The first ADC-class drug targeting FRα-expressing tumor cells was mirvetuximab soravtansine (MIRV) (IMGN853, ElahereTM) developed by ImmunoGen, which is composed of the anti-tubulin agent maytansinoid effector molecule DM4, a cleavable linker sulfo-SPDB ([N- succinimidyl 4-(2-pyridyldithio)-2-sulfobutanoate]), and a humanized anti-FRα MAB, M9346A (Figure 5) [103,104,105]. Here, FOLR1 is linked to neoplasm.