A Study of Atezolizumab Plus Bevacizumab Versus Active Surveillance as Adjuvant Therapy in Patients With Hepatocellular Carcinoma at High Risk of Recurrence After Surgical Resection or Ablation

Inclusion Criteria: * Participants with a first diagnosis of HCC who have undergone either a curative resection or ablation (radiofrequency ablation \[RFA\] or microwave ablation \[MVA\] only) within 4-12 weeks prior to randomization * Documented diagnosis of HCC that has been completely resected or ablated (RFA or MVA only) * Absence of major macrovascular invasion (except Vp1/Vp2) and extrahepatic spread * Absence of extrahepatic spread as confirmed by CT or MRI scan of the chest, abdomen, pelvis, and head prior to and following curative procedure * Full recovery from surgical resection or ablation within 4 weeks prior to randomization * High risk for HCC recurrence after resection or ablation * For patients who received post-operative transarterial chemoembolization: full recovery from the procedure within 4 weeks prior to randomization * For patients with resected HCC, availability of a representative baseline tumor tissue sample * ECOG Performance Status of 0 or 1 * Child-Pugh Class A status * Adequate hematologic and end-organ function * For women of childbearing potential: agreement to remain abstinent (refrain from heterosexual intercourse) or use contraceptive methods * For men: agreement to remain abstinent (refrain from heterosexual intercourse) or use a condom, and agreement to refrain from donating sperm Exclusion Criteria: * Known fibrolamellar HCC, sarcomatoid HCC, or mixed cholangiocarcinoma and HCC * Evidence of residual, recurrent, or metastatic disease a…