A randomized 4-arm multicenter study of interferon alfa-2b plus ribavirin in the treatment of patients with chronic hepatitis C relapsing after interferon monotherapy.

To determine whether a higher dosage of interferon (IFN) and/or a prolonged time of administration may improve the efficacy of combination therapy, we conducted a 4-arm randomized trial on patients with chronic hepatitis C relapsing after 1 or more previous treatment courses with IFN monotherapy. Group A (n = 70) received 3 MU IFN alfa-2b 3 times per week plus ribavirin 1,000 mg/d for 12 months; group B (n = 70) received 5 MU 3 times per week plus ribavirin for 12 months; group C (n = 82) received 3 MU 3 times per week plus ribavirin for 6 months, and group D (n = 73) received 5 MU 3 times per week plus ribavirin for 6 months. The primary end point was the clearance of viremia at the end of 6-month follow-up: test results for hepatitis C virus (HCV)-RNA were negative in 54% of group A, 56% of group B, 40% of group C, and 49% of group D patients (P = NS). Among patients with genotype 1 and 4, the sustained response was significantly higher in groups A and B than in group C (45%, 49% vs. 22%, P =.03; group D = 33%, P = NS). In patients with genotype 2 and 3, the sustained virologic response was not affected by the different regimens (group A = 69%, group B = 68%, group C = 62%, group D = 71%, P = NS). In conclusion, duration of therapy rather than IFN dosage is more important in increasing the sustained virologic rate among HCV-positive patients with genotype 1 and 4 relapsing after IFN monotherapy; patients with genotypes 2 and 3 can be effectively retreated with a 6-month course of combination therapy, avoiding unnecessary side effects and waste of resources.