DS-8201a, a HER2-targeting antibody-drug conjugate, to elicit immune responses and benefits in combination with an anti-PD-1 antibody.

1031 Background: DS-8201a, a HER2-targeting antibody–drug conjugate (ADC), with a topoisomerase I inhibitor, exatecan drivative (DX-8951 derivative, DXd) has been shown to have antitumor effects in preclinical xenograft models and clinical trials, but the involvement of the immune system in the antitumor efficacy of DS-8201a has not been elucidated yet. Methods: The antitumor efficacy of DS-8201a individually and in combination with an anti-PD-1...