Efficacy and Safety of Grazoprevir (MK-5172) and Uprifosbuvir (MK-3682) With Elbasvir (MK-8742) or Ruzasvir (MK-8408) for Chronic Hepatitis C Virus (HCV) Genotype (GT) 3, GT4, GT5, and GT6 Infection (MK-3682-012)

This is a randomized, three-part, parallel-group, open-label trial of grazoprevir (MK-5172) (100 mg) and uprifosbuvir (MK-3682) (300 mg or 450 mg) with either elbasvir (MK-8742) (50 mg) or ruzasvir (MK-8408) (60 mg), and with or without ribavirin (RBV), in treatment-naive (TN) or treatment-experienced (TE) cirrhotic (C) or non-cirrhotic (NC) participants infected with hepatitis C virus (HCV) genotype (GT) 3, GT4, GT5, or GT6. Part A will consist of 4 arms to evaluate the safety of dose combinations. In Part B, participants will take 2 uprifosbuvir (+) grazoprevir (+) ruzasvir (MK-3682B) fixed dose combination (FDC) tablets once daily (q.d.) by mouth, with or without twice-daily (b.i.d.) RBV (200 mg capsules; weight-based dosing). Participants who relapse following completion of therapy in Part A will be offered the option of retreatment with 16 weeks of uprifosbuvir (+) grazoprevir (+) ruzasvir with RBV in Part C (data obtained from Part C will not be used in the analysis of outcome measures).