Healthcare Costs for Metastatic Castration-Resistant Prostate Cancer Patients Treated with Abiraterone or Enzalutamide

Objective The aim was to assess the real-world healthcare resource use and direct medical costs for metastatic castration-resistant prostate cancer (mCRPC) patients treated with abiraterone or enzalutamide, in whom chemotherapy is not yet indicated (pre-chemotherapy) or who had previously received docetaxel-based chemotherapy (post-chemotherapy), before commencing these medicines. Methods A retrospective cost analysis of mCRPC patients who commenced abiraterone or enzalutamide between 2012 and 2015 was conducted. Routinely collected datasets from the largest health board in Scotland and the UK, Greater Glasgow and Clyde, were linked. They contained information on patient demographics, diagnosis, outpatient consultations, hospital admissions, treatments (abiraterone and enzalutamide), and supportive medicines. Unit costs were obtained from the Scottish Health Service Costs, Personal Social Services Research Unit, and British National Formulary. Generalised linear model-based regression was used to estimate total mean direct costs, and two-part models were used to estimate separate cost components. All models were adjusted for propensity score and key variables. Sensitivity analysis was conducted to explore the impact of hypothetical patient access scheme discounts. Results Estimated total mean direct medical costs of treating mCRPC patients were similar, albeit with wide and overlapping confidence intervals. Across both treatments, patients who received abiraterone or enzalutamide in a pre-chemotherapy setting incurred the highest total mean direct medical costs. However, post-chemotherapy patients were associated with higher outpatient clinic visits, inpatient hospital admissions, and supportive medicines. Regarding relative contribution to the total mean direct medical cost, the treatment costs were the main contributor, followed by inpatient admissions, outpatient clinic visits, and supportive medicines. Conclusion The total mean direct medical costs were similar for abiraterone and enzalutamide patients. The costs were not driven by the choice of treatment regimen, but treatment setting (pre-chemotherapy or post-chemotherapy indications) and related healthcare resource utilisation. Future studies should focus on economic evaluations, such as cost-effectiveness analyses, using real-world data.