Additional Study Information: This clinical trial is for patients who have cancer of the urinary system (urothelial cancer, including cancer of the bladder, renal pelvis, ureter or urethra) that has spread to nearby tissues or to other areas of the body who have already been treated with a kind of anticancer drug called an immune checkpoint inhibitor (CPI). This clinical trial uses an experimental drug, which has not been approved by the Food and Drug Administration (FDA) for sale in the United States to treat your disease. The experimental drug in this clinical trial is called enfortumab vedotin. We want to find out if enfortumab vedotin will treat urothelial cancer in patients who have already been treated with a CPI drug. We also want to find out about the side effects of the drug.