Study of Cabozantinib in Combination With Atezolizumab Versus Sorafenib in Participants With Advanced Hepatocellular Carcinoma (HCC) Who Have Not Received Previous Systemic Anticancer Therapy

Key Inclusion Criteria: * Histological or cytological diagnosis of HCC or clinical diagnosis of HCC in cirrhotic patients by Computed Tomography (CT) or Computed Tomography (MRI) per the American Association for the Study of Liver Diseases (AASLD) 2018 or European Association for the Study of the Liver (EASL) 2018 guidelines. * The participant has disease that is not amenable to a curative treatment approach (eg, transplant, surgery, ablation therapy) or locoregional therapy (eg, TACE). * Measurable disease per Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 as determined by the Investigator. * Barcelona Clinic Liver Cancer (BCLC) stage Category B or C. * Child-Pugh Score of A. * Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1. Key Exclusion Criteria: * Known fibrolamellar carcinoma, sarcomatoid HCC or mixed hepatocellular cholangiocarcinoma. * Prior systemic anticancer therapy for advanced HCC including but not limited to chemotherapy, small molecule kinase inhibitors, and immune checkpoint inhibitors (ICIs). Participants who have received local intratumoral or arterial chemotherapy are eligible; local anticancer therapy within ≥ 28 days before randomization * Radiation therapy for bone metastasis within 2 weeks, any other radiation therapy within 8 weeks prior to randomization. * Known brain metastases or cranial epidural disease unless adequately treated with radiotherapy and/or surgery (including radiosurgery) and stable for at least 8 weeks prior to randomization. * Concomitant anticoagulation with oral anticoagulants Note: Other protocol defined Inclusion/Exclusion criteria may apply.