Joe O’Sullivan, MD, Queen’s University, Belfast, UK, explores biomarkers in association with benefit to PARP inhibitors (PARPi) in patients with castration-resistant prostate cancer, including BRCA mutation status. Dr O’Sullivan talks on the importance of developing novel PARP inhibitors that show increased efficacy and reduced toxicity. This interview took place at the European Association of Urology (EAU) Meeting 2022.