A Study Evaluating Toripalimab Injection Combined With Standard Chemotherapy as a First-line Treatment for Locally Advanced or Metastatic Urothelial Carcinoma

Inclusion criteria 1. Have full knowledge on this study and are willing to sign informed consent form (ICF); 2. Age 18-75 years at time of signing ICF, male or female; 3. The investigator judged that the subject is eligible for platinum-based chemotherapy; 4. Presence of histopathologically confirmed unresectable locally advanced (T4, any N; or any T, N2-3) or metastatic urothelial carcinoma; 5. No prior systemic anti-tumor therapy; 6. Subjects who are able to provide tumor tissue slides (≥ 5 slides) for PD-L1 test and the corresponding pathology report and whose PD-L1 test must be positive before randomization; 7. With at least one measurable lesion as per RECIST 1.1 criteria; 8. ECOG performance status score of 0-1; 9. Adequate function of vital organs. Exclusion criteria 1. Have received anti-tumor treatments, including chemotherapy, radiotherapy or investigational product within 28 days before randomization; 2. Have received traditional Chinese medicines with anti-tumor activity or immunomodulators (eg. Interferon and Interleukin) within 14 days before randomization; 3. Previous use of anti-PD-1/PD-L1 agent or a drug acting on another co-inhibitory T cell receptor; 4. Subjects who are currently participating in or have participated in a study with investigational product within 4 weeks before administration; 5. Having received systemic corticosteroid therapy (dose equivalent to prednisone \> 10 mg/day) within 14 days before randomization; 6. Subjects with active central nervous system (CNS) metastasis; 7. Grade 2 or higher peripheral neuropathy or hearing loss.