and valuable consideration,
receipt of which is hereby acknowledged, to The Scripps Research Institute, a
California nonprofit public benefit corporation, (the "Holder") by DrueAbuse
Sciences, Inc., a California corporation (the "Company").

                  20. PURCHASE OF SHARES. Subject to the terms and conditions
hereinafter set forth, the Holder is entitled, upon surrender of this Warrant to
the Company, to purchase from the Company fully paid and non-assessable shares
of the Company's Common Stock (as adjusted pursuant to Section 10 hereof, the
"Shares").

                  21. PURCHASE PRICE. The purchase price per share for the
Shares shall be $.0225, (the "Warrant Price"). The number of shares of Common
Stock purchasable upon exercise of this Warrant shall be 166,148 shares.

                  22. EXERCISE PERIOD. This Warrant is exercisable upon the
completion of certain events related to the research and development of new
products by the Company and attached hereto as Schedule 1 (the "Milestones"), at
any time before the close of business on June 18, 2016.

                  23. METHOD OF EXERCISE. While this Warrant remains
outstanding, the Holder may exercise, in whole or in part, the purchase rights
evidenced hereby in accordance with Section 3 above. Such exercise shall be
effected by the surrender of this Warrant to the Chief Financial Officer of the
Company at its principal offices, together with the payment to the Company (i)
in cash, by check or by wire transfer to an account designated by the Company,
(ii) by cancellation by the Holder of any then-outstanding indebtedness of the
Company to the Holder, or (iii) by a combination of (i) and (ii) of an amount
equal to the aggregate purchase price for the number of Shares being purchased.

[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

<PAGE>

                  24. NET ISSUE EXERCISE. In lieu of the payment methods set
forth in Section 4 above, immediately prior to, or at any time after, the
closing of an Initial Public Offering, the Holder may elect to exchange all or a
portion of this Warrant for Shares equal to the value of the amount of the
Warrant being exchanged on the date of exchange. If the Holder elects to
exchange this Warrant as provided in this Section 5, the Holder shall tender to
the Company the Warrant for the amount being exchanged, with written notice of
the Holder's election to exchange some or all of the Warrant, and the Company
shall issue to the Holder the number of Shares computed using the following
formula:

                  X = Y (A-B)
                      -------
                         A

         Where             X        =       the number of Shares to be issued to
                                            the Holder.

                           Y        =       the number of Shares purchasable
                                            under the amount of the Warrant
                                            being exchanged (as adjusted to the
                                            date of such calculation).

                           A        =       the Fair Market Value of one Share.

                           B        =       the Purchase Price (as adjusted to
                                            the date of such calculation).

                  All references herein to an "exercise" of the Warrant shall
include an exchange pursuant to this Section 5. Upon receipt of a written notice
of the Company's intention to raise capital by selling shares of Common Stock in
an Initial Public Offering (the "IPO NOTICE"), which notice shall be delivered
to the Holder promptly after the date of filing with the Securities and Exchange
Commission of the registration statement associated with such Initial Public
Offering, the Holder shall use its reasonable efforts to determine whether or
not the Holder will exercise this Warrant pursuant to this Section 5 prior to
the completion of the Initial Public Offering. Notwithstanding whether or not an
IPO Notice has been delivered to the Holder or any other provision of this
Warrant to the contrary, if the Holder decides to exercise this Warrant while a
registration statement is on file with the Securities and Exchange Commission in
connection with the Initial Public Offering, this Warrant shall be deemed
exercised on the closing of the Initial Public Offering and the Fair Market
Value of a Share shall be the price at which one share of Common Stock was sold
to the public in the Initial Public Offering. If the Holder has elected to
exercise this Warrant pursuant to this Section 5 while a registration statement
is on file with the Securities and Exchange Commission in connection with an
Initial Public Offering and the Initial Public Offering is not completed, then
the Holder's exercise of this Warrant shall not be effective.

                  25. EXERCISE NOTICE AND INVESTMENT REPRESENTATIONS. On or
prior to the date of each exercise under this Warrant, Holder shall deliver an
executed copy of (a) the form of Notice of Exercise attached hereto as EXHIBIT 1
duly executed by the Holder and (b) the form of Investment Representation
Statement attached hereto as EXHIBIT 2.

                  26. CERTIFICATE OF ADJUSTMENT. Whenever the Warrant Price or
number or type of securities issuable upon exercise of this Warrant is adjusted,
as herein provided, the Company

[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

                                       2

<PAGE>

shall promptly deliver to the record holder of this Warrant a certificate of
an officer of the Company setting forth the nature of such adjustment and a
brief statement of the facts requiring such adjustment.

                  27. CERTIFICATES FOR SHARES. Upon the exercise of the purchase
rights evidenced by this Warrant, one or more certificates for the number of
Shares so purchased shall be issued as soon as practicable thereafter, and in
any event within thirty (30) days of the delivery of the subscription notice.

                  28. RESERVATION OF SHARES. The Company covenants that it will
at all times keep available such number of authorized shares of its Common
Stock, free from all preemptive rights with respect thereto, which will be
sufficient to permit the exercise of this Warrant for the full number of Shares
specified herein. The Company further covenants that such Shares, when issued
pursuant to the exercise of this Warrant, will be duly and validly issued, fully
paid and nonassessable and free from all taxes, liens and charges with respect
to the issuance thereof

                  29.      ADJUSTMENT OF WARRANT PRICE AND NUMBER OF SHARES.

                           (a)      SPLITS  AND  COMBINATIONS.  If the  Company
at any time subdivides any of its outstanding shares of Common Stock into a
greater number of shares, the Warrant Price in effect immediately prior to such
subdivision shall be proportionately reduced, and, conversely, if the
outstanding shares of Common Stock are combined into a smaller number of shares,
the Warrant Price in effect immediately prior to such combination shall be
proportionately increased. Upon any adjustment of the Warrant Price under this
Section 10(a), the number of shares of Common Stock issuable upon exercise of
this Warrant shall equal the number of shares determined by dividing (i) the
aggregate Warrant Price payable for the purchase of all shares issuable upon
exercise of this Warrant immediately prior to such adjustment by (ii) the
Warrant Price per share in effect immediately after such adjustment.

                           (b)      RECLASSIFICATIONS  AND EXCHANGES.  If the
Company changes any of the securities as to which purchase rights under this
Warrant exist into the same or a different number of securities of any other
class or classes, this Warrant shall thereafter represent the right to acquire
such number and kind of securities as would have been issuable as the result of
such change with respect to the securities that were subject to the purchase
rights under this Warrant immediately prior to such reclassification or other
change and the Warrant Price therefor shall be appropriately adjusted. If thirty
percent (30%) or more of the Company's outstanding Common Stock is voluntarily
exchanged for a different security issued by the Company, then the Investor
shall have the right to elect to receive such security rather than the Common
Stock on exercise or conversion of this Warrant.

                           (c)      DIVIDENDS  AND  DISTRIBUTION.  If the
Company declares a non-cash dividend or other distribution on the Common Stock
or if a dividend or other distribution on the Common Stock occurs pursuant to
the Articles of Incorporation (other than a cash dividend or distribution),
then, as part of such dividend or distribution, lawful provision shall be made
so that there shall thereafter be deliverable upon the exercise of this Warrant
or any portion thereof, in addition to the number of shares of Common Stock
receivable thereupon and without payment of any additional consideration, the
amount of the dividend or other distribution to which the holder

[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

                                       3

<PAGE>

of the number of shares of Common Stock obtained upon exercise hereof would
have been entitled to receive had the exercise occurred as of the record date
for such dividend or distribution.

                  30. NO SHAREHOLDER RIGHTS. Prior to exercise of this Warrant,
the Holder shall not be entitled to any rights of a shareholder including
(without limitation) the right to vote, receive preemptive rights or be notified
of shareholder meetings, and such Holder shall not be entitled to any notice or
other communication concerning the business or affairs or the Company.

                  31. RESTRICTED SECURITIES. The Holder understands that this
Warrant and the Shares purchasable hereunder constitute "restricted securities"
under the federal securities laws inasmuch as they are being, or will be,
acquired from the Company in transactions not involving a public offering and
accordingly may not, under such laws and applicable regulations, be resold or
transferred without registration under the Securities Act of 1933 or an
applicable exemption from registration. In this connection, the Holder
acknowledges that Rule 144 of the Securities and Exchange Commission is not now,
and may not in the future be, available for resales of the Shares purchased
hereunder. The Holder further acknowledges that the Shares and any other
securities issued upon exercise of this Warrant shall bear a legend
substantially in the form of the legend appearing on the face hereof.

                  THE SALE OF THESE SECURITIES HAS NOT BEEN QUALIFIED WITH THE
COMMISSIONER OF CORPORATIONS OF THE STATE OF CALIFORNIA AND THE ISSUANCE OF SUCH
SECURITIES OR THE PAYMENT OR RECEIPT OF ANY PART OF THE CONSIDERATION THEREFOR
PRIOR TO SUCH QUALIFICATION IS UNLAWFUL UNLESS SUCH SALE OR TRANSFER IS EXEMPT
FROM QUALIFICATION BY SECTION 25100, 25102 OR 25105 OF THE CALIFORNIA
CORPORATIONS CODE. THE RIGHTS OF ALL PARTIES TO THESE SECURITIES ARE EXPRESSLY
CONDITIONED UPON SUCH QUALIFICATION BEING OBTAINED UNLESS THE SALE IS SO EXEMPT.

                  32. CERTIFICATION OF INVESTMENT PURPOSE. Unless a current
registration statement under the Securities Act of 1933 shall be in effect with
respect to the securities to be issued upon exercise of this Warrant, the
Holder, by accepting this Warrant, covenants and agrees that, at the time of
exercise hereof, such Holder will deliver to the Company a written certification
satisfactory to the Company that the securities acquired by the Holder and
acquired for investment purposes only and that such securities are not acquired
with a view to, or for sale in connection with, any distribution thereof.

                  33. SUCCESSORS AND ASSIGNS. The terms and provisions of this
Warrant shall inure to the benefit of, and be binding upon, the Company and the
Holder hereof and their respective successors and assigns.

                  34. AMENDMENT. This Warrant is one of several warrants (the
"Bridge Warrants") issued by the Company in further consideration of certain
loans made to support the Company's continuing operations prior to the
arrangement of and commitment to close the Next Financing. Any term of this
Warrant may be amended if agreed to by the Company and holders of Bridge
Warrants representing a majority of the shares issuable upon exercise of all
Bridge Warrants then outstanding. Notwithstanding the foregoing, no such
amendment of this Warrant

[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

                                       4

<PAGE>

shall be effective if it would (i) alter the number of shares issuable
hereunder, or (ii) affect this Warrant in a manner different than the other
Bridge Warrants, unless the Holder hereof consents thereto.

                  35. NON-TRANSFERABILITY. The Holder of this note shall not
sell, transfer, pledge, hypothecate or otherwise dispose of any interest in this
note without the prior written consent of the Company, with one exception:
Scripps may transfer any portion of Scripps' interest in this note to the
inventors whose technology is covered by the License Agreement.

                  36. LOCKUP AGREEMENT. In consideration of the Company's
issuance of this Warrant, the Holder agrees in connection with an Initial Public
Offering not to sell, make any short sale of, loan, grant any option for the
purchase of, or otherwise dispose of any Shares issuable hereunder without the
prior written consent of an underwriter or underwriters in such Initial Public
Offering, for such period of time (not to exceed 180 days) from the effective
date of such registration as such underwriter or underwriters may specify.

                  37. COUNTERPARTS. For the convenience of the parties, any
number of counterparts of this Warrant may be executed by the parties hereto and
each such executed counterpart shall be, and shall be deemed to be, an original
instrument.

                  38. GOVERNING LAW. This Warrant shall be governed by the laws
of the State of California as applied to agreements among California residents
entered into and to be performed entirely within California.

                                          DRUGABUSE SCIENCES, INC.

                                          By:  /s/ Philippe Pouletty
                                             --------------------------------
                                          Title:  Chairman
                                                -----------------------------

Accepted and Agreed:

By:  /s/ Arnold LaGuardia
   -----------------------------------
             Signature

Arnold LaGuardia, Sr. V.P.
--------------------------------------
(Print name and, if applicable, title)


[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

                                       5
<PAGE>


                                    EXHIBIT 1

                               NOTICE OF EXERCISE

                    (To be executed upon exercise of Warrant)

DRUGABUSE SCIENCES, INC.

                  The undersigned hereby irrevocably elects to exercise the
Warrant for shares of capital stock, as provided for therein, and (check the
applicable box):

                  / /      Tenders payment of the purchase price in the form of
                           cash, by check or wire transfer, in the amount of
                           $____________________ for __________ shares of Common
                           Stock.

                  / /      Elects the Net Issue Exercise option pursuant to
                           Section 5 of the Warrant, and requests delivery of a
                           net of __________ shares of Common Stock.

                  The undersigned hereby affirms the statements and covenants
in Section 12 of the Warrant. Please issue a certificate or certificates for
such shares in the name of, and pay any cash for any fractional share to
(please print name, address and social security number)

Name:______________________________

Address:___________________________

Signature:_________________________

Note:    The above signature should correspond exactly with the name on the
         first page of this Warrant or with the name of the assignee appearing
         in the assignment form below.

                  If said number of shares shall not be all the shares
purchasable under the within Warrant, a new Warrant is to be issued in the name
of the Registered Holder for the balance remaining of the shares purchasable
thereunder together with cash in lieu of any fraction of a share in the amount
of the current Fair Market Value of one whole share as of the date of exercise
multiplied by such fraction.


[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

<PAGE>

                                    EXHIBIT 2

                       INVESTMENT REPRESENTATION STATEMENT

                                            __________ Shares of Common Stock of
                                                        DrugAbuse Sciences, Inc.

                  In connection with the purchase of the above-listed securities
the undersigned hereby represents to DrugAbuse Sciences, Inc. (the "Company") as
follows:

                  RECEIPT OF INFORMATION. The undersigned has received all the
information it considers necessary or appropriate for deciding whether to
purchase the Common Stock issuable upon exercise of the Warrant dated June __,
1996 (the "Warrant") issued by the Company to the undersigned, and it has
examined any information furnished to it by the Company in connection therewith.

                  INVESTMENT REPRESENTATION.

                  (a) The shares of Stock to be received by the undersigned
upon the exercise of the Warrant (the "Securities") will be acquired for
investment for its own account, not as a nominee or agent, and not with a view
to the sale or distribution of any part thereof, except that it is understood
that Scripps may transfer any portion of Scripps' interest in the Warrant and
shares of the Company to the inventors of the technology which is the subject
of the License Agreement and the undersigned has no present intention of
selling, granting participation in or otherwise distributing the same, but
subject, nevertheless, to any requirement of law that the disposition of its
property shall at all times be within its control. By executing this Statement,
the undersigned further represents that it does not have any contract,
undertaking, agreement or arrangement with any person to sell, transfer, or
grant participation to such person or to any third person, with respect to any
Securities issuable upon exercise of the Warrant, except as provided herein.

                  (b) The undersigned understands that the Securities issuable
upon exercise of the Warrant at the time of issuance may not be registered
under the Securities Act of 1933, as amended (the "Act"), and applicable state
securities laws, on the ground that the issuance of such securities is exempt
pursuant to Section 4(2) of the Act and state law exemptions relating to offers
and sales not by means of a public offering, and that the Company's reliance on
such exemptions is predicated on the undersigned's representations set forth
herein.

                  (c) The undersigned agrees that in no event will it make a
disposition of any Securities acquired upon the exercise of the Warrant unless
and until (i) it shall have notified the Company of the proposed disposition
and shall have furnished the Company with a statement of the circumstances
surrounding the proposed disposition, and (ii) it shall have furnished the
Company with an opinion of counsel satisfactory to the Company and the
Company's counsel to the effect that (A) appropriate action necessary for
compliance with the Act and any applicable state securities laws has been taken
or an exemption from the registration requirements of the Act and such laws is
available, and (B) that the proposed transfer will not violate any of said
laws. Notwithstanding the provisions of this paragraph, Scripps may transfer
any portion of the

[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

<PAGE>

Warrant and shares of the Company to Kim Janda and/or Peter Wirshing, the
inventors of the technology which is the subject of the License Agreement
without providing additional notice or advice of counsel.

                  (d) The undersigned represents that it is able to fend for
itself in the transactions contemplated by this Statement, has such knowledge
and experience in financial and business matters as to be capable of evaluating
the merits and risks of its investments, and has the ability to bear the
economic risks (including the risk of a total loss) of its investment. The
undersigned represents that it has had the opportunity to ask questions of the
Company concerning the Company's business and assets and to obtain any
additional information which it considered necessary to verify the accuracy of
or to amplify the Company's disclosures, and has had all questions which have
been asked by it satisfactorily answered by the Company.

                  (e) The undersigned acknowledges that the Securities issuable
upon exercise of the Warrant must be held indefinitely unless subsequently
registered under the Act or an exemption from such registration is available,
except as provided otherwise herein. The undersigned is aware of the provisions
of Rule 144 promulgated under the Act which permit limited resale of shares
purchased in a private placement subject to the satisfaction of certain
conditions, including, among other things, the existence of a public market for
the shares, the availability of certain current public information about the
Company, the resale occurring not less than two years after a party has
purchased and paid for the security to be sold, the sale being through a
"broker's transaction" or in transactions directly with a "market maker" (as
provided by Rule 144(f)) and the number of shares being sold during any
three-month period not exceeding specified limitations. The undersigned is
aware that the conditions for resale set forth in Rule 144 have not been
satisfied.


Dated:  __________

                                   ________________________________
                                   (Signature)


                                   ________________________________
                                   (Typed or Printed Name)


                                   ________________________________
                                   (Title)

[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

                                      2

<PAGE>


                                   SCHEDULE 1

                                   MILESTONES

                  1. Warrant W-2 is exercisable upon demonstration of human
clinical efficacy for a primary end point in a Phase II clinical trial
sponsored by Licensee or its Sublicensee in respect of a Licensed Product.


[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

<PAGE>


                                    EXHIBIT 3

                                   Milestones

                  1. Warrant W-1 is exercisable upon the filing of an
investigational new drug application ("IND") for an efficacy clinical trial
sponsored by Licensee or its Sublicensees with the U.S. Food and Drug
Administration in respect of a Licensed Product.

                  2. Warrant W-2 is exercisable upon demonstration of human
clinical efficacy for a primary end point in a Phase II clinical trial
sponsored by Licensee or its Sublicensee in respect of a Licensed Product.


[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

<PAGE>


                                    EXHIBIT C

                               FORM OF SUBLICENSE

                  This Sublicense Term Sheet is entered into and made effective
as of ____________________, 19__ by and between ______________________________,
a __________ located at _______________________________________________________
("Licensee") and ______________________________, a ____________________ located
at ________________________________________ ("Sublicensee").

                  GRANT OF SUBLICENSE. Licensee hereby grants to Sublicensee a
sublicense under and on all the same terms and conditions of that certain
License Agreement between Licensee and The Scripps Research Institute, a
California nonprofit public benefit corporation ("Scripps") attached hereto as
Exhibit I (the "Master License Agreement"), except as set forth below:

                  a.       Technology subject to Sublicense: _______________
____________________________________________________________________________
____________________________________________________________________________.

                  b.       Term: ___________________________________________
____________________________________________________________________________
____________________________________________________________________________.

                  c.       Royalty Payments: _______________________________
____________________________________________________________________________
____________________________________________________________________________.

                  d.       Commercial Development Obligations: _____________
____________________________________________________________________________
____________________________________________________________________________.

                  By its signature below, Sublicensee agrees to be bound by all
of the terms and conditions of the Master License Agreement, as modified
hereby, for the benefit of Licensee and Scripps.


LICENSEE:                                      SUBLICENSEE:


____________________________                   ________________________________

By:_________________________                   By:_____________________________

Title:______________________                   Title:__________________________


[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.

<PAGE>


                                    EXHIBIT D

                                   MILESTONES

                  1. The filing of an investigational new drug application
("IND") for an efficacy clinical trial sponsored by Licensee or its Sublicensee
with the U.S. Food and Drug Administration in respect of a Licensed Product.

                  2. Upon demonstration of human clinical efficacy for a
primary end point in a Phase II clinical trial sponsored by Licensee or its
Sublicensee in respect of a Licensed Product.











[*] CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY
WITH THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT
TO THE OMITTED PORTIONS.