Martin Schoen, MD, PhD, on selecting among ARPIs in prostate cancer

In this video, Martin Schoen, MD, PhD, discusses factors that influence the selection of androgen receptor pathway inhibitors (ARPIs) in prostate cancer and the role of real-world evidence in comparing these agents. Schoen is a medical oncologist at the VA Medical Center and a professor at Saint Louis University in St. Louis, Missouri.

With 4 ARPIs now widely used in clinical practice, Schoen explains that treatment selection often depends on the disease setting and the evidence supporting each agent in a particular clinical scenario. In castration-resistant prostate cancer, enzalutamide (Xtandi) and abiraterone (Zytiga) are FDA-approved options, while Schoen notes that clinicians may consider the agents broadly interchangeable given their similar mechanisms of action. In localized disease, however, the available clinical trial data can help guide selection, with abiraterone demonstrating efficacy in combination with radiation and apalutamide (Erleada) showing benefit in the neoadjuvant and adjuvant settings around prostatectomy.

Beyond clinical trial data, practical considerations such as insurance coverage and potential drug-drug interactions frequently influence ARPI selection. Schoen also emphasizes that the structural similarities among enzalutamide, apalutamide, and darolutamide (Nubeqa) contribute to clinicians' perception that these agents can often be used interchangeably when multiple options are appropriate.

“Commonly, the choice is made off of the scenario, but also patients' drug-drug interactions and their insurance status,” Schoen said.

Schoen describes real-world evidence as particularly valuable in an area where direct comparisons between ARPIs are limited. Observational studies and data from large practice networks, including the Veterans Health Administration, can provide comparative insights when agents are being used for similar indications and treatment populations. Because these datasets include large numbers of patients and allow investigators to account for some baseline differences, Schoen says they can help identify potential differences in effectiveness that randomized head-to-head trials have not yet established.