PARP1 and ovarian carcinoma: Likewise, another oral ATR inhibitor camonsertib (also known as RP3500, developed by Repare) reported single-agent activity in clinic.179 The RP2D of camonsertib monotherapy was determined at MTD of 160 mg QD, 3 days on/4 days off.164 In platinum drugs or PARP inhibitors pretreated ovarian cancer, 5 out of 20 benefited from camonsertib monotherapy, including 1 complete response, 3 PRs and 1 CA125 reduction (Table 6).