PARP inhibitors and immunotherapy in ovarian and endometrial cancers.

Advanced ovarian and endometrial cancers have historically been associated with poor prognosis and few treatment options, limited to single or doublet chemotherapy regimens. The introduction of novel target therapies has transformed the management of these cancers. In contrast to chemotherapy, which inhibits DNA replication and mitosis, targeted therapies target cancer signalling pathways, stroma, immune-microenvironment and vasculature in tumour tissues. The most notable advances in gynaecological cancers have come from the introduction of PARP inhibitors and immune checkpoint inhibitors for ovarian and endometrial cancer, respectively. Several PARP inhibitors, which target defective DNA repair, have been approved as maintenance therapy for advanced ovarian cancer in both the first line and platinum-sensitive relapsed settings. Immune checkpoint inhibitors such as anti-PD-1/PD-L1 antibodies have proven successful in advanced mismatch repair deficient endometrial cancers with use now being investigated beyond this population. This review will explore the biological rationale and clinical evidence behind the use of PARP inhibitors and immunotherapy in ovarian and endometrial cancers.