Stage IIIB Bladder Cancer AJCC v8

This phase Ib/II trial tests the safety, side effects, and best dose of quemliclustat in combination with enfortumab vedotin and pembrolizumab, and to see how well the combination works for the treatment of bladder, renal pelvis, or ureter urothelial cancer that cannot be removed by surgery (unresectable), that has spread to nearby tissue or lymph nodes (locally advanced) or that has spread from where it first started (primary site) to other places in the body (metastatic). Enfortumab vedotin is a monoclonal antibody, enfortumab, linked to an anticancer drug called vedotin. It works by helping the immune system to slow or stop the growth of cancer cells. Enfortumab attaches to a protein called nectin-4 on cancer cells in a targeted way and delivers vedotin to kill them. It is a type of antibody-drug conjugate. Immunotherapy with monoclonal antibodies, such as pembrolizumab, may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread. Quemliclustat may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Giving quemliclustat in combination with enfortumab vedotin and pembrolizumab and may be safe, tolerable and/or effective in treating patients with unresectable locally advanced and metastatic urothelial cancer.