A Study of Atezolizumab Plus Tiragolumab in Combination With Paclitaxel and Cisplatin Compared With Paclitaxel and Cisplatin as First-Line Treatment in Participants With Unresectable Locally Advanced, Unresectable Recurrent, or Metastatic Esophageal Carcinoma

- Palliative radiation treatment for EC within 4 weeks prior to initiation of study treatment - Evidence of complete esophageal obstruction not amenable to treatment - Symptomatic, untreated, or actively progressing central nervous system (CNS) metastases - Uncontrolled tumor-related pain, uncontrolled pleural effusion, pericardial effusion, or ascites requiring recurrent drainage procedures - Active or history of autoimmune disease or immune deficiency or leptomeningeal disease - History of idiopathic pulmonary fibrosis, organizing pneumonia, drug-induced pneumonitis, or idiopathic pneumonitis, or evidence of active pneumonitis - Malignancies other than EC within 2 years prior to screening with a negligible risk of metastasis or death adequately treated with expected curative outcome - Severe infection within 4 weeks prior to initiation of study treatment or any active infection that, in the opinion of the investigator, could impact patient safety - Positive test result for human immunodeficiency virus (HIV) - Active hepatitis B or hepatitis C - Prior treatment with CD137 agonists or immune checkpoint blockade therapies, anti-CTLA-4, anti-TIGIT, anti-PD-1, and anti-PD-L1 therapeutic antibodies - Treatment with any investigational therapy prior to initiation of study treatment - Poor peripheral venous access - Prior allogeneic stem cell or solid organ transplantation - Concurrent participation in another therapeutic clinical trial