Abstract on ACH-1625 accepted as late breaking poster presentation at The Liver Meeting 2010

ACH-1625 Protease Inhibitor Abstract Accepted as Late Breaking Poster

Growing Data Set Underscores Company's Significant HCV Franchise

Achillion Pharmaceuticals, Inc. (Nasdaq:ACHN), a leader in the discovery and development of treatments for the most challenging infectious diseases, today announced that its abstract titled "ACH-1625 Demonstrates Sustained Viral Suppression in Presence of Uncommon Drug Resistant HCV Variants: Pharmacokinetic, Pharmacodynamic and Clinical Virology Analysis of Phase I Study" has been accepted as a late breaking poster presentation at the 61^st Annual Meeting of the American Association for the Study of Liver Disease (AASLD) The Liver Meeting® 2010 being held October 29-November 2, 2010 in Boston.

Two additional abstracts on ACH-1625 titled "In Vitro Combination Studies of ACH-1625 (HCV NS3 Protease Inhibitor) and ACH-2928 (HCV NS5A inhibitor) in Presence and Absence of Ribavirin" and "Non-Clinical Studies to Assess Drug-Drug Interaction Potential of ACH-1625, a Clinically Effective HCV NS3 Protease Inhibitor" had previously been accepted for poster presentation.

In addition, an abstract on ACH-2684 titled "HCV NS3 Protease Inhibitor with Potent Activity against Multiple Genotypes and Known Resistant Variants" was previously accepted for poster presentation.

Achillion's late breaking poster will be displayed in the Late Breaking Poster Session on Monday, November 1 at 8:00 a.m. through the end of the day's session. The balance of the Company's posters will be displayed in the HCV Therapy: Preclinical and Early Clinical Development Poster Session on Tuesday, November 2 at 7:00 a.m. through the end of the day's session. 

"The Liver Meeting 2010 is noteworthy for Achillion because, for the first time, we are presenting a significant amount of clinical data in support of our expanding HCV pipeline of products. The clinical data for ACH-1625 further supports this compound's potential to be a best-in-class therapy, and our pre-clinical data elucidate the potential for powerful combination therapies with our own drug candidates," noted Michael Kishbauch, President and Chief Executive Officer

"We were especially pleased to have our data selected for a Late Breaking poster as it underscores the importance of our positive clinical data with ACH-1625 to treat HCV since only a few such submissions were chosen for Late Breaking presentation. We look forward to sharing our positive results with the clinical and scientific audience at AASLD and to advancing ACH-1625 into Phase 2 studies this month."