Efficacy and Safety Study of GS-9450 Treatment for 6 Months in Patients With Chronic Hepatitis C Virus Infection

This is a Phase 2b, randomized, double-blind, parallel-group, placebo-controlled, multicenter study investigating the safety, tolerability and efficacy of two oral doses of GS-9450 in adults with chronic Hepatitis C Virus (HCV). Approximately 240 subjects 18-65 years of age who meet study entry criteria will be randomized (in other words, selected at random, like flipping a coin) to one of three treatment groups (80 subjects per treatment group) as follows:GS-9450 10 mg once daily,GS-9450 40 mg once daily, or matching placebo once daily. Following randomization, subjects will return within seven business days for a Baseline (Day 1) visit, at which time study medication will be dispensed and subjects will enter a 26 week treatment phase. During the treatment phase, subjects will receive study drug once daily for 24 weeks and then taper off of study drug over the following 2 weeks by receiving study drug once every other day for one week and then every 3 days for one week. Following completion of the treatment phase, subjects will enter a 4-week off-treatment follow-up phase.