Sirtris Announces First U.S. Patent Issued On Class of SIRT1 Activators; Patent Covers First NCE to Enter Human Clinical Trials

March 19, 2008 - 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 United States Patent Office issued to Sirtris the first patent covering a broad class of compounds that activate the enzyme SIRT1. Several Sirtris compounds--or new chemical entities (NCEs)--from this class lower glucose and improve insulin sensitivity in preclinical models of Type 2 Diabetes. The patent covers the first NCE that Sirtris plans to take into a human clinical safety trial in the first half of 2008.

"Just five months ago in the publication Nature, we reported the identification of new chemical entities that lower glucose and improve insulin sensitivity in preclinical models that the FDA--in recent draft guidance--recommended for the development of Type 2 Diabetes drugs," says Christoph Westphal, M.D., Ph.D., Chief Executive Officer and Vice Chair of Sirtris Pharmaceuticals. "We are very pleased to have the first patent covering a class of compounds that have the potential to be a frontline therapy for Type 2 Diabetes."

"Sirtris has a strong intellectual property program with over 180 patent applications for broad coverage of sirtuin activators, including composition of matter, formulations, and methods of treatment claims," says Karl Normington, Ph.D., Senior Director of Intellectual Property at Sirtris Pharmaceuticals. "This is the first patent issued by the U.S. Patent Office covering a class of compounds known to activate SIRT1."

In 2006, consecutive papers in the journals Cell and Nature by Sirtris scientists and Sirtris co-founder David Sinclair, Ph.D. of Harvard Medical School, showed that resveratrol, a SIRT1 activator found in red wine, could reduce the impact of a high fat diet, increase stamina two fold and significantly extend lifespan of mice. However, it is estimated that a person would need to drink roughly 1000 bottles of red wine per day to obtain the equivalent dose of resveratrol used in these studies. Sirtris has developed SIRT1 activating molecules that are chemically distinct from, and up to 1000 times more potent in in-vitro studies than resveratrol.

The sirtuins are a family of seven enzymes that help regulate the body's natural defense against disease. In preclinical research, members of the sirtuin family have been shown to have protective effects against various diseases such as Type 2 Diabetes, metabolic diseases, cardiovascular disease, neurodegeneration, inflammation and cancer. Future sirtuin therapeutics may have the potential to treat diseases of aging in a new way.