Exhibit 10.59

                       FIRST AMENDMENT TO AGREEMENT THREE

Effective February 29, 1996, Agouron Pharmaceuticals, Inc., a California 
corporation with offices at 10350 North Torrey Pines Road, La Jolla, 
California 92037 ("Agouron"), and Japan Tobacco Inc., a Japanese corporation 
with offices at JT Building, 2-2-1 Toranomon, Minato-ku, Tokyo 105 Japan 
("JT"), for good and valuable consideration, agree as follows:

                                 Article I
                                 Background

1.01     Pursuant to the terms of the agreement which was originally entered 
into on February 28, 1994 (hereinafter referred to as "Agreement Three"), 
Agouron and JT have conducted a collaborative research program ("Research 
Program") consisting of a research project ("Research Project V") to discover 
novel anti-viral drugs to treat rhinovirus infections.  JT has assisted 
Agouron in the discovery activities of Research Project V to enable the 
parties to develop scientific skills and information and experimental data 
which have been made available to another collaborative research program 
which the parties are conducting ("Agreement Two").

1.02     Section 1.20 of Agreement Three provides for a two year Research 
Term expiring February   29, 1996, unless such Research Term is extended or 
shortened by the mutual written agreement of the parties or by operation of 
the provisions of Agreement Three, including Section 2.02 and Article VI.

1.03     The parties have elected not to extend Research Project V and, 
instead, wish to refocus the research efforts which would have been committed 
by Agouron scientists during the third year of Research Project V to the 
Agreement Two research program.  To affect the preceding and to clarify the 
parties' rights and obligations, the parties agree to amend the terms of 
Agreement Three by entering into this First Amendment to Agreement Three 
("First Amendment").

1.04     For purposes of this First Amendment, terms with initial 
capitalization shall have the same meanings as those set out in Agreement 
Three.

                                 Article II
                              First Amendment

2.01     The parties agree that the last day of the Research Term of 
Agreement Three is February   29, 1996 and that the Research Program ends on 
February 29, 1996.

2.02     The parties agree that only chemical compounds synthesized in the 
Research Program during the Research Term shall be subject to the provisions 
of Sections 3.05(c) and 5.03(c) of Agreement Three.

2.03     The parties agree that any chemical compounds not qualifying as 
Program Compounds under the definition of Section 1.04 of Agreement Three, 
which are synthesized in the Research Program during the Research Term shall 
be assigned to and owned jointly by the parties.



2.04     The parties agree that, subject to the provisions of Section 5.03 of 
Agreement Three, any Program Compounds shall be assigned to and owned solely 
by Agouron.  Any Patent Rights covering Program Compounds shall be assigned 
to and owned jointly by the parties pursuant to the terms of Section 3.05 of 
Agreement Three.

2.05     The parties agree that the chemical compounds to be contained in a 
List of Agreement Three Compounds to be dated as of February 29, 1996 ("List 
of Agreement Three Compounds") are the only chemical compounds synthesized in 
the Research Program during the Research Term.  The parties agree to use 
their best efforts to classify as soon as possible the chemical compounds 
contained in the List of Agreement Three Compounds, as being either Program 
Compounds or Non-Program Compounds; such classification shall be based on the 
definition of Program Compound which is set forth in Agreement Three, Section 
1.04.  The List of Agreement Three Compounds shall be reviewed and approved 
in writing by both of the parties.

2.06     The parties agree that the chemical compounds contained in the List 
of Agreement Three Non-Program Compounds dated as of February 29, 1996 do not 
qualify as Program Compounds.  The List of Agreement Three Non-Program 
Compounds shall be reviewed and approved in writing by both of the parties 
and shall be supplemented as the parties classify as being Non-Program 
Compounds those previously unclassified chemical compounds contained in the 
List of Agreement Three Compounds.

2.07     The parties agree that the chemical compounds contained in the List 
of Agreement Three Program Compounds dated as of February 29, 1996 qualify as 
Program Compounds.  The List of Agreement Three Program Compounds shall be 
reviewed and approved in writing by both of the parties, and shall be 
supplemented as the parties classify as being Program Compounds those 
previously unclassified chemical compounds contained in the List of Agreement 
Three Compounds.

2.08     The parties agree that Program Technology does not include any know-
how, trade secret, experimental data, formula, expert opinion, experimental 
procedure and other confidential and/or proprietary information (including 
crystallographic information and coordinates):  (i)   specifically concerning 
a Target Protein and/or (ii) specifically relating to the discovery of a 
Program Compound, intermediates thereof, or a Program Product, which is 
developed or acquired by or on behalf of Agouron or JT, independently or 
jointly, as the case may be, after the last day of the Research Term.

2.09     The parties shall cause their respective employees to cooperate as 
reasonably required to co-author manuscripts and to file patent applications 
on separately or jointly made inventions arising out of Agreement Three.

2.10     The parties agree that Research Project V terminates effective 
February 29, 1996, and agree to reallocate the research efforts which would 
have been committed by certain of Agouron scientists during the third year of 
Research Project V to Agreement Two.

2.11     Commencing March 1, 1996, Agouron shall be free, without any further 
action by Agouron or JT and without any further obligation to JT, to continue 
work to discover, develop, manufacture and market novel anti-viral drugs to 
treat rhinovirus infections and/or chemical compounds which interact with a 
Target Protein(s), on its own or with any third party.  JT, on its own or 


with any third party, agrees not to conduct research and development to 
discover, develop, manufacture and market novel anti-viral drugs to treat 
rhinovirus infections.  JT agrees not to use Program Technology to discover, 
develop, manufacture and/or commercialize novel anti-viral drugs to treat 
rhinovirus infections.  JT agrees not to disclose to third parties any 
Program Technology.  The parties hereby agree that any Program Technology 
shall be assigned to and owned jointly by the parties and that either party 
shall be free, subject to the preceding two sentences, to use Program 
Technology for any purpose.  If requested by either party, the other party 
will provide an acknowledgment to a third party concerning the continuing 
rights and obligations of the parties, if any, under Agreement Three.

2.12     The parties agree that effective February 29, 1996 Agreement Three 
is amended to delete Section 5.03(a).

2.13     Except as modified by the terms contained herein, the provisions of 
Agreement Three shall remain in full force and effect.


AGOURON PHARMACEUTICALS, INC.               JAPAN TOBACCO INC.



By:     /s/ Gary E. Friedman, Esq.          By:     /s/ Masakazu Kakei
        ------------------------------              -------------------------
        Gary E. Friedman, Esq.                      Masakazu Kakei
Title:  Vice President & General Counsel    Title:  Managing Director,
                                                    Pharmaceutical Business 

Date:   February 16, 1996                   Date:   March 4, 1996