Real-world clinical and economic outcomes in chemotherapy-naïve patients with metastatic castration-resistant prostate cancer

Background Real-world treatment and outcomes for patients with metastatic castration-resistant prostate cancer (mCRPC) are evolving.Research design and methods This retrospective study used data from the US Surveillance, Epidemiology, and End Results–Medicare Database (01/01/2009–12/31/2019). Patients with mCRPC who previously received one androgen receptor pathway inhibitor (ARPI) followed by either a second ARPI (ARPI cohort) or a taxane (taxane cohort) were included. Treatment patterns, serious adverse events (SAEs [based on hospitalization or ER claim]), healthcare resource utilization (HCRU), and costs were evaluated descriptively, with Kaplan–Meier analysis for overall survival (OS).Results Of 923 patients, 714 were in the ARPI cohort and 209 in the taxane cohort. Overall, 33.3% vs 53.6% of patients in the ARPI vs taxane cohorts received a subsequent treatment (p < 0.001), most commonly taxanes in both cohorts. Median OS was ≈1 year in both cohorts. SAEs were more frequent in the taxane cohort (66.0% vs 42.2%; p < 0.001). The taxane cohort had more ER, outpatient, and pharmacy visits (p < 0.0001), while the ARPI cohort had more hospitalizations (p < 0.0001).Conclusions Results demonstrate that patients with mCRPC receiving common treatment sequences have suboptimal survival, frequent SAEs, and high HCRU and costs. Interpretation is limited by historical data and residual confounding.