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                                           Filed Pursuant to Rule 424(b)(3)
                                           Registration Statement No. 333-41205
 
                       SUPPLEMENT DATED DECEMBER 15, 1997
         TO THE JOINT PROXY STATEMENT/PROSPECTUS DATED DECEMBER 3, 1997
 
     The following information supplements and must be read in conjunction with
the information contained in the Joint Proxy Statement/Prospectus, dated
December 3, 1997, of Arris Pharmaceutical Corporation ("Arris") and Sequana
Therapeutics, Inc ("Sequana"). Assuming necessary approvals at the special
meeting of the stockholders of Arris on January 7, 1998 and at the special
meeting of the shareholders of Sequana on January 7, 1998, Arris and Sequana
continue to expect the Merger to be consummated in January 1998. All capitalized
terms not otherwise defined herein have the meanings ascribed to them in the
Joint Proxy Statement/Prospectus.
 
THE COMPOSITION OF THE ARRIS BOARD OF DIRECTORS
 
     As provided in the Reorganization Agreement, John Walker, the President,
Chief Executive Officer and a director of Arris, and Irwin Lerner, the Chairman
of the Sequana Board of Directors, agreed upon the individuals to become (or
remain) members of the Arris Board of Directors after the effectiveness of the
Merger. Pursuant to this selection process, Messrs. Walker, Byers and Kailian
and Drs. Arvin, Evnin and Kennedy will remain members of the Arris Board of
Directors. Messrs. Kinsella and Lerner, current members of the Sequana Board of
Directors, and Dr. Read will be appointed to the Arris Board of Directors to
serve following the consummation of the Merger. Mr. Mendelson and Dr.
Sievertsson, current members of the Arris Board of Directors, have agreed to
resign from the Arris Board of Directors, effective upon the consummation of the
Merger. Prior to the Merger, the number of members of the Arris Board of
Directors will be increased from eight (8) to nine (9).
 
     Following the appointment of Messrs. Kinsella and Lerner and Dr. Read by
the Arris Board of Directors, each of the directors set forth below will hold
office until the next annual meeting of Arris' stockholders and until his or her
successor is elected and has qualified, or until such director's earlier death,
resignation or removal.
 
     The names of the directors, their ages as of December 15, 1997, and certain
information about them are set forth below:
 


                NAME                  AGE                          TITLE
- ------------------------------------- ----    ------------------------------------------------
                                        
John P. Walker                          49    President, Chief Executive Officer and Director
Ann M. Arvin, M.D.                      52    Director
Brook H. Byers                          52    Director
Anthony B. Evnin, Ph.D.                 56    Director
Vaughn M. Kailian                       53    Director
Donald Kennedy, Ph.D.                   66    Director
Kevin J. Kinsella                       51    Director
Irwin Lerner                            67    Director
J. Leighton Read, M.D.                  47    Director

 
     John P. Walker has been President, Chief Executive Officer and a director
of Arris since February 1993. From 1991 to 1993, he was a venture capitalist at
Alpha Venture Partners, a venture capital firm. Prior to that time, he was
Chairman, President and Chief Executive Officer of Vitaphone Corporation, a
medical device company which was acquired in April 1990 by Union Carbide
Chemicals and Plastics Company, Inc. Following that acquisition, Mr. Walker
served as the latter company's Vice President, Biomaterials Systems. From 1971
to 1985, Mr. Walker was employed by American Hospital Supply Corporation in a
variety of general management, sales and marketing positions, most recently
serving as President of American Hospital Company. Mr. Walker serves as a
director of Geron Corporation, Microcide Pharmaceuticals, Inc., Signal
Pharmaceuticals, Inc. and the Northern California Chapter of the M.S. Society
Board.
 
     Ann M. Arvin, M.D., has been a director of Arris since September 1997. Dr.
Arvin is Professor of Pediatrics and Microbiology/Immunology, at Stanford
University School of Medicine, Stanford, California.
 
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Dr. Arvin is also Associate Chair for Academic Affairs, Department of
Pediatrics, and Chief of the Infectious Disease Service of the Packard
Children's Hospital at Stanford. Since 1978, Dr. Arvin has taught at the
Stanford University School of Medicine. She is also currently a member of the
Scientific Advisory Board of Aviron, a biotechnology company.
 
     Brook H. Byers, through Kleiner Perkins Caufield & Byers, was an original
investor in Arris and has served as a member of the Board of Directors since
October 1990. Mr. Byers is a general partner of Kleiner Perkins Caufield &
Byers, a venture capital firm which he joined in 1977. He has been the founding
president and chairman of four life sciences companies: Hybritech Incorporated,
IDEC Pharmaceuticals Corporation, InSite Vision Inc. and Ligand Pharmaceuticals
Incorporated. Mr. Byers also serves as a director of a number of privately held
technology companies. Mr. Byers sits on the University of California, San
Francisco Foundation Board of Directors.
 
     Anthony B. Evnin, Ph.D., through Venrock Associates, was an original
investor in Arris and has served as a member of the Board of Directors since
April 1989. He is a general partner of Venrock Associates, a venture capital
firm that he joined in 1974. Dr. Evnin is a director of Centocor, Inc., Opta
Food Ingredients, Inc., Ribozyme Pharmaceuticals, Inc. and Triangle
Pharmaceuticals, Inc. He also serves as a director of several private companies.
 
     Vaughn M. Kailian has been a director of Arris since December 1995. Mr.
Kailian is also President, Chief Executive Officer and a director of COR
Therapeutics, Inc., a biotechnology company, and has served in such capacities
since March 1990. Mr. Kailian also serves as a director of Amylin
Pharmaceuticals, Inc.
 
     Donald Kennedy, Ph.D., has been a director of Arris since December 1996.
Dr. Kennedy is the Bing Professor of Environmental Science and President
Emeritus at Stanford University where he co-directs the Global Environmental
Forum in the Institute for International Studies. He has served in such
capacities since September 1993. From September 1980 to September 1992, Dr.
Kennedy was the President of Stanford University. He served previously as
Commissioner of the U.S. Food and Drug Administration. Dr. Kennedy also serves
as a director of Cortech, Inc.
 
     Kevin J. Kinsella will become a director of Arris upon consummation of the
Merger. Mr. Kinsella, the founder of Sequana, has been a director of Sequana
since its inception in February 1993. Mr. Kinsella served as the Chairman of the
Board of Directors and acting chief executive of Sequana until January 1995,
when he was named President and Chief Executive Officer. Mr. Kinsella also
served as Chief Financial Officer of Sequana from January 1995 to September
1995. Mr. Kinsella was previously the Managing General Partner of Avalon
Ventures, a venture capital firm founded by him. Avalon Ventures has established
over thirty companies, many of which are in the biopharmaceutical field,
including IMPATH Laboratories, Inc., Neurocrine Biosciences, Inc. and
Pharmacopeia, Inc. Mr. Kinsella founded Aurora Biosciences Corporation, Athena
Neurosciences Inc., NeoRx Corporation, Onyx Pharmaceuticals, Vertex
Pharmaceuticals Inc., Microcide Pharmaceuticals, Inc. and Landmark Graphics
Corporation. Mr. Kinsella is a director of Aurora Biosciences. See the Joint
Proxy Statement/Prospectus, "Approval of the Merger and Related
Transactions -- Interests of Certain Persons in the Merger" for a description of
certain interests of Mr. Kinsella in the Merger.
 
     Irwin Lerner will become a director of Arris upon consummation of the
Merger. Mr. Lerner has served as a director of Sequana since June 1994 and
became Chairman of the Board of Directors of Sequana in May 1995. Mr. Lerner
served as Chairman of the Board of Directors and of the Executive Committee of
Hoffmann-La Roche Inc., a pharmaceutical and health care company, from January
1993 until his retirement in September 1993, and also served as President and
Chief Executive Officer from 1980 through December 1992. He has served on the
Boards of Project Hope and the New Jersey Chamber of Commerce, where he founded
and chaired the New Jersey Governor's Council for a Drug-Free Workplace. Mr.
Lerner served for 12 years on the Board of the Pharmaceutical Manufacturers'
Association, where he chaired the Association's FDA Issues Committee. Mr. Lerner
also serves on the Boards of Directors of Public Service Enterprise Group,
Humana Inc., several private companies and is Chairman of the Board of Medarex
Inc. He is currently Distinguished Executive-in-Residence at Rutgers University
Graduate School of Management.
 
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     J. Leighton Read, M.D., will become a director of Arris upon consummation
of the Merger. Dr. Read has been Chairman of the Board and Chief Executive
Officer of Aviron, a biotechnology company, since 1992 and was Chief Financial
Officer of Aviron from 1992 until October 1996. In 1989, he co-founded Affymax
N.V., a biotechnology company, with Dr. Alejandro Zaffaroni, serving initially
as its Executive Vice President and Chief Operating Officer and later, from 1990
to 1991, as President of the Pharma Division and as a Managing Director of the
parent company to Affymax. From 1991 to 1993, Dr. Read was a principal with
Interhealth Limited, an investment partnership. Prior to 1989, Dr. Read held
appointments at the Harvard Medical School and School of Public Health, where
his research dealt with techniques for assessing the cost effectiveness of
pharmaceutical products. He has served on the boards of a number of private
biotechnology companies and is currently on the board of CV Therapeutics, Inc.
 
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