PARP Inhibitors in Prostate Cancer: Broad Use or Patient Selection?

We review evidence for the efficacy of PARP inhibitors in metastatic castration-resistant prostate cancer (mCRPC). Initial approval of these agents in mCRPC was for patients with alterations in BRCA and other homologous recombination repair (HRR) genes. The European Medicines Agency has broadened approval of PARPi combinations with androgen receptor pathway inhibitors to all patients with mCRPC. Nevertheless, the greatest benefits are consistently observed for patients with mutations in BRCA and certain other HRR genes. The safety profile is consistent across all patient groups. PATIENT SUMMARY: Our mini review looks at the evidence for drugs called PARP inhibitors for metastatic prostate cancer that does not respond to standard hormone therapy (mCRPC for short). Combination treatment with a PARP inhibitor and another type of drug called an androgen receptor pathway inhibitor is approved in Europe for all patients with mCRPC, but those who are most likely to benefit have mutations in genes that are involved in a type of DNA repair.