Background: IMbrave150 is the first study demonstrating the benefit of anti-PDL1 in the frontline treatment of aHCC, and established Atezo/Bev as a new 1^st line standard for aHCC. There is currently limited evidence to guide subsequent therapy for aHCC patients progressing on Atezo/Bev. ACCRU-GI-2008 is designed to determine the benefit of continuing Atezo into 2^nd line and the safety of Atezo plus a MKI in patients with aHCC who previously received Atezo/Bev. The study is being conducted across 12 centers in the United States (ClincalTrials.gov#: NCT05168163). Methods: This study utilizes a 2:1 randomized phase II design where eligible patients will receive either Atezo/MKI (experimental arm) or MKI alone (control). Patients will be stratified according to the MKI choice (cabozantinib or lenvatinib, per physician’s decision), etiology of HCC (viral vs. non-viral) and alpha-fetoprotein level ( < 400 vs. > = 400 ng/mL). The major eligibility criteria are histological/cytological diagnosis or clinical diagnosis of HCC per the AASLD or WASL 2018 guidelines, has advanced disease not amendable to curative treatment, previously received and progressed on Atezo/Bev, has received only 1 previous line of systemic therapy (2^nd line only), ECOG PS 0-1, Child Pugh Class A, adequate organ reserves and RECIST v1.1 measurable disease; previous MKI for advanced disease is excluded. The primary endpoints are overall survival (OS) and progression free survival (PFS). A total sample size of 122, with 89 PFS events, we will have 80% power to detect an improvement in median PFS from 4 to 7 months, assuming a one-sided significance level of 0.05. With approximately 84 deaths, we will have 80% power to detect an improvement in median OS from 10 to 18 months, assuming a one-sided significance level of 0.05. The overall one-sided significance level, for the study, is 0.1. An OS interim analysis will be conducted at 89 PFS events. Secondary endpoints include objective response, duration of response, and adverse events. Archival tumor and serial blood samples will be collected to evaluate for potential prediction biomarkers and mechanisms of sensitivity/resistance. Baseline and on-treatment tumor biopsy specimens will also be collected from the initial 10 patients of each arm. The study is approved by the ethics committee and enrollment to the study will be underway by Q2/3 2022. Clinical trial information: NCT05168163.