SRT501, the first SIRT1 activator to enter the clinic, shows safety, trends in lowering fasting plasma glucose, and a significant lowering of glucose in an oral glucose tolerance test as presented at the 26th Annual JPMorgan Healthcare Conference, January 7th 2008

CAMBRIDGE, Mass., Jan 07, 2008 (BUSINESS WIRE) -- 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 the Company's first product to enter the clinic, SRT501, was found to be safe and well-tolerated, and was found to significantly lower glucose in an oral glucose tolerance test conducted as part of a 28 day Phase 1b clinical study in patients with Type 2 Diabetes. These data were presented at the 26th Annual JPMorgan Healthcare Conference on Monday, January 7th 2008 at 1:30 pm PST in San Francisco.

This 28-day Phase 1b study was designed to assess the safety, tolerability and pharmacokinetics of once-daily, orally administered doses of either 2.5 g or 5 g of SRT501 in patients with Type 2 Diabetes who were naive to other diabetes drug treatments. Both doses of SRT501 were found to be safe and well-tolerated, and pharmacokinetics, a measure of drug levels in the blood, were identical at days one and 28, suggesting no drug accumulation. There were no serious adverse events and no dose-related adverse events. Importantly, SRT501 showed a statistically significant improvement in an oral glucose tolerance test on day 28 at two hours and a trend towards lower fasting plasma glucose levels.

SRT501 is also being tested in patients with Type 2 Diabetes in a Phase 1b BID (twice daily administration) study and in a Phase 2a study in combination with metformin, the current first-line therapy for Type 2 Diabetes. SIRT1 is the founding member of the human sirtuin family of enzymes which control the aging process. Specifically, SRT501 acts by increasing mitochondrial activity and therefore is targeted to address metabolic diseases, such as Type 2 Diabetes.

"This is the first time that a small molecule targeting sirtuins, the genes which control the aging process, has shown efficacy in a disease of aging," said Peter Elliott, Ph.D., Senior Vice President of Development at Sirtris. "These Phase 1b study results are an important step forward for Sirtris because they represent significant progress in our clinical development of sirtuin therapeutics. We are very pleased to see the safety profile observed in preclinical studies translate into a well-tolerated drug molecule in patients, and we are very encouraged by the glucose lowering effects measured in the oral glucose test."

Christoph Westphal, M.D., Ph.D., CEO and Vice Chair of Sirtris added, "Effective treatment for Type 2 Diabetes, a disease of aging, is an unmet medical need and sirtuin therapeutics may offer significant potential. SRT501 may represent a promising treatment option for these patients. We look forward to obtaining the results from our other Phase 1b clinical trial and the results from our Phase 2a clinical trial later this year."

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. Such statements include, but are not limited to, the potential therapeutic effects of SIRT1 activators including SRT501 for diseases of aging, such as Type 2 Diabetes, the progress and results of pre-clinical and clinical studies of SIRT1 activators, the potential therapeutic effects of SRT501 and other SIRT1 activators, and the potential of sirtuin modulators and activators to receive regulatory approval. 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 possibility that results of pre-clinical studies are not necessarily predictive of clinical trial results, the Company's potential inability to initiate and complete pre-clinical 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.

SOURCE: Sirtris Pharmaceuticals, Inc.

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