Sirtris Announces Clinical Results from Phase 1 Trials of SRT501, a Sirtuin Therapeutic.

Company Initiates Phase 1b Study in Type 2 Diabetes Patients

CAMBRIDGE, Mass. -- Sirtris Pharmaceuticals, the leading sirtuin therapeutics company, announced today that the company's initial clinical candidate, SRT501, was found to be safe and well tolerated when administered orally in

SRT501 targets SIRT1, the founding member of the human sirtuin family of enzymes. Specifically, SRT501 acts by increasing the number and function of mitochondria and is thus therapeutically targeted to address diseases of aging including metabolic diseases, such as diabetes and obesity.

In the Phase I studies, SRT501 was administered orally, once daily to 85 healthy male volunteers in separate study groups for seven days in order to evaluate dose, safety, tolerability and pharmacokinetics. SRT501 was found to be safe and well tolerated, and there were no serious adverse events.

"These Phase 1 study results are an important step forward for Sirtris and represent significant progress in the rapid clinical development of our robust sirtuin drug discovery platform," said Peter Elliott, Ph.D., Senior Vice President of Development at Sirtris.

Sirtris has initiated a Phase 1b trial in patients with Type 2 Diabetes. The Phase 1b trial is designed to evaluate the safety and the pharmacokinetics of SRT501 in 90 patients using daily oral administration of SRT501 for 28 days.

"Our platform of sirtuin therapeutics offers significant potential for metabolic and mitochondrial disorders," said Christoph Westphal, M.D., Ph.D., CEO of Sirtris Pharmaceuticals. "When combined, our Phase 1 and Phase 1b results will provide a solid foundation for understanding the safety and pharmacokinetics of SRT501, enabling us to advance the clinical development of sirtuin therapeutics."

About Sirtuins

Sirtuins are a recently discovered family of enzymes that promote normal cellular function. In particular, sirtuins improve the function of mitochondria which generate energy in cells. When organisms face adversity, sirtuins are activated as part of a natural process that maintains healthy function.

Therefore, sirtuins are attractive drug targets which may be therapeutically beneficial for diseases in which mitochondria are dysfunctional, often observed in diseases of aging. These diseases include metabolic diseases such as Type 2 Diabetes, neurological diseases, and other mitochondrial disorders. Sirtuin therapeutics offer the potential for a novel class of drugs that can treat significant diseases of aging in a new way.