Inclusion Criteria:

1. Histologically confirmed HCC
2. Barcelona Clinic Liver Cancer (BCLC) Stage C disease, or BCLC Stage B disease that was not amenable to or had progressed after loco-regional therapy, and was not amenable to a curative treatment approach
3. Tumor tissue required for an evaluable programmed cell death protein-ligand 1 (PD-L1) expression result
4. No prior systemic therapy for HCC
5. At least 1 measurable lesion as defined per RECIST v1.1
6. Adequate organ function during screening and before randomization

Exclusion Criteria:

1. Known fibrolamellar HCC, sarcomatoid HCC, or mixed cholangiocarcinoma and HCC histology
2. Prior therapy with antibody or drug specifically targeting T-cell costimulation or checkpoint pathway; prior treatment with bevacizumab or its biosimilars
3. Prior history of >= Grade 2 hepatic encephalopathy
4. Leptomeningeal disease or uncontrolled, untreated brain metastasis
5. Active autoimmune diseases or history of autoimmune diseases that may relapse
6. History of interstitial lung disease, non-infectious pneumonitis or uncontrolled lung diseases including pulmonary fibrosis, acute lung diseases
7. Infection (including tuberculosis) requiring systemic antibacterial, antifungal, or antiviral therapy within 14 days of randomization
8. Prior allogeneic stem cell transplantation or organ transplantation
9. Significant cardiovascular risk factors
10. Untreated or incompletely treated esophageal or gastric varices with bleeding or high risk of bleeding
11. History of severe hypersensitivity reactions to other monoclonal antibodies
12. Administered a live vaccine <=28 days before randomization

NOTE: Other protocol Inclusion/Exclusion criteria may apply