Pembrolizumab is a medicine that helps the immune system recognize and attack cancer cells. It works by blocking a protein called PD‑1, which normally tells the immune system to slow down. By stopping this “brake,” pembrolizumab may allow the body’s defenses to target the bladder cancer that has not responded to other PD‑1/PD‑L1 treatments. In this study, pembrolizumab is given through an IV infusion and is used either alone or together with other experimental drugs to see how well it works and how safe it is.

MK‑3120 (also known by the code name SKB410) is an experimental medication being tested for the first time in people with advanced bladder cancer. It is given as an IV infusion. The exact way it works is still being studied, but researchers hope it may help the immune system fight the cancer or work together with pembrolizumab to improve results. The trial is looking at how safe MK‑3120 is and whether it can shrink tumors.

Zilovertamab vedotin is a newer type of cancer drug called an antibody‑drug conjugate. It combines a special antibody that finds a protein on cancer cells with a chemotherapy‑like payload that kills those cells once attached. Like the other drugs, it is given by IV infusion. In this study, researchers are testing whether zilovertamab vedotin can reduce tumor size and how well patients tolerate it, either on its own or together with pembrolizumab.

Locally advanced or metastatic urothelial carcinoma – Locally advanced or metastatic urothelial carcinoma is a cancer that begins in the lining of the urinary tract, such as the bladder, ureters, or renal pelvis. In the locally advanced stage, the tumor grows beyond the inner lining and may involve nearby tissues or lymph nodes. When it becomes metastatic, cancer cells travel through the blood or lymph system to distant parts of the body, such as the bones, liver, or lungs. The disease typically progresses from a confined growth to wider spread, with tumors increasing in size and number over time.