Atezolizumab and bevacizumab in combination with TACE for patients with BCLC B HCC.

TPS584 Background: The combination of atezolizumab and bevacizumab (AB) is an effective regimen for patients with advanced HCC 1 . Moving effective systemic therapy to earlier stages of HCC is a priority in improving outcomes. Assessing the safety of the combination of AB and TACE is essential to evaluating this regimen. Methods: This is an open-label, single arm pilot study. The primary objective of this study is to examine the safety and tolerability of AB with TACE. The secondary objectives are response rate, time to progression, overall survival, time to TACE progression (TTTP), and time to untaceable progression. Approximately 24 patients will be enrolled. AB will be given every 3 weeks (A: 1200 mg; 15 mg/kg) weeks and TACE will be planned for each patient to be completed in up to 4 treatments. B will be held for cycles that are within 4 weeks before or after each TACE. Imaging will be every 8 weeks for the first year, then every 12 weeks for the second year. Based on data from the GO30140 and the IMbrave 150 studies, we assume the rate of grade 3 or higher AEs is approximately 55% for AB and will likely be higher with the addition of TACE. Safety will be continuously monitored using the Bayesian Predictive Probability (PP) approach 2 . The PP that the rate of grade 3 or higher AEs is related to the combination is greater than 70% by the end of the trial based on toxicity data in the current stage will be continuously updated. Inclusion criteria includes patients over 18 years old with an ECOG PS of 0 or 1, no cirrhosis or Child-Pugh A cirrhosis, diagnosis of HCC by imaging or biopsy, and EGD within 6 months with no evidence of gastroesophageal varices with bleeding or high risk of bleeding unless treated. Patients are excluded if they are candidates for curative intent therapy, have had hepatic encephalopathy in the last 12 months, have occlusion of the hepatic artery or main portal vein, or have history of significant autoimmune disease. 1. Finn, Richard S., et al. New England Journal of Medicine 382.20 (2020): 1894-1905. 2 Lee J and Liu D. Clinical Trials. 2008; 5(2): 93-106. Clinical trial information: NCT05776875 .