Pharmacoeconomic aspects of using enzalutamide for treatment of patients with nonmetastatic castration-resistant prostate cancer

Abstract

Background. Prostate cancer is one of the most common malignant diseases among men. Until recently, the most common treatment of nonmetastatic castration-resistant prostate cancer (nmCRPC) in Russia was to continue previously started hormonal therapy. Enzalutamide is a second-generation anti-androgen indicated for treatment of CRPC, regardless of a patient’s metastatic status, which significantly increases metastasis-free survival in nmCRPC compared with androgen deprivation therapy (ADT).Objective: to evaluate the incremental cost-effectiveness ratio (ICER) of enzalutamide use in patients with nmCRPC and the ICER of abiraterone as the first-line therapy for mCRPC from the Russian healthcare system perspective.Materials and methods. Standard ADT regimens for nmCRPC were used as a comparator as it was the only approved treatment for nmCRPC in Russia. We proposed a Markov model of CRPC progression on enzalutamide plus ADT (hereinafter enzalutamide) or ADT based on PROSPER trial data. Model was used to calculate progression-free life years and costs of nmCRPC and post-progression CRPC treatment. Simulation period was 5 years with one cycle of 1 month. In the “cost–effectiveness” analysis, we calculated enzalutamide ICER compared to ADT. In addition, we calculated ICER for abiraterone plus ADT and prednisolone (hereinafter abiraterone) vs ADT + prednisolone in the first-line therapy of metastatic CRPC (mCRPC) as a benchmark. In both cases, time to disease progression over a 5-year period was used as an efficacy criteria.Results. According to the Markov model, progression-free life-years gained for enzalutamide were 3.12 years compared to 1.79 for ADT within a 5-year period. The average enzalutamide therapy costs were 7,989,475.8 rubles/1 patient for 5 years, which were 5,716,983.5 rubles higher than when using ADT (2,272,492.3 rubles). ICER for enzalutamide (vs ADT) was 4,307,136.3 rubles per one progression-free life-year gained. ICER for abiraterone in the first line of mCRPC treatment (vs ADT + prednisolone) was 6,191,617.4 rubles per one progression-free life-year gained.Conclusion. In the Russian healthcare system, ICER for enzalutamide in nmCRPC was 4,307,136.3 rubles and the ICER for abiraterone in mCRPC was 6,191,617.4 rubles.