Efficacy of interferon alpha-2b induction therapy before retreatment for chronic hepatitis C

Chronic hepatitis C (HCV) patients who have failed previous treatment have low sustained viral response (SVR) rates with repeat treatment. We evaluated whether interferon (IFN) induction during retreatment improves response rates.

Two randomized, controlled trials were conducted in chronic HCV patients who failed IFN. In Study 1, patients received IFN 3 MU daily plus ribavirin (RBV) 1000 mg/day for 4 weeks, followed by IFN 3 MU TIW plus RBV 1000 mg/day for 44 weeks (induction; n=232), or IFN 3 MU TIW plus RBV 1000 mg/day for 48 weeks (non-induction; n=237). In Study 2, patients received IFN 5 MU B.I.D. plus RBV 1000-1200 mg/day for 2 weeks, followed by pegylated IFN (PEG-IFN) 75-150 mug weekly plus RBV 1000-1200 mg/day for 46 weeks (induction; n=201), or PEG-IFN 75-150 mug weekly plus RBV 1000-1200 mg/day for 48 weeks (non-induction; n=206). The primary end point for both trials was SVR.

Induction did not increase SVR compared with non-induction, but did increase the on-treatment response among genotype non-1 patients in Study 2. By intention-to-treat (ITT) analysis, SVR in Study 1 was 13% for induction vs. 9% for non-induction (P=NS). In Study 2 (ITT), SVR was 20% for induction vs. 24% for non-induction (P=NS). However, by non-ITT analysis of Study 2, genotype non-1-previous non-responders showed significantly higher response rates with induction than non-induction.

For chronic HCV patients who have failed IFN, induction with retreatment does not improve SVR, but may be beneficial for patients with genotype non-1 HCV.