Real-world evidence of treatment patterns and pharmacy costs among patients with metastatic castration-resistant prostate cancer (mCRPC) in a managed care population in the United States.

e19319 Background: Prostate cancer (PC) is the most common cancer among men in the United States. Once the disease progresses to mCRPC, initial castration modalities may not be sufficient. This real-world data study describes the treatment patterns and pharmacy costs of US-insured patients with mCRPC. Methods: Adult males in an administrative claims database who had ≥1 claim for PC (ICD-9: 185 or 233.4; ICD-10: C61 or D075), had undergone pharmacologic or surgical castration, and had a code for metastatic disease during the identification period were included in the analysis. A minimum of 6 months of continuous enrollment (CE) pre- and post-index date (first metastatic claim) was required. Patients with metastatic claims at baseline were excluded. Patients were followed until the earliest of death (unless prior to 6-month CE), end of study period, or disenrollment. Claims-based algorithms were used to identify locally advanced and distant mCRPC patients and lines of therapy (LOT). The entire study period (baseline period through follow-up) was January 2008-March 2018. Results: 3690 patients with mCRPC were identified, of which 3150 received at least one LOT; 85.4% had ≥1 LOT, 69.4% had ≥2 LOTs, and 50.7% had ≥3 LOTs following metastatic diagnosis (Table). The average duration of treatment was similar across groups: 83.8, 86.5, 71.7, and 70.2 days for LOTs 1–4, respectively. The five most common LOTs were leuprolide (36.6%), bicalutamide-leuprolide (6.6%), abiraterone (5.9%), bicalutamide (5.0%), and enzalutamide (4.7%). Mean monthly per-patient pharmacy costs increased with each LOT ($2683, $2654, $2911, $2924, $3611, for LOTs 1–5, respectively). Conclusions: This is the first study to examine treatment patterns and drug costs of patients with mCRPC. Given the large number of LOTs this population moves through and the increasing costs associated with each, the development of more efficacious novel therapies for use earlier in the metastatic treatment regimen to prolong life is warranted. [Table: see text]