GS 5885 Administered Concomitantly With GS-9451, Tegobuvir and Ribavirin (RBV) in Chronic Genotype 1 Hepatitis C Virus (HCV) Infection

Inclusion Criteria:

   - Adult subjects 18 to 70 years of age

   - Chronic HCV infection for at least 6 months prior to Baseline (Day 1)

   - Liver biopsy results (performed no more than 2 years prior to Screening) indicating
   the absence of cirrhosis

   - Monoinfection with HCV genotype 1a or 1b

   - HCV treatment-naïve

   - Body mass index (BMI) between 18 and 36 kg/m2

   - Creatinine clearance ≥ 50 mL/min

   - Subject agrees to use highly effective contraception methods if female of childbearing
   potential or sexually active male.

   - Screening laboratory values within defined thresholds

Exclusion Criteria:

   - Autoimmune disease

   - Decompensated liver disease or cirrhosis

   - Poorly controlled diabetes mellitus

   - Severe psychiatric illness

   - Severe chronic obstructive pulmonary disease (COPD)

   - Serological evidence of co-infection with human immunodeficiency virus (HIV),
   hepatitis B virus (HBV), or another HCV genotype

   - Suspicion of hepatocellular carcinoma or other malignancy (with exception of certain
   skin cancers)

   - History of hemoglobinopathy

   - Known retinal disease

   - Subjects who are immunosuppressed

   - Subjects with known, current use of amphetamines, cocaine, opiates (i.e., morphine,
   heroin), methadone, or ongoing alcohol abuse

   - Subjects must have no history of clinically significant cardiac disease, including a
   family history of Long QT syndrome, and no relevant electrocardiogram (ECG)
   abnormalities at screening