Improved Sustained Virological Response Following Treatment with Pegylated-Interferon Alpha-2b Compared with Alpha-2a, Both with Ribavirin, for Chronic Hepatitis C Infection with Genotypes 2 and 3

Purpose: The optimal formulation of pegylated interferon a (PEG-IFa) as a part of combination therapy with ribavirin (RBV) is uncertain for patients infected with hepatitis C Genotypes 2 and 3. Methods: A multivariate analysis of prospectively collected treatment data from two tertiary centres on 351 treatment na?ve HCV Genotype 2 or 3 patients who received PEG-IFa-2a or b plus ribavirin. Results: Univariate analyses demonstrate that PEG-IFa-2b based on regimens achieved a higher sustained virological response (SVR) than PEG-IFa-2a (77.9% versus 62.0%, P = 0.0012). On multivariate analyses, PEG-IFa-2b appeared superior to PEG-IFa-2a with an odds ratio (OR) and 95% confidence interval (CI95) for SVR of 2.19 (CI95 1.35-3.52, P = 0.0005). Genotype was a significant predictor of outcome in the multivariate model with 80% of Genotype 2 but only 67.7% of Genotype 3 subjects achieving SVR (OR 2.66 [CI95 1.35-5.92]). Increasing age was negatively associated with SVR (OR 0.97 [CI95 0.94-0.99]). Some of the differences in SVR are explained by higher relapse rates with PEG-IFa-2a (P = 0.009). Conclusions: PEG-IFa-2b and RBV achieve higher SVR rates than PEG-IFa-2a and RBV in Genotypes 2 and 3 chronic HCV infections. There is less relapse with PEG-IFa-2b. Genotype 2 infections are considerably easier to cure. SVR is higher in younger patients. These findings should influence a choice of PEG-IFa in the era of direct acting anti-viral drugs in therapy of Genotypes 2 and 3.