FOLR1 and peritoneum cancer: Mirvetuximab soravtansine is a folate receptor alpha (FRα)-targeting immunoglobulin G1 (IgG1) subtype 2 mAb with a DM4 payload approved in the United States (US)—but not yet in Europe—for the treatment of FRα-positive, platinum-resistant ovarian epithelial, fallopian tube, or primary peritoneal cancer in patients who have received 1-3 prior systemic regimens.55 It includes a boxed warning regarding the risk for ocular AEs, including visual impairment, keratopathy, dry eye, photophobia, eye pain, and uveitis.55