Abstract
The combination of enfortumab vedotin and pembrolizumab (EVP) has been recently approved for patients with locally advanced and metastatic urothelial carcinoma. This combination showed a higher objective response rate and superior progression-free survival and overall survival over traditional platinum-based chemotherapy in the frontline setting in the pivotal EV-302 trial. Despite the success, a subset of patients has primary refractory disease, and another subset will develop secondary resistance over time. Resistance to enfortumab vedotin may include the downregulation of nectin-4 expression to minimize antibody binding, upregulation of efflux pumps against the toxin, or direct resistance by the tubulin against the toxin. Resistance to pembrolizumab includes several methods to downregulate the immune system. Additionally, the type of histology of the urothelial carcinoma likely plays an important role in resisting EVP. This review summarizes these possible mechanisms of primary and secondary resistance, potential biomarkers predictive of response and resistance, and methods to overcome the resistance to EVP.