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)

This study (KEYMAKER-U04 Substudy 04D) is testing new treatment combinations added to enfortumab vedotin and pembrolizumab for people with advanced bladder cancer (urothelial carcinoma) that has spread and cannot be removed with surgery. Enfortumab vedotin and pembrolizumab are already approved as a first-line treatment for this cancer. **You may be eligible if...** - You have advanced or metastatic urothelial (bladder) cancer confirmed by biopsy - You have not yet received systemic treatment for advanced or metastatic disease - You can provide a tumor tissue sample - If you have HIV, it is well controlled on antiviral medication - If you have hepatitis B or C, your viral load is undetectable **You may NOT be eligible if...** - You have previously received chemotherapy or other systemic therapy for metastatic bladder cancer - You have active, uncontrolled autoimmune disease - You have severe nerve damage (peripheral neuropathy) - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.