This clinical trial is focused on studying a type of cancer called urothelial carcinoma, which affects the lining of the bladder and other parts of the urinary system. The study aims to compare the effectiveness of a new treatment combination against standard chemotherapy. The new treatment involves two medications: Disitamab Vedotin and Pembrolizumab. Disitamab Vedotin is a type of medication that targets cancer cells, while Pembrolizumab is an immunotherapy drug that helps the immune system fight cancer. The chemotherapy options being compared include Cisplatin, Carboplatin, and Gemcitabine, which are commonly used to treat various cancers.

The purpose of this study is to determine if the combination of Disitamab Vedotin and Pembrolizumab is more effective than the standard chemotherapy treatments for patients with advanced urothelial carcinoma that shows a specific protein called HER2. HER2 is a protein that can affect the growth of cancer cells. The study will involve patients who have not received prior treatment for their advanced cancer. Participants will be randomly assigned to receive either the new treatment combination or one of the standard chemotherapy options. Some participants may receive a placebo, which is a substance with no active medication, to help compare the effects of the treatments.

Throughout the study, participants will receive their assigned treatments through an intravenous infusion, which means the medication is given directly into a vein. The study will monitor the participants’ health and response to the treatment over a period of time to gather information on the effectiveness and safety of the treatments. The goal is to find out which treatment option provides better outcomes for patients with this type of cancer. This research could potentially lead to improved treatment options for people with advanced urothelial carcinoma.