Following multiple dosing of PegIntron (1.0 microgram/kg subcutaneously administered every week for four weeks) the clearance of PegIntron is reduced by a mean of 17% in patients with moderate renal impairment (creatinine clearance 30-49 ml/minute) and by a mean of 44% in patients with severe renal impairment (creatinine clearance 15-29 ml/minute) compared to subjects with normal renal function.