859TiPTALAPRO-1: An open-label, response rate phase II study of talazoparib (TALA) in men with DNA damage repair defects (DDR) and metastatic castration-resistant prostate cancer (mCRPC) who previously received taxane-based chemotherapy (CT) and progressed on ≥ 1 novel hormonal therapy (NHT). (23rd October 2018)