Leonard P. Guarente Joins Sirtris Pharmaceuticals Scientific Advisory Board as Co-Chair

Sirtris and Guarente Publish Review on the Therapeutic Potential of Sirtuins for Diseases of Aging

CAMBRIDGE, Mass.--()--Sirtris Pharmaceuticals, Inc. (NASDAQ: SIRT), a biopharmaceutical company focused on discovering and developing small molecule drugs to treat diseases of aging, announced today that Leonard P. Guarente, Ph.D., Novartis Professor of Biology at the Massachusetts Institute of Technology, has joined its Scientific Advisory Board as Co-Chair. Also, Sirtris has co-authored a review with Professor Guarente in the November 2007 issue of Trends In Biochemical Sciences (TIBS).

The review, entitled A Therapeutic Role for Sirtuins in Diseases of Aging? Westphal et al., 2007, highlights the effects of sirtuins, anti-aging genes, on mitochondria (the powerhouses of all cells) and the potential role of sirtuin therapeutics in diseases of aging including metabolic disorders such as Type 2 Diabetes, mitochondrial disorders such as MELAS, neurological disorders, and cancer.

I am delighted to join the Scientific Advisory Board of Sirtris as a Co-Chair. Sirtris is highly focused on developing therapeutics with breakthrough medical potential that target sirtuins for the treatment of diseases of aging, said Leonard P. Guarente, the Novartis Professor of Biology at the Massachusetts Institute of Technology.

David Sinclair, Ph.D., co-founder of Sirtris and Associate Professor of Pathology at Harvard Medical School said I am excited that Professor Guarente, a founder of the sirtuin field, is joining us as a Co-Chair of the Scientific Advisory Board of Sirtris.

Christoph Westphal, M.D., Ph.D., Chief Executive Officer and Vice Chair of Sirtris Pharmaceuticals, Inc. said, Professor Guarente is a well-respected thought leader in the sirtuin field, and we are pleased to have him join the other academic leaders on our Scientific Advisory Board as we develop SRT501, our proprietary formulation of resveratrol and new chemical entities which are up to 1000 times more potent than resveratrol, to address a broad range of diseases of aging.

The article can be accessed at:

http://www.sciencedirect.com

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 such as SRT501 and NCEs for diseases of aging such as metabolic disorders, mitochondrial disorders, neurodegenerative diseases, and cancer, the progress and results of pre-clinical studies of SIRT1 activators, and the potential of sirtuin modulators 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 Companys 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.

Contacts

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

Contacts

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