In clinical trial C/I98-580, 1,530 naïve patients were treated for one year with one of the following combination regimens: • Rebetol (800 mg/day) + peginterferon alfa-2b (1.5 micrograms/kg/week) (n = 511). • Rebetol (1,000/1,200 mg/day) + peginterferon alfa-2b (1.5 micrograms/kg/week for one month followed by 0.5 microgram/kg/week for 11 months) (n = 514). • Rebetol (1,000/1,200 mg/day) + interferon alfa-2b (3 MIU three times a week) (n = 505).