Exelixis (Nasdaq: EXEL) and its partner Bristol-Myers Squibb (NYSE: BMY) have identified and selected the first small molecule cancer targets in their new collaboration using Exelixis' proprietary screening platform to identify novel targets to combat cancer.

The current pool of targets come from genome-wide screens to identify genes that functionally interact with the p53 tumor suppressor in Drosophila (the fruit fly) and C. elegans (a laboratory worm). In conducting that screen, Exelixis has identified new strategies by which tumor cells evade normal growth control mechanisms. Mutations in p53 have been implicated in more than half of human cancers, including cancer of the breast, lung, colon, and liver. The cancer targets discovered by Exelixis will now advance into small molecule drug discovery programs at both companies with a goal of identifying novel anti-cancer agents.

“After only a few months, our collaboration with Bristol-Myers Squibb is already yielding targets for both parties that have truly unique, functional characteristics which make them promising targets for small molecule drugs,” stated George A. Scangos, Ph.D., president and chief executive officer of Exelixis. “And the high level of biological validation that characterizes these targets, achieved by conducting screens in living organisms should expedite their development.”

“We are excited by the identification of new and potentially druggable mechanisms by which tumor suppressors function in the deregulated growth of tumors,” stated Robert Kramer, Ph.D., Lawrenceville Biology Site Head, Bristol-Myers Squibb. “We are pleased with the rapid progress of our collaboration with Exelixis, and are confident that it will continue to generate a portfolio of targets and drug candidates that will enhance both companies' oncology pipelines.”

In July 2001, Exelixis established a broad collaboration and licensing agreement with Bristol-Myers Squibb to create a new generation of potential cancer drugs that selectively destroy cancers that harbor defects in tumor suppressor gene pathways. Exelixis will identify and validate various molecular targets that trigger cell death in cancer cells while leaving normal cells unharmed. Each company has the option to obtain worldwide rights to equal numbers of validated targets arising from the collaboration. As part of the agreement, Exelixis has received an exclusive worldwide license to develop and commercialize a specific analogue of the Bristol-Myers Squibb anticancer compound, DEAE Rebeccamycin, which has completed Phase I safety trials and is currently in Phase II clinical trials with the National Cancer Institute. Under terms of the agreement, Bristol-Myers Squibb made an equity investment in Exelixis, paid an up-front licensing fee and continues to provide research support to Exelixis.

Bristol-Myers Squibb is an $18 billion pharmaceutical products and related healthcare products company whose mission is to extend and enhance human life. For more information, please visit the company's web site at www.bms.com.

Exelixis is a leading genomics-based drug discovery company focused on product development through its expertise in comparative genomics and model system genetics. These technologies provide a rapid, efficient and cost effective way to move from DNA sequence data to knowledge about the function of genes and the proteins they encode. The company's technology is broadly applicable to all life sciences industries including pharmaceutical, diagnostic, agricultural biotechnology and animal health. Exelixis has partnerships with Aventis CropScience, S.A., Bayer Corporation, Bristol-Myers Squibb Company, Elan Pharmaceuticals, Inc., Pharmacia Corporation, Protein Design Labs, Inc., Scios Inc. and Dow AgroSciences LLC, and is building its internal development program in the area of oncology. For more information, please visit the company's website at www.exelixis.com.

This press release contains certain forward-looking statements regarding Bristol-Myers Squibb within the meaning of the Private Securities Litigation Reform Act of 1995 that may be identified by terminology such as "anticipates," and "expects" and other words or terms of similar expression or meaning. Such forward-looking statements are based on current expectations and involve inherent risks and uncertainties, including factors that could delay, divert or change any of them, and could cause actual outcomes and results to differ materially from current expectations. These factors include, among other things, uncertainties relating to clinical trials and product development, unexpected regulatory delays or government regulation generally. For further details and a discussion of these and other risks and uncertainties, see Bristol-Myers Squibb's Securities and Exchange Commission filings, including the company's 2000 annual report on Form 10-K. Bristol-Myers Squibb undertakes no obligation to publicly update any forward-looking statement, whether as a result of new information, future events or otherwise.