Up to 105 patients with chronic hepatitis C will be enrolled in a study of the combination of pegylated alpha interferon and ribavirin for 48 weeks with the option of early discontinuation of therapy for patients who do not respond within 24 weeks of starting therapy. Adult patients will be chosen who have chronic hepatitis C, HCV RNA in serum, HCV genotype 1 and liver histology showing chronic hepatitis C. Patients with advanced liver disease and clinical decompensation and patients who have received alpha interferon in the past will not be eligible. The 100 patients will consist of four groups: Groups A, B and D will comprise 25 patients each with typical uncomplicated chronic hepatitis C; Group C will comprise 25 patients with renal insufficiency or renal failure on chronic dialysis awaiting kidney transplantation. Group D will comprise up to 30 patients with typical uncomplicated chronic hepatitis C. After medical evaluation and liver biopsy, patients will begin receiving pegylated alpha interferon (peginterferon) by subcutaneous injection in a dose of 180 mcg per week. After the initial injection, patients will have blood taken and symptoms recorded at 12, 24, 48, 72 hours and weekly thereafter for four weeks. Patients in Groups A, B and C will receive peginterferon weekly, whereas patients in Group D will receive it twice weekly in a reduced dose (90 mcg per injection) for the first 4 weeks of treatment and weekly in a dose of 180 mcg per injection thereafter. Patients in Groups A and D will also begin receiving ribavirin orally in a dose of 1000 mg (if body weight is less than 75 kg) or 1200 mg daily (if body weight greater than or equal to 75 kg) given in capsules of 200 mg twice daily starting with the first dose of peginterferon. Patients in Group B will start ribavirin in the doses given above after the first month of therapy (with the fifth injection: week 4). Patients in Group C (renal disease) will start ribavirin in a dose of 200 mg daily after the first month (week 4) of therapy; in this group the dose of ribavirin will be gradually increased at 4 week intervals on the basis of tolerance (hemolysis and anemia). During the initial 24-week period of combination therapy, patients will be seen in the outpatient clinic for medical interview, physical examinations and blood tests at 2 to 4 week intervals. At 24 weeks, patients will be classified as either responders or non-responders based upon HCV RNA testing. Both groups will be offered therapy for another 24 weeks (total treatment = 48 weeks). Because sustained responses are rare in patients who have not become HCV RNA negative by 24 weeks, non-responders will be offered the option of stopping therapy early and being followed on no therapy. After stopping therapy, patients will be followed at 1 to 2 month intervals and undergo repeat medical evaluation (without liver biopsy) at the 72 week point (18 months after enrollment).

The primary criterion for success of therapy overall will be sustained loss of HCV RNA as assessed at 18 months. Secondary criteria will be normalization of ALT levels and improvement of symptoms. This study will allow for therapy of patients with chronic hepatitis C with the combination of peginterferon and ribavirin demonstrating whether early viral kinetics are predictive of outcome of therapy. This study will also allow for comparison of the kinetics of loss of HCV RNA comparing peginterferon alone to peginterferon with ribavirin, peginterferon given once weekly to peginterferon given twice weekly, and comparing kinetics between patients with and without renal disease. The study will also allow for assessment of the safety of addition of ribavirin in patients with renal compromise.