PD-1 blockade improves treatment responses to PARP inhibitor by targeting PD-1+regulatory T cells in patients with epithelial ovarian cancer

Poly (adenosine diphosphate [ADP]-ribose) polymerase inhibitors (PARPi) are becoming the standard of care options for epithelial ovarian cancer (EOC). In the current study, we investigated the immunologic effects of PAPRi on circulating regulatory T cells (Tregs) during PARPi maintenance therapy. Furthermore, we explored ways in which the addition of PD-1 blockade to PARPi maintenance therapy enhances survival outcomes in recurrent EOC.