Phase III Hallmark QUAD: ASV+DCV+Peg+Rib (Nulls/Partials)

Inclusion Criteria: * Males and females, ≥ 18 years of age * HCV Genotype 1 or 4 who previously failed treatment with Peginterferon alfa-2a or peginterferon alfa-2b and Ribavirin (P/R), classified as previous null and partial responders based on previous therapy * HCV RNA ≥ 10,000 IU/mL * Seronegative for Human immunodeficiency virus (HIV) and Hepatitis B surface antigen (HBsAg) * Subjects with compensated cirrhosis are permitted (compensated cirrhotics are capped at approximately 25% of treated population) Exclusion Criteria: * Prior treatment of HCV with HCV direct acting antiviral (DAA) * Evidence of a medical condition contributing to chronic liver disease other than HCV * Evidence of decompensated liver disease including, but not limited to, a history or presence of ascites, bleeding varices, or hepatic encephalopathy * Diagnosed or suspected hepatocellular carcinoma or other malignancies * Uncontrolled diabetes or hypertension * Total bilirubin ≥ 34 μmol/L (or ≥ 2 mg/dL) unless subject has a documented history of Gilbert's disease * Alanine aminotransferase (ALT) ≥ 5x Upper limit of normal (ULN) * Albumin \< 3.5 g/dL (35 g/L) * Alpha Fetoprotein (AFP) \> 100 ng/mL (\>82.6 IU/mL) or ≥ 50 and ≤ 100 ng/mL requires a liver ultrasound and subjects with findings suspicious of Hepatocellular carcinoma (HCC) are excluded * Absolute neutrophil count (ANC) \< 1.5 x 1000,000,000 cells/L (\< 1.2 x 1000,000,000 cells/L for Black/African-Americans) * Platelets \< 90 x 1000,000,000 cells/L * Hemoglobin \< 12 g/dL for females or \< 13 g/dL for males * Any criteria that would exclude the subject from receiving P/R