OBJECTIVES: In ALSYMPCA, radium-223+BSoC significantly prolonged overall survival by 3.6 months (HR=0.70; 95% CI, 0.58-0.83; P<0.001). Analysis of prospectively collected medical resource utilization (MRU) data from ALSYMPCA demonstrated that radium-223+BSoC vs BSoC reduced overall MRU, including number of hospitalization days/patient/year (8.1 vs 14.6; P<0.001). An existing cost-effectiveness analysis (CEA) model was modified by incorporating the prospective MRU data from ALSYMPCA to evaluate their effect on estimated cost-effectiveness of radium‑223+BSoC vs placebo+BSoC in Canada. METHODS: A Markov model was developed with 5 health states, reflecting disease progression and SSEs. The Canadian payer perspective was used. Quality of life data were from ALSYMPCA; cost inputs were from recognized Canadian sources. Costs and outcomes were discounted at a 5% annual rate. Model time horizon was 5 years. RESULTS: Incorporating MRU data reduced the incremental cost estimate by $11,065 relative to CEA without MRU data and improved the incremental cost-effectiveness ratio for radium-223+BSoC vs placebo+BSoC by ~35% to $73,408 ($20,098 incremental cost, 0.274 quality-adjusted life years [QALYs] gained), substantially lower than the frequently referenced, although not explicitly stated, Canadian cancer drug threshold ($100,000/QALY). Sensitivity analyses demonstrated robustness of cost-effectiveness results. Patient management costs were affected primarily by differential hospital utilization between treatment groups. CONCLUSIONS: Including directly observed MRU data in this model markedly improved the impact of radium-223 vs modeled benefits alone, confirming its cost-effectiveness as a treatment for CRPC with symptomatic bone metastases and no visceral metastases. Reduced hospital utilization with radium-223 may be driven by delays in time to symptomatic skeletal event (SSE) and reduced hospitalization days/patient/year after SSE (Cislo et al. ASCOQCS 2014).