Enfortumab vedotin induces immunogenic cell death and shows enhanced preclinical antitumor activity when combined with a PD-1 inhibitor.

Enfortumab vedotin is a Nectin-4-directed antibody-drug conjugate designed to deliver the microtubule-disrupting agent monomethyl auristatin E (MMAE) to tumor cells. Using preclinical models of urothelial cancer (UC), we expand the understanding of the multifaceted mechanism of action for enfortumab vedotin that includes direct cytotoxicity on Nectin-4-positive tumor cells, indirect bystander effect on neighboring Nectin-4-negative tumor cells, and MMAE-mediated induction of immunogenic cell death (ICD) and associated increase in activated immune cells in the tumor microenvironment. Importantly, vaccination with enfortumab vedotin-treated tumor cells results in protection against tumor rechallenge in mice, consistent with antitumor immunity. MMAE-mediated ICD induction modulates the tumor microenvironment in a complementary manner to immune checkpoint inhibition. Accordingly, enfortumab vedotin plus PD-1 inhibitor shows enhanced antitumor activity in vivo. These preclinical findings provide mechanistic hypotheses that may be relevant to the improved clinical outcomes observed for enfortumab vedotin plus pembrolizumab relative to chemotherapy.