Treatment Patterns and Survival Outcomes Among Androgen Receptor Pathway Inhibitor-Experienced Patients With Metastatic Castration-Resistant Prostate Cancer

Among 804 US patients with metastatic castration-resistant prostate cancer previously treated with androgen receptor pathway inhibitors (ARPIs), 57.1% received another ARPI and 23.9% switched to chemotherapy. Median time on treatment (4.1 months) and overall survival (15.2 months) were short, highlighting the need for additional, effective therapies. Background: There is limited real-world data regarding subsequent treatment utilization and clinical outcomes following initial androgen receptor pathway inhibitor (ARPI) exposure for the treatment of advanced prostate cancer. This study aimed to address this evidence gap. Methods: Electronic health records during 01/01/2013-07/31/2022 from Flatiron Health were used to identify adults with mCRPC, who had prior exposure to ARPIs (irrespective of the setting) and >= 1 post-ARPI line of therapy (LOT) in the mCRPC setting (index therapy: the first eligible LOT in the mCRPC setting). Treatment patterns and survival outcomes following the initiation of index therapy were reported. Results: Among 804 ARPI-experienced mCRPC patients, 459 patients (57.1%) received another ARPI as their index therapy and 192 (23.9%) received chemotherapy as their index therapy. In the overall population, median time on the index therapy and median time from index therapy to next therapy were 4.1 and 6.2 months, respectively. Median overall survival and radiographic progression-free survival from the initiation of index therapy were 15.1 and 7.0 months, respectively. Conclusions: In this real-world analysis, more than half of patients attempted at least 1 additional ARPI in the mCRPC setting, despite prior treatment with ARPIs. The short treatment duration and survival time highlight the unmet need for additional, effective therapies that may improve clinical outcomes in this population.