OBJECTIVES: mCRPC is a terminal disease, with a median survival of approximately 1 to 2 years. The AFFIRM study demonstrated that enzalutamide is highly efficacious, prolonging overall survival and progression-free survival compared to placebo in patients with mCRPC previously treated with docetaxel-based chemotherapy. The purpose of this analysis is to assess from the Canadian perspective the cost-effectiveness of enzalutamide 160mg once-daily compared with abiraterone acetate (AA) (+ prednisone) and intravenous (IV) cabazitaxel in mCRPC patients previously treated with docetaxel-based chemotherapy METHODS: A Markov model was developed to capture time spent by patients in various health states, including progression, progression free survival (PFS) and death. Results were reported as incremental costs per additional quality adjusted life-years (QALY) gained over a 10-year period. Transition probabilities were derived from patient-level data from AFFIRM and an indirect treatment comparison from available published literature. The base case analysis focused on direct medical costs from the perspective of the Canadian Ministry of Health (MoH), with the second analysis focusing on the societal perspective. Cost data for 2013, obtained from a variety of sources were reported as Canadian Dollars. A 5% discount rate was applied to both costs and patient outcomes. Multiple sensitivity analyses were undertaken to test the robustness of the model RESULTS: From the MoH perspective, enzalutamide had an incremental cost-utility ratio (ICUR) of $42,325 and $43,105 per additional QALY gained compared to AA and cabazitaxel, respectively.  Results were similar from the societal perspective. Results were robust over a wide range of one-way and probabilistic sensitivity analyses. In greater than 85% of iterations the incremental cost-effectiveness ratio ICER was below a willingness-to-pay threshold of $100,000 per QALY for the comparison versus either AA or cabazataxel. CONCLUSIONS: Enzalutamide is a cost-effective treatment compared to AA and cabazitaxel in mCRPC patients previously treated with docetaxel-based chemotherapy