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

The study is being conducted to evaluate the efficacy and safety of Toripalimab Injection in combination with chemotherapy compared to placebo in combination with chemotherapy in subjects with PD-L1-positive unresectable locally advanced or metastatic urothelial carcinoma who have received no previous systemic therapy.

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.