Safety, Tolerability, Pharmacokinetics, and Antiviral Activity of GS-9857 in Subjects With Chronic Hepatitis C Virus Infection

Inclusion Criteria:

- Chronic genotype 1-4 HCV infection

- For Cohorts 1-9, HCV RNA ≥ 100,000 IU/mL at screening (no HCV RNA restriction for
Cohort 10)

- Screening laboratory values within defined thresholds

- Use of two effective contraception methods if female of childbearing potential or
sexually active male

Exclusion Criteria:

- Pregnant or nursing female or male with pregnant female partner

- Presence of cirrhosis

- Prior exposure to approved or experimental HCV Protease Inhibitors

- Co-infection with HIV or hepatitis B virus (HBV)

- Current or prior history of clinical hepatic decompensation

- Chronic use of systemic immunosuppressive agents

- History of clinically significant illness or any other medical disorder that may
interfere with subject treatment, assessment or compliance with the protocol