Combination Antiangiogenic and Immunotherapy for Advanced Hepatocellular Carcinoma: Evidence to Date

For over a decade, sorafenib remained the only systemic agent with proven clinical efficacy for patients with advanced hepatocellular carcinoma (HCC). Recent years have seen a proliferation of agents. In the first line, lenvatinib was found to be non-inferior to sorafenib in terms of overall survival (OS), with significantly better progression-free survival and objective response rate. Meanwhile, encouraging efficacy signals were observed in phase I/II studies of immune checkpoint inhibitors as monotherapy in HCC. Although subsequent phase III trials failed to demonstrate statistically significant benefit in OS, other clinically meaningful outcomes were observed, including long-term disease control with a favorable toxicity profile. In addition, a synergistic response has been postulated based on the interplay between antiangiogenic molecular targeted agents and immunotherapy. On this basis, interest has turned toward combination strategies of immunotherapy with these standard-of-care medications in the hope of improving treatment efficacy for advanced HCC, while maintaining tolerable safety profiles. Indeed, preliminary results from phase I studies of lenvatinib plus pembrolizumab and atezolizumab plus bevacizumab have proved favorable, prompting phase III investigations in the frontline setting, and for atezolizumab plus bevacizumab, these positive findings have been substantiated by recent reporting of phase III data from IMbravel 50. In this review, we will present the currently available data on combination therapy atezolizumab plus bevacizumab in advanced HCC, and compare these findings to other promising combination treatments, most notably that of lenvatinib plus pembrolizumab.