This was a double-blind, placebo-controlled, dose-escalating, multiple-dose study of orally administered ST-246 to 30 healthy volunteers ages 18-50 years, randomized to receive either active drug (8 subjects) or placebo (2 subjects) in 1 of 3 dosing groups (250, 400 or 800mg groups). Each dose group of 10 was divided into two cohorts of 5 subjects (4 active and 1 placebo). The first cohort was dosed approximately 4-8 weeks before the second cohort of each dose group. Dose groups completed the study treatment approximately 5 weeks prior to the start of the following dose group. Study procedures included several overnight stays, medical history/exam, laboratory testing done by blood draw, and electrocardiograms.