A Study Evaluating GS-9620 in Treatment Naive Subjects With Chronic Hepatitis B

A Double-Blind, Randomized, Placebo-Controlled, Single and Multiple- Dose Ranging, Adaptive Study Evaluating the Safety, Tolerability, Pharmacokinetics, Pharmacodynamics, and Antiviral Activity of GS-9620 in Treatment Naive Subjects With Chronic Hepatitis B Virus Infection

Dose cohorts may be dosed with one of up to 4 possible total weekly doses (0.3 mg, 1 mg, 2 mg, 4 mg). Dose escalation or repetition will be governed by pre-specified safety and activity rules. Subjects will be confined on either days 1-3 or days 1-3 and 8-10. Follow-up visits are also required periodically through day 43, and potential viral load follow-up visits at weeks 3 and 6 months post last dose. Study procedures involve blood draws for pharmacokinetic, pharmacodynamic, virologic, and safety assessments

Inclusion Criteria:

• Chronic HBV infection ≥ 6 months
• HBsAg ≥ 250 IU/mL
• HBV treatment naïve
• Absence of extensive bridging fibrosis (Metavir 3 or greater) or cirrhosis
• Creatinine clearance ≥ 70 mL/min

Exclusion Criteria:

• Co-infection with hepatitis C virus (HCV), hepatitis D virus (HDV), or HIV
• History of Gilberts disease
• Laboratory parameters not within defined thresholds for leukopenia, neutropenia, anemia, thrombocytopenia, thyroid-stimulating hormone (TSH), or other evidence of hepatic decompensation
• Diagnosis of autoimmune disease, poorly controlled diabetes mellitus, significant psychiatric illness, severe chronic obstructive pulmonary disease(COPD), malignancy, hemoglobinopathy, retinal disease, or patients who are immunosuppressed
• Evidence of hepatocellular carcinoma