FOLR1 and ovarian carcinoma: Results from a pivotal Phase 1 expansion study (NCT01609556) reported in 2017 demonstrated the first evidence of efficacy in platinum-resistant ovarian cancer (PROC), with an objective response rate (ORR) of 26% and progression-free survival (PFS) of 4.8 months in a heavily pretreated patient cohort.85 The subsequent FORWARD I Phase 3 trial (NCT02631876) failed to demonstrate improved PFS for MIRV compared to chemotherapy in FRα-positive PROC patients who received 1–3 prior therapies (Table 2).