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

Abstract

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-naïve mCRPC patients treated with enzalutamide or abiraterone acetate in the USA.MethodsChemotherapy-naïve mCRPC patients initiating treatment with enzalutamide or abiraterone acetate were identified from administrative claims. Continuous enrollment ≥ 6 months before and ≥ 3 months 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, 920 chemotherapy-naïve patients initiated enzalutamide and 2310 initiated abiraterone acetate (median follow-up, 10.7 and 13.5 months, respectively). More enzalutamide-treated patients had corticosteroid-sensitive comorbidities at baseline. Treatment duration was longer with enzalutamide versus abiraterone acetate (median, 10.7 vs. 8.8 months; 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-naïve 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.Electronic supplementary materialThe online version of this article (10.1007/s12325-018-0774-1) contains supplementary material, which is available to authorized users.

Economic Outcomes in Patients with Chemotherapy-Naïve Metastatic Castration-Resistant Prostate Cancer Treated with Enzalutamide or Abiraterone Acetate Plus Prednisone

“…Our results were based on real-world data including patients who may not be eligible for clinical trials, which may have led to more frequent HCRU and higher costs compared with a model based on a healthier patient population. Findings of lower all-cause emergency room and PC-related inpatient costs in enzalutamide-treated patients have also been previously reported, although these patients incurred higher all-cause and PC-related pharmacy costs [ 18 ], whereas in our study, enzalutamide-treated patients had lower costs in all categories.…”

“…There were fewer all-cause outpatient and pharmacy visits for enzalutamide-treated patients compared with abiraterone-treated patients. Schultz et al also found that treatment with enzalutamide, despite a higher occurrence of comorbid conditions, was associated with fewer inpatient and emergency department visits than abiraterone, likely attributed to corticosteroid use among abiraterone-treated patients [18]. In our PSM-matched cohorts, more abiraterone-treated patients used corticosteroids during the pre-index period than did enzalutamide-treated patients (45.69% vs 26.90%, respectively).…”

“…Very few real-world studies have assessed HCRU and costs of novel therapies in mCRPC in the USA. A recent study, using real-world data from patients with chemotherapy-naïve mCRPC in a commercially insured population, reported lower HCRU and PC-related inpatient and emergency department costs for enzalutamide compared with abiraterone [ 18 ]. Another recent real-world study described treatment patterns, healthcare costs, and survival in patients with mCRPC who were commercially insured or Medicare covered and showed that enzalutamide and abiraterone were the most common first-line treatments (more than 65% in total); however, no direct cost comparisons between the treatments were reported [ 19 ].…”

Real-World Treatment Patterns Among Patients Initiating Small Molecule Kinase Inhibitor Therapies for Thyroid Cancer in the United States

“…Treatment duration is a composite measure that does not distinguish between efficacy, tolerability and other causes of therapy discontinuation. However, it is a commonly reported metric in clinical trials and often a key outcome in observational studies of oncology treatments [30–33]. Kaplan–Meier estimates of median time to discontinuation differed significantly by regimen in the first line of therapy: sorafenib had the shortest estimate (2.8 months) and vandetanib had the longest estimate (16.2 months).…”

Treatment-Related Healthcare Costs of Metastatic Castration-Resistant Prostate Cancer in Germany: A Claims Data Study

“…Focusing on COI analyses in the field of mCRPC, a recently published worldwide review [14] reported a broad range of cancer-specific healthcare costs, depending on the characteristics of included patients. However, only few studies have stratified costs by treatment, with most focusing exclusively on selected treatments-for example, hormonal therapy [15][16][17]-only considering pharmacy costs [15,18,19], and/or estimating costs for a hypothetical patient population (literaturebased cost analysis) [16,20]. Since mCRPC healthcare costs have not previously been reported for Germany [14,21] and the evidence for real-world outcomes of mCRPC stratified by contemporary treatment are limited, this study's purpose is to analyze the healthcare resource utilization (HRU) for patients with mCRPC and the costs of treatment with cabazitaxel, docetaxel, abiraterone, and enzalutamide in comparison with BSC.…”