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                                                                    EXHIBIT 99.1

                          [OSI PHARMACEUTICALS LOGO]

               OSI Pharmaceuticals, Genentech and Roche to Develop
                And Commercialize OSI-774, OSI's Lead Cancer Drug

         UNIONDALE, N. Y., SOUTH SAN FRANCISCO, Calif., and BASEL, Switzerland,
Jan. 8 /PRNewswire/ -- OSI Pharmaceuticals, Inc. (Nasdaq: OSIP), Genentech Inc.
(NYSE: DNA) and Roche announced today that they have entered into concurrent
agreements for the global co-development and commercialization of OSI's lead
anti-cancer drug, OSI-774. An inhibitor of the epidermal growth factor receptor
(EGFR), OSI-774 is currently in Phase II clinical studies for non-small cell
lung, head & neck and ovarian cancers. Taken together these agreements could
result in up to $187 million in upfront fees, equity investments, and scheduled
milestone payments to OSI. Milestone payments will be based on the successful
filing and registration of the drug in major markets. Genentech and OSI will
employ an essentially equal cost and profit sharing arrangement for
commercialization in the United States, while Roche will pay royalties on net
sales to OSI in markets outside of the United States. The overall costs of the
tripartite development program will be split equally among the three parties.

         Under the agreement, Genentech and Roche have each agreed to purchase
$35 million of OSI common stock and will pay up-front fees. Although OSI has
retained certain co-promotion rights in the United States, Genentech will be
primarily responsible for commercializing the product in the United States
should the product gain FDA approval. Roche will be responsible for gaining
regulatory approval and marketing in territories outside the United States. The
transaction is subject to review by the Federal Trade Commission under the
Hart-Scott-Rodino Antitrust Improvements Act of 1976.

         "This alliance allows OSI to partner with two world-class
organizations, providing us with the strength to competitively develop and,
following approval, market OSI-774 on a global basis," stated Colin Goddard,
Ph.D., Chairman and Chief Executive Officer of OSI. "The agreements ally OSI
with a Genentech team that has already demonstrated success in developing and
marketing next generation anti-cancer drugs, and a Roche team that represents a
strong worldwide oncology portfolio. Moreover, this collaboration not only
produces a substantial strategic and economic benefit to us, it provides all of
the essential elements for the rapid, comprehensive and competitive development
of OSI-774."

         "It is with great excitement that we add OSI-774 to our robust
BioOncology initiative and enter into this important collaboration with a new
partner, OSI, and a proven international partner of Roche," stated Arthur O.
Levinson, Ph.D., Chairman and Chief Executive Officer of Genentech. "We believe
that new agents such as OSI-774 will continue to advance the future of cancer
therapy and enhance Genentech's strong presence as a leading oncology company.'


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         "EGFR inhibitors represent a promising class of novel anti-cancer
agents," stated Franz Humer, Chief Executive Officer, Roche. "OSI-774 has the
potential to significantly strengthen our already powerful oncology portfolio
thereby further consolidating our position as a leading company in this
important therapeutic area."

         OSI-774 is a selective and orally active inhibitor of the EGFR,
tyrosine kinase, that is associated with the aberrant growth characteristic of
certain cancer cells. OSI recently reported updated findings from two ongoing
Phase II single agent open label clinical studies for OSI-774 at the European
Organization for the Research and Treatment of Cancer (EORTC) Symposium in
Amsterdam.

         OSI Pharmaceuticals is a leading biopharmaceutical company with a
substantial portfolio of product opportunities for commercialization with the
pharmaceutical industry. OSI's research programs are focused in the areas of
cancer therapeutics, respiratory diseases, diabetes, and cosmeceuticals. OSI
utilizes a comprehensive drug discovery and development capability to facilitate
the rapid and cost-effective discovery and development of novel, small molecule
compounds against more than 40 gene targets.

         Genentech, Inc. is a leading biotechnology company that discovers,
develops, manufactures and markets human pharmaceuticals for significant unmet
medical needs. Fourteen of the currently approved biotechnology products stem
from Genentech science. Genentech markets nine biotechnology products directly
in the United States. The company has headquarters in South San Francisco,
California and is traded on the New York Stock Exchange under the symbol DNA.

         Headquartered in Basel, Switzerland, Roche is one of the world's
leading research-oriented healthcare groups in the fields of pharmaceuticals,
diagnostics, and vitamins. Roche's products and services address prevention,
diagnosis and treatment of diseases, thus enhancing people's well-being and
quality-of-life.

         Investors may access a webcast regarding this announcement over the
Internet by logging onto: www.osip.com or www.gene.com or
http://www.vcall.com/NASApp/VCall/EventPage?ID=62105 on Monday, January 8th at
10:00 AM Eastern time. A replay of this call will also be available until
January 9th at 12:00 PM Eastern time by dialing, 800-633-8284 or 858-812-6440 --
call number: 17555613

         Additional information on OSI Pharmaceuticals is available on the World
Wide Web at: http://www.osip.com

         This news release contains forward-looking statements. These statements
are subject to known and unknown risks and uncertainties that may cause actual
future experience and results to differ materially from the statements made.
Factors that might cause such a difference include, among others, uncertainties
related to the identification of lead compounds, the successful pre-clinical
development thereof, the completion of clinical trials, the FDA review


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process and other governmental regulation, pharmaceutical collaborators' ability
to successfully develop and commercialize drug candidates, competition from
other pharmaceutical companies, product pricing and third part reimbursement,
and other factors described in OSI Pharmaceuticals' filings with the Securities
and Exchange Commission.

SOURCE          OSI Pharmaceuticals, Inc.
    -0-             01/08/2001

         /CONTACT: Kathy Galante of OSI Pharmaceuticals, 516-222-0023; or Ethan
Denkensohn, investors, or Kathy L. Jones, Ph.D, media, both of Burns McClellan
for OSI, 212-213-0006; or Marie Kennedy, media, 650-225-8751, or Neil Cohen,
media, 650-225-8681, or Susan Bentley, investor relations, 650-225-1034, all for
Genentech/

         /Web site:        http://www.osip.com
                           http://www.gene.com /

(OSIP DNA)