Robust tumor regressions were observed in multiple CLDN6+ xenograft models and tumor inhibition lead to markedly enhanced survival of CLDN6+ PDX tumors following treatment with CLDN6-23-ADC….We report the development of a novel antibody-drug conjugate, CLDN6-23-ADC, that selectively targets CLDN6, a potential onco-fetal-antigen which is highly expressed in ovarian and endometrial cancers.