KEYMAKER-U04 Substudy 04D: A Clinical Study of New Treatments Given With Enfortumab Vedotin and Pembrolizumab in People With Urothelial Cancer (MK-3475-04D/KEYMAKER-U04)

Researchers are looking for new ways to treat people with urothelial cancer (UC) that is locally advanced or metastatic. The standard treatment for locally advanced or metastatic UC is enfortumab vedotin (EV) given with pembrolizumab. The goals of this study are to learn about: * The safety of the study treatment when given with standard treatment and if people tolerate it * The number of people who have the cancer respond (cancer gets smaller or goes away) with the new study treatment when given with standard treatment.