SIRT Sierra Natl BK Tehachapi Calif (MM)

Sirtris Pharmaceuticals, Inc. (NASDAQ: SIRT), a biopharmaceutical company focused on discovering and developing small molecule drugs to treat diseases of aging such as Type 2 Diabetes, announced today that it was added to the Russell 3000(R) Index as well as the Russell Microcap(R) Index when Russell Investment Group reconstituted its family of U.S. indexes on June 22, 2007. �Being included among the leading growth companies in the U.S. in the Russell Indexes is an honor. We believe that this achievement is a reflection of the scientific progress we have made in developing new therapies to treat diseases of aging," said Christoph Westphal, M.D., Ph.D., Chief Executive Officer of Sirtris Pharmaceuticals, Inc. Membership in the Russell 3000(R), which remains in place for one year, means Sirtris will automatically be included in the Russell Microcap (R), as well as appropriate growth and value style indexes. Russell determines membership for its equity indexes primarily by objective, market-capitalization rankings and style attributes. According to Russell, Russell indexes are widely used by investment managers and institutional investors for index funds and as benchmarks for both passive and active investment strategies. $4 trillion in assets currently are benchmarked to Russell indexes, and investment managers who oversee these funds purchase shares of member stocks according to that company's weighting in the particular index. 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 that control the aging process. The company's headquarters are in Cambridge, Massachusetts. This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 concerning Sirtris Pharmaceuticals, its product candidates, and those candidates' clinical potential. These forward-looking statements about future expectations, plans and prospects of Sirtris Pharmaceuticals involve significant risks, uncertainties and assumptions, including risks related to the lack of results that would provide a basis for predicting whether any of the Company�s product candidates will be safe or effective, or receive regulatory approval, the Company's potential inability to initiate and complete preclinical studies and clinical trials for its product candidates, the fact that none of the Company's product candidates has received regulatory approvals, the potential inability of the�Company to gain market acceptance of the Company's product candidates, and those other risks factors�that can be found in the�Company's filings with the Securities and Exchange Commission. Actual results may differ materially from those Sirtris Pharmaceuticals contemplated by these forward-looking statements. Sirtris Pharmaceuticals does not undertake to update any of these forward-looking statements to reflect a change in its views or events or circumstances that occur after the date of this release.