A Study of Tislelizumab (BGB-A317) in Combination With Chemotherapy as First Line Treatment in Participants With Advanced Esophageal Squamous Cell Carcinoma

Inclusion Criteria

• Pathologically (histologically) confirmed diagnosis of ESCC
• Stage IV unresectable ESCC at first diagnosis OR unresectable, locally advanced recurrent or metastatic disease (per American Joint Committee on Cancer 7th Edition), if there is prior neoadjuvant/adjuvant therapy with platinum-based chemotherapy, a treatment-free interval of at least 6 months is required. Key

Exclusion Criteria

• Palliative radiation treatment for ESCC within 4 weeks of study treatment initiation
• Prior systemic therapy for unresectable, locally advanced recurrent or metastatic ESCC
• Received prior therapies targeting programmed cell death protein-1 (PD-1), programmed cell death protein ligand-1 (PD-L1) or PD-L2
• Participants with evidence of fistula (either esophageal/bronchial or esophageal/aorta)
• Uncontrollable pleural effusion, pericardial effusion, or ascites requiring frequent drainage or medical intervention (clinically significant recurrence requiring an additional intervention within 2 weeks of intervention)
• Evidence of complete esophageal obstruction not amenable to treatment
• Unintentional weight loss ≥ 5% within one month prior to randomization or Nutritional Risk Index (NRI) < 83.5 per investigator's choice
• Locally advanced esophageal carcinoma that is resectable or potentially curable with radiation therapy per local investigator.
• Participants with untreated chronic hepatitis B or chronic hepatitis B virus (HBV) carriers whose HBV DNA is ≥ 500 IU/mL or participants with active hepatitis C virus (HCV) NOTE: Other protocol defined Inclusion/Exclusion criteria may apply.