Safety, Pharmacokinetics and Pharmacodynamics of Elbasvir (MK-8742) in Hepatitis C Infected Males (MK-8742-002)

The purpose of this study is to assess the safety, pharmacokinetics (PK) and pharmacodynamics of elbasvir (MK-8742) in Hepatitis C Virus (HCV)-infected participants. There will be 3 parts to this study; Part I will enroll only genotype (GT) 1 HCV-infected participants, Part II will enroll GT3 HCV-infected participants, and Part III will enroll only GT1a HCV-infected participants. All parts may run concurrently, or Parts II and III may be staggered. Hypothesis (Part I): At a once-daily dose that is sufficiently safe and well tolerated in HCV-infected participants, elbasvir administered for 5 consecutive days has superior antiviral activity in GT1 HCV-infected participants compared to placebo, as measured by change from baseline in plasma HCV ribonucleic acid (RNA; log 10 copies/mL) at Day 5, 24-hour postdose timepoint. (a true mean viral RNA reduction of at least 3 log10 is anticipated). Hypothesis (Part II): At a dose that is sufficiently safe in GT3 HCV-infected participants, the mean maximum reduction in HCV viral load is greater following multiple dose oral administration of elbasvir as compared to placebo. Hypothesis (Part III): At a once-daily dose that is sufficiently safe and well tolerated in HCV-infected participants, elbasvir administered for 5 consecutive days has superior antiviral activity in GT1a HCV-infected participants compared to placebo, as measured by change from baseline in plasma HCV RNA (log 10 copies/mL) at Day 5, 24-hour postdose timepoint. (a true mean viral RNA reduction of at least 3 log10 is anticipated).