Exhibit 10.83

[*] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY
BRACKETS, IS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE
24B-2 OF THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED

FIRST AMENDMENT TO LICENSE AGREEMENT

This Amendment to License Agreement (“Amendment”) is made effective as of
May 19. 2005 (the “Effective Date”) by and between Japan Tobacco Inc., a
Japanese corporation having a principal place of business at JT Bldg. 2-1,
Toranomon 2-chome, Minato-ku, Tokyo 105-8422, Japan (hereinafter, “JT”), and
Gilead Sciences, Inc., a corporation having a principal place business at 333
Lakeside Drive, Foster City, California, U.S.A. (hereinafter, “GILEAD”).

RECITALS

WHEREAS, JT and GILEAD have previously entered into a License Agreement dated
March 22, 2005 relating to JTK-303 (the “Agreement”).

WHEREAS, JT and GILEAD desire to amend certain terms of the Agreement

NOW THEREFORE, based on the foregoing premises and the mutual covenants and
obligations set forth below, the parties agree as follows:

1.     Amendments

A.     Section 6.4(a)     Section 6.4(a) of the Agreement shall be amended and
restated as follows:

“In the event that either Party obtains from a Third Party a license to Patents,
Know-How and/or a trademark that is necessary for, or actually used during the
Term in, the Party’s Development or Commercialization of a Product, such Party
shall, subject to Section 6.4(b), use its commercially reasonable efforts to
include in such license aright to grant a sublicense on the same terms and
conditions to the other Party solely to support the license grants contained in
Sections 6.1 and 6.2.”

B.     Section 16.1     Section 16.1 of the Agreement shall be amended and
restated as follows:

“16,1.       Entire Agreement; Amendment.

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[*] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY
BRACKETS, IS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE
24B-2 OF THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED

 

(a)       This Agreement, including the Schedules attached hereto and
incorporated herein, sets forth the complete, final and exclusive agreement and
all the covenants, promises, agreements, warranties, representations, conditions
and understandings between the Parties with respect to the subject matter hereof
and supersedes and terminates all prior agreements and understandings between
the Parties, except for the Confidential Disclosure Agreements and Material
Transfer Agreements with respect to such subject matter, as amended pursuant to
Section 16.1(b) hereof.

(b)       The Confidential Disclosure Agreements (other than the Confidential
Disclosure Agreement dated February 1, 2005 (Gilead as recipient with respect to
JTK-403)) and the Material Transfer Agreements are hereby considered amended to
the extent necessary to provide that, notwithstanding any provision in such
agreements to the contrary, any information and materials provided by one Party
to the other Party pursuant to the Confidential Disclosure Agreements or the
Material Transfer Agreements may be used by a Party to fulfill any obligation or
to pursue any rights such Party has under this Agreement, including without
limitation for the Development of Products.

(c)       Except for the Confidential Disclosure Agreements and Material
Transfer Agreements, there are no covenants, promises, agreements, warranties,
representations, conditions or understandings, either oral or written, between
the Parties with respect to the subject matter hereof other than as are set
forth in this Agreement. No subsequent alteration, amendment, change or addition
to this Agreement shall be binding upon the Parties unless reduced to writing
and signed by an authorized officer of each Party.”

C.     Section 16.6     Section 16.6 of the Agreement shall be amended and
restated as follows:

“Neither Party may assign or transfer this Agreement or any rights or
obligations hereunder without the prior written consent of the other Party,
except that, subject to Section 16.7, a Party may make such an assignment or
transfer without the other Party’s consent to the assigning Party’s Affiliates
or to its successor to all or substantially all of the business of such Party in
the field to which this Agreement relates (whether by merger, sale of stock,
sale of assets or other transaction), provided that any such successor (other
than an Affiliate) shall, in a writing reasonably acceptable to the other Party,
expressly assume performance of such rights or obligations. The JT Technology
and the Gilead Technology shall exclude any intellectual property held or
developed by such a successor of the relevant Party not in connection with
Compound or Products. Any such assignment shall be binding on the successors of
the assigning Party. Any assignment or attempted assignment by either Party in
violation of the terms of this Section 16.6 shall be null and void.”

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[*] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY
BRACKETS, IS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE
24B-2 OF THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED

 

2.     The Parties have each designated the three representatives to serve on
the Joint Committee, one representative to serve as Alliance Manager and the
three representatives to serve on the IP subcommittee, respectively, named on
Schedule 2.2, Schedule 2.3 and Schedule 9.2, attached hereto.

3.     Defined Terms

Unless otherwise defined herein, all of the capitalized terms used in this
Amendment shall have the respective meanings ascribed to them in the Agreement

4.     Effect

Except as expressly amended by this Amendment, the Agreement remains in full
force and effect.

5.     Governing Law

This Amendment shall be governed and construed in accordance with the
substantive laws of the State of New York and the federal law of the United
States of America.

IN WITNESS WHEREOF, the parties have caused this Amendment to be executed by
their duly authorized representatives as of the Effective Date.

 

JAPAN TOBACCO INC.     GILEAD SCIENCES, INC. BY:   /s/ Noriaki Okubo     BY:  
/s/ John F. Millingan

NAME: Noriaki Okubo

    NAME: John F. Milligan, Ph.D.

TITLE: President, Pharmaceutical Business

   

TITLE: Executive Vice President & CFO

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[*] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY
BRACKETS, IS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE
24B-2 OF THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED

 

SCHEDULE 2.2

Members of the Joint Committee

Gilead:

[*]

[*]

[*]

JT:

[*]

[*]

[*]

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[*] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY
BRACKETS, IS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE
24B-2 OF THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED

 

SCHEDULE 2.3

Alliance Managers

Gilead:

[*]

JT:

[*]

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[*] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY
BRACKETS, IS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE
24B-2 OF THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED

 

SCHEDULE 9.2

IP subcommittee members

Gilead:

[*]

[*]

[*]

JT:

[*]

[*]

[*]