Achillion Pharmaceuticals, Inc, a leader in the discovery and development of small molecule drugs to combat the most challenging infectious diseases, announced that the US Patent & Trademark Office has granted Achillion US Patent No 7,476,686 related to the Achillion NS4A antagonists to treat the hepatitis C virus (HCV). This new patent, entitled 'Substituted Aryl Thioureas and related compounds; inhibitors of viral replication', includes novel mechanism of action claims and expires in 2025.

"In addition to securing intellectual property protection for these novel compounds, we believe this key patent grant underscores Achillion's strength in discovery and development and provides a cornerstone of our patent portfolio for novel NS4A antagonists," commented Michael D Kishbauch, Achillion's president and chief executive officer. "In partnership with Gilead Sciences, the NS4A programme continues to advance toward human clinical trials, which we hope to commence in 2009."

In collaboration with Gilead Sciences, Achillion is evaluating a series of product candidates that specifically recognize a new HCV target, NS4A. As a result of their novel mechanism of action, broad potency against HCV, potential for oral administration and demonstrated lack of cross resistance, Achillion believes there could be significant market opportunity for its compounds in this area of unmet medical need.

Based upon extensive virology and biochemistry studies, the novel mechanism of action of Achillion's NS4A antagonists involves targeting the NS4A protein of HCV.

Achillion is an innovative pharmaceutical company dedicated to bringing important new treatments to patients with infectious disease.