Patient description: A 53-year-old man presents with chronic HCV infection for the past 2 years. His past medical history is only significant for inguinal hernia surgery when he was 20 years old. He is on IFN (100 mg/week) plus RBV (400 mg/day) combination therapy for the past 9 months. Direct antiviral drugs were added to his treatment 6 months ago. His medical record shows previous positive HCV RNA tests as well as positive enzyme immunoassay for anti-HCV-antibodies. The recent biopsy was negative for hepatocellular carcinoma and was only remarkable for chronic inflammation compatible with a chronic viral hepatitis. There is no evidence of alcoholic liver disease, bleeding from esophageal varices, hemochromatosis, autoimmune hepatitis or metabolic liver disease. He is an alert male with no acute distress. His BP: 130/75, HR: 90/min and BMI: 27. His abdomen is soft with no ascites or tenderness. The lower extremities are normal with no edema.

Clinical trial eligibility criteria: eligible ages (years): 18.0-999.0,  Hepatitis C Virus (HCV) Infection Be a current resident of France Have HCV RNA (≥ 10,000 IU/mL in peripheral blood) at the time of screening Have documented chronic HCV GT4 (with no evidence of non-typeable or mixed genotype) infection Have liver biopsy performed within 24 months of Day 1 of this study (if participant has cirrhosis, there is no time restriction on biopsy), or have FibroScan® performed within 12 months of Day 1 of this study with interpretable result in kilopascals (kPa) as follows: Fibrosis score of F0-F2, Fibrosis score of F3, or Cirrhosis (F4) Have a prior treatment history of either HCV TN or HCV TE with interferon (IFN) +/- ribavirin (RBV) +/ Sofosbuvir (SOF) (on-treatment failure, relapser, or other/intolerant) Females who are of reproductive potential must agree to avoid becoming pregnant while receiving study drug and for 14 days after the last dose of study drug by complying with one of the following: (1) practice abstinence from heterosexual activity OR (2) use (or have her partner use) acceptable contraception during heterosexual activity If Human Immunodeficiency Virus (HIV) co-infected, then have HIV-1 infection documented prior to screening  Had prior treatment (defined as 1 dose or more) with direct-acting antiviral (DAA) therapy Has evidence of decompensated liver disease manifested by the presence of or history of ascites, esophageal or gastric variceal bleeding, hepatic encephalopathy, or other signs or symptoms of active advanced liver disease Classified as Child-Pugh B or C or has a Child Pugh-Turcotte score (CPT) > 6 Has cirrhosis and liver imaging within 6 months of Day 1 showing evidence of hepatocellular carcinoma (HCC) or is under evaluation for HCC Hepatitis B virus surface antigen (HBsAg) positive at screening. Participants who are HBsAg negative and hepatitis B core antibody (anti-HBc) positive at screening may be included Under evaluation for active or suspected malignancy, except for adequately treated basal cell or squamous cell skin cancer or in situ cervical cancer Currently participating or has participated in a study with an investigational compound within 30 days of signing informed consent and is not willing to refrain from participating in another such study during the course of this study