A comparison of peginterferon α-2a and α-2b for treatment-naive patients with chronic hepatitis C virus: A meta-analysis of randomized trials

Background: The standard treatments for chronic infection with the hepatitis C virus (HCV) are peginterferon α-2a or α-2b plus ribavirin, but it remains unclear if one has a better efficacy and safety profile. Objective: The aim of this study was to perform a meta-analysis of randomized controlled trials (RCTs) comparing peginterferon α-2a and α-2b (in combination with ribavirin) treatments for chronic HCV. Methods: The Cochrane Central Register of Controlled Trials, MEDLINE, Science Citation Index, and EMBASE were searched (1966–April 2010) to identify RCTs that evaluated the sustained virologic response (SVR) to peginterferon α-2a and peginterferon α-2b in patients with chronic HCV. The inclusion criteria were: RCT studies designed to compare the therapeutic effects of peginterferon α-2a (180 μg/wk) and peginterferon α-2b (1.5 μg/kg/wk) for treatment-naive patients with chronic HCV; patients treated for ≥24 weeks if infected with HCV genotypes 2 or 3 and for ≥48 weeks if infected with genotypes 1 or 4, with 24-week follow-ups; and publications written in any language. Reports of duplicated studies were excluded by examining the author list, parent institution, sample size, and results. The primary outcome was the SVR, and the other measures included the liver-related morbidity, all-cause mortality, and adverse events leading to treatment discontinuation. Results: The literature search yielded 5580 studies, and 7 RCTs comprising 3212 patients matched the inclusion/exclusion criteria. Overall, the SVR rate was significantly higher in patients treated with peginterferon α-2a than in patients treated with peginterferon α-2b (50% vs 46%, respectively; relative risk [RR] = 1.11; 95% CI, 1.02–1.20; P < 0.05) and varying levels of ribavirin treatment. The subgroup analysis found that, in patients with genotypes 1 or 4, the difference between SVR rate in patients treated with peginterferon α-2a and patients treated with peginterferon α-2b was not statistically significant (43% vs 39%; RR = 1.25; 95% CI, 0.99–1.57). A significantly higher SVR rate was achieved in the HCV patients with genotypes 2 or 3 treated with peginterferon α-2a compared with the patients treated with peginterferon α-2b (86% vs 77%; RR = 1.11; 95% CI, 1.02–1.22; P = 0.02). The meta-analysis of adverse events leading to treatment discontinuation revealed no significant differences between the 2 treatments. Conclusions: The evidence reviewed in this meta-analysis suggests that peginterferon α-2a treatment was associated with a higher SVR rate than peginterferon α-2b treatment in patients with chronic HCV also treated with ribavirin. However, the available evidence on adverse events was insufficient to make recommendations. [Copyright &y& Elsevier]