Comparison of peginterferon alfa-2a and alfa-2b for treatment of patients with chronic hepatitis C:a retrospective study using the Japanese Interferon Database

Izumi Sato,1 Takuro Shimbo,2 Yohei Kawasaki,3 Naohiko Masaki41Department of Clinical Study and Informatics, Center for Clinical Sciences, National Center for Global Health and Medicine, Tokyo, Japan; 2Ohta Nishinouchi Hospital, Fukushima, Japan; 3Department of Mathematics, Tokyo University of Science, Tokyo, Japan; 4The Research Center for Hepatitis and Immunology, National Center for Global Health and Medicine, Chiba, JapanPurpose: We aimed to compare the rates of sustained virologic response (SVR) achieved with peginterferon (PEG-IFN) alfa-2a and alfa-2b in combination with ribavinin (RBV) for chronic hepatitis C, using a large database of hepatitis cases to improve the generalizability of these results.Methods: We identified patients with chronic hepatitis C who were treated with PEG-IFN alfa-2a or alfa-2b and RBV, from the Japanese Interferon Database, between December 2009 and April 2013. This database contains the medical records of IFN treatment collected from 36 prefectures in Japan. Multivariable logistic regression analysis was used to compare SVR rates obtained with PEG-IFN alfa-2a and alfa-2b, in combination with RBV. Results: A total of 16,349 patients were recorded in the Japanese Interferon Database. After application of the exclusion criteria, 12,706 patients (3,578 [1,710 males, 1,868 females] on PEG-IFN alfa-2a; and 9,128 [4,652 males, 4,476 females] on PEG-IFN alfa-2b) were included in this analysis. The SVR rate in the PEG-IFN alfa-2b group was 62.0%, as compared with a rate of 55.1% in the PEG-IFN alfa-2a group (crude odds ratio =1.31; 95% confidence interval [CI]: 1.23 to 1.44). There was no significant difference in the adjusted SVR rates between the two groups (adjusted odds ratio =0.96; 95% CI: 0.88 to 1.05). Similar proportions of adverse events were observed in the two groups, with the exception of thrombocytopenia, retinopathy, and anemia.Conclusion: There was no significant difference in the SVR rates and safety profile between chronic hepatitis C patients treated with the PEG-IFN alfa-2a and alfa-2b.Keywords: sustained virologic response, HCV genotype, sustained virologic response, adverse event