A Phase Ⅱ Study of F520 in Patients With Urothelial Carcinoma

Inclusion Criteria: 1. Histologically or cytologically confirmed,locally advanced（T4b,any N or any T,N2-3 or metastatic carcinoma（including renal pelvic, ureter bladder and urethra）; 2. Cohort 1：Patients with First-line platinum ineligible must meet criteria for either option a or option b (below): 1. Has a tumor(s) with PD-L1 combined positive and is considered ineligible to receive cisplatin-based combination therapy, based on 1 of the following: * Eastern Cooperative Oncology Group (ECOG) performance status (PS) score of 2 within 7 days prior to randomization * National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) Version 5.0 Grade ≥2 audiometric hearing loss * NCI CTCAE Version 5.0 Grade ≥2 peripheral neuropathy OR 2. In the opinion of the investigator, is considered ineligible to receive any platinum-based chemotherapy (i.e., ineligible for cisplatin and carboplatin) based on: * ECOG PS of 2 within 7 days prior to randomization. and ≥1 of the following: * Documented visceral metastatic disease * NCI CTCAE Version 5.0 Grade ≥2 audiometric hearing loss * NCI CTCAE Version 5.0 Grade ≥2 peripheral neuropathy Cohort 2: Inoperable Patients in sencond line（or beyond）with locally advanced or metastatic urothelial carcinoma who have disease recurrence or progression during or after a platinum-based chemotherapy regimen; * Eastern Cooperative Oncology Group (ECOG) performance status (PS) score of 0 or 1 * Calculated creatinine clearance ≥ 30 milliliter (mL)/min (Cockcroft-Gault formula) Exclusion Criteria: 1. Has received prior therapy with an anti-PD-1, anti-PD-L1 agent or with CTLA-4 receptor; 2. Has a known hypersensitivity to anti-PD-1 / PD-L1 agent; 3. Known pia meningeal metastasis or active central nervous system (CNS) metastasis revealed by CT or MRI. Participants with asymptomatic brain metastases may participate without evidence of progression for at least 1 month. NOTE: Other protocol defined Inclusion/Exclusion criteria may apply.