A Phase 3, Multicenter, Randomized, Active-Controlled Study to Investigate the Safety and Efficacy of PSI-7977 and Ribavirin for 12 Weeks Compared to Pegylated Interferon and Ribavirin for 24 Weeks in Treatment-Naïve Patients with Chronic Genotype 2 or 3 HCV Infection

1) Males or females at least 18 years old, or the legal age of consent, whichever is older, at Screening. Subjects or their heterosexual partner(s) must either be of non-childbearing potential or they must use effective contraception from 2 weeks before the initiation of therapy until 6 months (or the duration recommended locally for ribavirin if longer) after the last dose of study medication.;2) Chronic Genotype 2 or 3 HCV-infection documented by at least one measurement of serum HCV RNA * 10,000 IU/mL;3) Patients with Childs A cirrhosis may be included (up to 20% of patients randomized);4) Subjects must be naïve to all HCV antiviral treatment(s), including but not limited to immunomodulatory and nucleoside/tide treatments for chronic HCV infection.;5) A body mass index (BMI) of *18kg/m2;6) Otherwise suitable for participation as determined by the medical history, physical examination, ECG, and clinical laboratory measurements performed at Screening;7) Able to effectively communicate with the Investigator and other center personnel. Willing to give written informed consent and comply with the study restrictions and requirements

1) Positive test at Screening for HBsAg, anti-HBc IgM Ab, or anti-HIV Ab.;2) History of any other clinically significant chronic liver disease.;3) A history of consistent with decompensated liver disease including ascites, variceal hemorrhage, hepatic encephalopathy, hepatorenal syndrome and hepatopulmonary syndrome, among others.;4) History or current evidence of psychiatric illness, immunologic disorder, hemoglobinopathy, pulmonary disease (including pneumonia or pneumonitis), cardiac disease, seizure disorder or anticonvulsant use, poorly controlled diabetes, cancer, or a history of malignancy that in the opinion of the investigator makes the patient unsuitable for the study. Chronic medical conditions, especially if treated with medications (such as hypertension), must be stable at the time of screening. No new therapies should be started prior to the study that may confound the assessment of study drug safety.;5) Clinical signs and symptoms of acute pancreatitis with elevated lipase;6) Clinically significant ECG findings at screening, screening QTc * 450 ms (non-cirrhotic) or * 500 ms (cirrhotic), or a personal or family history of Torsades de pointes.;7) History of major organ transplantation with an existing functional graft.;8) Active substance abuse which, in the opinion of the investigator, would make the candidate inappropriate for participation in this study.;9) History of uncontrolled thyroid disease or abnormal TSH levels as defined <0.8 x LLN or >1.2 x ULN at Screening (subjects will be eligible with an abnormal TSH if the T3 and T4 are within normal limits).;10) Abnormal haematological and biochemical parameters.;11) Donation or loss of more than 400 mL blood within 2 months prior to first dose administration.;12) History of clinically significant drug allergy to nucleoside/nucleotide analogs.;13) History of having received any systemic antineoplastic or radiation therapy within 6 months prior to the first dose of study drug or the expectation that such treatment will be needed at any time during the study.;14) Subjects receiving oral or intravenous strong p-glycoprotein inhibitors (including cyclosporine, quinidine, dronedarone, itraconazole, verapamil or ritonavir) within 28 days of dosing. Additional concomitant medications disallowed in this study are outlined in Section 7.7. of the protocol.;15) Participation in a clinical study with an investigational drug, biologic, or device within 3 months prior to first dose administration.;16) Pregnant/Breastfeeding women or males whose partners are currently pregnant.;17) Poor venous access making the patient unable to complete the required laboratory testing
schedule.