(UroToday.com) Inhibition of poly(ADP-ribose) polymerase (PARP) is synthetically lethal in cells with homozygous deletions, deleterious alterations, or both, in DNA damage response genes involved either directly or indirectly in homologous recombination repair. PARP inhibitors have recently been approved for the treatment of mCRPC, including both rucaparib and olaparib in May 2020. TALAPRO-1 is the first multinational phase 2 trial to evaluate the antitumor activity and tolerability of talazoparib monotherapy in heavily pre-treated men with mCRPC and HRR gene alterations. At the primary completion date, the objective response rate was 29.8% for all men and 45.9% for men with BRCA1/2 alteration, and the median rPFS was 5.6 and 11.2 months for all men and those with BRCA1/2 alterations, respectively. At the 2021 ASCO annual meeting, Dr. Niven Mehra and colleagues presented results of the TALAPRO-1 safety profile of talazoparib in men with mCRPC with the aim of understanding how patients with adverse events were managed during the trial.