A Study Investigating Alternate Schedules of Tislelizumab Plus Chemotherapy in Japanese Patients With First-line Advanced ESCC

The purpose of this study is to evaluate the pharmacokinetic (PK) profile, safety, and efficacy of tislelizumab administered once every 2 weeks (Q2W) or once every 4 weeks (Q4W) in combination with chemotherapy as first-line treatment in Japanese participants with previously untreated, unresectable locally advanced, or metastatic esophageal squamous cell carcinoma (ESCC).

Inclusion Criteria: * Able to provide written informed consent by the participant or by the participants' legally acceptable representative and can understand and agree to comply with the requirements of the study * Histologically confirmed, unresectable locally advanced, recurrent or metastatic ESCC not amenable to curative approaches such as definitive chemoradiation or surgery. * No previous systemic therapy for unresectable locally advanced, recurrent or metastatic ESCC * At least 1 measurable lesion per RECIST v1.1 as determined by investigator * Eastern Cooperative Oncology Group (ECOG) Performance Status score ≤ 1 * Adequate organ function as indicated by the laboratory values ≤ 14 days prior to the first dose of study drugs * Females of childbearing potential must have a negative urine or serum pregnancy test≤ 7 days prior to the first dose of study drugs and be willing to use a highly effective method of birth control for the duration of the study until at least 120 days after the last dose of tislelizumab. Further contraception requirements after completing chemotherapy should follow the approved product labeling for each specific cytotoxic agent Exclusion Criteria: * Participants who are unable to comply with the requirements of the protocol * Participants with evidence of esophageal or gastroesophageal perforation or fistula ( esophageal/bronchial or esophageal/aorta), or complete esophageal obstruction not amenable to treatment within 6 months prior to the first dose of study drugs * Uncontrollable pleural effusion, pericardial effusion, or ascites requiring frequent drainage (clinically significant recurrence requiring an additional intervention within 2 weeks of intervention) and/or diuretics within 7 days prior to the first dose of study drugs (the cytological confirmation of any effusion is permitted) * Have an estimated life expectancy \< 3 months, per the judgment of the investigator * Participants with active leptomeningeal disease or uncontrolled, untreated brain metastasis * Prior therapy with anti-programmed death protein-1 (anti-PD-1), anti-programmed death protein ligand-1(anti-PD-L1), anti-programmed death protein ligand- 2 (anti-PD-L2), or any other antibody or drug specifically targeting T-cell co-stimulation or checkpoint pathways Note: Other protocol defined Inclusion/Exclusion criteria may apply.