The purpose of this study is to:

• Assess the relative bioavailability of 2 oral formulations of samatasvir (capsule and tablet prototype test formulation)
• Compare the amount of study drug that is in the blood after taking either the capsule form of the drug or the tablet form of the drug while fasting.
• Determine the amount of study drug that is in the blood after eating a meal.
• Evaluate the safety of the tablet form of samatasvir in healthy people.

Each participant will receive each of the formulations in a crossover design. Part A Periods 1 and 2: Participants will receive either samatasvir capsules or tablets according to randomization under fasting conditions on Days 1 and 8. Part A Period 3: All participants will receive samatasvir tablets under fed conditons on Day 15.

Each dose will be separated by a 7-day wash-out period. Part B: All participants will receive samatasvir capsules under fed conditons on Day 1.

Inclusion Criteria:

• Must be a healthy male with body mass index (BMI) between 18 and 35 kg/m
• Must agree to use an acceptable double-barrier method of birth control.
• Must provide written informed consent after the study has been fully explained.

Exclusion Criteria:

• History of clinically significant diseases, as determined by the investigator.
• Safety laboratory abnormalities at screening which are clinically significant.
• Positive screening test for hepatitis B virus, hepatitis C virus or human immunodeficiency virus (HIV).
• Use of chronic prescription medications within 3 months, acute prescription medications within 14 days, or systemic over-the-counter (OTC) medications within 7 days of the starting the study.
• Current abuse of alcohol or illicit drugs, or history of alcohol or illicit drug abuse within the preceding two years.