Mirvetuximab Soravtansine (MIRV) is an investigational antibody drug conjugate designed to selectively kill cancer cells. The antibody (protein) part of MIRV targets tumors by delivering a cell-killing drug to the tumor cells carrying a tumor-associated protein called folate receptor alpha (FRα). It is being developed as maintenance therapy for the treatment of subjects with recurrent platinum-sensitive, highgrade epithelial ovarian, primary peritoneal, or fallopian tube cancers with high folate receptor-alpha expression. Patients must have confirmation of FRα positivity by the Ventana FOLR1 Assay.