Press Release: TorreyPines Therapeutics and Eisai Extend Alzheimer's Disease Collaboration Agreement

TorreyPines Therapeutics and Eisai Extend Alzheimer's Disease Collaboration Agreement LA JOLLA, Calif., Feb. 22, 2007 -- TorreyPines Therapeutics, Inc. today announced the extension of an exclusive collaboration agreement between TorreyPines and Eisai Co., Ltd. that began in February 2005. This collaboration, focusing on the discovery of novel, small molecules to treat Alzheimer's disease, is TorreyPines' second discovery collaboration with Eisai. In a separate series of agreements, dating back to 2001, Eisai and TorreyPines are collaborating in a genetics program to discover Alzheimer's disease targets using whole-genome family- based association screening. The goal of the small molecule program is to discover novel Alzheimer's disease modifying compounds based on the study of the mechanism of the disease's pathogenesis. Under the original agreement, Eisai has exclusive rights of first negotiation and refusal for validated compounds that are discovered through the research. TorreyPines and Eisai may enter into development agreements involving the validated compounds. "We are excited about extending this agreement with Eisai, a leader in Alzheimer's disease research and treatment," said Neil Kurtz, M.D., President and Chief Executive Officer of TorreyPines. "We look forward to advancing the small molecule program further with Eisai's support, as well as to continuing to work with them on our initial research collaboration to identify genetically-validated pharmaceutical targets for Alzheimer's disease." About TorreyPines Therapeutics, Inc. TorreyPines Therapeutics is a clinical stage biopharmaceutical company that discovers and develops small molecule drugs to treat diseases and disorders of the central nervous system (CNS). Led by an accomplished management team, TorreyPines is leveraging novel drug targets and technologies to potentially deliver new CNS therapies for chronic pain, including migraine and neuropathic pain; and cognitive disorders, including cognitive impairment associated with schizophrenia and Alzheimer's disease. TorreyPines' common stock is traded on The NASDAQ Global Stock Market under the symbol "TPTX." For detailed company information, including copies of this and other press releases, please visit TorreyPines'website at www.torreypinestherapeutics.com. This press release contains forward-looking statements or predictions. Such forward-looking statements include, but are not limited to, statements regarding the potential for compounds derived from the small molecule program to treat Alzheimer's disease and references to a potential development agreement between TorreyPines and Eisai. Such statements are subject to numerous known and unknown risks, uncertainties and other factors, which may cause TorreyPines' actual results to be materially different from historical results or from any results expressed or implied by such forward-looking statements. In particular there is no guarantee that TorreyPines will be successful in discovering any compounds that treat Alzheimer's disease, that any such discovered compounds will become validated compounds or that TorreyPines and Eisai will reach agreement on a potential development agreement. These and other risks which may cause results to differ are described in greater detail in TorreyPines' registration statement on Form S- 4, as amended, as filed with the Securities and Exchange Commission, the "Risk Factors" section of TorreyPines' Form 10-Q for the quarter ended September 30, 2006 and TorreyPines' other filings with the Securities and Exchange Commission. The forward-looking statements are based on current information that is likely to change and speak only as of the date hereof. CONTACT: Evelyn Graham of TorreyPines Therapeutics, Inc., +1-858-623-5665,x118, ; or Media, Pat Garrison,+1-917-322-2567, , or Investors, Rhonda Chiger,+1-917-322-2569, , both of Rx Communications, forTorreyPines Therapeutics, Inc. [email protected] [email protected] [email protected]