Non-cash stock compensation expense totaled $4.3 million for the nine months ended September 30, 2013 as compared with $2.7 million for the same period in 2012, and is included in research and development and general and administrative expenses.About HCV The hepatitis C virus is the most common cause of viral hepatitis, which is an inflammation of the liver. It is currently estimated that more than 170 million people are infected with HCV worldwide including more than 5 million people in the United States, making HCV more than twice as widespread as HIV. Three-fourths of the global HCV patient population is undiagnosed; it is a silent epidemic and a major global health threat. Chronic hepatitis, if left untreated, can lead to permanent liver damage that can result in the development of liver cancer, liver failure or death. Few therapeutic options currently exist for the treatment of HCV infection. The current standard of care is limited by its specificity for certain types of HCV, significant side-effect profile, and injectable route of administration. For additional information on Achillion's ongoing clinical trials please visit: http://clinicaltrials.gov About Achillion Pharmaceuticals Achillion is an innovative pharmaceutical company dedicated to bringing important new treatments to patients with infectious disease. Achillion's discovery, clinical development, and commercial teams have advanced multiple novel product candidates with proven mechanisms of action into studies and toward the market. Achillion is focused on solutions for the most challenging problems in infectious disease including HCV and resistant bacterial infections. For more information on Achillion Pharmaceuticals, please visit www.achillion.com or call 1-203-624-7000. Forward-Looking Statements This press release includes forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 that are subject to risks, uncertainties and other important factors that could cause actual results to differ materially from those indicated by such forward-looking statements, including statements with respect to: our plans to initiate clinical trials of ACH-3422, continue to engage in discussions with FDA regarding the sovaprevir clinical hold, and initiate additional clinical trials of ACH-3102 and ACH-2684; and our belief that our cash will be sufficient to reach value creating milestones and fund operations for more than two years. We may use words such as "expect," "anticipate," "project," "intend," "plan," "believe," "seek," " estimate," "may" and similar expressions to identify such forward-looking statements. Among the important factors that could cause actual results to differ materially from those indicated by such forward-looking statements are risks relating to, among other things our ability to: demonstrate in any potential future clinical trials the requisite safety, efficacy and combinability of our drug candidates; advance the preclinical and clinical development of our drug candidates under the timelines we project; satisfactorily respond to the FDA's requirements for removing the clinical hold placed on sovaprevir by the FDA; obtain and maintain necessary regulatory approvals; obtain and maintain patent protection for our drug candidates and the freedom to operate under third party intellectual property; establish commercial manufacturing arrangements; identify, enter into and maintain collaboration agreements with appropriate third-parties; compete successfully with other companies that are seeking to develop improved therapies for the treatment of HCV; manage expenses; manage litigation; raise the substantial additional capital needed to achieve our business objectives; and successfully execute on our business strategies. These and other risks are described in the reports we file with the U.S. Securities and Exchange Commission, including our Quarterly Report on Form 10-Q for the fiscal quarter ended June 30, 2013 and its subsequent SEC filings.