PARP inhibitors on the move in prostate cancer: spotlight on Niraparib & update on PARP inhibitor combination trials.

PARP inhibitors were recently introduced as a novel targeted therapy for biomarker positive metastatic castration resistant prostate cancer (mCRPC) patients, a population that inevitably acquires resistance to existing standard care regimens. Olaparib and rucaparib are now FDA-approved for mCRPC, while talazoparib and niraparib are advancing through the clinical stage of development. We highlight the recent results of the GALAHAD trial testing the efficacy of niraparib in mCRPC patients with DNA damage repair gene defects and compare its performance to key PARP inhibitor trials (PROFOUND, olaparib; TRITON2, rucaparib; TALAPRO-1, talazoparib). Finally, we briefly discuss recent updates on emerging PARP inhibitor and androgen receptor targeting combination trials as a novel treatment strategy for upfront treatment of mCRPC and in earlier disease settings.