A Study to Investigate Tislelizumab (BGB-A317) Versus Placebo in Combination With Concurrent Chemoradiotherapy in Participants With Localized Esophageal Squamous Cell Carcinoma

Key Inclusion Criteria:

1. 18 to 75 years on the day of signing the informed consent form
2. Histologically confirmed diagnosis of localized ESCC
3. Measurable and/or non-measurable disease defined per RECIST v1.1
4. Eastern Cooperative Oncology Group (ECOG) Performance Status ≤ 1
5. Adequate organ function

Key Exclusion Criteria:

1. Indicators of severe malnutrition
2. Clinically uncontrolled pleural effusion, pericardial effusion, or ascites requiring frequent drainage or medical intervention within 2 weeks prior to randomization
3. Known to be intolerable or resistant to treatment with the protocol-specified chemotherapy
4. Received prior radiotherapy or therapies targeting PD-1, PD-L1, PD-L2 or other immune-oncology therapies
5. Active autoimmune diseases or history of autoimmune diseases that may relapse

NOTE: Other protocol defined Inclusion/Exclusion criteria may apply.