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) Male or female (of non-childbearing potential or using allowed contraceptive methods) at least 18 years of age time of Screening Participant had a positive anti-hepatitis C virus (HCV) antibody (Ab) and plasma HCV ribonucleic acid (RNA) greater than or equal to 1000 IU/mL at the Screening Visit Participant had an estimated glomerular filtration rate (eGFR) less than 45 mL/min/1.73 m^2 as estimated by the Modification of Diet in Renal Disease (MDRD) method at Screening according to the following formula: eGFR (mL/min/1.73 m^2 ) = 175 × (Serum Creatinine) ^-1.154 × Age^-0.203 × (0.742 if female) × (1.212 if black), or were dialysis dependent. Subjects requiring dialysis had to have been receiving dialysis for at least 1 month prior to enrollment, and may have been on hemodialysis or peritoneal dialysis Cirrhotic participants only: absence of hepatocellular carcinoma (HCC) as indicated by a negative ultrasound, computed tomography (CT) scan, or magnetic resonance imaging (MRI) within 3 months prior to Screening or a negative ultrasound at Screening. Participants who had an ultrasound with results suspicious of HCC followed by a subsequent negative CT or MRI of the liver were eligible for the study  Female participants who were pregnant, breastfeeding, or were considering becoming pregnant during the study or for approximately 30 days after the last dose of study drug Current hepatitis B virus (HBV) or human immunodeficiency virus (HIV) infection on screening tests, defined as Positive test result at Screening for hepatitis B surface antigen (HBsAg), or HBV deoxyribonucleic acid (DNA) greater than lower limit of quantification (LLOQ) in participants with isolated positive hepatitis B core antibody (HBcAb), (i.e., negative HBsAg and Anti-HBsAg), or Positive anti-HIV antibody (Ab) Any current or historical clinical evidence of decompensated cirrhosis, including any current or past evidence of Child-Pugh B or C classification, hepatic encephalopathy or variceal bleeding; radiographic evidence of small ascites; or prior or current empiric use of lactulose/rifaximin for neurologic indications. Prophylactic use of beta blockers was not exclusionary Clinical history of acute renal failure in the 3 months prior to Screening History of severe, life-threatening, or other significant sensitivity to any excipients of the study drugs Clinically significant abnormalities or co-morbidities, or recent (within 6 months prior to study drug administration) alcohol or drug abuse that could preclude adherence to the protocol in the opinion of the investigator Receipt of any investigational or commercially available direct acting anti-HCV agents other than sofosbuvir