Mirvetuximab soravtansine is an antibody-drug conjugate that consists of an FRα-binding antibody, cleavable linker, and maytansinoid DM4, which is a potent tubulin-targeting agent. It was tested in a single-arm phase 3 trial that included 106 patients with platinum-resistant, high-grade serous epithelial ovarian, fallopian tube, or primary peritoneal cancers with high FRα expression. The investigator-assessed ORR was nearly triple the benchmark set in prior studies of less heavily pretreated platinum-resistant ovarian cancer populations. The ORR was similar regardless of the number of prior lines of therapy or prior PARP inhibitor exposure. The rapid and durable response seen with mirvetuximab in patients with FRα-positive, platinum-resistant ovarian cancer may position it to become a practice-changing, biomarker-driven standard of care treatment option.