A Study Evaluating Atezolizumab and Bevacizumab, With or Without Tiragolumab, in Participants With Untreated Locally Advanced or Metastatic Hepatocellular Carcinoma (HCC) (IMbrave152)

Inclusion Criteria: * Locally advanced or metastatic and/or unresectable HCC with diagnosis confirmed by histology/cytology or clinically by American Association for the Study of Liver Diseases (AASLD) criteria in cirrhotic participants * Disease that is not amenable to curative surgical and/or locoregional therapies * No prior systemic treatment for locally advanced or metastatic and/or unresectable HCC-measurable disease according to RECIST v1.1 * Eastern cooperative oncology group (ECOG) performance status of 0 or 1 within 7 days prior to randomization * Child-pugh Class A within 7 days prior to randomization * Adequate hematologic and end-organ function * Female participants of childbearing potential must be willing to avoid pregnancy within 5 months after the final dose of atezolizumab, within 6 months after the final dose of bevacizumab, and within 90 days after the final dose of tiragolumab/placebo * Male participants with a female partner of childbearing potential or pregnant female partner must remain abstinent or use a condom during the treatment period and for 6 months after the final dose of bevacizumab and for 90 days after the final dose of tiragolumab/placebo to avoid exposing the embryo. Exclusion Criteria: * Pregnancy or breastfeeding within 5 months after the final dose of atezolizumab, within 6 months after the final dose of bevacizumab, and within 90 days after the final dose of tiragolumab/placebo * Prior treatment with cluster of differentiation 137 (…