Peginterferon Dose Evaluations for Previously Untreated Subjects With Chronic Hepatitis C Infected With Genotype 1 (Study P03471)

The objective is to compare the safety and efficacy of the following three treatment regimens in previously untreated adult subjects with chronic hepatitis C infected with Genotype 1: (1) PegIntron 1.5 µg/kg/wk in combination with weight based REBETOL (800-1400 mg/day); (2) PegIntron 1µg/kg/wk in combination with weight based REBETOL (800-1400 mg/day); and (3) PEGASYS 180 µg/wk plus COPEGUS 1000-1200 mg/day.

PegIntron Dose will be administered once weekly subcutaneously on the same day of the week: Screening 2 Weight 40-50 kg Volume to Inject (mL) 0.22; Screening 2 Weight 51-60 kg Volume to Inject (mL) 0.28; Screening 2 Weight 61-75 kg Volume to Inject (mL) 0.33; Screening 2 Weight 76-85 kg Volume to Inject (mL) 0.41; Screening 2 Weight 86-104 kg Volume to Inject (mL) 0.48; Screening 2 Weight 105-125 kg Volume to Inject (mL) 0.58 from two vials REBETOL Dosage (for Use With PegIntron): Screening 2 Weight 40-65 kg Daily Dose 800 mg; Screening 2 Weight \>65-85 kg Daily Dose 1000 mg; Screening 2 Weight \>85-105 kg Daily Dose 1200 mg; Screening 2 Weight \>105-125 kg Daily Dose 1400 mg The PEGASYS dose of 1 mL (180 µg) will be administered once weekly subcutaneously on the same day of the week COPEGUS Dosage (for Use With PEGASYS): Screening 2 Weight \<75 kg Daily Dose 1000 mg; Screening 2 Weight \> or = 75 kg Daily Dose 1200mg NOTE: Double Blind for PegIntron; Open Label for REBETOL, PEGASYS and COPEGUS NOTE: REBETOL is the Schering-Plough brand name for ribavirin. COPEGUS is the Hoffman-La Roche brand name for ribavirin.