Feb 3, 2012

Achillion Announces Executive Promotion

NEW HAVEN, Conn., Feb. 3, 2012 (GLOBE NEWSWIRE) -- Achillion Pharmaceuticals, Inc. (Nasdaq:ACHN), a leader in the discovery and development of small molecule drugs to combat the most challenging infectious diseases, today announced the promotion of Mr. Joseph Truitt to Senior Vice President of Business Development. Mr. Truitt maintains his position as Chief Commercial Officer and previously served as Vice President of Business Development.

"Joe, with his extensive commercial and business development experience, has been an invaluable addition to the Achillion team since he came aboard in 2009. Joe has spearheaded a number of important strategic projects that have brought clarity to the nuanced HCV market and the significant role Achillion's portfolio of protease and NS5A inhibitors will play in this market, which we predict could surpass $20 billion by 2020," commented Michael D. Kishbauch, Chief Executive Officer of Achillion. "We recognize Joe not only for his contributions over the past several years, but for driving our business development and marketing efforts that have truly placed Achillion at the center of the HCV revolution."

About Achillion Pharmaceuticals

Achillion is an innovative pharmaceutical company dedicated to bringing important new treatments to patients with infectious disease. Achillion's proven discovery and development teams have advanced multiple product candidates with novel mechanisms of action. Achillion is focused on solutions for the most challenging problems in infectious disease including hepatitis C and resistant bacterial infections. For more information on Achillion Pharmaceuticals, please visit 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. There are various important factors that could cause actual results to differ materially from those indicated by such forward-looking statements including the risk factors described in the reports filed by Achillion with the U.S. Securities and Exchange Commission, including its Annual Report on Form 10-K for the fiscal year ended December 31, 2010 and its subsequent SEC filings.

In addition, any forward-looking statement in this press release represents Achillion's views only as of the date of this press release and should not be relied upon as representing its views as of any subsequent date. Achillion disclaims any obligation to update any forward-looking statement, except as required by applicable law.

CONTACT: Company Contact:

         Glenn Schulman

         Achillion Pharmaceuticals, Inc.

         Tel. (203) 752-5510



         Mary Kay Fenton

         Achillion Pharmaceuticals, Inc.

         Tel. (203) 624-7000



         Christin Culotta Miller

         Ogilvy PR

         Tel. (212) 880-5264