This was a Phase 2a, blinded, randomized, placebo-controlled clinical trial in hepatitis C virus (HCV)-infected adults with 2 planned sequential evaluations, Part 1 and Part 2. The study evaluated the safety, tolerability, antiviral activity, and pharmacokinetics of ABT-333 or placebo monotherapy, followed by 26 days of ABT-333 or placebo with pegylated interferon a-2a (pegIFN) and ribavirin (RBV) combination therapy. Review of safety and efficacy in Part 1 of the study showed similar response rates across ABT-333 doses so Part 2 of the study was not performed. The study also assessed emergence of resistant HCV in conjunction with kinetics of viral load decay and rebound in treatment-naïve, HCV-infected participants.