<PAGE>


                                                            Exhibit No. 10.17



     CONFIDENTIAL MATERIALS OMITTED AND FILED SEPARATELY WITH THE SECURITIES
              AND EXCHANGE COMMISSION. ASTERISKS DENOTE OMISSIONS.



                              AMENDED AND RESTATED

                             COLLABORATION AGREEMENT

                                     BETWEEN

                             COR THERAPEUTICS, INC.

                                       AND

                           KYOWA HAKKO KOGYO CO., LTD.

                                DECEMBER 11, 2001


<PAGE>


                  AMENDED AND RESTATED COLLABORATION AGREEMENT


         THIS AMENDED AND RESTATED COLLABORATION AGREEMENT ("Agreement") is made
effective as of the 11th day of December, 2001 (the "Amendment and Restatement
Effective Date") by and between COR Therapeutics, Inc., a Delaware corporation
having its principal place of business at 256 East Grand Avenue, South San
Francisco, California, U.S.A. 94080 ("COR") and Kyowa Hakko Kogyo Co., Ltd., a
Japanese corporation having its principal place of business at 1-6-1 Ohtemachi,
Chiyoda-ku, Tokyo, Japan ("Kyowa Hakko").

                                    RECITALS

         1. COR and Kyowa Hakko entered into that certain Collaboration
Agreement, dated as of November 30, 1992, as amended effective May 9, 1994, July
13, 1994, August 1, 1995, November 10, 1995, December 17, 1996, December 1, 1997
and November 30, 1998 under which the parties conducted collaborative research
to support a drug discovery program for [**], and for development and
commercialization of certain agents resulting from the research program. The
Amendment No. 5 to the Agreement added to the collaboration [**] which
specifically [**], in which COR owned sole rights.

         2. The Research Term (as defined below) expired November 30, 1999. The
parties wish to conduct further research and development independently, to
reallocate the territories in which each will bear development responsibilities
and have commercialization opportunities, eliminate the possible [**],
reallocate the manufacturing rights and obligations, and to adjust the economic
obligations and compensation accordingly as set forth herein. In addition, the
parties wish to restate their respective rights and obligations in light of the
previous amendments, the expiration of the Research Term, and the termination by
Kyowa Hakko of Amendment No. 5 to the Collaboration Agreement by letter dated
November 25, 1999.

                                    ARTICLE 1
                                   DEFINITIONS

         The following terms shall have the following meanings as used in this
Agreement:

         1.1 "AFFILIATE" means an entity that, directly or indirectly, through
one or more intermediaries, controls, is controlled by or is under common
control with COR or Kyowa Hakko. For the purposes of this definition, control
means the direct or indirect ownership of at least 50% or, if less than 50%, the
maximum percentage as allowed by applicable law, of the outstanding voting
securities of such entity.

         1.2 "ASIAN TERRITORY" means [**] including all territories and
possessions thereof.

         1.3 "COMPOUND" means [**] within the [**] of a [**] of a [**] listed in
Schedule 1.3 attached hereto.

<PAGE>


         1.4 "CONTROL" means possession of the ability to grant a license or
sublicense as provided for herein without violating the terms of any agreement
or other arrangement with, or the rights of, any Third Party.

         1.5 "COR KNOWHOW" means Information which (i) COR discloses to Kyowa
Hakko under this Agreement for use in the Research and (ii) during the Research
Term is within the Control of COR.

         1.6 "COR PATENTS" means the rights granted by any governmental
authority under a Patent which covers a method, apparatus, material or
manufacture useful in the Field, which Patent is owned or Controlled by COR or
its Affiliates, excluding, however, Program Patents.

         1.7 "COR TECHNOLOGY" means the COR Knowhow and COR Patents,
collectively.

         1.8 "COR TERRITORY" shall mean the entire world, excluding only the
Asian Territory.

         1.9 "DRUG APPROVAL APPLICATION" means an application for Regulatory
Approval required before commercial sale or use of a Product as a drug in a
regulatory jurisdiction.

         1.10 "EFFECTIVE DATE" means November 30, 1992, which was the effective
date of the Original Agreement.

         1.11 "FIELD" means the discovery, development, manufacture, use and
sale of Compounds and Products for all human and animal uses, including, but not
limited to, the prevention or treatment of restenosis following angioplasty,
[**] Excluded from the field are [**].

         1.12 "INFORMATION" shall mean (i) present and future techniques,
inventions, practices, methods, knowledge, knowhow, skill, experience, test data
including pharmacological, toxicological and clinical test data, analytical and
quality control data, marketing, pricing, cost, sales and manufacturing data and
descriptions relating to the Field; (ii) present and future compounds,
compositions, assays and any biological materials relating to the Field; and
(iii) all Information exchanged between the parties pursuant to the Original
Agreement.

         1.13 "KYOWA HAKKO KNOWHOW" means Information which (i) Kyowa Hakko
discloses to COR under this Agreement for use in the Research and (ii) during
the Research Term is within the Control of Kyowa Hakko.

         1.14 "KYOWA HAKKO PATENTS" means the rights granted by any governmental
authority under a Patent which covers a method, apparatus, material or
manufacture useful in the Field, which Patent is owned or Controlled by Kyowa
Hakko or its Affiliates, excluding, however, Program Patents.

         1.15 "KYOWA HAKKO TECHNOLOGY" means the Kyowa Hakko Knowhow and Kyowa
Hakko Patents, collectively.

<PAGE>


         1.16 "NET SALES" means the amount billed by a party or an Affiliate,
assignee or sublicensee of such party for sales of Products under this Agreement
to a Third Party less: (i) discounts, including cash discounts, or rebates,
retroactive price reductions or allowances actually allowed or granted from the
billed amount, (ii) credits or allowances actually granted upon claims,
rejections or returns of Products, including recalls, regardless of the party
requesting such, (iii) freight, postage, shipping and insurance charges paid for
delivery of Product, to the extent billed, and (iv) taxes, duties or other
governmental charges levied on or measured by the billing amount when included
in billing, as adjusted for rebates and refunds. In the event a party is
receiving royalties under this Agreement from any Product sold in the form of a
combination Product containing one or more active ingredients, Net Sales for
such combination Product will be calculated by multiplying actual Net Sales by
the greater of [**]% or the fraction A/(A+B) where A is the fair market value of
the portion of the combination Product that contains a Product and B is the fair
market value of the other active ingredients included in such combination
Product, as determined by market prices of such portions if separately priced
and sold, or if not so priced and sold, as determined by mutual agreement of the
parties. As used herein, the term "active ingredient" does not include
ingredients the primary effect of which is the enhancement of drug delivery,
even if such ingredients have pharmacological activity.

         1.17 "ORIGINAL AGREEMENT" means the Collaboration Agreement between COR
Therapeutics, Inc. and Kyowa Hakko Kyogo Co., Ltd, dated as of November 30,
1992.

         1.18 "PATENT" means (i) a valid and enforceable patent, including any
extension, registration, confirmation, reissue, reexamination or renewal thereof
and (ii) to the extent valid and enforceable rights are granted by a
governmental authority thereunder, a patent application.

         1.19 "PATENT COSTS" means the fees and expenses paid to outside legal
counsel and other third parties, and filing and maintenance expenses, incurred
in connection with the establishment, maintenance of rights under Patents
applicable to Products including costs of patent interference proceedings.

         1.20 "PRODUCT" means any form or dosage of a Compound for human
pharmaceutical or any other use.

         1.21 "PROGRAM PATENTS" mean Patents and applications for Patents which
cover a method, apparatus, material or manufacture useful in the Field and the
subject of which is an invention conceived or reduced to practice by either of
the parties or by the parties jointly in the course of the Research or their
respective work in the Field during the [**] period following the Research Term.
Any reference to a particular party's Program Patents shall include those
Program Patents owned by the party plus that party's interest in Program Patents
that are jointly owned under this Agreement.

         1.22 "REGULATORY APPROVAL" means any approvals, licenses, registrations
or authorizations of any federal, state or local regulatory agency, department,
bureau or other government entity, necessary for the manufacture, use, storage,
import, transport or sale, of Products in a regulatory jurisdiction.

<PAGE>


         1.23 "RESEARCH" means all work performed by the parties in the Field
during the Research Term.

         1.24 "RESEARCH TERM" means the period commencing on the Effective Date
and ending on November 30, 1999.

         1.25 "THIRD PARTY" means any entity other than COR or Kyowa Hakko or an
Affiliate of COR or Kyowa Hakko.

         1.26 "UNITED STATES" means the United States and all possessions and
territories thereof.

                                    ARTICLE 2
                                    RESEARCH

         2.1 COLLABORATIVE RESEARCH. COR and Kyowa Hakko conducted the Research
on a collaborative basis with the goal of identifying potentially useful
compounds and developing them into commercially successful Products. Pursuant to
Amendment No. 5 to the Original Agreement, COR and Kyowa Hakko further
collaborated to [**] which specifically [**], to which COR owned sole rights.
The Research Term expired on November 30, 1999 and Amendment No. 5 was
terminated effective February 29, 2000.


                                    ARTICLE 3
                                   DEVELOPMENT

         3.1 DEVELOPMENT OF PRODUCTS. Kyowa Hakko will have the sole right to
develop all Products in the Asian Territory and shall own all Drug Approval
Applications for each Product in such territory. COR will have the sole right to
develop all Products in the COR Territory and shall own all Drug Approval
Applications for each Product in such territory. Each party shall bear all costs
it incurs with respect to development of such Products in its respective
territory.

                                    ARTICLE 4
                                    LICENSES

         4.1 LICENSES TO KYOWA HAKKO WITHIN THE FIELD. COR hereby grants to
Kyowa Hakko a license under the COR Technology and COR's Program Patents to
make, have made, use, import, offer for sale, sell and have sold all Products in
the Asian Territory. Such license shall be [**] except as provided in Section
4.5. Such license shall be exclusive with respect to COR Patents and COR's
Program Patents and non-exclusive with respect to COR Knowhow.

         4.2 LICENSES TO COR WITHIN THE FIELD. Kyowa Hakko hereby grants to COR
a royalty-bearing license under the Kyowa Hakko Technology and Kyowa Hakko's
Program Patents to make, have made, use, import, offer for sale, sell and have
sold all Products in the COR Territory. Such license shall be exclusive with
respect to Kyowa Hakko Patents and Kyowa Hakko's Program Patents and
non-exclusive with respect to Kyowa Hakko Knowhow.

<PAGE>


         4.3 SUBLICENSING. Kyowa Hakko shall have the right to sublicense any of
its rights under Section 4.1 in the Asian Territory to any Third Party, without
the prior written consent of COR. COR shall have the right to sublicense any of
its rights under Section 4.2 in the COR Territory to any Third Party, without
the prior written consent of Kyowa Hakko.

         4.4 RIGHTS TO USE PROGRAM PATENTS OUTSIDE OF THE FIELD. The parties
have provided in Article 11 below for the allocation of ownership of Program
Patents. While it is contemplated that Program Patents will have primary utility
within the Field, the parties recognize that such patents may also have
application outside of the Field and desire to allocate rights to practice such
patents outside the Field on the basis of inventorship of the relevant Program
Patent. Accordingly:

             (a) Kyowa Hakko hereby grants to COR [**] license to make, have
made, use and sell products outside of the Field under those Program Patents
owned by Kyowa Hakko as to which COR was the sole or joint inventor. Such
license shall be exclusive with respect to such Program Patents for which COR is
the sole inventor, and non-exclusive with respect to Program Patents for which
COR is a joint inventor. COR shall have the right to sublicense any of its
rights under this Section 4.4 with the prior written consent of Kyowa Hakko.

             (b) COR hereby grants to Kyowa Hakko [**] license to make, have
made, use and sell products outside of the Field under those Program Patents
owned by COR as to which Kyowa Hakko was the sole or joint inventor. Such
license shall be exclusive with respect to such Program Patents for which Kyowa
Hakko is the sole inventor, and non-exclusive with respect to such Program
Patents for which Kyowa Hakko is a joint inventor. Kyowa Hakko shall have the
right to sublicense any of its rights under this Section 4.4 with the prior
written consent of COR.

         As used herein, "inventorship" by COR or Kyowa Hakko shall mean
inventorship by the employees of such company or consultants engaged by it, and
joint inventorship shall mean inventorship by employees and/or consultants of
each of the parties. Each party agrees to discuss in good faith any request by
the other to grant a sublicense hereunder.

         4.5 SUBLICENSES OF THIRD PARTY TECHNOLOGY. The licenses granted herein
include sublicenses under any technology applicable to the Field which has been,
or during the term of this Agreement is, licensed by a party from any Third
Party and is within the Control of such party. For any such Third Party
technology licensed by a party [**]such licensing party [**]. The parties agree
that COR shall not be required to obtain Kyowa Hakko's consent to obtain a
license under technology in the COR Territory and Kyowa Hakko shall not be
required to obtain COR's consent to obtain a license under technology in the
Asian Territory. No license applicable to Products in the COR Territory shall be
entered into except with the consent of COR. No license applicable to Products
in the Asian Territory shall be entered into except with the consent of Kyowa
Hakko. Except as provided in the second sentence of this paragraph, each party
receiving a sublicense of Third Party technology hereunder shall comply with the
terms and conditions of such sublicense imposed by the Third Party, including
accounting for Net Sales of Products.

<PAGE>


         4.6 TERRITORIAL LIMITATIONS. To the extent permitted by law, neither
COR nor Kyowa Hakko shall sell Products to any Third Party the selling party
believes will resell in a manner inconsistent with the commercialization
arrangements set forth in this Agreement.

                                    ARTICLE 5
                                COMMERCIALIZATION

         5.1 COMMERCIALIZATION. Kyowa Hakko shall develop and maintain, in its
sole discretion, a program for commercializing the Product in the Asian
Territory. COR shall develop and maintain, in its sole discretion, a program for
commercializing the Products in the COR Territory.

         5.2 TRADEMARKS. Each party shall prosecute applications for, own and
maintain the trademarks for each Product in its respective territory.

                                    ARTICLE 6
                                   COMMITTEES

         6.1 DELETED. This Article has been deleted in its entirety.

                                    ARTICLE 7
                                ROYALTY PAYMENTS

         7.1 PRODUCT ROYALTY. COR shall pay Kyowa Hakko a royalty of [**]
percent ([**]%) of Net Sales of Products in the COR Territory. Such royalties
shall terminate as to each Product and as to each country in the COR Territory
upon the later to occur of (i) the expiration of the last to expire patent in
which Kyowa Hakko has an ownership interest and a claim of which covers a
Product in such country or (ii) 10 years after the first commercial sale of such
Product in such country. Upon the termination of COR's royalty obligation
hereunder as to each Product in the relevant country, COR shall have [**]
license under the Kyowa Hakko Knowhow to make, have made, use, import, offer for
sale, sell and have sold all Product in such country.

         7.2 ACCRUAL; CURRENCY; TAXES; STATEMENT. Such royalties shall be paid
quarterly within 60 days after the end of each calendar quarter. Such royalties
shall be calculated on the basis of Net Sales in the local currency of each
country, and converted into U.S. Dollars and paid in U.S. Dollars on the basis
of the currency exchange rate published in the Wall Street Journal or comparable
newspaper of international circulation on the last business day of the quarter
in which such sales were made. In the event of Net Sales being made in a
currency as to which conversion into U.S. Dollars is then blocked, COR shall
make payment to Kyowa Hakko in such local currency in a bank account designated
by Kyowa Hakko. COR shall withhold any taxes on such royalties required by law.
Each royalty payment shall be accompanied by a statement of such royalties
showing the Net Sales of each Product during such quarter, the calculation of
the royalties due, and showing evidence of payment as to any taxes paid on Kyowa
Hakko's behalf. Any refunds or rebates of taxes paid to COR on behalf of Kyowa
Hakko shall be remitted promptly by COR to Kyowa Hakko.


<PAGE>


         7.3 [**] LICENSE AND ROYALTIES.

             (a) Effective November 25, 1999, Kyowa Hakko terminated
Amendment No. 5 to the Original Agreement. Upon such termination, all of Kyowa
Hakko's rights in the [**] Field under the Original Agreement terminated
worldwide. Accordingly, Kyowa Hakko hereby grants to COR an exclusive, worldwide
license under Kyowa Hakko [**] Patents and Kyowa Hakko's [**] Program Patents,
and a nonexclusive, worldwide license under Kyowa Hakko [**] Knowhow, to
develop, make, use and sell [**] Products. In connection with the activities
under Amendment No. 5 to the Original Agreement, Kyowa Hakko developed and
provided to COR a [**]Ab produced in a high-expressing cell line. In
consideration thereof, COR shall pay Kyowa Hakko a royalty of [**] percent
([**]%) of worldwide Net Sales of [**] Products incorporating the Kyowa Hakko
provided [**]; provided that such royalties shall cease when the cumulative
royalties paid to Kyowa Hakko amount to [**] Dollars ($[**]).

             (b) As used in this Section, the following terms shall have the
following meanings:

                 (i) "KYOWA HAKKO [**] KNOWHOW" means all Information useful in
the [**] Field which Kyowa Hakko Controls during the term of this Agreement.

                 (ii) "KYOWA HAKKO [**] PATENTS" means the rights granted by any
governmental authority under a Patent which covers a method, apparatus, material
or manufacture useful in the [**] Field, which Patent is owned or Controlled by
Kyowa Hakko or its Affiliates, excluding, however, [**] Program Patents.

                 (iii) [**] means COR's [**] and which is the [**] provided by
COR to Kyowa Hakko prior to the effective date of Amendment No. 5. [**] also
includes [**].

                 (iv) "[**] FIELD" means the discovery, development,
manufacture, use and sale of [**] Products for all human and animal
pharmaceutical uses, including, but not limited to, the prevention or treatment
of restenosis following angioplasty, but excluding any diagnostic use.

                 (v) "[**] PRODUCTS" means any form or dosage of a [**] for
human and animal pharmaceutical use, excluding any diagnostic use. The parties
acknowledge that [**] Products do not fall within the scope of the definition of
"Product", and that the class of [**] Products is separate from the class of
Product.

                 (vi) "[**] PROGRAM PATENTS" means Patents and applications for
Patents which cover a method, apparatus, material or manufacture useful in the
[**] Field and the subject of which is an invention conceived or reduced to
practice by either of the parties or by the parties jointly in the course of
their respective work in the [**] Field prior to termination of Amendment No. 5.
Any reference to a particular party's [**] Program Patents shall include those
[**] Program Patents owned by that party plus that party's interest in [**]
Program Patents that were jointly owned under Amendment No. 5.

<PAGE>


                                    ARTICLE 8
                                  MANUFACTURING

         8.1 MANUFACTURE OF PRODUCTS. Each party shall be responsible for
manufacture of Products in its respective territory.

                                    ARTICLE 9
                        DEVELOPMENT AND COMMERCIALIZATION
                               OF CANCER PRODUCTS

         9.1 DELETED. This Article has been deleted in its entirety.


                                   ARTICLE 10
                                 CONFIDENTIALITY

         10.1 CONFIDENTIALITY; EXCEPTIONS. Except to the extent expressly
authorized by this Agreement or otherwise agreed in writing, the parties agree
that, for the term of this Agreement and for [**] years thereafter, the
receiving party shall keep confidential and shall not publish or otherwise
disclose or use for any purpose other than as provided for in this Agreement any
Information and other information and materials furnished to it by the other
party pursuant to this Agreement (collectively, "Confidential Information"),
except to the extent that it can be established by the receiving party by
competent proof that such Confidential Information:

              (a) was already known to the receiving party, other than under
an obligation of confidentiality, at the time of disclosure by the other party;

              (b) was generally available to the public or otherwise part of
the public domain at the time of its disclosure to the receiving party;

              (c) became generally available to the public or otherwise part
of the public domain after its disclosure and other than through any act or
omission of the receiving party in breach of this Agreement; or

              (d) was disclosed to the receiving party, other than under an
obligation of confidentiality, by a Third Party who had no obligation to the
disclosing party not to disclose such information to others.

         10.2 AUTHORIZED DISCLOSURE. Each party may disclose the other's
Confidential Information to the extent such disclosure is reasonably necessary
in filing or prosecuting patent applications, prosecuting or defending
litigation, complying with applicable governmental regulations or conducting
preclinical or clinical trials, provided that if a party is required by law or
regulation to make any such disclosure of the other party's Confidential
Information it will except where impracticable for necessary disclosures, for
example in the event of medical emergency, give reasonable advance notice to the
other party of such disclosure requirement and, except to the extent
inappropriate in the case of patent applications, will use its best efforts to
secure confidential treatment of such Confidential Information required to be
disclosed.

<PAGE>


         10.3 SURVIVAL. This Article 10 shall survive the termination or
expiration of this Agreement for a period of [**] years.

                                   ARTICLE 11
                       OWNERSHIP OF INTELLECTUAL PROPERTY
                                AND PATENT RIGHTS

         11.1 OWNERSHIP OF PROGRAM PATENTS. The ownership of Program Patents and
responsibility for the prosecution and maintenance of such patents, and the
handling of interference proceedings with respect to such patents, shall be
allocated as follows:

              (a) Program Patents [**] shall be owned jointly by Kyowa Hakko
and COR in all countries of the world. The initial patent application for such
Program Patents shall be prepared and filed by COR in the United States.

              (b) Program Patents with respect to [**] as to which the [**]
within a [**] shall be owned by Kyowa Hakko in the Asian Territory, and shall be
owned jointly by Kyowa Hakko and COR in the COR Territory.

                  (i) With respect to [**], the initial patent application [**]
shall be prepared and filed by Kyowa Hakko in Japan.

                  (ii) With respect to [**], the initial patent application [**]
shall be prepared and filed by COR in the United States.

              (c) Program Patents with respect [**] as to which the [**]
shall be owned by COR in the COR Territory and shall be owned jointly by Kyowa
Hakko and COR in the Asian Territory. The initial patent application for [**]
shall be prepared and filed by COR in the United States.

         In the event inventions are made which cover more than one category set
forth above, the parties shall consult and cooperate to cause their patent
filings to be in accord as nearly as practicable to the categories set forth
above, and to allocate ownership and rights with respect to individual claims as
provided above. The parties hereby assign to each other any ownership interest
in Program Patents which they may obtain inconsistent with the agreement set
forth above, and will assist each other in every proper way to effect such
assignment.

         11.2 KYOWA HAKKO RESPONSIBILITY FOR PATENT FILINGS. Kyowa Hakko will
diligently file, prosecute and issue Program Patents to effectively cover
discoveries and inventions relating to the Field which are within categories
11.1(a), 11.1(b) and 11.1(c) for all countries in the Asian Territory. Kyowa
Hakko will endeavor to ensure whenever possible that claims are filed and will
issue in such Patents specifically directed to the Field and that all Patents
are filed before any public disclosure by Kyowa Hakko to maintain the validity
of Patents filed outside of the United States. Kyowa Hakko will give COR
immediate notice of any decision to prepare a Patent application which is
subject to this Section 11.2. For all Patent applications other than new
chemical entities, Kyowa Hakko will provide COR and its patent counsel [**] of
any such Patent applications and COR will have [**] days from receipt of such
drafts to comment on such applications. For Patent applications for new chemical
entities, Kyowa Hakko will provide COR

<PAGE>


and its patent counsel [**] of any such Patent applications; COR will have [**]
days from receipt of such drafts to comment on such applications. Such drafts of
Patent applications for new chemical entities delivered to COR for review will
include the [**]. In each event, Kyowa Hakko will confer with COR, and make
every effort to adopt COR's suggestions, regarding the prosecution of such
Patents. As soon as practical subsequent to filing, Kyowa Hakko will provide COR
with [**] of any filing. In addition, Kyowa Hakko will copy COR with any
official action and Kyowa Hakko submissions in such Patents, including an
English translation thereof.

         11.3 COR RESPONSIBILITY FOR PATENT FILINGS. COR will diligently file,
prosecute and issue Program Patents to effectively cover discoveries and
inventions relating to the Field for those inventions which are within
categories 11.1(a), 11.1(b) and 11.1(c) for all countries in the COR Territory.
COR will endeavor to ensure whenever possible that claims are filed and will
issue in such Patents specifically directed to the Field and that all Patents
are filed before any public disclosure to COR to maintain the validity of
Patents filed in the COR Territory. COR will give Kyowa Hakko immediate notice
of any decision to prepare a Patent application which is subject to this Section
11.3. For all Patent applications other than new chemical entities, COR will
provide Kyowa Hakko and its patent counsel [**] of any such Patent applications
and Kyowa Hakko will have [**] days from receipt of such drafts to comment on
such applications. For Patent applications for new chemical entities, COR will
provide Kyowa Hakko and its patent counsel [**] of any such Patent applications;
Kyowa Hakko will have [**] days from receipt of such drafts to comment on such
applications. Such drafts of Patent applications for new chemical entities
delivered to Kyowa Hakko for review will include the [**]. In each event, COR
will confer with Kyowa Hakko, and make every effort to adopt Kyowa Hakko's
suggestions, regarding the prosecution of such Patents. In addition, COR will
copy Kyowa Hakko with any official action and COR's submissions in such Patents.

         11.4 INITIAL FILINGS IF MADE BY KYOWA HAKKO IN THE ASIAN TERRITORY.
Kyowa Hakko agrees to use reasonable efforts to assure that any Patent it files
in the Asian Territory prior to a U.S. filing will be in a form sufficient to
establish the date of original filing as a priority date for the purposes of a
subsequent U.S. filing.

         11.5 ENFORCEMENT RIGHTS. With respect to infringement in the Field of
any of the COR Patents, Kyowa Hakko Patents or Program Patents, (i) COR shall
have the right, but not the obligation, to institute, prosecute and control any
action or proceeding with respect to such infringement in the COR Territory;
(ii) Kyowa Hakko shall have the right, but not the obligation, to institute,
prosecute and control any action or proceeding with respect to such infringement
in the Asian Territory. The parties shall consult regarding the institution,
prosecution and control of any action or proceeding with respect to infringement
outside of the Field of any of the COR Patents, Kyowa Hakko Patents or Program
Patents. In the absence of agreement with respect to infringement outside of the
Field, each party may proceed in such manner as the law permits. In each case
relating to infringement within the Field, Kyowa Hakko shall bear the costs of
patent enforcement within the Asian Territory and retain for its own account any
amounts recovered from Third Parties; COR shall bear the costs of patent
enforcement within the COR Territory and retain for its own account any amounts
recovered from Third Parties.

<PAGE>


         11.6 PATENT COSTS. Patent Costs for Products in the Asian Territory
shall be borne solely by Kyowa Hakko; Patent Costs for Products in the COR
Territory shall be borne solely by COR.

         11.7 ASSIGNMENT. Neither party may assign its rights under any jointly
owned Program Patent except with the prior written consent of the other party;
provided, however, that either party may assign such rights without consent to
an Affiliate or other permitted assignee of this Agreement.

                                   ARTICLE 12
                         REPRESENTATIONS AND WARRANTIES

         12.1 REPRESENTATIONS AND WARRANTIES. Each of the parties hereby
represents and warrants as follows:

              (a) This Agreement is a legal and valid obligation binding upon
such party and enforceable in accordance with its terms. The execution, delivery
and performance of the 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 is bound, nor violate any law or regulation of any court,
governmental body or administrative or other agency having jurisdiction over it.

              (b) Such party has not, and during the term of the Agreement
will not, grant any right to any Third Party relating to its respective
Technology in the Field which would conflict with the rights granted to the
other party hereunder.

                                   ARTICLE 13
                          REPORTS, RECORDS AND SAMPLES

         13.1 WRITTEN REPORTS. COR and Kyowa Hakko will each deliver to the
other periodic written reports in English presenting a meaningful summary of
their respective Product development work performed hereunder. Each party shall
deliver its initial report upon commencement of its first human clinical trial
for the relevant Product, and shall provide a follow-up report with respect to
that Product at the completion of each clinical phase prior to receipt of
regulatory approval for such Product.

         13.2 RECORDS OF NET SALES. COR party will maintain complete and
accurate records of Net Sales which are relevant to payments to be made under
this Agreement and such records shall be open during reasonable business hours
for a period of [**] years from creation of individual records for examination
at Kyowa Hakko's expense and not more often than once each year by a certified
public accountant selected by Kyowa Hakko and acceptable to COR for the sole
purpose of verifying for Kyowa Hakko the correctness of calculations or payments
made under this Agreement.

         13.3 PUBLICITY REVIEW. COR and Kyowa Hakko will jointly discuss and
agree, based on the principles of this Section 13.3, on any statement to the
public regarding this Agreement or any aspect of this Agreement subject in each
case to disclosure otherwise required by law or regulation. If either party is
required by law or regulation to make a public disclosure or announcement
concerning the Research or this Agreement or the subject matter thereof, such

<PAGE>


party shall give reasonable prior advance notice of the proposed text of such
disclosure or announcement to the other parties for their review and comment. In
the discussion and agreement referred to above, the principles observed by COR
and Kyowa Hakko will be: accuracy, the requirements for confidentiality under
Article 10, the advantage a competitor of COR or Kyowa Hakko may gain from any
public or Third Party statements under this Section 13.3, the requirements of
disclosure under any applicable securities laws, including those associated with
public offerings, and the standards and customs in the pharmaceutical industry
for such disclosures by companies comparable to COR and Kyowa Hakko. The terms
of this Agreement may also be disclosed to Third Parties with the consent of the
other party, which consent shall not be unreasonably withheld so long as such
disclosure is made under a binder of confidentiality.

         13.4 PUBLICATIONS. Each party agrees that it shall not publish or
present the results of studies carried out as part of the Research without the
opportunity for prior review by the other party. Each party shall provide to the
other the opportunity to review any proposed abstracts, manuscripts or
presentations (including information to be presented verbally) which relate to
the Field at least thirty days prior to their intended submission for
publication and such submitting party agrees, upon written request from the
other party, not to submit such abstract or manuscript for publication or to
make such presentation until the other party is given a reasonable period of
time to secure patent protection for any material in such publication or
presentation which it believes is patentable.

                                   ARTICLE 14
                              TERM AND TERMINATION

         14.1 TERM. This Agreement shall commence as of the Amendment and
Restatement Effective Date and, unless sooner terminated as provided herein,
shall continue in effect until the latest of (a) the expiration of the last to
expire of the Program Patents or (b) the date on which COR is no longer
obligated to pay royalties to Kyowa Hakko under Section 7.1.

         14.2 SURVIVING RIGHTS. The obligations and rights of the parties under
Articles 1, 10, 11, 14, 15 and Sections 13.2 and 16.10 of this Agreement will
survive termination (in the case of Article 10 and Section 13.2, for the periods
set forth therein).

         14.3 ACCRUED RIGHTS, SURVIVING OBLIGATIONS. Termination, relinquishment
or expiration of the Agreement for any reason shall be without prejudice to any
rights which shall have accrued to the benefit of either party prior to such
termination, relinquishment or expiration, including damages arising from any
breach hereunder. Such termination, relinquishment or expiration shall not
relieve either party from obligations which are expressly indicated to survive
termination or expiration of the Agreement.


<PAGE>


                                   ARTICLE 15
                                 INDEMNIFICATION

         15.1 INDEMNIFICATION IN ASIAN TERRITORY. Kyowa Hakko shall indemnify
and hold COR harmless from and against any and all liability, damage, loss, cost
(including reasonable attorneys' fees) and expense resulting from any claim of
bodily injury or property damage (a) relating to the development, manufacture,
use, distribution or sale of any Product in the Asian Territory, or (b) due to
the negligence or willful misconduct of Kyowa Hakko or its employees or agents.

         15.2 INDEMNIFICATION IN THE COR TERRITORY. COR shall indemnify and hold
Kyowa Hakko harmless from and against any and all liability, damage, loss, cost
(including reasonable attorneys' fees) and expense resulting from any claim of
bodily injury or property damage (a) relating to the development, manufacture,
use, distribution or sale of any Product in the COR Territory, or (b) due to the
negligence or willful misconduct of COR or its employees or agents.

                                   ARTICLE 16
                                  MISCELLANEOUS

         16.1 REASONABLE EFFORTS. As used herein, the term "reasonable efforts"
shall mean efforts and resources commonly used in the research-based
pharmaceutical industry for a product at a similar stage in its product life
taking into account the establishment of the product in the marketplace, the
competitiveness of the marketplace, the proprietary position of the product, the
regulatory structure involved, the profitability of the product and other
relevant factors. Such resources and efforts shall be determined for a
particular Product and it is anticipated that the level of effort will change
over time reflecting changes in the status of the Product and the marketplace.

         16.2 ASSIGNMENT TO AFFILIATES. Either party may assign any of its
rights or obligations under this Agreement in any country to any Affiliates;
provided, however, that such assignment shall not relieve the assigning party of
its responsibilities for performance of its obligations under this Agreement.
The parties recognize that each may perform some of its obligations hereunder
through Affiliates; provided, however, that each party shall remain responsible
and be guarantors of the performance by their Affiliates and shall cause their
Affiliates to comply with the provisions of this Agreement in connection with
such performance.

         16.3 ASSIGNMENT TO NON-AFFILIATES; SALE OR MERGER. Either party may
assign its rights or obligations under this Agreement or its ownership interest
in jointly owned Program Patents to a non-Affiliate only as provided in Section
16.4, or in connection with the sale of all or substantially all of its assets,
or otherwise with the prior written consent of the other party. This Agreement
shall survive any merger of either party with or into another party and no
consent shall be required hereunder; provided, that in the event of such merger,
no intellectual property rights of the acquiring corporation shall be included
in the COR Technology or the Kyowa Hakko Technology, as applicable.

<PAGE>


         16.4 RESEARCH AND DEVELOPMENT ENTITIES. COR may assign its rights and
obligations under this Agreement to an entity or entities (e.g., partnership or
corporation) that are specifically formed for financial purposes and that
finance research and development performed by COR; provided, however, that such
assignment shall not relieve COR of responsibility for performance of its
obligations under this Agreement. COR shall provide prior notice of such
assignment to Kyowa Hakko and shall consider any comments provided by Kyowa
Hakko with respect to such arrangements.

         16.5 RETAINED RIGHTS. Nothing in this Agreement shall limit in any
respect the right of either party to conduct research and development with
respect to and market products outside the Field using such party's Technology,
but no license to use the other party's technology to do so is granted herein
expressly or by implication.

         16.6 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 government
action, war, fire, explosion, flood, 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; provided, however, in no event shall a party
be required to settle any labor dispute or disturbance.

         16.7 FURTHER ACTIONS. Each party agrees to execute, acknowledge and
deliver such further instruments, and to do all such other acts, as may be
necessary or appropriate in order to carry out the purposes and intent of this
Agreement.

         16.8 NO TRADEMARK RIGHTS. Except as otherwise provided herein, no
right, express or implied, is granted by the Agreement to use in any manner the
name "COR" or "Kyowa Hakko" or any other trade name or trademark of the other
party in connection with the performance of the Agreement.

         16.9 NOTICES. All notices and other communications hereunder shall be
in writing and shall be deemed given if delivered personally or by facsimile
transmission (receipt verified), telexed, mailed by registered or certified mail
(return receipt requested), postage prepaid, or sent by express courier service,
to the parties at the following addresses (or at such other address for a party
as shall be specified by like notice; provided, that notices of a change or
address shall be effective only upon receipt thereof):

         If to COR, addressed to:

         COR Therapeutics, Inc.
         256 East Grand Avenue
         South San Francisco, CA  94080
         Attention:  Senior Vice President - Corporate Development
         Telephone:  (650) 244-6800
         Telecopy:   (650) 244-9208

<PAGE>


         With copy to:

         Cooley Godward LLP
         Five Palo Alto Square
         3000 El Camino Real
         Palo Alto, CA  94306
         Attention:  Robert L. Jones, Esq.
         Telephone:  (650) 843-5000
         Telecopy:   (650) 849-7400

         If to Kyowa Hakko, addressed to:

         Kyowa Hakko Kogyo Co., Ltd.
         1-6-1 Ohtemachi
         Chiyoda-ku
         Tokyo, Japan
         Attention:  General Manager, Licensing & International Development
                     Telephone:  011-81-3-3282-0037
                     Telecopy:   011-81-3-3282-0031

         16.10 GOVERNING LAW. 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. Any claim or controversy arising out of or
related to this contract or any breach hereof which is not resolved through
negotiation between the parties shall be submitted to a court of competent
jurisdiction in the State of California, and the parties hereby consent to the
jurisdiction and venue of such court. The parties each recognize their right to
a jury trial and hereby expressly waive such right and agree to submit any claim
or controversy arising out of or related to this contract or any breach hereof
to a trial by a judge.

         16.11 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 of any other of such party's rights or remedies provided in
this Agreement.

         16.12 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 (i) 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 (ii) 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 alter-native 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.

         16.13 AMBIGUITIES. Ambiguities, if any, in this Agreement shall not be
construed against any party, irrespective of which party may be deemed to have
authored the ambiguous provision.

<PAGE>


         16.14 ENTIRE AGREEMENT. Pursuant to Section 16.14 of the Original
Agreement, the parties hereby amend and restate the Original Agreement, as
amended by the amendments thereto, and this Agreement sets forth all 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, 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.

         IN WITNESS WHEREOF, the parties have executed this Agreement in
duplicate originals by their proper officers as of the date and year first above
written.

COR THERAPEUTICS, INC.                            KYOWA HAKKO KOGYO, LTD.

By:    VAUGHN M. KAILIAN                          By:    ILLEGIBLE
       --------------------------                        ----------------------

Title: PRESIDENT AND CEO                          Title:
       --------------------------                        ----------------------


<PAGE>


                                  SCHEDULE 1.3#


[**]






# The listing in this Schedule 1.3 of any division, continuation,
continuation-in-part, reissue, extension or foreign counterpart is illustrative
only and is not necessarily a complete listing of all divisions, continuations,
continuations-in-part, reissues, extensions or foreign counterparts of a parent
application in existence as of the Amendment and Restatement Effective Date.