Sirtris Pharmaceuticals, Inc. Announces Initiation of Phase 1b Clinical Trial of SRT501 in MELAS

  
    
  
  
    
      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, today announced the 
      initiation of a Phase 1b clinical trial of SRT501 in patients in Europe 
      with MELAS Syndrome (Mitochondrial Encephalopathy Lactic Acidosis and 
      Stroke-like episodes). MELAS is a progressive and fatal disorder caused 
      by a mutation in the DNA of the mitochondria that mainly affects muscles 
      and nerves leading to reduced exercise capacity and eventually muscle 
      failure. There are currently no known treatments for patients with MELAS 
      Syndrome.
    
    
      “We are pleased to continue to advance the 
      clinical development of SRT501 into this area of significant unmet 
      medical need. We believe MELAS represents an orphan drug opportunity,” 
      said Peter Elliott, Ph.D. Senior Vice President of Development at 
      Sirtris.
    
    
      This Phase 1b trial is designed to test the primary endpoints of safety 
      and pharmacokinetics of SRT501 in patients with MELAS. SRT501 will be 
      administered to a group of 15 patients once daily for three months and 
      an additional group of 15 patients will receive placebo. Secondary 
      endpoints include exercise tolerance, and fasting blood glucose and 
      insulin levels. Sirtris expects data from this trial by the end of 2008.
    
    
      “In addition to MELAS, SRT501 is also being 
      evaluated in two Phase 1b clinical trials in patients with Type 2 
      Diabetes with results expected in the first of these trials later this 
      year. SRT501 represents the first in a portfolio of sirtuin activators, 
      including novel chemical entities which are even more potent than 
      SRT501, intended to treat a range of diseases of aging,” 
      said Christoph Westphal, M.D., Ph.D., Chief Executive Officer of Sirtris.
    
    
      About SRT501
    
    
      SRT501, Sirtris’ proprietary version of 
      resveratrol and initial clinical candidate, activates the sirtuin, 
      SIRT1. SIRT1 is a member of the human sirtuin family of enzymes. 
      Specifically, SRT501 acts by increasing mitochondrial activity and may 
      target metabolic diseases like Type 2 Diabetes as well as mitochondrial 
      disorders such as MELAS.
    
    
      Sirtuins are a recently-discovered family of enzymes that appear to 
      regulate certain beneficial effects of calorie restriction. There are 
      seven human sirtuins (SIRT1-7), each having a different sub-cellular 
      localization. Sirtris believes that sirtuins are attractive drug targets 
      since some have a specialized function in mitochondrial activity which 
      may be therapeutically beneficial for metabolic and neurological 
      diseases. By harnessing a natural process, Sirtris believes sirtuin 
      therapeutics offer the potential for a novel class of drugs that can 
      treat significant diseases of aging in a new way.
    
    
      About MELAS Syndrome
    
    
      Based on market research, Sirtris estimates that there are between 5,000 – 
      10,000 patients with MELAS both in the United States and Europe, 
      although the true rate of incidence is unknown. MELAS is a rare 
      mitochondrial disorder caused by a mutation in the genetic material of 
      an intracellular structure that releases energy (mitochondria). The most 
      characteristic symptom of MELAS is exercise intolerance and recurring, 
      stroke-like episodes in which sudden headaches are followed by vomiting 
      and seizures. Short stature, an accumulation of lactic acid in the blood 
      (lactic acidosis), and muscular weakness on one side of the body are 
      often also associated with MELAS.
    
    
      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 for multiple neurodegenerative diseases and 
      other types of disorders, 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 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.