Polyethylene glycol-interferon: current status in hepatitis C virus therapy.

In chronic hepatitis C infection, combination therapy with interferon (IFN)-alpha and ribavirin leads to sustained virological response rates of 40-45%. However, treatment outcome is still disappointing in patients infected with hepatitis C virus (HCV) genotype 1, high viral load or advanced liver fibrosis. Due to significant side-effects of therapy, dose reductions and discontinuations of therapy are frequent and lead to further decreased response rates. The development of modified IFN is the latest step to improve treatment options for chronic hepatitis C. Conjugation of the polymer polyethylene glycol (PEG) to IFN extends half-life in comparison to conventional IFN and thereby increases antiviral activity. It allows once-weekly dosing and increases sustained response rates without changing the safety profile. The PEG-IFN monotherapy is twice as effective as IFN-alpha three times weekly. The combination of PEG-interferon and ribavirin improves the overall sustained response rates to 54-56% and represents the new standard therapy for patients with chronic hepatitis C infection in most patients. Copyright 2002 Blackwell Publishing Asia Pty Ltd