Phase IV Study to Evaluate the Efficacy/Safety to Extend Treatment and High Dose of Ribavirin in co-Infected Patients

Inclusion Criteria: * Male and female patients \> 18 years of age * Serologic evidence of anti-HCV * Detectable plasma HCV-RNA * Serologic evidence of HIV-1 infection * CD4 cell count \>/= 250 cell/mm3 * Stable status of HIV-1 infection in the opinion of the investigator * Patients on stable antiretroviral therapy (HAART) for at least 6 weeks prior to baseline whose HAART regimen (drugs and dosage) is expected to remain unaltered for the first 6 weeks of this study * Patients who have not been on HAART for at least 6 weeks prior to randomization who are willing to delay initiation of HAART therapy for at least 6 weeks * Negative urine or blood pregnancy test (for women of childbearing potential) documented within the 24-hour period prior to the first dose of study drug * Willingness to give written informed consent Exclusion Criteria: * Women with ongoing pregnancy or breast feeding * Male partners of women who are pregnant * IFN/ribavirin therapy at any previous time * Child Pugh \> 6 (Child Pugh B or C) * History or conditions consistent with decompensated liver disease * Any investigational drug 6 weeks prior to the first dose of study drug (expanded access programs for HIV treatment are allowed) * Patients treated with didanosine and/or zidovudine * Positive test at anti-HAV IgM Ab, HBsAg, anti-HBc IgM Ab, HBeAg * History or other evidence of a medical condition associated with chronic liver disease other than HCV * Hepatocarcinoma observed in the liver ecography * Serum concentrations of ceruloplasmin or alfa1-antitrypsin at screening consistent with an increased risk of metabolic liver disease * Active HIV-related opportunistic infection and/or malignancy requiring acute systemic therapy * Absolute neutrophil count (ANC) \< 1500 cells/mm3 * Hgb \< 11 g/dL in women or 12 g/dL in men or any patient for whom anemia would be medically problematic * Hemoglobinopathy or any other cause of or tendency for hemolysis * Platelet count \< 50,000 cells/mm3 * History of G-CSF, GM-CSF or epo treatment during 3 months prior to the first dose of study drug * Serum creatinine level \> 1.5 times the upper limit of normal at screening * History of severe psychiatric disease, especially depression * History of a severe seizure disorder or current anticonvulsant use * History of immunologically mediated disease * History or other evidence of chronic pulmonary disease associated with functional limitation * History of significant cardiac disease that could be worsened by acute anemia * History of thyroid disease poorly controlled on prescribed medications * Evidence of severe retinopathy * History of major organ transplantation with an existing functional graft * History or other evidence of severe illness, malignancy or any other conditions which would make the patient, in the opinion of the investigator, unsuitable for the study * History of any systemic anti-neoplastic or immunomodulatory treatment 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 * Concomitant medication with rifampin/rifampicin, rifabutin, pyrazinamide, isoniazid, gancyclovir, thalidomide, oxymetholone, immunomodulatory treatments and systemic antiviral agents as adjuvant therapy for CHC * Drug use within 6 months of 1st dose and excessive alcohol consumption