Safety and Efficacy Study of Pegylated Interferon Lambda Versus Pegylated Interferon Alfa, Plus Ribavirin in Subjects With Hepatitis C

Inclusion Criteria: * Chronic hepatitis C, Genotype 1 or 4 * HCV Ribonucleic acid (RNA) ≥ 100,000 IU/mL at screening * Liver biopsy documenting no cirrhosis (within prior 2 years) or cirrhosis (from any time prior to randomization). Where approved for staging of liver disease, non-invasive imaging may be used to assess the extent of liver disease. Subjects with compensated cirrhosis can enroll and will be capped at 10% * Naive to prior anti-HCV therapy Exclusion Criteria: * Infected with HCV other than Genotype 1 or 4 * Positive Hepatitis B surface antigen (HBsAg), or Human immunodeficiency virus-1 (HIV-1)/HIV-2 antibody or hepatitis D virus (HDV) at screening * Evidence of liver disease other than HCV * Active substance abuse * Use of hematologic growth factors within 90 days prior to study randomization * Evidence of decompensated cirrhosis based on radiologic criteria or biopsy results and clinical criteria