This study is a Phase II, double-blind, randomized, placebo-controlled, multi-center (3 sites) trial to assess the safety, tolerability, and pharmacokinetics of 400 mg and 600 mg Form I ST-246 when administered as a single daily oral dose for 14 days to 107 healthy, fed volunteers between 18 and 74 years of age. Safety parameters included adverse events, vital signs, physical examinations, laboratory tests (hematology, blood chemistry, and urinalysis) and electrocardiograms.