Cost Effectiveness of Peginterferon alpha-2a Plus Ribavirin versus Interferon alpha-2b Plus Ribavirin as Initial Therapy for Treatment-Naive Chronic Hepatitis C

Introduction: In adults with previously untreated chronic hepatitis C (CHC), the combination of peginterferon alpha-2a plus ribavirin produces a higher rate of sustained virological response (SVR) than interferon alpha-2b plus ribavirin, but it is still unproven whether this increase is cost effective. The objective of this study was to determine if the gain in SVR with peginterferon alpha-2a plus ribavirin is worth the incremental cost. Methods: We constructed a Markov model of disease progression in which cohorts of patients received peginterferon alpha-2a plus ribavirin or interferon alpha-2b plus ribavirin for 48 weeks (hepatitis C virus [HCV] genotype 1 and non-1 patients with fibrosis) or 24 weeks (genotype non-1 patients without fibrosis), and were followed for their expected lifetimes. The reference patient was a 45-year-old male with CHC without cirrhosis. The SVRs with peginterferon alpha-2a plus ribavirin and interferon alpha-2b plus ribavirin used to populate the model were 46% and 36% for patients infected with HCV genotype 1 and 76% and 61% for patients infected with HCV non-1 genotypes, respectively. QOL and costs for each health state were based on literature estimates and on Italian treatment patterns. Costs were in 2002 euros and benefits were discounted at 3%. Sensitivity analyses on key clinical and economic parameters were performed. The analysis was reported from the perspective of the Italian National Health Service. Results: In patients infected with HCV genotype 1, peginterferon alpha-2a plus ribavirin increased life-years (LYs) by 0.78 years and QALYs by 0.67 years, compared with interferon alpha-2b and ribavirin. The incremental cost per LY and QALY gained was Conclusion: Our model suggests that peginterferon alpha-2a plus ribavirin is cost effective compared with conventional interferon alpha-2b plus ribavirin for treatment of naive adults with CHC, regardless of HCV genotype, under a wide range of assumptions regarding treatment effectiveness and costs.