Tislelizumab in Combination With Chemotherapy as First-Line Treatment in Adults With Inoperable, Locally Advanced or Metastatic Gastric, or Gastroesophageal Junction Carcinoma

Inclusion Criteria

• Locally advanced unresectable or metastatic gastric cancer (GC) or gastroesophageal junction (GEJ) carcinoma and have histologically confirmed adenocarcinoma
• No previous systemic therapy for locally advanced unresectable or metastatic gastric/GEJ cancer. NOTE: Participants may have received prior neoadjuvant or adjuvant therapy as long as it was completed and have no recurrence or disease progression for at least 6 months.
• Eastern Cooperative Oncology Group performance status (ECOG PS) ≤ 1 within 7 days prior to randomization
• Adequate organ function ≤ 7 days prior to randomization Key

Exclusion Criteria

• Has squamous cell or undifferentiated or other histological type GC
• Active leptomeningeal disease or uncontrolled brain metastasis
• Diagnosed with gastric or GEJ adenocarcinoma with positive HER2
• Prior therapy with an anti-programmed cell death protein-1 (PD-1), anti-programmed cell death protein ligand-1 (PD-L1), anti-programmed cell death protein ligand-2 (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.