Sirtris Pharmaceuticals IPO of 6 Million Shares Priced at $10/Share

CAMBRIDGE, Mass.--(BUSINESS WIRE)--Sirtris Pharmaceuticals, Inc. (NASDAQ: SIRT - News), a biopharmaceutical company focused on discovering and developing small molecule drugs to treat diseases of aging such as Type 2 Diabetes, today announced the pricing of its initial public offering of 6,000,000 shares of its common stock at $10.00 per share, before underwriting discounts and commissions. All of the common stock is being offered by Sirtris. In addition, Sirtris has granted the underwriters a 30-day option to purchase up to an additional 900,000 shares to cover over-allotments, if any. J.P. Morgan Securities Inc. is acting as the sole book-running manager and CIBC World Markets Corp., Piper Jaffray & Co., JMP Securities LLC, and Rodman & Renshaw, LLC are acting as co-managers for the offering. The shares will trade on the NASDAQ Global Market under the symbol "SIRT."

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: addressing.services@jpmorgan.com.

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.

Contact: Sirtris Pharmaceuticals, Inc. Investor Contact: Michelle Dipp, 617-252-6920 or Pure Communications Media Contact: Sheryl Seapy, 949-608-0841

Source: Sirtris Pharmaceuticals, Inc.