Poly(ADP-ribose) polymerase inhibitors in prostate cancer: a cornerstone in precision oncology.

Poly-(ADP-ribose) polymerase (PARP) inhibitors act in cells with defects in homologous recombination DNA repair (HRR) caused by genomic aberrations such as mutations. This phenomenon called synthetic lethality is known now to be more common in prostate cancer than previously thought. Olaparib and rucaparib, two PARP inhibitors, were successfully tested in clinical trials for HRR-deficient metastatic castration-resistant prostate cancer. They received a breakthrough US FDA approval in HRR altered metastatic castration-resistant prostate cancer in May 2020. Consequently, the combination of PARP inhibitors with other agents such as androgen receptor pathway inhibitors, immune checkpoint inhibitors or DNA damage inducing chemotherapy are being currently largely studied. In our review, we aim to summarize the key PARP inhibitors published and ongoing trials in prostate cancer.