A randomized trial of induction doses of interferon alone or in combination with ribavirin or ribavirin plus amantadine for treatment of nonresponder patients with chronic hepatitis C

Background Efficacy and safety of interferon induction therapy alone or in combination with ribavirin or ribavirin plus amantadine were evaluated in chronic hepatitis C patients who were nonresponders to primary antiviral treatment. Methods The study was designed to have 225 HCV nonresponder patients, but at an interim analysis the response rate difference between groups was lower than expected and the enrollment was stopped when 75 patients had been randomized to receive interferon-α2a (group A, n = 26), interferon-α2a plus 15 mg/kg per day of ribavirin (group B, n = 24), or interferon-α2a plus ribavirin plus 200 mg/day of amantadine hydrochloride (group C, n = 25). Treatment duration was 48 weeks. The dose of interferon was 6 MU/day for 4 weeks followed by 3 MU/day for the remaining 44 weeks. Results On intention-to-treat, the sustained virological response at 24 weeks of follow-up was 11.5% in group A, 12.5% in group B, and 12% in group C. Therapy was discontinued because of adverse effects in three patients in group A (11.5%), three in group B (12.5%), and two in group C (8%). Conclusions Nonresponders with chronic hepatitis C may achieve a sustained virological response rate of approximately 12% if retreated with interferon induction treatment followed by administration of a daily dose. The addition of ribavirin or amantadine did not seem to improve the response rates.