Meta–Analysis of Interferon Randomized Trials in the Treatment of Viral Hepatitis C: Effects of Dose and Duration

Abstract

The aims of this study were to evaluate the benefits of higher doses or of longer duration in comparison with a standard interferon regimen (3 MU three times per week for 6 months) in chronic hepatitis C, and to assess the efficacy of interferon in acute hepatitis C. Meta–analysis made use of the Peto et al. and the Der Simonian and Laird methods, with heterogeneity and sensitivity analyses. In chronic hepatitis, a total of 17 trials versus controls and of 16 trials comparing different interferon regimens were included. Standard regimen, 3 MU three times per week for 6 months, was associated with an increase of the complete alanine transaminase (ALT) response rate and sustained (ALT) response rate by 45% (95% confidence interval: 35% to 55%; P < .001) and 21% (13% to 28%; P < .001), respectively, with the natural course being less than 2% of spontaneous responses. There was a significant dose effect (6 vs. 3 MU three times per week) upon the sustained response rate at 12 months, with a mean 17% increase (7% to 28%; P < .001), but not at 6 months. There was a significant duration effect (12 vs. 6 months) upon the sustained response rate both at the dose of 3 MU with a mean of 16% (9% to 23%; P < .001), and at the dose of 6 MU three times per week with a mean of 20% (7% to 33%; P = .003). In acute hepatitis C, 3 months of interferon treatment showed significant efficacy versus controls (4 trials), upon the complete ALT response (69% vs. 29%; P < .001), the sustained response rate during the 12 months following treatment (53% vs. 32%; P = .02), and hepatitis C virus (HCV)–RNA clearance (41% vs. 4%; P < .001). The best efficacy/risk ratio was in favor of 3 MU three times per week for at least 12 months in patients with chronic hepatitis C who had never been treated with interferon. Patients with acute hepatitis should be treated with at least 3 MU three times per week for 3 months.