Interferon-based therapy for hepatitis C virus infections

Abstract

Interferon-alpha (IFN-α) therapy was associated with normalization of alanine aminotransferase (ALT) in some patients diagnosed as having non-A, non-B hepatitis even before the hepatitis C virus (HCV) was identified as the chief etiologic agent in this diagnosis (Hoofnagle et al., 1986). In 1989, the first cases of successful treatment of documented chronic hepatitis C (CHC) with IFN-α were reported, although relapse after the cessation of treatment was common (Davis et al., 1989; Di Bisceglie et al., 1989). The introduction of combination therapy with IFN-α and ribavirin has markedly improved treatment response. However, more than one-half of patients with CHC remain unable to experience a favorable response to the combination therapy (Lai et al., 1996; McHutchison et al., 1998; Poynard et al., 1998). Until recently, the attachment of inert polyethylene glycol to conventional IFN-α-pegylated IFN-α (PegIFN-α)-reduced degradation and clearance, prolonging the half-life of IFN and permitting less frequent, weekly dosing while maintaining higher sustained IFN levels (compared with 3 times weekly for conventional IFN). Now, a PegIFN-α-ribavirin combination treatment has been recommended for all patients infected with HCV. For patients infected with HCV genotype 1 (HCV-1), the recommended treatment duration is 48 weeks, whereas for patients infected with HCV-2 or -3, the recommended treatment duration is 24 weeks (National Institutes of Health 2002; Strader et al., 2004). © 2008 Springer Science+Business Media, LLC.