This medical study looks at how adding a drug called *durvalumab* to chemotherapy before surgery might help people with a type of cancer in the urinary tract, specifically the high-grade upper tract urothelial cancer (UTUC). **Durvalumab** is a type of medicine that helps the body's immune system fight cancer. It is given through an IV drip. Researchers want to see if combining it with chemotherapy helps shrink the cancer more effectively before surgery. **Chemotherapy** involves drugs like *methotrexate, vinblastine, doxorubicin, and cisplatin* to kill or stop cancer cells from growing. The study has three arms: Arm A and Arm B for patients who can take cisplatin, and Arm C for those who cannot. Each arm involves different treatment plans with durvalumab and chemotherapy. **Key Points**: - The study requires multiple visits over several months, including chemotherapy cycles and surgery. - Participants will have frequent medical tests, including blood samples and scans like CT or MRI. - While the study treatments may offer benefits, they also come with potential side effects and risks. Participants need to meet specific health criteria and must be willing to follow the study’s requirements closely.