Background/aims: Retreatment of relapses of chronic hepatitis C with a standard regimen of interferon plus ribavirin for 6 months obtains a sustained response in a minority of patients with high viraemia and genotype 1b. We aimed to assess whether increasing the interferon dose and prolonging the time of combined treatment may enhance the effectiveness, and also to evaluate the tolerability, and to identify the determinants of sustained response.
Methods: Fifty subjects with chronic hepatitis C who had relapsed after one or more courses of a-interferon monotherapy were randomised to receive alpha2b interferon (6 MU tiw) plus ribavirin (1000-1200 mg daily) for 6 or 12 months. ALT normalisation and serum HCV-RNA clearance at the end of treatment and 6 months after stopping therapy were used as markers for sustained response.
Results: End-of-treatment response was achieved in 48 patients (96%) and 27 (54%) had a complete sustained response. Patients treated for 12 months had a higher rate of sustained response (18/25, 72%; 95% C.I. 0.54-0.89) than those treated for 6 months (9/25, 36%; 95% C.I. 0.17-0.55, p=0.01). Twelve months of therapy was significantly more effective for patients with genotype 1b and baseline serum HCV-RNA greater than 450 000 copies/ml (p=0.005). Seven subjects (14%) discontinued treatment because of side effects. Logistic regression analysis showed 12 months of therapy, young age and low pre-treatment serum HCV-RNA to be independent predictors of sustained response.
Conclusions: Relapsers with genotype 1b and high levels of HCV-RNA will benefit from a 12-month course of 6 MU tiw interferon plus ribavirin, while subjects with genotype 1b and low levels of serum HCV-RNA or with genotype other than 1b may be treated for 6 months.