Treatment Duration, Healthcare Resource Utilization, and Costs Among Chemotherapy-Naive Patients with Metastatic Castration-Resistant Prostate Cancer Treated with Enzalutamide or Abiraterone Acetate: A Retrospective Claims Analysis

摘要

IntroductionEnzalutamide and abiraterone acetate (plus prednisone) are new hormonal treatments for metastatic castration-resistant prostate cancer (mCRPC). This study compared treatment duration, healthcare resource utilization (HRU), and treatment costs for chemotherapy-naive mCRPC patients treated with enzalutamide or abiraterone acetate in the USA.MethodsChemotherapy-naive mCRPC patients initiating treatment with enzalutamide or abiraterone acetate were identified from administrative claims. Continuous enrollment 6months before and 3months after the index date (initiation date of enzalutamide or abiraterone acetate) was required. Treatment duration, all-cause and prostate cancer-related HRU, and costs were estimated during the post-index period. Multivariable analyses compared HRU and costs between cohorts, adjusting for baseline characteristics.ResultsOverall, 920chemotherapy-naive patients initiated enzalutamide and 2310 initiated abiraterone acetate (median follow-up, 10.7 and 13.5months, respectively). More enzalutamide-treated patients had corticosteroid-sensitive comorbidities at baseline. Treatment duration was longer with enzalutamide versus abiraterone acetate (median, 10.7 vs. 8.8months; P=0.008). Enzalutamide was associated with fewer all-cause inpatient admissions [adjusted incidence rate ratio (95% confidence interval) 0.87 (0.76, 0.99)], days of hospitalization [0.84 (0.70, 1.02)], and outpatient visits [0.94 (0.90, 0.98)], and fewer prostate cancer-related outpatient visits [0.92 (0.87, 0.96)] compared with abiraterone acetate. Enzalutamide was also associated with lower prostate cancer-related inpatient and emergency department costs [adjusted differences, $122 (P=0.024) and $28 (P=0.009), respectively].ConclusionChemotherapy-naive mCRPC patients treated with enzalutamide versus abiraterone acetate had longer treatment duration and incurred lower HRU and prostate cancer-related inpatient and emergency department costs.FundingAstellas Pharma Inc.