Clinical Research Directory

Inclusion Criteria for Stage 1: * ECOG Performance Status of 0 or 1 * Inoperable locally advanced, metastatic, or advanced GC or GEJC, with adenocarcinoma confirmed as the predominant histology * No prior systemic treatment for advanced or metastatic disease * Life expectancy \>= 3 months, as determined by the investigator * Human epidermal growth factor receptor 2 (HER2)-negative tumors * Measurable disease according to RECIST v1.1 * Adequate hematologic and end-organ function * Patients without hepatitis B virus (HBV) infection at screening * Negative hepatitis C virus (HCV) antibody test at screening, or positive HCV antibody test followed by a negative HCV RNA test at screening * Negative HIV test at screening * For women of childbearing potential: agreement to remain abstinent or use contraception, and agreement to refrain from donating eggs, as outlined for each specific treatment arm * For men: agreement to remain abstinent or use contraception, and agreement to refrain from donating sperm, as outlined for each specific treatment arm Exclusion Criteria for Stage 1: * Prior treatment with CD137 agonists or immune checkpoint blockade therapies * Treatment with investigational therapy within 28 days prior to initiation of study treatment * Any contraindications to any of the study drugs of the chemotherapy regimen * Eligible only for the control arm * Patients with a signet ring cells dominant carcinoma * Symptomatic, untreated, or actively progressing CNS metastases * History of leptomeningeal disease * Active or history of autoimmune disease or immune deficiency * Significant cardiovascular disease within 3 months prior to initiation of study treatment, unstable arrhythmia, or unstable angina * History of malignancy other than GC or GEJC within 2 years prior to initiation of study treatment, with the exception of malignancies with a negligible risk of metastasis or death Exclusion Criteria for Tiragolumab-Containing Arm: * Prior treatment with an anti-TIGIT agent * Active Epstein-Barr virus (EBV) infection or known or suspected chronic active EBV infection at screening