Antibody-drug conjugates (ADCs) are promising cancer treatments that include delivering toxic drugs to specific tumor cells. Xenograft tumor models based on immunodeficient mice are suitable for evaluating the anti-tumor effect of ADCs. Tumor models of immunocompetent animals may be more suitable when evaluating antibody-mediated immune response of ADCs and the combined effect of ADCs and immunotherapy. Aiming at this issue, we developed humanized mouse models to evaluate the efficacy of ADCs in combination with immunotherapy.