Pfizer Announces Discontinuation of Phase III Clinical Trial for Patients with Advanced Melanoma

Pfizer Inc announced today the discontinuation of a Phase III clinical trial (A3671009), of single-agent tremelimumab (CP-675,206) in patients with advanced melanoma, after the review of interim data showed that the trial would not demonstrate superiority to standard chemotherapy. Pfizer has communicated with worldwide regulatory authorities and investigators regarding the discontinuation of the trial. Investigators will work with their patients to determine if they are benefiting from treatment and therefore should continue treatment with tremelimumab. All patients are encouraged to contact their physician with questions about their treatment. "Although this outcome is disappointing, Pfizer remains committed to investigating new treatment options for patients with melanoma, a high risk area of research with significant unmet medical need. We continue to focus on additional studies involving tremelimumab alone and in combination with other therapies which are currently ongoing in patients with several types of cancer,” said Charles Baum, M.D., Ph.D., Vice President and Oncology Therapeutic Area Head at Pfizer Global Research and Development. "We will continue to assess the study data to understand the clinical benefit seen in some patients who received tremelimumab.” The full data set from study A3671009 is being analyzed, and more details are expected to be available at the upcoming American Society for Clinical Oncology Annual Meeting in June 2008. "We have a robust pipeline within Pfizer Oncology and we remain committed to the discovery and development of novel cancer treatments which hold promise for patients with cancer,” said Dr. Baum. "We are extremely grateful for the strong support we have received for this clinical trial from the physicians, study staff, and most importantly from the patients.” Pfizer is developing several classes of agents in its Immuno-Oncology pipeline including CD40 agonists, toll-like receptor (TLR) agonists and vaccines. DISCLOSURE NOTICE: The information contained in this release is as of April 1, 2008. Pfizer assumes no obligation to update any forward-looking statements contained in this release as the result of new information or future events or developments. This release contains forward-looking information about an investigational compound, including its potential benefits, that involves substantial risks and uncertainties. Such risks and uncertainties include, among other things, the uncertainties inherent in research and development; decisions by regulatory authorities regarding whether and when to approve any drug applications that may be filed for such compound as well as their decisions regarding labeling and other matters that could affect its availability or commercial potential; and competitive developments. A further description of risks and uncertainties can be found in Pfizer’s Annual Report on Form 10-K for the fiscal year ended December 31, 2007 and in its reports on Form 10-Q and Form 8-K.