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                                                                   EXHIBIT 10.57


             COLLABORATIVE RESEARCH, PURCHASE AND LICENSE AGREEMENT

                                     BETWEEN

                                  N.V. ORGANON

                                       AND

                         Aurora Biosciences Corporation


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             COLLABORATIVE RESEARCH, PURCHASE AND LICENSE AGREEMENT


THIS AGREEMENT is entered into as of the Effective Date by and between N.V.
ORGANON, a company organized and existing under the laws of The Netherlands and
having offices at Molenstraat 110, P.O. Box 20, 5340 BH Oss, The Netherlands,
("Organon"), and AURORA BIOSCIENCES CORPORATION, a Delaware corporation having
offices at 11010 Torreyana Road, San Diego, California 92121 ("Aurora").

                                    RECITALS

WHEREAS, Aurora has expertise in the development of screening systems and
screening biologies/chemistries used therein; and

WHEREAS, Aurora has the scientific expertise and capacity to undertake the
alliance activities and provide the services, materials and instrumentation
described below; and

WHEREAS, Organon desires screen development services and has the capability to
undertake screening and development of drug products for the prevention and
treatment of human and veterinary diseases and disorders.

NOW, THEREFORE, in consideration of the foregoing premises and of the covenants,
representations and agreements set forth below, the parties agree as follows:

1. DEFINITIONS

As used herein, the following terms shall have the following meanings:

        1.1.    "Affiliate" means any corporation, association or other entity,
        which directly or indirectly controls, is controlled by or is under
        common control with the party in question. As used herein, the term
        control shall mean direct or indirect beneficial ownership of more than
        *** of the voting or income interest in such corporation or other
        business entity.

        1.2.    "Agreement" means this agreement, together with all appendices,
        exhibits and schedules hereto, and as the same may be amended or
        supplemented from time to time hereafter by a written agreement duly
        executed by authorized representatives of each party hereto.

        1.3.    "Aurora Copyrights" means all copyrights throughout the world
        Controlled by Aurora.

        1.4.    "Aurora Patent Rights" means the Patent Rights Controlled by
        Aurora described in Exhibit 2 attached hereto *** Effective Date.


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        1.5.    "Aurora Reporter" means any of the reporters described in
        Exhibit 1.2 attached hereto.

        1.6.    "Aurora Screen Development Resource" shall have the meaning set
        forth in Section 2.2.1.

        1.7.    "Aurora Screening Program" shall have the meaning set forth in
        Section 2.1.5.

        1.8.    "Aurora Technology" means Technology Controlled by Aurora
        necessary for Aurora Reporters and the development of Collaborative
        Screens, ***

        1.9.    "Collaborative Period" means the period during which the parties
        are developing Collaborative Screens and ending on the third anniversary
        of the Effective Date unless extended by written mutual agreement or
        concluded earlier in accordance with Section 9.

        1.10.   "Collaborative Screen" means a screen or assay developed by
        Aurora for an Organon Target under a CSP Work Plan as defined in Section
        2.1.3.

        1.11.   "Collaborative Screen Program or CSP" shall have the meaning set
        forth in Section 2.1.

        1.12.   "Compound" means *** Aurora *** in a Collaborative Screen or
        tested by Organon in a Collaborative Screen and excluding *** in
        accordance with Section 2.1.6.

        1.13.   "Compound Supply" shall have the meaning set forth in Section
        2.1.6.

        1.14.   "Confidential Information" means all confidential information,
        data, and materials received by either party from the other party
        pursuant to this Agreement, which if in writing is marked confidential,
        and all information, data, and materials developed pursuant to this
        Agreement which if in writing is marked confidential, including, without
        limitation, Technology of each party, subject to the exceptions set
        forth in Section 6.1.2.

        1.15.   "Control" or "Controlled" means, with respect to intellectual
        property, possession by a party of the ability to grant a license or
        sublicense in accordance with the terms of this Agreement, and without
        violating the terms of any agreement by such party with any Third Party
        that is in effect on the Effective Date.

        1.16.   "Copyrights" means rights that protect expression in a tangible
        form, such as the U.S. Copyright Laws.


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        1.17.   "CSP Steering Committee" shall have the meaning set forth in
        Section 2.1.1.

        1.18.   "CSP Work Plan" shall have the meaning set forth in Section
        2.1.3.

        1.19.   "Derivative" means *** Organon based ***, including i) *** , ii)
        *** , or iii) *** Organon that *** has a ***. It is understood that a
        ***, provided that the Derivative of a ***.

        1.20.   "Development Compound" means *** for Organon. For the purpose of
        this definition, a *** includes, but is not limited ***, and as defined
        in the U.S. Code of Federal Regulations ***, or its foreign counterparts
        and which is conducted under ***. In the event a *** reaches *** without
        *** Organon, such ***.

        1.21.   "Effective Date" means the date that this Agreement is executed
        by the last party to so execute.

        1.22.   "FDA" shall mean the United States Food and Drug Administration,
        or any successor agency having regulatory jurisdiction over the
        manufacture, distribution and sale of drugs in the United States or
        equivalent in any other jurisdiction.

        1.23.   "Hit" means *** in the course of *** Organon using a *** on ***;
        provided, however, a chemical developed *** incorporating or utilizing
        an Aurora Technology, Aurora Patent Rights or an Aurora Reporter ***
        indication. Organon ***.

        1.24.   "IND" means the first to occur of the following: (i) the filing
        with and acceptance by the FDA of an Investigational New Drug
        application; or (ii) any corresponding application filed in any country
        other than the United States; or (iii) the first administration of a
        Development Compound into a human subject.


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        1.25.   "Internal Research" means any *** solely *** for the *** to be
        developed and ***, its Licensor(s) or its Licensee(s). Internal Research
        does not include use requiring the *** under this Agreement.

        1.26.   "Invention" means any new and useful ***, or improvement
        thereto, whether or not patentable.

        1.27.   "Know-How" means information and data which is not generally
        known to the public, comprising: ***.

        1.28.   "Licensee" means a Third Party to whom *** grants a license,
        sublicense or other right to manufacture, use, sell, offer for sale,
        distribute and/or import one or more ***.

        1.29.   "Licensor" means a Third Party that grants *** a license,
        sublicense or other right to manufacture, use, sell, offer for sale,
        distribute and/or import one or more ***.


        1.30.   "Materials" means any reagents, promoters, enhancers, vectors,
        plasmids, genes, polynucleotides, cell lines, proteins and fragments
        thereof, peptides, antigens, antibodies, antagonists, agonists,
        inhibitors, Compounds and chemicals.

        1.31.   "NDA" means a new drug application or product license
        application, as appropriate in the United States or a foreign equivalent
        in a foreign country.

        1.32.   "***" shall mean, with respect to Product(s), *** to customers
        for all Product(s) sold *** the following items:

        i)      ***;


        ii)     ***;


        iii)    ***; and


        iv)     ***.


        v)      ***.


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        Such amounts shall be determined from the books and records of ***
        maintained in accordance with generally accepted accounting principles
        ("GAAP") consistently applied.

        1.33.   "Organon Copyrights" means all copyrights throughout the world
        Controlled by Organon.

        1.34.   "Organon Patent Rights" means Patent Rights Controlled by
        Organon.

        1.35.   "Organon Target" shall have the meaning set forth in Exhibit
        1.35 and Section

        1.36.   "Organon Technology" means Technology Controlled by *** Aurora.

        1.37.   "Patent Rights" means all U.S. or foreign (including regional
        authorities such as the European Patent Office) regular or provisional
        patent applications, including any continuation, continuation-in-part,
        or division thereof or any substitute application therefor or equivalent
        thereof, and any patent issuing thereon, including any reissue,
        reexamination or extension thereof and any confirmation patent or
        registration patent or patent of additions based on any such patent,
        containing one or more claims to an Invention (and in the case of an
        issued patent, containing one or more Valid Claims), and for which a
        party hereto owns or Controls, individually or jointly, any title
        thereto or rights thereunder.

        1.38.   "Phase III Clinical Trial" means that portion of a clinical
        development program which provides for the testing of a Development
        Compound designed to assess the safety and efficacy of such a product at
        a dosage regimen identified in Phase II dose ranging studies on a
        sufficient number of human patients to support an NDA.

        1.39.   "Product" means any composition of matter developed *** use that
        incorporates a Development Compound ***.

        1.40.   "Royalty Term" means, in the case of any Product and as to any
        country, the period of time commencing on the first commercial sale for
        use or consumption of such Product in such country and ending upon the
        earlier of: (i) the date that there no longer exists a Valid Claim in a
        patent owned or Controlled by Organon or its Affiliates, or the
        Licensors or Licensees covering the manufacture, use or sale of such
        Product in such country, or (ii) the date that is *** after the date of
        such first commercial sale for use or consumption of such Product in
        such country; provided, however, Organon *** royalties on a Product in a
        country *** in such country *** in such country ***. *** for *** in such
        country ***.


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        1.41.   "Selection Procedure" of molecular targets shall have the
        meaning set forth in Section 2.1.2.

        1.42.   "Technology" means Materials and Know-How.

        1.43.   "Term" means the period beginning on the Effective Date and
        terminating in accordance with this Agreement, as set forth in Section
        9.

        1.44.   "Third Party" means any entity other than Aurora and Organon or
        their respective Affiliates.

        1.45.   "Tracking Record" shall have the meaning set forth in Section
        4.4.2.

        1.46.   "Validation" shall have the meaning set forth in Section 2.1.4.

        1.47.   "***" shall mean the parameters, standards, and results
        established by the CSP Steering Committee for each Collaborative Screen
        and will generally be in agreement with Aurora's standard assay ***
        indicated in Exhibit 1.48.

        1.48.   "Valid Claim" means: (a) an issued claim under an issued patent
        within the Patent Rights, which has not (i) expired or been canceled,
        (ii) been declared invalid by an unreversed and unappealable decision of
        a court or other appropriate body of competent jurisdiction, (iii) been
        admitted to be invalid or unenforceable through reissue, disclaimer or
        otherwise, and/or (iv) been abandoned; or (b) a claim included in a
        pending patent application within the Patent Rights that is being
        actively prosecuted in accordance with this Agreement and which has not
        been (v) canceled, (vi) withdrawn from consideration, (vii) finally
        determined to be unallowable by the applicable governmental authority
        for whatever reason (and from which no appeal is or can be taken), or
        (viii) abandoned.

        1.49.   "***" means ***reader purchased by Organon under this Agreement
        and described on Exhibit 2.7.

        1.50.   "***" means *** which are to be used by ***.

2.      COLLABORATIVE SCREEN PROGRAM AND INSTRUMENT PURCHASE

        2.1.    Collaborative Screen Program.



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        For a period of three (3) years following the Effective Date, unless
        terminated earlier or extended by mutual agreement, the parties will
        collaborate in the development and validation of Collaborative Screens
        as part of a *** (the "Collaborative Screen Program or CSP"). Organon
        and Aurora will collaborate to develop Collaborative Screens at Aurora
        for *** during the Collaborative Period.


                2.1.1.  CSP Steering Committees. No later than *** after the
                        Effective Date, the parties shall establish a CSP
                        Steering Committee (the "CSP Steering Committee"). The
                        mission of the CSP Steering Committee is to manage the
                        experimental science and all other matters of the CSP
                        including the selection of targets for screen
                        development at Aurora (each such target provided by
                        Organon is an "Organon Target") as provided for under
                        Section 2.1.2. The CSP Steering Committee shall consist
                        of *** representatives designated by Organon from
                        Organon and *** representatives designated by Aurora
                        from Aurora. Each representative to the CSP Steering
                        Committee will have *** vote resulting in each party
                        having exactly *** votes.

                        The CSP Steering Committee will meet no later than ***
                        days after the Effective Date and at least *** times per
                        year using mutually agreed upon meeting locations and
                        formats including tele- and video-conferencing. On an
                        alternating basis, one party shall promptly prepare and
                        deliver to the members of the CSP Steering Committee
                        minutes in respect thereof, for review and approval of
                        both parties. Decisions in the CSP Steering Committee
                        will be ***, at a meeting where all *** voting
                        representatives are present.

                        Where meetings are to be held between the Parties, which
                        includes CSP Steering Committee meetings, each Party ***
                        attending such meetings.

                2.1.2.  Screen Selection. Attached as Exhibit 1.35 is a list of
                        at least *** Organon Targets for ***. Additional
                        potential Organon Targets (at least *** and of ***
                        listed on Exhibit A, with a *** by ***; i.e *** and ***
                        or ***, e.g., ***, etc.) will be presented by Organon to
                        Aurora at *** days prior to the *** of the Effective
                        Date during the Collaboration Period. Aurora will
                        develop Collaborative Screens for at least *** Organon
                        Targets (of which *** unless otherwise agreed by the CSP
                        Steering Committee) in the ***, of the Collaborative
                        Period, *** Collaborative Screens for Organon Targets
                        (of which *** may be *** unless otherwise agreed by the
                        CSP Steering Committee) in the *** of the Collaborative
                        Period, subject to Sections 2.1.3.3 and 2.1.3.4.


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                        2.1.2.1.The *** listed in Exhibit A and *** Organon
                                shall be *** Organon reasonably *** using Aurora
                                Technology. Aurora may reasonably request
                                further information regarding ***. Within *** of
                                first receiving such information, Aurora shall
                                notify Organon in writing in the event that
                                Aurora reasonably *** is *** obligations or if
                                Aurora *** for a *** would not reasonably be
                                scientifically *** based on available
                                information and that ***. If Aurora *** proposed
                                by ***, Aurora will *** Organon ***, to the
                                extent that Aurora does not have to reveal
                                confidential *** Third Party. Consequently, the
                                parties agree that in some instances Aurora ***
                                a ***.

                        2.1.2.2.Additional Rights Necessary for Screen
                                Development. During the course of screen
                                selection or development the parties may
                                identify Third Party Materials (such as cell
                                lines or proteins) that may be useful for screen
                                development. If such Materials are deemed
                                necessary for screen development by the CSP
                                Steering Committee, *** required for their use.







                2.1.3.  Screen Development.

                        2.1.3.1 CSP Work Plan. The CSP Steering Committee will
                        coordinate the preparation of a work plan (a "CSP Work
                        Plan"), which shall set forth the respective
                        responsibilities of the parties for the development of
                        each Collaborative Screen, and which must be approved by
                        the CSP Steering Committee in accordance with Section
                        2.1.1. Each such CSP Work Plan will also *** to be
                        produced, the ***, the dates by which such activities
                        are expected to be accomplished by the parties, and ***
                        for each Collaborative Screen.

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                        2.1.3.2 Screen Development. The CSP Steering Committee
                        will coordinate screen development (including the
                        preparation and management of a CSP Work Plan, and the
                        ***) for each Collaborative Screen within a time frame
                        set by the CSP Steering Committee that can satisfy the
                        objectives of the CSP Steering Committee and the
                        parties. Promptly following the approval of each CSP
                        Work Plan, the parties will use reasonable efforts to
                        commence their respective duties under the CSP Work Plan
                        ***. Organon shall provide to Aurora all necessary
                        materials for screen development, including ***, etc.,
                        in an appropriate form and a timely manner (materials
                        *** Organon Targets in the *** of the Collaborative
                        Period, and materials for *** Organon Targets within ***
                        of the Effective Date), consistent with the CSP Work
                        Plans. Should such materials not be properly provided in
                        a timely manner, the parties shall discuss remedies ***.
                        All work under a CSP Work Plan shall be performed in
                        accordance with the provisions of this Agreement, and
                        each party will *** to complete its obligations under
                        the CSP Work Plan as ***. In situations where an *** is
                        required for a Collaborative Screen and Organon has
                        provided Aurora ***, if *** at Aurora a *** for a given
                        Organon Target, then work on that Target *** selected.
                        *** Aurora will be performed in conjunction with screen
                        development efforts ***. *** reagents for screening, and
                        methods thereof, are ***. Aurora may *** under
                        additional funding by Organon.

                        2.1.3.3 Additional Screens. Should Aurora complete the
                        development of *** for Organon Targets *** during the
                        Collaborative Period, Aurora may, with the approval of
                        the CSP Steering Committee, direct the Aurora Screen
                        Development Resource (see 2.2.1 below) to the
                        development of additional Collaborative Screens for
                        Organon Targets. Such work shall be conducted under a
                        CSP Work Plan approved by the CSP Steering Committee,
                        and Aurora shall be compensated *** in accordance with
                        Section 2.2.4.

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                        2.1.3.4 Fewer Screens. Should Aurora *** development of
                        *** Organon Targets *** during the Collaborative Period,
                        *** research and *** Aurora screen development resources
                        to *** of such *** Collaborative Screens within *** of
                        the ***, such resources to *** to the Aurora effort
                        during the Collaborative Period (i.e., ***). Such ***
                        Collaborative Screens shall be *** of *** Targets *** as
                        the parties shall mutually agree in writing. By the ***
                        the Effective Date *** Collaborative Screens will ***,
                        and by the *** the Effective Date *** Collaborative
                        Screens will ***, unless terminated earlier in
                        accordance with Section 9.4.

                2.1.4.  *** Collaborative Screens. When Aurora *** a
                        Collaborative Screen, including it's ***, which Organon
                        *** expense if desired, a written report describing the
                        Collaborative Screen and *** with the CSP Work Plan
                        including *** shall be provided by *** to the CSP
                        Steering Committee. The CSP Steering Committee will ***
                        report and *** each Collaborative Screen according to
                        the *** in the CSP Work Plan ("***")*** on the ***, if
                        any, necessary for ***. When so directed in writing by
                        *** and consistent with *** obligations, which
                        obligations shall not *** Organon, Aurora shall ***
                        Organon *** in accordance with the licenses described in
                        Section 3.1.

                2.1.5   *** Screening by Aurora. During the Collaborative
                        Period, Organon shall *** screening of *** Collaborative
                        Screens to Aurora and subject to Section 2.2.5. For each
                        such Collaborative Screen developed pursuant to a CSP
                        Work Plan of Section 2.1.3, *** screening by Organon and
                        agreed by the parties in writing, Aurora will use *** to
                        screen Compounds or other chemicals agreed to by the
                        parties pursuant to Section 2.1.6. Aurora shall, with
                        regard to each Collaborative Screen, screen Compounds in
                        a manner determined by the CSP Steering Committee and
                        *** Compounds for ***, and *** as determined by the CSP
                        Steering Committee (such screening by Aurora of each
                        Collaborative Screen to be referred to as an "Aurora
                        Screening Program"), provided, however, the screening
                        *** utilized will be *** of *** performing such
                        Collaborative Screen *** equipment. Aurora will use ***
                        to provide such screening service *** which is *** used
                        *** as provided for in Section 2.2.5. The *** for any
                        given Collaborative Screen will *** wells or datapoints,
                        including standards and controls.


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                2.1.6   Libraries. Organon shall, ***, *** Compounds *** Organon
                        for an Aurora Screening Program. Conversely, in the
                        event that Organon desires to have Aurora test in an
                        Aurora Screening Program a chemical (including a library
                        of compounds) owned, accessed or Controlled by ***, the
                        parties agree *** under which such chemical may be
                        screened. Any chemical supplied by *** for use in an
                        Aurora Screening Program shall be *** in *** (the
                        "Compound Supply", which refers only to compounds ***
                        Organon). The current *** is provided as Exhibit
                        2.1.6.). The quantities needed for each screen will be
                        specified in writing in the CSP Work Plan. Aurora agrees
                        *** received from *** or to use *** Collaborative
                        Screens without ***. Aurora *** Compound Supply received
                        *** to Organon of the action taken and successfully
                        completed, upon written notice by Organon of how it
                        would like the Compound Supply provided by Organon
                        handled upon completion of any screening by Aurora.

        2.2     Aurora Screen Development Resource, Technology Access and
        Payments. Aurora will provide access to Aurora Technology, Aurora
        Reporters, Aurora Patent Rights, and the Aurora Screen Development
        Resource at Aurora to Organon as follows:

                2.2.1   Aurora Screen Development Resource. During the
                        Collaborative Period, upon payment by Organon of the
                        funding provided for in Section 2.2.2, Aurora will
                        commit a *** number of Aurora personnel (the "Aurora
                        Screen Development Resource") to develop at least ***
                        Collaborative Screens for the Organon Targets each year
                        of the Collaborative Period.


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                2.2.2.  Payments for Technology Access and Support of the Screen
                        Development Resource. As partial consideration for use
                        of the Aurora Screen Development Resource under Section
                        2.2.1 and *** to use *** during the Collaborative Period
                        in accord with Section 3.1, Organon shall pay Aurora ***
                        for ***. Such amount shall be payable in *** payments
                        *** each, the first payment to be made within *** of the
                        Effective Date, and subsequent payments to be made on or
                        before each of the following *** and *** during the
                        Collaborative Period, for a total of *** payments. Such
                        payments shall be ***. The total of the *** above
                        mentioned payments if so made would be *** dollars ***.

                2.2.3.  Payments for a License Subsequent to the Initial Term.
                        Organon will pay to Aurora starting on the date of ***
                        and on each *** thereafter a *** annual license fee to
                        maintain its license under Section 3.1. This license fee
                        shall *** dollars ($***) for *** of the Collaborative
                        Period ("First Payment"), and *** dollars ($***) per
                        year for *** ("Subsequent Payments") up to a maximum of
                        *** years. Such payments shall be made within *** days
                        of the anniversary of the Effective Date. Such license
                        fees are applicable *** Organon *** makes the First
                        Payment as described. Organon *** license granted under
                        Section 3.1 *** with *** to Aurora. ***, should Organon
                        have interest *** license or *** license, the ***
                        license shall *** the parties.

                2.2.4   Payments for Additional Screens. For each *** developed
                        by Aurora for an Organon Target *** per a given year of
                        the Collaborative Period, or *** during the
                        Collaborative Period as described in Section 2.1.3.3,
                        Organon shall pay to *** dollars ($***) ***, due within
                        *** of *** Collaborative Screen *** for a given year of
                        the Collaborative Period by the CSP Steering Committee.

                2.2.5   Payments for Screening by Aurora.


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                        As partial consideration for screening by Aurora and the
                        generation of datapoints during the Collaborative Period
                        pursuant to Section 2.1.5, Organon will pay Aurora ***
                        payments as follows: for datapoints generated in an ***
                        a ***, Organon will pay Aurora, in advance, ***, and for
                        datapoints generated in *** in a screening ***, Organon
                        will pay Aurora in advance, ***. Such payments *** costs
                        incurred by Aurora related to *** a Collaborative
                        Screen). The parties shall agree on the *** for any
                        assay to be performed, and *** above ***. Additionally
                        the prices indicated above are *** Aurora in accordance
                        with Section 2.1.6.

        2.3     Milestones and Royalties.
        In addition to such payments as are made by Organon to Aurora pursuant
        to Section 2 hereof, the following payments shall be made to Aurora for
        each Collaborative Screen:

                2.3.1   Milestones. When *** Compound, Hit or Derivative from
                        any Collaborative Screen reaches the following
                        milestones, Organon will promptly notify Aurora of same
                        and within *** of such notification, Organon will pay
                        Aurora the amount corresponding to such milestone. It is
                        understood that Organon *** the milestone payments for a
                        Compound, Hit or Derivative it *** Compound, Hit or ***
                        such *** is *** Compound, Hit or Derivative.
                        Notwithstanding the above, each milestone shall be paid
                        *** Collaborative Screen.


<TABLE>
<CAPTION>
               Milestone                Amount ($US)
               ---------                ------------
<S>                                     <C>
               ***                              ***

               ***                              ***

               ***                              ***

               ***                              ***
</TABLE>

                2.3.2.  Royalties. With respect to each Product, Organon shall
                        pay a royalty on *** of such Product during the Royalty
                        Term for such Product. The royalty applicable is the
                        product of the worldwide *** summed from each applicable
                        country multiplied by the royalty rate of *** for annual
                        worldwide ***.


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        2.4     Supply of Aurora Reporters.
        So long as Organon has made payments in accordance with Section 2.2. and
        2.3 as applicable, at Organon 's written request or other agreed upon
        means available, Aurora will *** within *** days after receipt of a
        written purchase order therefor, Materials pertaining to the Aurora
        Reporters as Organon may require *** Collaborative Screens *** Aurora as
        provided for in Section 2.1.3 and *** Organon as provided for under
        Section 2.1.4. Organon will *** all supplies so delivered at Aurora's
        then *** ( *** are indicated in Exhibit 2.4). Organon will pay for all
        Materials so ordered within *** days after delivery to Organon. If
        within *** weeks after Organon receives an Aurora Reporter *** by
        Aurora, then *** of Organon's *** perform.

        2.5     Ownership of Compounds and Data.
        *** shall own all *** it, and Hits, Derivatives, Development Compounds
        and Products arising from the Compound Supply *** it under this
        Agreement. All results and data concerning any such Hits or Development
        Compounds *** generated *** resulting from any Collaborative Screen ***
        and shall be treated as *** Confidential Information hereunder. *** will
        not *** any biological materials ***, provided, however, the parties
        agree that *** biological materials to *** *** acquired by ***, its ***
        or ***.

        2.6.    Development of Products.
        *** will be responsible for all ***, including all regulatory filings,
        of Hits and Development Compounds arising out of this Agreement at no
        expense ***. Such development shall be at *** sole discretion, and ***
        shall use ***, consistent with commercial business practices, to conduct
        the activities associated with the development of any Development
        Compound, all regulatory activities relating to the manufacture, use or
        sale of any Development Compound or Product, and the commercialization
        and marketing of any Product in any country. All regulatory filings made
        or filed by *** for any Development Compound or Product shall be owned
        ***. At *** and expense, *** to the extent *** necessary to permit
        Organon to perform the foregoing activities.

        2.7     Purchase of an Aurora VIPR.
        Organon shall purchase an Aurora VIPR for the purpose of performing
        Collaborative Screens *** in accordance with Exhibit 2.7.

3.      INTELLECTUAL PROPERTY RIGHTS


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        3.1     Grant of Rights from Aurora to Organon.
        License to Collaborative Screens developed by Aurora. Aurora, subject to
        payments under Section 2.2, grants to Organon a *** under Aurora Patent
        Rights and Aurora Technology to *** for Internal Research, and to ***
        Internal Research *** developed by Aurora in accordance with Sections
        2.1 and 2.2, *** CSP Steering Committee and *** Organon in accordance
        with Section 2.1.4. The grant of rights from Aurora to Organon does not
        include the right to ***. The Parties agree to *** for a license in
        favor of *** for the practice of *** for other *** needed for *** out or
        to be *** by *** or product development by ***.

        3.2.    Grant of Rights from Organon to Aurora.
        Organon grants to Aurora *** license, ***, and *** Aurora to ***. ***
        this Section 3.2, Aurora *** provided by Organon ***; provided however,
        Aurora *** as provided for in Section 2.1.5.

        3.3.    Ownership of Intellectual Property and Property.

                3.3.1.  Transfer of Rights. All rights not expressly licensed or
                        assigned by Organon are retained by Organon. All rights
                        not expressly licensed or assigned by Aurora are
                        retained by Aurora. Except as otherwise expressly
                        provided in this Agreement, nothing in this Agreement is
                        intended to convey or transfer ownership by one party to
                        the other of any rights, title or interest in any
                        Confidential Information, Technology, Copyrights or
                        Patent Rights owned or Controlled by a party. Except as
                        expressly provided in this Agreement, nothing in this
                        Agreement shall be construed as a license or sublicense
                        by one party to the other of any rights in any
                        Technology, Copyrights, or Patent Rights owned or
                        Controlled by a party.

                3.3.2.  Organon Inventions. *** shall *** Inventions and other
                        Technology made solely by its employees and agents, and
                        all patent applications and


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<PAGE>   17
                        patents claiming such Inventions and other Technology.
                        If Organon has a license pursuant to Sections 3.1,
                        Aurora *** that *** relating to *** and Organon ***.

                3.3.3   Aurora Inventions. *** shall *** Inventions and other
                        Technology made solely by its employees and agents, and
                        all patent applications and patents claiming such
                        Inventions and other Technology, provided, however, that
                        *** and other Technology *** Organon (including *** from
                        the *** where such *** by Organon) and *** Aurora in
                        performance of this Agreement and Aurora *** Organon.

                3.3.4.  Joint Inventions. During the period from the Effective
                        Date to *** thereafter, all Inventions and other
                        Technology conceived jointly by employees or agents of
                        Organon and employees or agents of Aurora shall be owned
                        by ***; provided, however, that if a) ***, Aurora ***
                        such Inventions and other Technology that *** and
                        Organon *** Aurora and b) Organon will *** all
                        Inventions and other *** Organon and *** and Aurora ***
                        Organon.

                3.3.5   Other Inventions. Any Inventions not included in
                        Sections 3.3.2, 3.3.3, 3.3.4 (a) or 3.3.4 (b) above
                        shall be owned by their inventors.

                3.3.6.  Inventorship and Assignment. Inventorship of patentable
                        inventions shall be determined by U.S. patent law.
                        Organon and Aurora agree to execute all documentation
                        necessary to perfect all assignments of Inventions,
                        Technology and Patent Rights.

4.      PAYMENTS OF ROYALTIES, ACCOUNTING FOR ROYALTIES AND RECORDS.

        4.1.    Payment and Reporting.
        The royalties due under Article 2 and as follows in this Article 4,
        shall be paid within *** after the end of *** in which such royalties
        are earned during the Royalty Term for each Product. With each such ***,
        Organon shall furnish Aurora a summary statement setting forth on a
        country-by-country basis the relevant sales information, including the
        total number of units of each such Product sold and other information
        employed to calculate *** for such Product.


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        4.2.    Currency of Payment.
        All payments to be made under this Agreement, including the milestones
        and royalties payable to Aurora by Organon, shall be paid in U.S.
        dollars by wire transfer or other mutually acceptable means to a bank
        account designated by Aurora upon an invoice received from Aurora.
        Translation of sales recorded in local currencies to U.S. dollars will
        be performed in a manner consistent with *** used to prepare its audited
        financial statements for internal and external reporting purposes, which
        uses a widely accepted source of published exchange rate.

        4.3.    Taxes Withheld.
        Any income or other tax that Organon or any of its Affiliates, Licensees
        or Licensors is required by a government agency to withhold and pay on
        behalf of Aurora with respect to the royalties payable under this
        Agreement shall be deducted from and offset against said royalties prior
        to remittance to Aurora; provided, however, that in regard to any tax so
        deducted, Organon shall give or cause to be given to Aurora such
        assistance as may reasonably be necessary to enable Aurora to claim
        exemption therefrom or credit therefor, and in each case shall furnish
        Aurora proper evidence of the taxes paid on Aurora's behalf.

        4.4.    Records.

                4.4.1.  ***Royalty Calculations. During the Royalty Term and for
                        *** from the date of each payment of royalties, Organon
                        shall keep complete and accurate records of sales and
                        all other information necessary to calculate Net Sales
                        of each Product in sufficient detail to allow the
                        accrued royalties to be determined accurately in
                        accordance with GAAP. Aurora, with reasonable written
                        notice to Organon but not more than once each calendar
                        year, shall have the right to cause Aurora's nationally
                        recognized independent, certified public accountant to
                        audit such records at the place or places of business
                        where such records are customarily kept in order to
                        verify the accuracy of the reports of *** and royalty
                        payments. Such accountant shall execute a
                        confidentiality agreement prior to entering Organon's
                        premises, obligating such accountant to keep all
                        information disclosed to it confidential and shall only
                        be permitted to disclose to Aurora the extent of any
                        discrepancy between royalty payments made by Organon
                        hereunder and the actual royalty required to be so paid.
                        Aurora shall bear the full cost of such audit unless
                        such audit discloses a variance of more than *** from
                        the amount of the royalties due under this Agreement, in
                        which event, Organon shall bear the full cost of such
                        audit. Aurora agrees not to disclose Confidential
                        Information concerning royalty payments and reports, and
                        all information learned in the course of any audit or
                        inspection, except to the extent necessary for Aurora to
                        reveal such information in order to enforce its rights
                        under this Agreement or if disclosure is required by
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                4.4.2.  Tracking Records for Collaborative Screens.

                        4.4.2.1.***. Organon will ***, to inspect the Tracking
                                Records once per year or upon reasonable request
                                by Aurora for the sole purpose of determining
                                the attainment of a milestone or royalty under
                                Article 2. The Tracking Records shall be
                                securely retained for no less *** years from the
                                last use of a Collaborative Screen. When a
                                compound, such as a Hit, Derivative or
                                Development Compound is selected for a good
                                laboratory practice safety or toxicology study,
                                Organon will *** to Aurora under strict
                                confidentiality.

                        4.4.2.2.Upon reasonable request by Aurora and at a
                                minimum ***, Organon will provide Aurora with a
                                summary of the status of Development Compounds
                                and Products that may be used to calculate
                                royalties or milestones.

        4.5.    Trade Secret Milestones and Royalty.

        The parties acknowledge that the principal value contributed by Aurora
        under this Agreement is the enhanced probability of identifying leads
        for Products, such as human pharmaceutical products (or other products
        having commercial value), and the potential to generate multiple leads,
        either or both of which the parties reasonably believe will lessen the
        time required to bring pharmaceutical products to market and increase
        the efficiency of drug discovery and development processes and
        technologies. Additionally, the parties acknowledge that Aurora may ***
        covering the manufacture, sale, use or importation of a particular
        Development Compound or Product. Organon acknowledges and agrees that
        the value it receives hereunder is in the access and use of a
        Collaborative


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<PAGE>   20
        Screen or Aurora Technology. Accordingly, Organon *** Aurora may *** a
        Development Compound or a Product.

5.      INTELLECTUAL PROPERTY ENFORCEMENT AND DEFENSE OF CLAIMS

        5.1.    Intellectual Property Enforcement.
        Organon and Aurora shall have the right, but not the obligation, to
        bring proceedings against any Third Party for the inappropriate use,
        including patent infringement, of Technology or Patent Rights solely
        owned or Controlled by it, and at its own risk and expense. If one party
        brings such action such party shall be entitled to control such action,
        hire and retain counsel, make decisions, settle on any terms, and retain
        any and all awards or damages obtained in any such proceeding. At the
        request and expense of either party, the other party shall give the
        requesting party all reasonable assistance required to file and conduct
        any such proceeding.

        5.2.    Defense of Infringement Claims for Organon Hits, Development
                Compounds and Products.
        Aurora will cooperate with Organon, at Organon's expense, in the defense
        of any suit, action or proceeding against Organon and Organon's
        Affiliates or Aurora alleging the infringement of the intellectual
        property rights of a Third Party by reason of the manufacture, use or
        sale of a Hit, Derivative, Compound, Development Compound or Product
        from a Compound screened in a Collaborative Screen by Organon or Aurora.
        Each party shall give the other party prompt written notice of the
        commencement of any such suit, action, proceeding or claim of
        infringement. Aurora *** to defend, hire counsel, make decisions or
        settle on any terms any such suit, action or proceeding *** documents,
        provide pertinent records, and take all other actions, including
        requiring persons within its control to give testimony, which may be
        reasonably required in connection with the defense or settlement of such
        litigation.

        5.3.    Defense of Infringement Claims for Aurora Technology, the VIPR
                and Aurora Patent Rights.
        Organon will cooperate with Aurora, in the defense of any suit, action
        or proceeding against Aurora or Organon alleging the infringement of the
        intellectual property rights of a Third Party by reason of Aurora's or
        Organon's use of any Aurora Patent Rights, the VIPR and Aurora
        Technology licensed to Organon under this Agreement. The parties shall
        notify each other promptly in writing of the commencement of any such
        suit, action, proceeding or claim of infringement. Organon shall *** to
        defend, hire counsel, make decisions or settle on any terms any such
        suit, action or proceeding *** all documents, provide pertinent records,
        and take all other actions, including requiring persons within its
        control to give testimony, which may be reasonably required in
        connection with the defense or settlement of such litigation.

6.      TREATMENT OF CONFIDENTIAL INFORMATION; PUBLICITY


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        6.1.    Confidentiality.

                6.1.1.  Subject to the terms and conditions of this Agreement,
                        Organon and Aurora each agree that, during the term of
                        this Agreement and for *** years thereafter, it will
                        keep confidential, and will cause its Affiliates to keep
                        confidential, all Confidential Information that is
                        disclosed to it or to any of its Affiliates by the other
                        party in connection with the performance of this
                        Agreement. Neither Organon nor Aurora nor any of their
                        respective Affiliates shall use the other party's
                        Confidential Information except as expressly permitted
                        in this Agreement.

                6.1.2.  Organon and Aurora each agree that any disclosure of the
                        other's Confidential Information to any officer,
                        employee, contractor, consultant, sublicensee or agent
                        of the other party or of any of its Affiliates shall be
                        made only if and to the extent necessary to carry out
                        its responsibilities under this Agreement and to
                        exercise the rights granted to it hereunder, shall be
                        limited to the extent consistent with such
                        responsibilities and rights, and shall be provided only
                        to such persons or entities who are bound to maintain
                        same in confidence in a like manner as the party
                        receiving same hereunder is so required. Each party
                        shall use reasonable efforts to take such action, and to
                        cause its Affiliates to take such action, to preserve
                        the confidentiality of each other's Confidential
                        Information, which shall be the same efforts as it would
                        customarily take to preserve the confidentiality of its
                        own Confidential Information.

                        Either party may be required to disclose some
                        Confidential Information of the other party in a patent
                        application filed related to Compounds, Technology or
                        uses thereof. The disclosing party shall limit this type
                        of information to the minimum necessary and the
                        disclosing party shall inform the non-disclosing party
                        of exactly what Confidential Information will be
                        disclosed in the patent application *** before such
                        application is filed.

                        Upon termination of this Agreement, each party, upon the
                        other's request, will return all the Confidential
                        Information received from the other party pursuant to
                        this Agreement, including all copies and extracts of
                        documents, within *** of the request of the other party.
                        6.1.3.

                        Confidential Information shall not include any
                        information, which the receiving party can prove by
                        competent evidence:

                        i)      is now, or hereafter becomes, through no act or
                        failure to act on the part of the receiving party,
                        generally known or available;


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<PAGE>   22
                        ii)     is known by the receiving party at the time of
                        receiving such information, as evidenced by its records;

                        iii)    is hereafter furnished to the receiving party
                        without restriction as to disclosure or use by a Third
                        Party lawfully entitled to so furnish same;

                        iv)     is independently developed by the employees,
                        agents or contractors of the receiving party without the
                        aid, application or use of the disclosing party's
                        Confidential Information;

                        v)      is the subject of a written permission to
                        disclose provided by the disclosing party; or

                        vi)     is provided by the disclosing party to a Third
                        Party without restriction as to confidentiality.

                        A party may also disclose Confidential Information of
                        the other where required to do so by law or legal
                        process, provided that, in such event, the party
                        required to so disclose shall give maximum practical
                        advance written notice of same to the other party and
                        will cooperate with the other party's efforts to seek,
                        at the request and expense of the other party, all
                        confidential treatment and protection for such
                        disclosure as is permitted by applicable law.

                        The parties agree that the material financial terms of
                        this Agreement will be considered Confidential
                        Information of both parties. Notwithstanding the
                        foregoing, either party may disclose such terms in legal
                        proceedings or as are required to be disclosed in its
                        financial statements, by law, or under strictures of
                        confidentiality to bona fide potential sublicensees.
                        Either party shall have the further right to disclose
                        the material financial terms of this Agreement under
                        strictures of confidentiality to any potential acquirer,
                        merger partner, bank, venture capital firm, or other
                        financial institution to obtain financing.

                        The parties agree that information developed pursuant to
                        *** will be considered Confidential Information of both
                        parties and shall be subject to the confidentiality
                        requirements of this Section 6.1. Notwithstanding the
                        foregoing, ***.

        6.2.    Publication of Results.


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<PAGE>   23
        Subject to Section 6.1 hereof, results and data obtained by either party
        in the course of a Collaborative Screen Program through use of an Aurora
        Reporter may be submitted for publication by Organon in accordance with
        Organon's customary practices, provided, however, that Organon shall
        credit Aurora in such publication as the developer and/or provider of
        the technology that produced, in part, the published results or data.
        Organon shall send a copy of the proposed publication and shall allow
        Aurora *** from the date of receipt in which to determine whether such
        publication contains subject matter for which patent protection should
        be sought prior to disclosure, or otherwise contains Aurora Confidential
        Information. If no answer is received from Aurora within *** of receipt
        of the proposed publication, Organon shall be free to submit such
        proposed publication.

        6.3.    Publicity. Except as required by law and as provided in this
        Article 6, neither party may make any public announcement or otherwise
        disclose the terms of this Agreement without the prior written consent
        of the other party, which consent shall not be unreasonably withheld.

        6.4.    Press Release. Notwithstanding the foregoing, the parties will
        agree on a press release to announce the execution of this Agreement and
        to be released by Aurora and to be mutually agreed upon. Thereafter,
        Organon and Aurora may each disclose to Third Parties the information
        contained in the mutually agreed upon press release without the need for
        further approval by the other.


7.      PATENT PROSECUTION AND COPYRIGHTS

        7.1.    Patents.
        The control and expense of the filing, prosecution (including an
        opposition or interference) and maintenance of patents and patent
        applications claiming Inventions will be the sole responsibility of the
        party filing the patent application and the party not filing the patent
        application will cooperate in such filing, prosecution and maintenance
        of the validity of such patent position. Organon and Aurora will
        cooperate in the filing, prosecution and maintenance of jointly owned
        patents and patent applications claiming inventions conceived or made
        pursuant to activities under Article 2, and share equally in the
        expenses incurred thereto.

        7.2.    Copyrights.
        The parties agree to treat and handle, to the maximum practical extent,
        any copyrights owned or Controlled by a party in the same manner as
        Patent Rights owned or Controlled by such party.

8.      REPRESENTATIONS, WARRANTIES AND INDEMNIFICATION

        8.1.    Mutual Representations and Warranties.


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        The parties make the following representations and warranties to each
other:

                8.1.1.  Corporate Power. Each party hereby represents and
                        warrants that such party (a) is duly organized and
                        validly existing under the laws of the state of its
                        incorporation and has full corporate power and authority
                        to enter into this Agreement and to carry out the
                        provisions hereof; (b) has the requisite power and
                        authority and the legal right to own and operate its
                        property and assets, to lease the property and assets it
                        operates under lease, and to carry on its business as it
                        is now being conducted; and (c) is in compliance with
                        all requirements of applicable law, except to the extent
                        that any noncompliance would not have a material adverse
                        effect on the properties, business, financial or other
                        condition of it and would not materially adversely
                        affect its ability to perform its obligations under the
                        Agreement.

                8.1.2.  Due Authorization. Each party hereby represents and
                        warrants that such party (a) has the requisite power and
                        authority and the legal right to enter into the
                        Agreement and to perform its obligations hereunder; and
                        (b) has taken all necessary action on its part to
                        authorize the execution and delivery of the Agreement
                        and to authorize the performance of its obligations
                        hereunder and the grant of rights extended by it
                        hereunder.

                8.1.3.  Binding Agreement. Each party hereby represents and
                        warrants to the other that (a) this Agreement has been
                        duly executed and delivered on its behalf and is a legal
                        and valid obligation binding upon it and is enforceable
                        in accordance with its terms; (b) the execution,
                        delivery and performance of this Agreement by such party
                        does not conflict with any agreement, instrument or
                        understanding, oral or written, to which it is a party
                        or by which it may be bound, nor violate any law or
                        regulation of any court, governmental body or
                        administrative or other agency having authority over it;
                        and (c) all necessary consents, approvals and
                        authorizations of all governmental authorities and other
                        persons required to be obtained by it in connection with
                        the Agreement have been obtained.

        8.2.    Warranties and Aurora Technology.
        Aurora represents and warrants to Organon as of the Effective Date the
        following:

                8.2.1.  To the best knowledge of Aurora: (a) ***; (b) ***; (c)
                        ***; and (d) ***.


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               8.2.2. Except as set forth in Section 8.2.1 above, Aurora
                      (including its officers, employees and agents) expressly
                      disclaims any representations and warranties, whether
                      express or implied, relating to ***. Aurora further
                      disclaims i) any express or implied warranty of
                      merchantability or fitness for a particular purpose of the
                      ***, ii) any express or implied warranty that the practice
                      or use of the ***will not infringe a patent, copyright,
                      trademark or other right of a Third Party, and iii) any
                      express or implied warranty regarding ***.

        8.3.    *** Indemnification.
        *** hereby agrees to indemnify, defend and hold ***, and its officers,
        directors, employees, and agents (collectively, the " *** Indemnitees")
        harmless from and against all damages or other amounts payable to a
        Third Party, including reasonable attorneys' fees and costs of
        litigation, resulting from a suit brought or threatened by a Third Party
        against a *** Indemnitee based on (a) *** gross negligence or willful
        misconduct (but not patent infringement) relating to *** contractual
        performance under this Agreement, and (b) *** contractual performance
        under this Agreement in the course of the Collaborative Screen Program
        at ***, except to the extent such damages or other amounts payable are
        attributable to: (i) the misappropriation by any such *** Indemnitee of
        the trade secrets of any Third Party, (ii) any breach of this Agreement
        by a *** Indemnitee or misrepresentation contained herein, or iii) trade
        secret use or patent infringement by *** of Compounds provided under
        this Agreement by ***, a target selected or screen components provided
        by *** that are owned or otherwise controlled by a Third Party or a
        Third Party's patent rights. In no event shall *** be liable for any
        incidental or consequential damages suffered by *** resulting from the
        exercise of any rights granted in accordance with this Agreement.

        8.4.    Warranties and Organon Technology.
        Organon warrants to Aurora as of the Effective Date the following:

                8.4.1.  To the best knowledge of Organon as of the Effective
                        Date: (a) ***; (b) ***; and (c) ***.


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<PAGE>   26
                8.4.2.  Except as set forth in Section 8.4.1 above, Organon
                        (including its officers, employees and agents) expressly
                        disclaim any representations and warranties, whether
                        express or implied, relating ***. Organon further
                        disclaims: i) ***; ii) ***; and iii) ***.

        8.5.    *** Indemnification.
        *** hereby agrees to indemnify, defend and hold ***, and its respective
        officers, directors, employees, and agents (collectively, the "***
        Indemnitees") harmless from and against all damages or other amounts
        payable to a Third Party, including reasonable attorneys' fees and costs
        of litigation, resulting from a suit or other threat brought or
        threatened by a Third Party against an *** Indemnitee based on a) any
        development, manufacture, use or sale of a Development Compound or
        Product by or through *** or its Affiliates or its Licensees or
        Licensors, and b) infringement by *** of Patent Rights as a result of
        using a target in a Collaborative Screen, or Compounds provided under
        this Agreement by ***; except to the extent such damages or other
        amounts payable are attributable to: (i) a violation of any contractual
        or fiduciary duty owed by any *** Indemnitee to a Third Party, (ii) any
        breach of this Agreement by an *** Indemnitee or misrepresentation
        contained herein and (iii) trade secret use or patent infringement by
        *** (other than of a target or screen component provided by ***) that
        are owned or otherwise controlled by a Third Party or a Third Party
        patent right. In no event shall *** be liable for any incidental or
        consequential damages suffered by *** resulting from the exercise of any
        rights granted in accordance with this Agreement.

        *** hereby agrees to indemnify, defend and *** and its respective
        officers, sponsors, directors, employees, and agents (collectively, the
        "IP Indemnitees") harmless from and against all damages or other amounts
        payable to a Third Party, including reasonable attorneys' fees and costs
        of litigation, resulting or arising from the exercise of rights under
        the licenses granted herein and pursuant to ***, including product
        liability. This provision is pursuant to *** license agreement.

9.      TERM AND TERMINATION

        9.1     Term.


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<PAGE>   27
        The term of this Agreement will begin on the Effective Date and shall
        continue until there is no longer a royalty obligation owed by Organon
        to Aurora unless terminated earlier in accordance with the provisions of
        Sections 9.2 or 9.3 hereof.

        9.2.    Termination By Mutual Agreement.
        The parties may at any time terminate this Agreement, in whole or in
        part, by written agreement executed by both Aurora and Organon. In such
        event, the document effecting such termination shall specify the
        continuation or termination of any license rights granted hereunder, as
        well as any other terms agreed to by both parties.

        9.3.    Termination for Cause.
        Either party shall have the right to terminate this Agreement at any
        time for a material breach of this Agreement by the other party,
        provided that the non-breaching party shall have given the breaching
        party *** days written notice of the breach and intention to terminate
        this Agreement in the absence of a cure within ninety *** (*** days in
        the case on non-payment) of receipt of such notice by the breaching
        party. Upon termination of this Agreement for cause, all licenses and
        sublicenses granted in accordance with this Agreement shall be
        terminated and all Materials transferred in accordance with this
        Agreement shall be returned to the supplying party or destroyed at the
        discretion of such party. The non-breaching party, upon termination of
        this Agreement may seek actual or general damages and remedies available
        to it at law or in equity. NO PUNITIVE OR CONSEQUENTIAL DAMAGES MAY BE
        SOUGHT BY EITHER PARTY.

        9.4     Termination without Cause.

Either party shall have the right to terminate the Research *** by providing
written notification thereof *** days ***.

        9.5.    Effect of Expiration or Termination.

        The obligations and rights of the parties under ***, thereof, as well as
        any provisions, which, by their intent or meaning are intended to so
        survive, shall survive termination or expiration of this Agreement.
        Except as otherwise expressly provided in this Agreement, the rights and
        obligations of the parties under Article 2 hereof shall terminate and be
        of no further force or effect whatsoever upon any termination of this
        Agreement. Upon expiration or other termination of the Agreement all
        licenses granted will terminate and Materials and Collaborative Screens
        will be destroyed or returned, at the sole discretion of the providing
        party, to the party providing such Materials and Collaborative Screens
        within *** days.

10.     MISCELLANEOUS

        10.1.   Assignment.


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<PAGE>   28
        *** may assign its rights or obligations under this Agreement in
        connection with the sale of all or substantially all of its assets, or
        may otherwise assign its rights or obligations under this Agreement ***;
        provided, however, if such assignment is to an Affiliate that is wholly
        owned by *** such consent shall not be necessary. This Agreement shall
        survive any merger or consolidation of either party with or into another
        party and no consent for any such merger, consolidation or similar
        reorganization shall be required hereunder. In the event of such merger,
        consolidation or similar reorganization or in the event of a sale of all
        assets, no intellectual property rights of the acquiring or acquired
        company shall be included in the technology licensed hereunder.

        10.2.   Binding Effect.
        This Agreement shall be binding upon and inure to the benefit of the
        successors and permitted assigns of the parties. Any assignment not in
        accordance with this Agreement shall be void.

        10.3.   Force Majeure.
        Neither party shall lose any rights hereunder or be liable to the other
        party for damages or losses on account of failure of performance by the
        defaulting party if the failure is occasioned by war, fire, explosion,
        flood, earthquake, strike, lockout, embargo, act of God, or any other
        similar cause beyond the control of the defaulting party, provided that
        the party claiming force majeure has exerted all reasonable efforts to
        avoid or remedy such force majeure and thereafter takes all reasonable
        steps to mitigate any such delay in performance hereunder and any
        damages that may be incurred by the other party thereby.

        10.4.   Notices.
        Any notices or communications provided for in this Agreement to be made
        by either of the parties to the other shall be in writing, in English,
        and shall be made by prepaid air mail or overnight carrier with return
        receipt addressed to the other at its address set forth below. Any such
        notice or communication may also be given by hand, or facsimile to the
        appropriate designation. Notices shall be sent:

        If to Organon, to:   N.V. Organon
                             Molenstraat 110
                             P.O. Box 20
                             5340 BH Oss
                             The Netherlands

        Facsimile number:    (31) 412 662617

        Attention:           C. David Nicholson, Ph.D.
                             Director, Research


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<PAGE>   29
        If to Aurora, to:    Aurora Biosciences Corporation
                             11010 Torreyana Road
                             San Diego, CA 92121

        Facsimile number:    (619) 404-6714

        Attention:           Michael J. Dunn
                             Vice President, Business Development

        provided that if such notice or communication relates to an amendment to
        this Agreement or to any notice pursuant to Article 9 hereof, a copy
        shall also be sent to:

        If to Organon, to:   Head of the Legal Department

        If to Aurora, to:    John D. Mendlein
                             General Counsel

        Either party may by like notice specify or change an address to which
        notices and communications shall thereafter be sent. Notices sent by
        mail, facsimile or cable shall be effective upon receipt and notices
        given by hand shall be effective when delivered.

        10.5.   Governing Law and Jurisdiction.
        This Agreement shall be governed by the laws of the State of California,
        as such laws are applied to contracts entered into and to be performed
        within such state.

        10.6.   Waiver.
        Except as specifically provided for herein, the waiver from time to time
        by either of the parties of any of their rights or their failure to
        exercise any remedy shall not operate or be construed as a continuing
        waiver of same or any of the other of such party's rights or remedies
        provided in this Agreement.

        10.7.   Severability.
        If any term, covenant or condition of this Agreement or the application
        thereof to any party or circumstance shall, to any extent, be held to be
        invalid or unenforceable, then the remainder of this Agreement, or the
        application of such term, covenant or condition to parties or
        circumstances other than those as to which it is held invalid or
        unenforceable, shall not be affected thereby and each term, covenant or
        condition of this Agreement shall be valid and be enforced to the
        fullest extent permitted by law; and the parties hereto covenant and
        agree to renegotiate any such term, covenant or application thereof in
        good faith in order to provide a reasonably acceptable alternative to
        the term, covenant or condition of this Agreement or the application
        thereof that is invalid or unenforceable, it being the intent of the
        parties that the basic purposes of this Agreement are to be effectuated.

        10.8.   Independent Contractors.


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        It is expressly agreed that Aurora and Organon shall be independent
        contractors and that the relationship between the parties shall not
        constitute a partnership or agency of any kind. Neither Aurora nor
        Organon shall have the authority to make any statements, representations
        or commitments of any kind, or to take any action, which shall be
        binding on the other, without the prior written authorization of the
        other party to do so.

        10.9.   Entire Agreement.
        This Agreement between the parties of even date herewith sets forth all
        of the covenants, promises, agreements, warranties, representations,
        conditions and understandings between the parties hereto, and supersedes
        and terminates all prior agreements and understanding between the
        parties, with respect to the subject matter hereof. There are no
        covenants, promises, agreements, warranties, representations conditions
        or understandings, either oral or written, between the parties other
        than as set forth herein and therein. No subsequent alteration,
        amendment, change or addition to this Agreement shall be binding upon
        the parties hereto unless reduced to writing and signed by the
        respective authorized officers of the parties. This Agreement shall not
        be strictly construed against either party hereto. Any conflict between
        the terms set forth in the text of this Agreement and the terms of any
        Exhibit hereto shall be resolved in favor of the text of this Agreement.

        10.10.  No Third Party Beneficiaries.
        No third party, including any employee of any party to this Agreement,
        shall have or acquire any rights by reason of this Agreement. Nothing
        contained in this Agreement shall be deemed to constitute the parties
        partners with each other or any third party.

        10.11.  Construction.
        The term "Article" or "Section" can refer to any single paragraph level
        found herein or any collection of multiple paragraphs thereunder.

        10.12.  Dispute Resolution.
        The parties recognize that disputes as to certain matters may from time
        to time arise during the term of this Agreement which relate to either
        party's rights and/or obligations hereunder. It is the objective of the
        parties to establish procedures to facilitate the resolution of disputes
        arising under this Agreement in an expedient manner by mutual
        cooperation and without resort to arbitration. The parties agree that
        prior to any arbitration concerning this Agreement, a member of
        Organon's senior management and Aurora's president will meet in person
        or by video-conferencing in a good faith effort to resolve any disputes
        concerning this Agreement. Within *** days of a formal request by either
        party to the other, any party may, by written notice to the other, have
        such dispute referred to their respective officers designated or their
        successors, for attempted resolution by good faith negotiations, such
        good faith negotiations to begin within *** days after such notice is
        received. Any dispute arising out of or relating to this Agreement which
        is not resolved between the parties or the designated officers of the
        parties pursuant to Section 10.12 shall be resolved by final and binding
        arbitration conducted in *** (unless the parties mutually agree to
        another location) under the then


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<PAGE>   31
        current Licensing Agreement Arbitration Rules of the American
        Arbitration Association ("AAA"). The arbitration shall be conducted by
        three (3) arbitrators who are knowledgeable in the subject matter which
        is at issue in the dispute. One arbitrator is selected by Organon and
        one arbitrator is selected Aurora and the third arbitrator is appointed
        by the AAA. In conducting the arbitration, the arbitrators shall
        determine what discovery will be permitted, consistent with the goal of
        limiting the cost and time which the parties must expend for discovery
        (and provided that the arbitrators shall permit such discovery they deem
        necessary to permit an equitable resolution of the dispute), ensure that
        the total time of the arbitration from filing to a final decision or
        executed settlement agreement is less than *** months, and be able to
        decree any and all relief of an equitable nature, including but not
        limited to such relief as a temporary restraining order, a preliminary
        injunction, a permanent injunction, specific performance or repletion of
        property. The arbitrators shall also be able to award actual or general
        damages, but shall not award any other form of damage (e.g.,
        consequential, punitive or exemplary damages). The parties shall share
        equally the arbitrator's fees and expenses pending the resolution of the
        arbitration unless the arbitrator, pursuant to its right but not its
        obligations, requires the non-prevailing party to bear all or any
        portion of the costs of the prevailing party. The decision of the
        arbitrator shall be final and may be sued on or enforced by the party in
        whose favor it runs in any court of competent jurisdiction at the option
        of such party. Notwithstanding anything to the contrary in this Section
        10.12, either party may seek immediate injunctive or other interim
        relief from any court of competent jurisdiction with respect to any
        breach of Articles 3 or 6 hereof, or otherwise to enforce and protect
        the patent rights, copyrights, trademarks, or other intellectual
        property rights owned or Controlled by such party. In addition,
        arbitration shall not be used to resolve disputes about patent rights.
        Patent right disputes including but not limited to disputes concerning
        patent ownership, claim language, claim scope and issues of validity
        shall be settled in a court of law. Any arbitration ruling that relies
        on an interpretation of patent rights shall have no binding effect in a
        court of law on any patent rights related to this Agreement, unless such
        patent rights have been adjudicated in a court of law. In no event shall
        a demand for arbitration be made after the date when the institution of
        a legal or equitable proceeding based on such claim, dispute or other
        matter in question would be barred by the applicable statute.

        10.13.  Counterparts.
        This Agreement may be executed in two (2) or more counterparts, each of
        which shall be deemed an original, but all of which together shall
        constitute one and the same instrument. Counterparts may be signed and
        delivered via facsimile, each of which shall be binding when sent, and
        in each case an original shall be sent via overnight courier.


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<PAGE>   32
        IN WITNESS WHEREOF, the parties have caused this Agreement to be
        executed by their duly authorized representatives.


N.V. Organon                            Aurora Biosciences Corporation

By:                                     By:
   -------------------------------         -------------------------------
Name:   C. David Nicholson, Ph.D.       Name:  Harry Stylli, Ph.D.
Title:  Director, Research              Title: Senior Vice President,
                                               Commercial Development

Date:                                   Date:


By:
   -------------------------------

Name: H. J. Vergouwen, Ph.D.

Title:  Managing Director R&D

Date:


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<PAGE>   33
                                LIST OF EXHIBITS


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<PAGE>   34
                                   EXHIBIT 1.2

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<PAGE>   35
                                  EXHIBIT 1.35

                             LIST OF ORGANON TARGETS

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<PAGE>   36
                                  EXHIBIT 1.48

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                                    EXHIBIT 2

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<PAGE>   40
                                   EXHIBIT 2.4

                         PRICE LIST FOR AURORA REPORTERS

                                  CONFIDENTIAL
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<PAGE>   41
                                   EXHIBIT 2.7

                           PURCHASE OF AN AURORA VIPR

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<PAGE>   42
                                       ***




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