Sirtris Pharmaceuticals, Inc. Completes Initial Public Offering CAMBRIDGE, Mass, -- Sirtris Pharmaceuticals, Inc., a biopharmaceutical company focused on discovering and developing small molecule drugs to treat diseases of aging such as Type 2 Diabetes, announced today the completion of its initial public offering of 6,900,000 shares of common stock, which included 900,000 shares sold pursuant to the underwriters' exercise in full of their over-allotment option. All shares were sold at an initial public offering price of $10.00 per share, resulting in aggregate net proceeds to Sirtris of approximately $62.4 million after deducting underwriting discounts and commissions and estimated offering expenses. J.P. Morgan Securities Inc. acted as the sole book-running manager and CIBC World Markets Corp., Piper Jaffray & Co., JMP Securities LLC, and Rodman & Renshaw, LLC acted as co-managers for the offering. A registration statement relating to these securities was declared effective by the Securities and Exchange Commission on May 22nd, 2007. The public offering is being made by means of a written prospectus. Copies of the final prospectus relating to the offering may be obtained from: J.P. Morgan Securities Inc., Attention: Prospectus Department, 4 Chase Metrotech Center, CS Level, Brooklyn, NY 11245. Phone: (718) 242-8002. Email: [email protected] This press release shall not constitute an offer to sell or the solicitation of an offer to buy, nor shall there be any sale of these securities in any state in which such offer, solicitation or sale would be unlawful prior to their registration or qualification under the securities laws of any such state. About Sirtris Pharmaceuticals Sirtris Pharmaceuticals is a biopharmaceutical company focused on discovering and developing proprietary, orally available, small molecule drugs with the potential to treat diseases associated with aging, including metabolic diseases such as Type 2 Diabetes. Our drug candidates are designed to mimic certain beneficial health effects of calorie restriction, without requiring a change in eating habits, by activation of sirtuins, a recently discovered class of enzymes. The company's headquarters are in Cambridge, Massachusetts.