A Phase II Study of Nivolumab + Ipilimumab in Advanced HCC Patients Who Have Progressed on First Line Atezolizumab + Bevacizumab

Inclusion Criteria: * Age \>= 18 years. * HCC diagnosis confirmed by histology/cytology or clinically by American Association for Study of Liver Diseases (AASLD) criteria in cirrhotic patients. * Measurable disease as defined by Response Evaluation Criteria in Solid Tumors (RECIST) version (v)1.1 * Locally advanced, metastatic, or unresectable disease. * Child Pugh class A. * Barcelona clinic liver cancer (BCLC) stage B (not amenable to liver directed therapy) or stage C. * Prior treatment with atezolizumab and bevacizumab combination with radiographic progression that necessitates change in treatment per treating physician. Patients with rapid progression on atezolizumab and bevacizumab (defined as patients who progressed radiographically in the first restaging scan that necessitates change in treatment) are excluded. * Washout period \>= 4 weeks prior to registration is required since last atezolizumab and bevacizumab dose. * Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0 or 1. (Form is available on the Academic and Community Cancer Research United \[ACCRU\] website). * Absolute neutrophil count (ANC) \>= 1000/mm \^ 3 (obtained =\< 28 days prior to registration). * Platelet count \>= 60,000/mm\^3 (obtained =\< 28 days prior to registration). * Hemoglobin \>= 8.5 g/dL (obtained =\< 28 days prior to registration). * Total bilirubin =\< 3 x upper limit of normal (ULN) (obtained =\< 28 days prior to registration). * Alanine aminotransferase (ALT) and aspar…