Background & AimsThe combination of atezolizumab and bevacizumab offers a novel approach to immunomodulation, showing efficacy as a primary treatment in advanced hepatocellular carcinoma (HCC). Concerns about graft safety and rejection have limited its exploration in the neoadjuvant setting of liver transplantation (LT).This study investigates the clinical efficacy and the safety profile related to the pre-transplant administration of atezolizumab and bevacizumab for HCC. MethodsProspective assessment of 17 patients with HCC treated with neoadjuvant preoperative atezolizumab and bevacizumab prior to LT for HCC, obtained from December 2020 and December 2023 at seven Western transplant centers. ResultsAmong the 17 patients with HCC included in the study, 16 (94.1%) had a tumor burden outside of Milan Criteria (MC). Neoadjuvant loco-regional therapies along with the administration of atezolizumab plus bevacizumab (median:5 months; discontinued at least 4 weeks prior LT), achieved an ORR 94% (Complete response: 59%), downstaging to within MC (82%) and a pathological response at explant examination of 88%. Grade 3-4 TRAE accounted for 17.6% of cases and were manageable. During the 25 months median follow-up period, 2 cases of mild (RAI ≤ 4), biopsy-proven rejection were reported but no instances of severe allograft rejection or graft loss. The 1-year and 3-year post-LT survival rates were 94.2% and 88.2%, respectively. ConclusionsThis study highlights the favorable oncological and survival outcomes from a multicentric cohort of HCC patients treated with atezolizumab and bevacizumab in the pre-LT setting. This immune-based combination was safe in terms of TRAE, and absence of severe post-transplant rejection or graft loss. These preliminary results could pave the way for expanding transplant eligibility criteria in patients at more advanced HCC stages. Impact and Implications•The combination of atezolizumab and bevacizumab in the neoadjuvant setting prior to liver transplantation for hepatocellular carcinoma (HCC) has been limitedly explored despite its potential to enhance anti-tumor response and downstaging due to raising concerns about its safety profile.•Among 17 patients who underwent successful liver transplantation following neoadjuvant atezolizumab/bevacizumab, 82% achieved downstaging to within MC, 94% radiological objective response and 88% pathology response, without drop-outs due to TRAEs or graft loss.•The neoadjuvant combination of atezolizumab plus bevacizumab prior liver transplantation in HCC shows an encouraging safety profile and stands out as a promising pre-transplant optimization treatment adjunct, leading to improved oncological outcomes