Peg-Intron/Ribavirin in G 1 HCV for Non-Extended Versus 24 Week Extended Treatment After 24 Weeks (Study P04144)(COMPLETED)

Inclusion Criteria: * Subject must be willing to give written informed consent and be able to adhere to dose and visit schedules. * Males and non-pregnant females and aged \>= 18 years, subjects who are over 65 years of age must be in generally good health and must be discussed with and approved by the principal investigator prior to entry. * The laboratory evaluation within 6 months prior to entering the Pilot Treatment Program must meet the following criteria: * Hemoglobin values of \>= 12 g/dL for females and \>= 13 g/dL for males * Neutrophil count \>= 1.5 X10\^9/L * Platelets count \>= 100 x 10\^9/L * Total bilirubin \< 1.5 mg/dL * Serum creatinine within normal limits * Positive serum HCV-RNA (\>= 50 IU (100 copy numbers)/mL) * Anti-HCV positive * Available HCV genotype 1 * Liver biopsy performed within 12 months prior to entry to this protocol with a pathology report confirming that the histological diagnosis is consistent with chronic hepatitis (METAVIR system \>=F1). * Compensated liver disease with the following hematological, biochemical, and serologic criteria at the screening visit: * Hemoglobin values of \>= 9 g/dL * Neutrophil count \>= 0.75 x 10\^9/L * Platelets count \>= 50 x 10\^9/L * Prothrombin time (PT) prolong \<= 3 sec, International Normalized Ratio (INR) \<= 1.2 * Total bilirubin \<= 3 mg/dL * Within normal limits (subjects requiring medication to maintain TSH levels in the normal range are eligible if all other inclusion/exclusion criteria are met). * Anti-Human Immunodeficiency Virus (HIV) negative. * Alpha-fetoprotein (AFP) value within normal limits obtained within 12 months prior to entry. Results above the upper limit of normal but \<= 50 ng/mL require both of the following: * AFP value \<= 50 ng/mL obtained within 9 months prior to entry in the study or during the Screening period, and Ultrasound obtained within 9 months prior to entry or in the screening period in the study for evidence of not having hepatocellular carcinoma. * A urine pregnancy test obtained prior to the initiation of pilot treatment must be negative. Female subjects must not be breast feeding. * Reconfirmation that sexually-active subjects are practicing acceptable methods of contraception during screening period. * Complete 24 weeks treatment of the Pilot Treatment Program with Peg-Intron + Ribavirin. * Must be never treated with interferon for HCV infected hepatitis (treatment naïve) before the Pilot Treatment Program. * The total amount of Peg-Intron and Ribavirin received during the pilot treatment program must achieve more than 80% of the recommended dosage. Exclusion Criteria: * Women who are pregnant or nursing. * Have decompensated cirrhosis. * History of severe psychiatric disease, especially depression. * Concurrent malignancies (including hepatocellular carcinoma). * Unstable or significant cardiovascular diseases. Subjects with (ECG) showing clinically significant abnormalities. * Prolonged exposure to known hepatotoxins such as alcohol or drugs. * History of thyroid disease poorly controlled on prescribed medication. * Poorly controlled diabetes mellitus. * Has suspected or confirmed significant hepatic disease from an etiology other than HCV. * Patients co-infected with hepatitis B and /or human immunodeficiency virus (HIV). * Severe renal disease or myeloid dysfunction. * History of organ transplantation other than cornea and hair transplant. * Any medical condition requiring, or likely to require during the course of the study, chronic systemic administration of steroids. * Any other condition which in the opinion of the investigator would make the subject unsuitable for enrollment, or could interfere with the subject participating in and completing the protocol. * Allergy to interferon.