Meta-analysis: pegylated interferon α-2a achieves higher early virological responses than α-2b in chronic hepatitis C.

BACKGROUND: A Cochrane meta-analysis established that pegylated interferon α-2a is more effective than peginterferon α-2b in terms of sustained virological response (SVR) in the treatment of chronic hepatitis C. Rapid virological response (RVR) and early virological response (EVR) are crucial to reach SVR and to make clinical decisions. AIM: To compare RVR and EVR rates of peginterferon α-2a vs. peginterferon α-2b through a meta-analysis of previously published randomised control trials (RCT). METHODS: MEDLINE, EMBASE and LILACS databases were systematically searched up to September 2011. Seven RCT that reported complete early virological response (cEVR) were selected. A meta-analysis focusing on RVR and cEVR outcomes was conducted and Relative Efficacy (RE) was calculated. RESULTS: Meta-analysis of cEVR included seven trials (n = 4359), and yielded an estimated effect in favour of peginterferon α-2a: Crude Efficacy (CEf) was 53.3% vs. 43.8%, RE = 1.118 (CI 95% = 1.039-1.203; P = 0.0028), heterogeneity Q = 8.959; I² = 33.0% (P = 0.1759). A sub-analysis of three studies with 3409 genotype-1 patients yielded CEf: 49.4% vs. 40.2%, RE = 1.151 (CI 95% = 0.968-1.369; P = 0.1124), Q = 9.802; I² = 79.6% (P = 0.0074). Meta-analysis of RVR included five trials (n = 3833) with an estimated effect in favour of peginterferon α-2a: CEf = 25.0% vs. 16.8%, RE = 1.151 (CI 95%:1.042-1.272; P = 0.0056), Q = 1.461;I² = 0.0% (P = 0.8335). Analysis of four studies reporting RVR including 3499 patients with genotypes 1 and 4 resulted in CEf: 18.3% vs. 12.7% RE = 1.206 (CI 95% = 1.059-1.374; P = 0.0048), Q = 1.116; I² = 0.0% (P = 0.7733). CONCLUSIONS: Peginterferon α-2a may be associated with a higher cEVR and RVR than peginterferon α-2b. These findings could help to achieve higher SVR rates and support clinical decision-making in the present scenario of triple combination therapy.