Achillion Pharmaceuticals Inc., of New Haven, Conn., began dosing in a Phase I trial of ACH-2684, a pan-genotypic protease inhibitor in development for chronic hepatitis C virus (HCV) infection. The study is designed to test the safety, tolerability, pharmacokinetic profile and antiviral activity of the drug in three segments: a single ascending dose segment in healthy volunteers, a 14-day multiple ascending doses segment in healthy volunteers and evaluation of three days of oral ascending repeat doses in subjects with either genotype 1 or genotype 2 HCV. Up to 78 healthy volunteers and 40 HCV-infected patients will be enrolled.