A randomized, double-blind controlled trial of interferon alpha-2b and ribavirin vs. interferon alpha-2b and amantadine for treatment of chronic hepatitis C non-responder to interferon monotherapy

Background/Aims: Interferon-based regimens (alone or with ribavairin) are standard therapies for chronic hepatitis C. The aim of this study was to compare a 24-week regimen of interferon alpha-2b+ribavirin (IFN+RIBA) to interferon alpha-2b+amantadine (IFN+AMANT) in non-responders to previous interferon monotherapy. Methods: In a multi-center, double-blind clinical trial, 118 patients (non-responders to previous interferon monotherapy) were equally randomized into the two arms: interferon alpha-2b (3 MU thrice weekly) and ribavirin (800 mg daily) vs. interferon alpha-2b (3 MU thrice weekly) and amantadine (200 mg daily). Results: After 24 weeks of therapy, HCV RNA became undetectable in 34.8% (95% CI: 23.7–49.2) of IFN+RIBA and 19.6% (95% CI: 10.6–34.7) of IFN+AMANT (P=0.10). This response was sustained in 3.9% (95% CI: 1.0–14.9) of IFN+RIBA and 0% of IFN+AMANT (P=0.16). Ten patients from IFN+AMANT (17%) and 12 patients (20%) from IFN+RIBA were discontinued before completion of therapy. Of these, 7% in IFN+AMANT and 12% in IFN+RIBA were discontinued due to adverse effects. Conclusions: Re-treatment of interferon non-responders with a 24-week course of IFN+AMANT was not associated with any sustained viral eradication. Although IFN+RIBA in this group was associated with a reasonable end of treatment response, relapses were common and sustained responses were low.