Document:

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                                                                  EXHIBIT 10.31

[*] CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY
    BRACKETS, HAS BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND
    EXCHANGE COMMISSION PURSUANT TO RULE 406 OF THE SECURITIES EXCHANGE ACT OF
    1933, AS AMENDED.

                            COLLABORATION AGREEMENT

THIS COLLABORATION AGREEMENT (the "Agreement") is made and entered into as of
the last execution date by a Party to this Agreement ("Effective Date") by and
between EXELIXIS, INC., a Delaware corporation having a principal place of
business at 170 Harbor Way, P.O. Box 511, South San Francisco, California
94083-0511 ("Exelixis"), and CYTOKINETICS, INC., a Delaware corporation having a
place of business at 280 East Grand Avenue, South San Francisco, California
94080 ("Cytokinetics"). As used herein, references to Cytokinetics and Exelixis
shall also include their respective Affiliates.

                                   BACKGROUND

      A.    Cytokinetics is engaged in the research, development and
            commercialization of biotechnology and pharmaceutical products;

      B.    Exelixis is engaged in the research, development and
            commercialization of biotechnology, pharmaceutical, agrochemical and
            agricultural products and has developed novel proprietary methods
            for the generation of compound libraries;

      C.    Cytokinetics desires to obtain, and Exelixis desires to supply,
            certain of such compounds for screening and further evaluation and
            development by each Party, all on the terms and conditions set forth
            below.

NOW, THEREFORE, for and in consideration of the covenants, conditions, and
undertakings hereinafter set forth, it is agreed by and between the Parties as
follows:

   1.    DEFINITIONS.

         1.1 "AFFILIATE" shall mean an entity which controls, is controlled by
or is under the common control with a Party. An entity shall be regarded as in
control of another entity for purposes of this definition if it owns or controls
more than fifty percent (50%) of the shares of the subject entity entitled to
vote in the election of directors (or, in the case of an entity that is not a
corporation, for the election of the corresponding managing authority).

         1.2 "COLLABORATION" shall mean a collaborative relationship between a
Party and a third party(ies), the subject of which is the research, discovery,
development, manufacturing and/or commercialization of pharmaceuticals.

         1.3 "COMPOUND" shall mean each chemically distinct compound that is
synthesized by Exelixis that fulfills the Quality Control Criteria on a per
Plate basis and is delivered to Cytokinetics in accordance with Section 3.4.

         1.4 "COMPOUND PATENT" shall mean patents and patent applications
covering the composition, use, or method of preparation, of any Compound, filed
after the date of synthesis of such Compound hereunder, whether foreign or
domestic, all patents arising from such applications, and all patents and patent
applications based on, or claiming or corresponding to the priority dates, of

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any of the foregoing and any renewals, reissues, extensions (or other
governmental actions that provide exclusive right to the owner thereof in the
patented subject matter beyond the original expiration date), substitutions,
confirmations, registrations, revalidations, reexaminations, additions,
continuations, continued prosecutions, continuations-in-part or divisions of or
to any of the foregoing, including, without limitation, supplementary protection
certificates or the equivalent thereof.

            1.5 "CONFIDENTIAL INFORMATION" shall have the meaning as set forth
in Article 5.

            1.6 "DESIGN CRITERIA" shall mean the criteria for the design and/or
synthesis of the Compounds as established by the JRC pursuant to Section 3.2.

            1.7 "DRUG PRODUCT" shall mean a composition of matter used in the
treatment, prevention or diagnosis of disease, state or condition, which
composition of matter is (i) a Compound, or (ii) derived from the use of a
Compound as [*] of such composition of matter.

            1.8 "DRUG PRODUCT USE" shall mean use solely to research, develop
and/or commercialize a Drug Product, internally or as part of a Collaboration,
including the right to have any of the foregoing conducted on a Party's
(including Collaboration partners') behalf by a third party.

            1.9 "EXELIXIS BACKGROUND TECHNOLOGY" shall mean Exelixis Patent
Rights and Exelixis Know-How.

                  1.9.1 "EXELIXIS PATENT RIGHTS" shall mean (i) patents and
patent applications, whether foreign or domestic, that claim, or are necessary
or useful to exploit (A) a Compound or composition-of-matter containing such
Compound or a method of use thereof or (B) a process developed prior to the
Effective Date and/or under the Research Program, in each case, for the
synthesis of Compounds (or analogs or derivatives thereof as provided in Section
4.2.2), and (ii) any divisions, continuations, continuations-in-part, reissues,
reexaminations, or extensions to the extent the same have an earliest effective
filing date prior to the date described in (i) above, and any (iii)
substitutions, confirmations, registrations, or revalidations of any of the
foregoing, in each case, which are owned or controlled by Exelixis (solely or
jointly), to the extent Exelixis has the right to license or sublicense the
same.

                  1.9.2 "EXELIXIS KNOW-HOW" shall mean synthetic protocols
developed prior to the Effective Date and/or under the Research Program, in each
case, which are necessary or useful for the synthesis of the Compounds (or
analogs or derivatives thereof as provided in Section 4.2.2), and any technical
information, know-how, process, procedure, composition, method, formula,
technique, software, design, drawing or data directly relating to the Compounds
or necessary or useful for the manufacture, use or exploitation thereof.

            1.10 "INTERNAL RESEARCH USE" shall mean use solely for research
and/or pharmaceutical lead discovery purposes, internally or as part of a
Collaboration, including the right to have any of the foregoing conducted on a
Party's (including Collaboration partners') behalf by a

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third party; provided, it is understood and agreed that such use shall exclude
the right to develop and/or commercialize the Compounds.

            1.11 "PARTY" OR "PARTIES" shall mean individually Exelixis,
Cytokinetics or an Affiliate of the same, and collectively, Exelixis,
Cytokinetics and their Affiliates.

            1.12 "PLATE" shall have the meaning as set forth in Appendix B.

            1.13 "PROGRAM COMPOUND INFORMATION" shall mean data, methods,
results, conclusions, information and/or deliverables generated in connection
with the design and/or production of the Compounds under the Research Program
that are necessary for a person trained in the art of compound synthesis to make
the Compounds, including without limitation, Design Criteria, structure,
composition, results from Quality Control Criteria analysis of each Compound by
LC-MS, methods of synthesis, synthons, and non-commercially available building
blocks relating to the Compounds.

            1.14 "QUALITY CONTROL CRITERIA" OR "QCC" shall mean the quality
control criteria established by the Parties as described in Appendix B, as may
be amended by the JRC from time to time.

      2. RESEARCH PROGRAM.

            2.1 GENERAL. Cytokinetics and Exelixis will conduct a research
program on a collaborative basis with the principal goal of producing a high
throughput screen library consisting of up to a total of [*] ([*]) Compounds
(the "Research Program"). The Research Program shall be conducted in accordance
with the Design Criteria as established by the JRC, unless otherwise agreed by
the Parties in writing. Each Party agrees to keep the other Party informed of
its progress and activities within the Research Program. The scientific scope of
the Research Program is further described in Appendix A, attached hereto, as may
be amended in writing by the JRC from time to time under Section 3.2.

            2.2 LIBRARY. Exelixis shall diligently utilize its combinatorial
chemistry expertise and apply its related technologies, as directed by the JRC,
to generate the Compounds on behalf of the Parties. Exelixis shall be
responsible for all components of library production, analytics, informatics and
formatting.

            2.3 NOVEL COMPOUNDS. Exelixis and Cytokinetics shall each use their
respective diligent efforts to design Compounds that are not covered by any
Exelixis or Cytokinetics intellectual property either (i) existing as of the
Effective Date and excluded from the Research Program or (ii) arising outside of
the Research Program during the Term (as defined in Section 8.1) that is owned,
assigned and/or licensed by Exelixis or Cytokinetics. Without limiting the
foregoing, each Party shall use its diligent efforts to not (i) design and/or
synthesize any Compounds under this Agreement that have been, or are in the
process of being, designed and/or synthesized under any other collaboration(s)
it has with a third party, and/or (ii) design and/or synthesize any other
compounds under any other collaboration(s) it has with a third party that have
been, or are in the process of being, designed and/or synthesized as a Compound
under this Agreement.

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   the Commission. Confidential treatment has been requested with respect to the
   omitted portions.

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            2.4 PERSONNEL. In accordance with Section 5.1, Exelixis may disclose
to employees and personnel of Exelixis (each, a "Research Program Personnel"),
on a need to know basis under circumstances that ensure the confidentiality
thereof, information within the Program Compound Information, including any
Cytokinetics Confidential Information, Design Criteria, and/or Quality Control
Criteria included therein, solely to conduct their designated activities under
the Research Program. Exelixis may disclose to third parties who are under
contractual relationship with Exelixis to synthesize scaffolds and/or generic
structures (each a "Exelixis Third Party Supplier") information within the
Program Compound Information (but excluding Design Criteria, Quality Control
Criteria, specific structures or compositions of the Compounds to be produced
hereunder, or results from Quality Control Criteria analysis of the Compounds by
[*]) to the extent necessary for such Exelixis Third Party Supplier to perform
its activities as described hereunder. Any Exelixis Third Party Supplier
performing such activities shall be under a confidentiality agreement with
Exelixis on terms no less restrictive than the confidentiality provisions of
this Agreement.

            2.5 NO CONFLICTING ACTIVITIES. During the Term of this Agreement,
Exelixis shall not, and shall ensure that the Research Program Personnel shall
not, conduct the Research Program in conjunction with any other projects being
conducted at, or on behalf of, Exelixis that would (a) conflict with any of the
provisions of this Agreement, or (b) preclude Exelixis from complying with the
provisions hereof. In addition, Exelixis shall not enter into agreements with
Exelixis Third Party Suppliers that conflict with any of the provisions of this
Agreement and shall use diligent efforts to ensure compliance with the
confidentiality provisions, documentation requirements and intellectual property
rights provisions of this Agreement.

            2.6 RECORDS. In connection with the performance of the Research
Program, Exelixis shall ensure that the Research Program Personnel who perform
such services shall maintain laboratory notebooks, records and data ("Records")
in accordance with good laboratory and research practices.

            2.7 REPORTS. Exelixis shall promptly provide to the JRC
documentation as to the Compounds, Program Compound Information, Records,
methods, results, conclusions, information and/or other deliverables made,
conceived, reduced to practice or otherwise generated in connection with this
Agreement ("Reports"). All Reports, Records, including any required laboratory
notebooks, records and data pursuant to any research services conducted under
the Research Program, shall be [*] by [*] and [*], shall be treated in all
respects as [*] Confidential Information of [*] and [*], and [*] shall have the
right to disclose, use and exploit such information in conjunction with its
disclosure, use and exploitation of the Compounds and Program Compound
Information in accordance with Article 4. The JRC shall deliver to Cytokinetics
such documentation from time to time and without request by Cytokinetics.

            2.8 FURTHER ASSURANCES. Exelixis shall provide to Cytokinetics
documentation reasonably requested by Cytokinetics in order to assist
Cytokinetics in determining whether any Compounds, Program Compound Information,
Plates, Records, Reports, and/or other deliverables comply fully with this
Article 2, Article 3 and Appendices A and B.

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   omitted portions.

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      3. RESEARCH PROGRAM OVERVIEW.

            3.1 JOINT RESEARCH COMMITTEE. Promptly after the Effective Date, the
Parties shall establish a six (6) member committee (the "Joint Research
Committee" or "JRC") composed of three (3) representatives from each Party to
manage the Research Program. Each representative of the JRC shall have one (1)
vote. All decisions of the JRC shall be made by unanimous vote. In the event a
unanimous decision can not be reached, then either Party may, by written notice
to the other Party, have such issue referred to the [*] of Cytokinetics and
Exelixis, [*] and [*], Ph.D., respectively, for resolution by good faith
negotiations within thirty (30) days after such notice is received. Minutes of
the JRC shall be taken, and shall, at a minimum, record all decisions made. Such
minutes shall be approved by both Parties. Each Party may replace its appointed
JRC representatives at any time upon written notice to the other Party.

            3.2 JRC RESPONSIBILITIES. The JRC shall be responsible for planning,
overseeing, reviewing and coordinating the work being done under the Research
Program, including: (i) making decisions regarding the specific details of
templates and Compounds for synthesis, including without limitation the Design
Criteria for the Compounds; (ii) evaluating progress against timelines
established by the JRC for the Research Program, including without limitation
the design, quality assurance testing and delivery of Compounds; (iii)
establishing and monitoring the schedule for delivery of Compounds; (iv)
establishing, maintaining and updating on an ongoing basis a database record of
the design of each of the Compounds and each Party's contribution to such
design, as further described in Section 4.3.2; (v) recording and approving
meeting minutes; and (vi) having the authority to accept or reject any Plates
and/or Compound(s) synthesized that failed the Quality Control Criteria
established by the Parties as set forth in Appendix B attached hereto, as may be
amended in writing by the JRC from time to time.

            3.3 MEETINGS. The JRC shall meet quarterly, or as more or less often
as otherwise mutually agreed by the Parties, at such locations as the Parties
agree. It is understood that such meetings shall be held at least quarterly in
person, otherwise by telephone, in writing or by electronic mail. The JRC shall
provide monthly written updates to each Party as to the progress of the Research
Program.

            3.4 DELIVERABLES.

                  3.4.1 COMPOUNDS. Exelixis shall deliver to Cytokinetics, in
accordance with the timelines as established by the JRC, the number of unique
Compounds as set forth in Table 1 below, such Compounds to be delivered in
Plates in accordance with the provisions of Appendices A and B:

<TABLE>
<CAPTION>
Table 1:
Year                                No. Of Compounds
----                                ----------------
<S>                                 <C>
[*]                                 [*]
[*]                                 [*]
[*]                                 [*]
[*]                                 [*]
[*]                                 [*]
Total :                             [*]
</TABLE>

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The JRC shall use diligent efforts to establish the Design Criteria for the
Compounds, and schedule the synthesis thereof, such that the Plates will be
delivered to Cytokinetics on a regular basis, with the goal of making such
deliveries [*], but in no event [*] (with goal of each such delivery equaling
approximately [*] if [*] (and [*] if [*]) of the total amount of Compounds
scheduled to be delivered in such year), or, as may be mutually agreed by the
Parties, on an alternative schedule.

Exelixis shall deliver Plates to Cytokinetics promptly following the synthesis
and quality assurance testing of the Compounds formatted thereon; provided,
Exelixis shall use diligent efforts to complete such synthesis, quality
assurance testing, and delivery of Plates within [*] ([*]) months after the JRC
has established the Design Criteria of the Compounds formatted thereon. In the
event Exelixis is unable to maintain such scheduled synthesis, quality assurance
testing, and/or deliveries it shall provide Cytokinetics with prompt written
notice thereof.

                  3.4.2 PLATE FORMAT. All Compounds shall be formatted according
to Appendix A; provided, that if requested by Cytokinetics, Exelixis may deliver
a format that consists of [*] ([*]) compounds per Plate. Other formats proposed
by Cytokinetics shall be reviewed and agreed in writing by the JRC. Any
additional final custom formatting for Cytokinetics' purpose shall be performed
at Cytokinetics.

                  3.4.3 ACCEPTANCE/REJECTION/RESYNTHESIS/REPLACEMENT OF
PLATE(S). All Plates that fulfill the Quality Control Criteria set forth in
Appendix B and are delivered to Cytokinetics shall be deemed accepted ("Accepted
Plates"). Plates that do not fulfill Quality Control Criteria will be reviewed
by the JRC and accepted, rejected or designated for re-synthesis by the JRC. If
a Plate is accepted by the JRC, the compounds on such Plate shall be considered
to have met the Quality Control Criteria and shall be deemed Compounds. If a
Plate is rejected, upon agreement with the JRC, the entire Plate may be
resynthesised. The re-synthesis of Plates shall not involve either reformatting
of compounds, removal or replacement of compounds. Exelixis shall promptly
notify the JRC of the existence of any excess template material. Any excess
template material shall be [*] the Parties and made available to each of the
Parties within a reasonable time after the JRC's receipt of such notification
from Exelixis. With respect to Plates, and/or compounds synthesized by Exelixis
under the Research Program which are rejected by the JRC, the JRC shall
determine whether such Plates and/or compounds, including any related Program
Compound Information, shall be destroyed and/or [*] between the Parties. It is
understood and agreed, that neither Party shall have the right to disclose, use
and/or exploit such rejected Plates and/or compounds, including any related
Program Compound Information, except as expressly authorized by the JRC in
writing. In the event that the Plate(s) delivered to Cytokinetics contain
Compound(s) that do not substantially match with the Program Compound
Information supplied by Exelixis, Cytokinetics shall notify Exelixis within [*]
thereof, and Exelixis shall promptly replace such Plate(s) with Plate(s) of
Compounds substantially matching such Program Compound Information, [*] to
Cytokinetics. Notwithstanding the above, Exelixis shall not be responsible for
losses resulting from, relating to or arising from (i) acts or omissions or the
gross negligence or willful misconduct of Cytokinetics or (ii) damage to Plates
or Compounds that occur after delivery to Cytokinetics.

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                  3.4.4 PROGRAM COMPOUND INFORMATION. At the time of delivery of
each Plate, Exelixis shall deliver to Cytokinetics Program Compound Information
substantially relating to each Compound contained on such Plate. Exelixis and
Cytokinetics will diligently work to define a suitable electronic format, and
subject to electronic file format compatibility, Exelixis shall make the Program
Compound Information available in electronic files for batch registration as set
forth in Appendix B.

                  3.4.5 OTHER DELIVERABLES. Without limiting the foregoing,
Exelixis shall deliver to Cytokinetics the deliverables set forth on Appendix A
in accordance with the time schedules set forth therein.

      4. OWNERSHIP AND USE OF MATERIALS AND INFORMATION AND LICENSES.

            4.1 COMPOUNDS AND [*]. All right, title and interest in and to the
Compounds and [*] shall be jointly owned by Cytokinetics and Exelixis, shall be
treated in all respects as jointly owned Confidential Information of Exelixis
and Cytokinetics, and each Party shall have the right to disclose, use and
exploit such Compounds and [*] in accordance with the rights and licenses
granted in this Article 4. Each Party shall have a worldwide, [*], assignable,
fully paid-up, royalty free, co-exclusive right, with the right to grant and
authorize sublicenses subject to Section 4.1 (i) and (ii) below, under such
right, title and interest to disclose, use and exploit the Compounds and [*],
including the right to resynthesize such Compounds, for (i) Internal Research
Use, and (ii) Drug Product Use, without any accounting to the other Party;
provided, in each case, neither Party shall have the right to sell, license,
sublicense, lend, lease, assign or otherwise transfer the Compounds and/or [*]
to any third party, except (a) for contract research, contract development,
contract manufacturing or Collaboration purposes or (b) as a Drug Product. The
Parties expressly understand and agree that no rights or licenses are granted by
one Party to the other under this Section 4.1, whether by implication, estoppel
or otherwise, except as expressly set forth in this Section 4.1. The Parties
shall have the right to research, develop, make, have made, import, have
imported, use, sell and offer for sale analogs and derivatives of the Compounds
without limitation, but no rights or licenses are granted, or obligations
imposed, by one Party to the other pertaining to such analogs and derivatives.
Subject to the confidentiality provisions contained herein, the Parties shall
also have the right to practice and use [*] with such analogs and derivatives.

            4.2 LICENSE TO EXELIXIS BACKGROUND TECHNOLOGY.

                  4.2.1 COMPOUNDS. For each Compound on an Accepted Plate and
its corresponding Program Compound Information, Exelixis hereby grants to
Cytokinetics a worldwide, nonexclusive, royalty-free, fully-paid-up, [*],
sublicenseable subject to Section 4.2.1(i) and (ii) below, right and license,
under the Exelixis Background Technology to practice and use all intellectual
property rights therein with respect to such Compound and Program Compound
Information, including the right to resynthesize such Compounds, for (i)
Internal Research Use, and (ii) Drug Product Use; provided, Cytokinetics shall
not have the right to license or sublicense the Exelixis Background Technology
to any third party, except as it relates to its practice and use of the
Compounds and/or Program Compound Information (a) for contract research,
contract development, contract manufacturing or Collaboration purposes, or (b)
as a Drug Product.

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                  4.2.2 ANALOGS AND DERIVATIVES OF COMPOUNDS. In addition,
Exelixis hereby grants to Cytokinetics a worldwide, nonexclusive, royalty-free,
fully-paid-up, [*] sublicenseable (as provided below), right and license,
under the Exelixis Background Technology to practice and use all methods of
synthesis developed prior to the Effective Date and/or under the Research
Program, in each case, to research, develop, make, have made, import, have
imported, use, sell and offer for sale analogs and derivatives of such
Compounds and Program Compound Information for the same uses described in
Section 4.2.1 (i) and (ii) above, except such uses, including sublicensing
rights, shall apply to such analogs and derivatives rather than such Compounds.

            4.3 PATENTS AND PATENT APPLICATIONS.

                  4.3.1 COMPOUND PATENTS. It is anticipated that each Party may
independently file Compound Patents claiming Compounds when utility has been
established for such Compounds by or on behalf of a Party. Each Party hereby
grants to the other Party a worldwide, perpetual, irrevocable, assignable, fully
paid-up, royalty-free, non-exclusive license, (with the right to sublicense to
third parties pursuant to a Collaboration), under its Compound Patents to
practice and use any and all methods of use and compositions of matter claims
contained therein obtained on the Compound(s), including the right to
resynthesize such Compound(s), in each case, solely for Internal Research Use.
Notwithstanding the foregoing, it is understood that a patent claim of a
Compound Patent may encompass many compounds in addition to the Compound(s), and
that no license or other intellectual property right is granted to the other
Party in respect of such additional compounds encompassed by the claims,
including any methods of use or compositions of matter thereof, that are not
Compound(s).

                  4.3.2 NOVEL COMPOUNDS: INVENTORSHIP AND COMPETING FILINGS.

                        (a) DESIGN CRITERIA. The JRC shall, with respect to each
Compound designed and/or synthesized under the Research Program, mutually
determine in good faith whether the chemical identity of such Compound was
designed solely by Cytokinetics, solely by Exelixis, or jointly. After this
mutual determination is made, the JRC shall document the full names of each
Party's personnel responsible for the design of such Compound in question in a
suitable database or other permanent record to which both Parties and their
counsel shall have access. The Parties acknowledge that their determination of
design under this Section 4.3.2 will be made in the absence of any knowledge
concerning the specific utility of such Compounds. Accordingly, any
determination made under this Section 4.3.2 shall be limited to design, alone,
and shall not, per se, be construed as a determination of inventorship of such
Compounds in question.

                        (b) INVENTORSHIP AND COMPETING FILINGS.

                              (i) The timing and strategy of filing Compound
Patents shall be at the sole discretion of the Party wishing to file ("the
Applicant Party"); provided both Parties agree not to file any Compound Patent
claiming one (1) or more Compounds until utility has been in good faith
reasonably established for such Compounds by or on behalf of such Party. The
Applicant Party shall be under no obligation to discuss or disclose any portion
of any Compound Patents to the other Party (the "Non-Applicant Party"), except,
and only to the extent, as may be required by law to

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enable the Non-Applicant Party to perform its obligations under this Section
4.3.2. Subject to the foregoing, in no event shall the Applicant Party be
required to disclose additional subject matter of the patent claims in such
Compound Patents, such as specific uses recited or generic structures that
encompass the Compound(s) and/or other compounds claimed. If an employee of the
Non-Applicant Party is determined to be an inventor on a claim covering a
Compound within a Compound Patent of the Applicant Party, then the Non-Applicant
Party hereby assigns and agrees to assign its rights (subject to Section
4.3.2(b)(ii) below), and shall use its best efforts to ensure that such employee
inventors assign their rights, of inventorship and ownership in such claim to
the extent such claim is specifically directed to such Compound (but not to any
other compounds covered in such claim), obtained by virtue of holding said
rights under a duty to assign, to the Applicant Party, and to take all
reasonable steps necessary, at the Applicant Party's expense, to perfect such
assignment. It is understood and agreed that such claims on novel Compounds
assigned under this Section 4.3.2 shall be subject to the licenses set forth in
Section 4.3.1, including any rights and restrictions contained therein.

                              (ii) For the avoidance of doubt, it is understood
by the Parties that both may file Compound Patents on the same Compound(s) with
the same or substantially the same utility, and that under this set of
circumstances, the national patent laws in each country where competing filings
are made shall be applied in and by the respective patenting authorities to
determine questions of priority and patentability and shall determine the
ownership of the competing claims. Each Party further agrees to cooperate, and
shall use [*] efforts to ensure that its employee inventors cooperate, with the
other in making any declarations, oath, assignments and the like necessary to
perfect such filings. With respect to any information disclosed by a Party to
the other Party pursuant to this Section 4.3.2, notwithstanding anything to the
contrary in this Agreement, the receiving Party acknowledges that it shall have
no right to use or disclose such information of the disclosing Party without the
disclosing Party's prior written consent.

                        (c) SUBSEQUENT DISCLOSURES. With respect to any further
disclosures that may be required in order to prosecute and maintain claims
already assigned under this Section 4.3.2, the assigning Party (the "Assignor")
agrees to cooperate with the Party to whom such claims have been assigned (the
"Assignee"), and to take all [*] steps necessary to perfect such assignment,
including without limitation to use [*] efforts to ensure that each of its
employee inventors on such claims cooperates with the Assignee on such further
disclosures. On a case-by case basis, the Parties shall discuss and agree upon a
mechanism by which such employee inventors of the Assignor on such claims may
communicate and cooperate directly with the Assignee, including without
limitation, having such employee inventors enter into a separate confidentiality
agreement (which covers only such further disclosures) directly with the
Assignee.

                  4.3.3 PROSECUTION OF PATENTS. Each Party shall be solely
responsible, at its own expense and discretion, for prosecuting, maintaining,
enforcing and defending patents solely owned by such Party, including without
limitation those patent claims assigned to it by the other Party pursuant to
Section 4.3.2.

      5. CONFIDENTIAL INFORMATION.

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            5.1 CONFIDENTIALITY. Each Party agrees to maintain, for a period of
ten (10) years from the date of disclosure, as confidential and not use for any
purpose or disclose to any third party (except to (i) Exelixis Third Party
Suppliers under Section 2.4, (ii) third party contractors from academic and
contract research and/or development organizations authorized to conduct
activities for a Party (including its Collaboration partners) under Article 4,
and (iii) Collaboration partners, in each case, on a need to know basis under
circumstances that ensure the confidentiality thereof), all information
disclosed by one Party to the other Party under this Agreement, whether in
writing or presented, stored or maintained in or by electronic, magnetic or
other means, and marked "Confidential" at the time of such disclosure, or if
disclosed orally, confirmed in writing and marked as "Confidential" within
thirty (30) days following such oral disclosure, including without limitation
all such information relating to the business, plans and/or technology of the
Parties hereto, including, but not limited to technical information, including
inventions, discoveries, methods, plans, processes, specifications,
characteristics, raw data, equipment design, know-how, show-how, experience and
trade secrets; developmental, marketing, sales, operating and performance
information; computer programming techniques; computational chemistry data or
processes; information relating to the design of chemical structures and
compounds, synthetic protocols, analytical data and procedures, including but
not limited to, the Research Program, the Compounds and/or Program Compound
Information for drug discovery and/or parallel synthesis directed to
therapeutic, diagnostic, prophylactic, prognostic, agrochemical or agricultural
applications; and all record-bearing media containing or disclosing the
foregoing information and techniques, including written business plans, patents
and patent applications, grant applications, notes and memoranda (collectively
"Confidential Information").

            5.2 EXCLUSIONS. Notwithstanding the foregoing, the Parties'
obligations of confidentiality shall not apply to any information contained
within the Confidential Information, to the extent such information:

                  (a) was known to the receiving Party at the time of receiving
such information, as evidenced by its contemporaneous written records;

                  (b) is now, or hereafter becomes, through no act or failure to
act on the part of the receiving Party, generally known or available in the
public domain;

                  (c) is the subject of a written permission to disclose
provided by the disclosing Party;

                  (d) is independently developed by or for the receiving Party
without access to, or knowledge of, the disclosing Party's Confidential
Information as evidenced by its contemporaneous written record; or

                  (e) is hereafter furnished to the receiving Party by a third
party, as a matter of right and without restriction on disclosure.

            5.3 RESTRICTIONS ON USE OF CONFIDENTIAL INFORMATION. Notwithstanding
the provisions of Section 5.1 above, each Party may disclose the other Party's
Confidential Information (i) solely to the extent necessary to exercise the
rights granted, and obligations assigned, to it

                                      -10
<PAGE>

hereunder (provided it uses reasonable efforts to protect such information
commensurate with the efforts used to protect its own most sensitive information
of a similar nature), (ii) as reasonably necessary to prosecute or defend
litigation; in connection with financings, securities offerings, or merger or
acquisitions; to provide information to tax or other governmental authorities,
(iii) or to the extent such disclosure is reasonably necessary to comply with
applicable governmental laws, regulations, or orders (provided that, if a Party
is required to make any such disclosure of the other Party's Confidential
Information, it will, to the extent it may legally do so, give reasonable
advance notice to the latter Party of such disclosure and will use its
reasonable efforts to secure confidential treatment of such information prior to
its disclosure (whether through protective orders or otherwise)).

            5.4 NONDISCLOSURE OF TERMS. Each of the Parties agrees not to
disclose to any third party the terms of this Agreement without the prior
written consent of the other Party hereto, except to such Party's attorneys,
advisors, investors, potential investors or acquirers or partners and others on
a need to know basis under circumstances that reasonably ensure the
confidentiality thereof, or to the extent required by law.

      6. PAYMENTS.

            6.1 INITIAL PAYMENT. Cytokinetics shall pay Exelixis an upfront fee
of (i) [*] U.S. Dollars ($[*]) upon signing of the Agreement, and (ii) [*] U.S.
Dollars ($[*]) upon delivery of the first [*] ([*]) Compounds hereunder
(collectively, the "Upfront Fee"), which Upfront Fee is intended to [*] the
Compounds to be delivered to Cytokinetics during the [*] of the Research
Program. Exelixis shall invoice Cytokinetics for the first payment on the
Effective Date, and the second payment upon the delivery of the first [*] ([*])
Compounds. Cytokinetics shall pay such invoices [*] of receipt. The [*] shall be
[*] of Compounds by Cytokinetics. It is understood and agreed that Exelixis'
right to receive and retain such payment is contingent upon Exelixis' obligation
to deliver to Cytokinetics that number of Compounds (including their
substantially related Program Compound Information) that correspond to such
payments.

            6.2 PAYMENT SCHEDULE. In consideration of Exelixis providing
Compounds to Cytokinetics, Cytokinetics shall pay Exelixis at the rate of [*]
U.S. Dollars ($[*]) per Accepted Plate, based upon a rate of [*] U.S. Dollars
($[*]) per Compound and [*] ([*]) Compounds per Plate up to a [*] of [*] ([*])
Compounds. All Accepted Plates shall be delivered promptly to Cytokinetics.
Exelixis shall invoice Cytokinetics for each Accepted Plate at the rate provided
herein within [*] days after the first business day of each calendar quarter.

            6.3 DELIVERY TERMS. All deliveries shall be F.O.B. Exelixis shipping
dock at the address located at the front of this Agreement, and Cytokinetics
shall assume all shipping and insurance charges for delivery of such Compounds,
which shall be billed directly to Cytokinetics from the carrier, unless
otherwise agreed by the Parties.

            6.4 PAYMENT TERMS. Subject to the acceptance of Compounds by
Cytokinetics as set forth in Section 3.4.3, payments by Cytokinetics to Exelixis
shall be due within [*] upon receipt of invoice from Exelixis; provided, it is
understood and agreed that Cytokinetics shall have no

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

                                      -11
<PAGE>

obligation to make any payments to Exelixis, until such time as the [*] is [*]
of the first [*] ([*]) of such Compounds by Cytokinetics.

      7. REPRESENTATIONS AND WARRANTIES.

            7.1 Each of the Parties hereby represents and warrants, as of the
Effective Date, as follows:

                  (a) It is a corporation or entity duly organized and validly
existing under the laws of the state or other jurisdiction of its incorporation
or formation.

                  (b) It has the full corporate power and authority to execute
and deliver this Agreement and to consummate the transactions contemplated
hereby.

                  (c) All corporate acts and other proceedings required to be
taken to authorize such execution, delivery and consummation have been duly and
properly taken and obtained.

                  (d) This Agreement has been duly executed and is a legal and
valid obligation binding upon such Party and enforceable in accordance with its
terms.

                  (e) It has not previously granted, and during the Term (as
defined in Section 8.1) will not make any commitment or grant any rights which
are in conflict with the rights and licenses granted to other Party herein.

            7.2 Each of the Parties hereby agrees to promptly notify the JRC of
any change in its business which would be reasonably expected to materially
delay or impair its ability to perform its obligations hereunder, so that the
JRC may discuss and agree upon a reasonable resolution that addresses any
POTENTIAL harm caused to the other Party by such anticipated delay or
impairment.

      8. TERM; TERMINATION.

            8.1 TERM. The term of this Agreement shall commence on the Effective
Date and, unless earlier terminated as provided in this Article 8, continue in
full force and effect until five (5) years from the Effective Date, as may be
extended by Cytokinetics pursuant to Section 8.3 (the "Term").

            8.2 PERMISSIVE TERMINATION. Commencing upon the second anniversary
of the Effective Date, this Agreement may be terminated by Cytokinetics, with no
penalty, at any time for any reason upon ninety (90) days prior written notice
to Exelixis. Without limiting the foregoing right of Cytokinetics to terminate
this Agreement, upon any such notice of termination under this Section 8.2, the
Parties shall agree upon and issue a joint press statement announcing their
decision to mutually terminate this Agreement.

            8.3 EXTENSION OF DELIVERY SCHEDULE OF COMPOUNDS. Cytokinetics, [*],
may extend the overall timeline for design, development and delivery of the
Compounds (as summarized in Section 3.4.1-Table 1, for Years [*]), and,
concurrent with such extension, extend the Term of this Agreement up to an
additional [*], upon ninety (90) days prior written notice to Exelixis.

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

                                      -12
<PAGE>

Notwithstanding the above, the number of Compounds to be delivered by Exelixis
to Cytokinetics in Year [*] shall be [*] ([*]) Compounds, and upon mutual
agreement of the Parties, Cytokinetics may [*] the number of Compounds to be
delivered by Exelixis in any given year, but such [*] shall not be [*] ([*])
Compounds per year.

            8.4 TERMINATION FOR MATERIAL BREACH. Either Party may terminate this
Agreement for any material breach of this Agreement by the other Party, if such
breach is not cured within sixty (60) days after the breaching Party receives
written notice of such breach by the nonbreaching Party. Such termination shall
be effective upon expiration of such sixty (60) day period.

            8.5 EFFECTS OF TERMINATION.

                  8.5.1 ACCRUED RIGHTS. Termination of this Agreement shall not
affect the rights and obligations of the Parties that accrued prior to the
effective date of such termination.

                  8.5.2 CONFIDENTIAL INFORMATION. Upon request, each Party
agrees to destroy any copies of Confidential Information of the other Party
whenever the work hereunder for which they have been supplied is completed,
discontinued or otherwise terminated, other than any Confidential Information
contained within the Compounds and/or Program Compound Information, Reports
and/or Records. Notwithstanding the above, the Parties expressly agree that one
(1) complete set of Confidential Information may be retained solely for
evidentiary purposes.

                  8.5.3 MATERIALS. Upon any termination of this Agreement, other
than for uncured failure to make payments due by Cytokinetics in accordance with
Sections 6.1, 6.2, and/or 8.5.4, Exelixis shall cooperate fully and timely with
Cytokinetics regarding the transfer to Cytokinetics of Cytokinetics' [*] Plates,
Compounds (including any partial or completed compounds paid for by
Cytokinetics), templates, starting materials, intermediates, synthons and
building blocks relating to such Compounds (including any partial or completed
compounds paid for by Cytokinetics) and necessary or useful for the synthesis
thereof, Program Compound Information, Reports and Records.

                  8.5.4 COSTS AND PAYMENTS.

                        (a) Upon notice of any termination of this Agreement
prior to expiration of its Term, Exelixis shall stop all further work under the
Research Program, and use its best efforts to cancel any cancelable costs.
Notwithstanding anything to the contrary in this Agreement, Cytokinetics shall
have no obligation to make any payments to Exelixis for any Compounds delivered
after notice of such termination that fail to meet the QCC.

                        (b) If Cytokinetics elects to terminate this Agreement
under Section 8.2, Cytokinetics shall pay Exelixis (i) in full (at the rate
specified in Section 6.2) for any compounds submitted to Exelixis for synthesis
by the JRC prior to Exelixis' receipt of notice of such termination; provided,
such compounds meet the QCC or are accepted by the JRC as Compounds (or if the
JRC is no longer in existence, by mutual agreement of the Parties), and are
delivered to Cytokinetics, with their substantially relating Program Compound
Information, within [*] ([*]) months after such submission for synthesis by the
JRC, and (ii) [*] of all actual, reasonable,

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

                                      -13
<PAGE>

documented, non-cancelable costs incurred by Exelixis prior to the effective
date of such termination, to the extent such costs were approved by the JRC (or
if incurred after the effective date of such termination, to the extent such
costs are approved by Cytokinetics and are necessary to synthesize and deliver
such Compounds), and subject to Exelixis using its best efforts to cancel all
cancelable costs. Within thirty (30) days of delivery of the last of the
Compounds in accordance with this Section 8.5.4(b), Exelixis shall provide
Cytokinetics with an invoice setting forth the amount owed for such Compounds
(as specified by the rate in Section 6.2), its actual, reasonable, documented,
non-cancelable costs incurred by Exelixis for the conduct of the Research
Program prior to the effective date of such termination, and such costs incurred
by Exelixis and approved by Cytokinetics after the effective date of such
termination and prior to the effective date of delivery of the last of the
Compounds (and to the extent any amounts remain from any moneys previously paid
by Cytokinetics to Exelixis, the outstanding balance in such account).

                        (c) If Exelixis terminates this Agreement pursuant to
Section 8.4 due to Cytokinetics' material breach, Cytokinetics agrees to pay
Exelixis (i) in full (at the rate specified in Section 6.2) for any compounds
that meet the QCC or are accepted by JRC as Compounds, and are delivered to
Cytokinetics, with their substantially relating Program Compound Information,
prior to the effective date of termination, and (ii) [*] of all actual,
reasonable, documented, non-cancelable costs incurred by Exelixis prior to the
effective date of termination, to the extent such costs were approved by the JRC
and subject to Exelixis using its best efforts to cancel all cancelable costs.
Within thirty (30) days of any such termination, Exelixis shall provide
Cytokinetics with an invoice setting forth the amount owed for such Compounds
(as specified by the rate in Section 6.2), and its actual, reasonable,
documented, non-cancelable costs incurred by Exelixis for the conduct of the
Research Program prior to the effective date of such termination (and to the
extent any amounts remain from any moneys previously paid by Cytokinetics to
Exelixis, the outstanding balance in such account).

                        (d) If Cytokinetics terminates this Agreement pursuant
to Section 8.4 due to Exelixis' material breach, without limiting any remedies
Cytokinetics may have at law, Cytokinetics agrees to pay Exelixis in full (at
the rate specified in Section 6.2) for any compounds that meet the QCC or are
accepted by JRC as Compounds, and are delivered to Cytokinetics, with their
substantially relating Program Compound Information, prior to the effective date
of termination. Within thirty (30) days of any such termination, Exelixis shall
provide Cytokinetics with an invoice setting forth the amount owed for such
Compounds (as specified by the rate in Section 6.2) (and to the extent any
amounts remain from any moneys previously paid by Cytokinetics to Exelixis, the
outstanding balance in such account).

                        (e) Subject to delivery to Cytokinetics of the materials
and information listed in Section 8.5.3, and verification by Cytokinetics of
Exelixis' invoice, within thirty (30) days after receipt of adequate
documentation therefor, the Parties shall settle, in accordance with this
Section 8.5.4, any such outstanding amounts. If there is a balance owed to
Exelixis, Cytokinetics shall make a payment to Exelixis (and/or Exelixis may
retain from moneys previously paid by Cytokinetics) for such Compounds and,
except for termination of this Agreement due to Exelixis' material breach, such
Exelixis' costs. Following settlement of such outstanding amounts, if there is a
balance remaining in Exelixis' accounts from any moneys previously paid by
Cytokinetics to Exelixis, Exelixis shall refund such amounts to Cytokinetics.

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

                                      -14
<PAGE>

            8.6. SURVIVAL. The provisions of Articles 4, 5, 7, 9, 10, 11, 12,
13, 14, 15, 16, 17, 18, 19, 20 and 21 and Sections 6.1, 8.5 and 8.6 shall
survive termination or expiration of this Agreement for any reason. Upon any
termination of this Agreement, neither Party shall have any ongoing obligation
to the other Party, except as expressly provided herein.

      9. PUBLICITY. The Parties shall issue a mutually agreed-upon joint press
release to announce the signing of this Agreement; thereafter, Exelixis and
Cytokinetics may each disclose to third parties the information contained in
such press release without the need for further approval by the other.

      10. PUBLIC PRESENTATIONS. The Parties acknowledge that they, independently
or jointly, may wish to make a Public Presentation of information and data
generated in the course of the Research Program. The term "Public Presentation"
shall mean the submission for publication of any manuscript, abstract or other
form of public presentation, including, without limitation, posters, doctoral
theses, slides and texts of oral presentations, and texts of any transmission
through any electronic media, e.g. any computer access system such as the
Internet, World Wide Web, etc.

The Party wishing to make a Public Presentation (the "Publishing Party") shall
provide to the other Party (the "Non-Publishing Party") a complete copy of its
proposed publication at least thirty (30) days prior to the date of its intended
submission for publication, and agrees, upon request, not to submit any such
abstract or manuscript for publication until (i) the Non-Publishing Party is
given a reasonable period of time to secure patent protection for any material
in such proposed publication which it believes to be patentable, and (ii) to
remove, at the Non-Publishing Party's reasonable request, any Confidential
Information of the Non-Publishing Party and/or any [*] contained within such
proposed publication. Both Parties understand that a reasonable commercial
strategy may require delay of publication of information contained within a
Public Presentation for filing of patent applications. Neither Party shall have
the right to publish or present Confidential Information of the other Party or
any [*] in any Public Presentation without the other Party's prior written
consent. Subject to the foregoing, at the Non-Publishing Party's reasonable
request, the Publishing Party shall remove the [*] and Non-Publishing Party's
Confidential Information from such proposed publication. The Publishing Party
agrees to provide the Non-Publishing Party with a final copy of the proposed
publication prior to its disclosure.

Nothing contained in this Article 10 is intended to grant any right or license
to either Party to commercialize or file patent applications on any information
of the Publishing Party that is included in such Public Presentation. Any
disputes between the Parties regarding delaying a Public Presentation to permit
the filing of a patent application shall be referred to the JRC.

      11. INDEMNIFICATION.

            11.1 INDEMNIFICATION. Each Party agrees to be responsible and assume
liability for its own acts, gross negligence, and/or willful misconduct,
including those of its employees, Affiliates, independent contractors and other
agents, to the full extent permitted by law, and shall indemnify and hold the
other Party, and its employees, Affiliates, directors and agents, harmless from
and against any third party claims or liabilities (including, without
limitation, reasonable attorney's fees) arising from any such acts or gross
negligence, and/or willful misconduct; provided, however, that

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

                                      -15
<PAGE>

the Party entitled to indemnification pursuant to this Article 10 shall
cooperate with the indemnifying Party in defending against any such claims or
liabilities and shall not settle any such claim without the prior consent of the
indemnifying Party, which consent shall not be unreasonably withheld.

            11.2 PROCEDURES. A Party (the "Indemnitee") that intends to claim
indemnification under this Article 11 shall promptly notify the other Party (the
"Indemnitor") in writing of any claim, complaint, suit, proceeding or cause of
action in respect of which the Indemnitee intends to claim such indemnification
(for purposes of this Section 11.2, each a "Claim"), and the Indemnitor shall
have sole control of the defense and/or settlement thereof; provided that the
Indemnitee shall have the right to participate, at its own expense, with counsel
of its own choosing in the defense and/or settlement of such Claim. The
indemnification under this Article 11 shall not apply to amounts paid with
respect to settlement of any Claim if such settlement is effected without the
consent of the Indemnitor, which consent will not be unreasonably withheld or
delayed. The failure to deliver written notice to the Indemnitor within a
reasonable period of time after the commencement of any such claim, suit or
proceeding, if prejudicial to its ability to defend such action, shall relieve
such Indemnitor of any liability to the Indemnitee under this Article 11, but
the omission to so deliver written notice to the Indemnitor shall not relieve
the Indemnitor of any liability to any Indemnitee otherwise than under this
Article 11. Without limiting the foregoing, the Indemnitee shall keep the
Indemnitor fully informed of the progress of any Claim for which it intends to
claim indemnification under this Article 11.

      12. FORCE MAJEURE. Except with respect to the payment of monies due
hereunder and the responsibility to maintain the confidentiality of Confidential
Information and the obligations of non-disclosure and non-use thereof, neither
Party shall be considered in default in the performance of any obligation
hereunder to the extent that the performance of such obligation is prevented or
delayed by fire, flood, explosion, strike, war, insurrection, embargo,
government requirement, civil or military authority, natural disaster or any
other event, occurrence or condition which is not caused, in whole or in part,
by that Party and which is beyond the reasonable control of that Party.

      13. DISCLAIMER.

            13.1 EACH PARTY ACKNOWLEDGES THAT THE COMPOUNDS AND PROGRAM COMPOUND
INFORMATION WHICH WILL BE PRODUCED PURSUANT TO THE RESEARCH PROGRAM ARE
EXPERIMENTAL AND THEIR PROPERTIES ARE NOT COMPLETELY KNOWN. EACH PARTY SHALL
BEAR FULL RESPONSIBILITY FOR SAFE HANDLING, STORAGE, TRANSFER AND USE OF ANY
COMPOUNDS AND PROGRAM COMPOUND INFORMATION IN ITS POSSESSION.

            13.2 EACH PARTY AGREES TO ACT IN ACCORDANCE WITH ALL IMPORT/EXPORT
LAWS AND ENVIRONMENTAL AND DRUG LAWS AND REGULATIONS AND ALL OTHER LAWS AND
REGULATIONS APPLICABLE TO THE USE AND POSSESSION OF THE COMPOUNDS AND PROGRAM
COMPOUND INFORMATION.

            13.3 EXCEPT AS EXPRESSLY SET FORTH HEREIN, COMPOUNDS AND PROGRAM
COMPOUND INFORMATION PROVIDED HEREUNDER ARE PROVIDED "AS IS" AND WITHOUT
WARRANTY OR CONDITIONS OF ANY KIND, EXPRESS, IMPLIED,

                                      -16
<PAGE>

STATUTORY OR OTHERWISE, INCLUDING WITHOUT LIMITATION ANY WARRANTY OF
MERCHANTABILITY, OR FITNESS FOR A PARTICULAR PURPOSE.

            13.4 WITHOUT LIMITING THE PARTIES' RESPECTIVE INDEMNIFICATION
OBLIGATIONS UNDER ARTICLE 11, IN NO EVENT SHALL EITHER PARTY BE LIABLE FOR ANY
INCIDENTAL, CONSEQUENTIAL OR SPECIAL DAMAGES INCURRED BY THE OTHER PARTY,
INCLUDING LOST PROFITS OR ANTICIPATED REVENUES OR PROFITS RELATING TO THE SAME),
ARISING FROM OR RELATING TO THIS AGREEMENT OR THE SUBJECT MATTER HEREOF, WHETHER
BASED IN CONTRACT, TORT (INCLUDING WITHOUT LIMITATION NEGLIGENCE) OR OTHERWISE,
EVEN IF SUCH PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. THESE
LIMITATIONS SHALL APPLY NOTWITHSTANDING ANY FAILURE OF ESSENTIAL PURPOSE OR ANY
LIMITED REMEDY PROVIDED HEREIN.

      14. GOVERNING LAW. The validity and interpretation of this Agreement and
the legal relations of the Parties under this Agreement shall be governed by the
laws of the State of California, without reference to its conflict of laws
principles.

      15. ASSIGNMENT. This Agreement shall not be assignable by either Party
without the prior written consent of the other Party; except that Exelixis or
Cytokinetics may assign, at their discretion, the Agreement without such consent
(i) to an Affiliate, or (ii) to a third party pursuant to merger, acquisition,
consolidation, reorganization or sale of all or substantially all of its assets
to which this Agreement relates; provided that, such assignee or transferee has
agreed in writing to be bound by the terms and conditions of this Agreement. Any
attempted assignment contrary to this Article 15 shall be void. Subject to the
foregoing, this Agreement shall be binding upon and inure to the benefit of the
Parties, their successors and assigns.

      16. 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.

      17. INDEPENDENT CONTRACTOR. For the purposes of this Agreement and all
services to be provided hereunder, each Party shall be, and shall be deemed to
be, an independent contractor and not an agent or employee of the other Party.
Neither Party shall have authority to make any statements, representations or
commitments of any kind, or take action, which shall be binding on the other
Party, except as may be explicitly provided for herein or authorized by the
other Party in writing.

      18. SEVERABILITY. If any one or more provisions of this Agreement shall be
found to be illegal or unenforceable in any respect, the validity, legality and
enforceability of the remaining provisions shall not in any way be affected or
impaired thereby, provided the surviving agreement materially comports with the
parties' original intent.

      19. WAIVER. Waiver or forbearance by either Party or the failure by either
Party to claim a breach of any provision of this Agreement or exercise any right
or remedy provided by this

                                      -17
<PAGE>

Agreement or applicable law, shall not be deemed to constitute a waiver with
respect to any subsequent breach of any provision hereof.

      20. NOTICES. Any notice, payment or report required or permitted to be
given under this Agreement shall be deemed to have been sufficiently given if
mailed by first class certified or registered airmail addressed to the Parties
as follows:

            Exelixis - U.S. Postal Service:
                     Exelixis, Inc.
                     170 Harbor Way
                     P.O. Box 511
                     South San Francisco, California  94083-0511 USA
                     Attention: Vice President, Corporate Technology Development

            Exelixis - Other Mail Delivery Carrier:
                     Exelixis, Inc.
                     169 Harbor Way
                     South San Francisco, California  94080 USA
                     Attention: Vice President, Corporate Technology Development

            Cytokinetics:
                     Cytokinetics, Inc.
                     280 East Grand Avenue
                     South San Francisco, California  94080
                     Attention: Senior Vice President, Finance and Corporate
                                Development Chief Financial Officer

      21. ENTIRE AGREEMENT. This instrument contains the entire agreement
between the Parties hereto as to the subject matter hereof. The provisions of
the Confidential Disclosure Agreement, entered into on February 12, 2001, is
expressly superseded and terminated hereby, and any confidential or proprietary
information disclosed thereunder shall be subject to the terms of this
Agreement. No verbal agreement or representation between the Parties hereto
either before, during or after execution of this Agreement shall affect or
modify any of the terms or obligations herein. No amendment or modification of
any term, provisions or conditions of this Agreement shall be binding or
enforceable unless in writing and signed by each of the Parties. This Agreement
may be executed in counterparts, each of which taken together shall be
considered part of the entire document.

The undersigned represent that they are duly authorized to execute this
Agreement.

CYTOKINETICS, INC.                        EXELIXIS, INC.

By:___________________________________    By:___________________________________

Name:_________________________________    Name:_________________________________

Title:________________________________    Title:________________________________

                                      -18
<PAGE>

Date:_________________________________    Date:_________________________________

                                      -19
<PAGE>

                                   APPENDIX A

                                RESEARCH PROGRAM

1) LIBRARY SCOPE & SIZE:

A library of [*] compounds based on [*] will be designed jointly by Cytokinetics
and Exelixis and subsequently synthesized by Exelixis.

2) LIBRARY CONSTRUCTION:

[*] compounds will be derived from [*] libraries of [*] compounds. Each of the
[*] libraries will be derived from [*] of [*] and a [*] of [*] per [*] (each, a
"Library"). The details and identity of [*] component for the [*] will be
determined by the JRC. Approximately [*] of each compound will be prepared and
quality controlled by [*]. [*]. For [*] compounds per plate, a [*] of [*] per
Plate will be transferred to Cytokinetics (that is, [*]). Following delivery of
the [*] Plate within a Library, Exelixis shall deliver to Cytokinetics a [*] of
[*] of each [*] used in such Library. Cytokinetics shall own all right, title
and interest in such delivered [*], and shall have the right to use and exploit
such [*] without limitation or obligation to account to Exelixis to the extent
allowed under Section 4 of the Agreement.

3) EXELIXIS COMPOUND PLATE FORMAT:

Exelixis formats screening plates in a [*] plate format with [*], i.e., a total
of [*] compounds per plate.

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

                                      -20
<PAGE>

                                   APPENDIX B

                            QUALITY CONTROL CRITERIA

[*]

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

                                      -21<PAGE>
                                                                     EXHIBIT 4.1

                    (FORM OF STOCK CERTIFICATE - FRONT SIDE)

NUMBER                                                                    SHARES

                               ANIMAS CORPORATION

              INCORPORATED UNDER THE LAWS OF THE STATE OF DELAWARE

          PAR VALUE $0.01                                  CUSIP 03525Y 10 5
                                          SEE REVERSE FOR CERTAIN DEFINITIONS

THIS certifies that

is the owner of

             FULLY PAID AND NON-ASSESSABLE SHARES OF COMMON STOCK OF
                               ANIMAS CORPORATION

transferable on the books of the Corporation by the holder hereof in person or
by duly authorized Attorney upon surrender of this Certificate properly
endorsed. This Certificate and the shares represented hereby are issued and
shall be held subject to all of the provisions of the Certificate of
Incorporation of the Corporation, By-Laws and all Amendments thereto, to all of
which the holder, by acceptance hereof assents.

     This Certificate is not valid unless countersigned and registered by the
Transfer Agent and Registrar.

     WITNESS the facsimile seal of the Corporation and the facsimile signatures
of its duly authorized officers.

Dated:

                            (SEAL)
----------------------------               ------------------------------
Richard Baron                              Katherine D. Crothall
Secretary                                  President and Chief Executive Officer

                       Countersigned and Registered:

                                       STOCKTRANS, INC.
                                       44 West Lancaster Ave.
                                       Ardmore, PA 19003

                                       Transfer Agent
                                       and Registrar,

                                       By

                                       Authorized Signature
<PAGE>
                     (Form of Stock Certificate - Back Side)

                               ANIMAS CORPORATION

         The Corporation will furnish without charge to each stockholder who so
requests the powers, designations, preferences and relative, participating,
optional, or other special rights of each class of stock or series thereof of
the Corporation, and the qualifications, limitations or restrictions of such
preferences and/or rights.

         The following abbreviations, when used in the inscription on the face
of this Certificate, shall be construed as though they were written out in full
according to applicable laws or regulations:

TEN COM  -  as tenants in common
TEN ENT  -  as tenants by the entireties

JT TEN   -  as joint tenants with right of
            survivorship and not as tenants in
            common

UNIF GIFT MIN ACT -            Custodian
                    ----------           ----------
                     (Cust)               (Minor)
             under Uniform Gifts to Minors

             Act --------------------------
                          (State)

                Additional abbreviations may also be used though
                             not in the above list.

For value received,                        hereby sell, assign and transfer unto
                    ----------------------

PLEASE INSERT SOCIAL SECURITY OR OTHER
IDENTIFYING NUMBER OF ASSIGNEE

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

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

--------------------------------------------------------------------------------
  (PLEASE PRINT OR TYPEWRITE NAME AND ADDRESS, INCLUDING ZIP CODE, OF ASSIGNEE)

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

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

                                                                          shares
------------------------------------------------------------------------

of the common stock represented by the within Certificate and do hereby
irrevocably constitute and appoint
                                     -------------------------------------------
Attorney to transfer the said stock on the books of the within named Corporation
with full power of substitution in the premises.

Dated:
      -----------------------------------

                                            ------------------------------------
                                            NOTICE: THE SIGNATURE TO THIS
                                            ASSIGNMENT MUST CORRESPOND WITH THE
                                            NAME AS WRITTEN UPON THE FACE OF THE
                                            CERTIFICATE IN EVERY PARTICULAR,
                                            WITHOUT ALTERATION OR ENLARGEMENT,
                                            OR ANY CHANGE WHATSOEVER.

Signature(s) Guaranteed:

-------------------------------------------------------------------
THE SIGNATURE(S) SHOULD BE GUARANTEED BY AN ELIGIBLE GUARANTOR INSTITUTION
(BANKS, STOCKBROKERS, SAVINGS AND LOAN ASSOCIATIONS AND CREDIT UNIONS WITH
MEMBERSHIP IN AN APPROVED SIGNATURE GUARANTEE MEDALLION PROGRAM), PURSUANT TO
S.E.C. RULE 17Ad-15.

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00065-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00065-of-00352.parquet"}]]