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 ormetastatic carcinoma（including renal pelvic, ureter bladder and urethra）;
2. Cohort 1：Patients with First-line platinum ineligible must meet criteria for eitheroption a or option b (below):
3. Has a tumor(s) with PD-L1 combined positive and is considered ineligible toreceive cisplatin-based combination therapy, based on 1 of the following:

• Eastern Cooperative Oncology Group (ECOG) performance status (PS) score of 2within 7 days prior to randomization
• National Cancer Institute (NCI) Common Terminology Criteria for AdverseEvents (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 anyplatinum-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 metastaticurothelial carcinoma who have disease recurrence or progression during or after aplatinum-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-4receptor;
2. Has a known hypersensitivity to anti-PD-1 / PD-L1 agent;
3. Known pia meningeal metastasis or active central nervous system (CNS) metastasisrevealed by CT or MRI. Participants with asymptomatic brain metastases may participatewithout evidence of progression for at least 1 month. NOTE: Other protocol defined Inclusion/Exclusion criteria may apply.