Organ-specific response with first-line atezolizumab-bevacizumab versus lenvatinib for patients with advanced hepatocellular carcinoma.

Background: Immune checkpoint inhibitor (ICI)-based treatments have become the mainstay of first-line treatment for unresectable hepatocellular carcinoma (HCC), but there has been a concern that intrahepatic HCC lesions may be less responsive to ICI monotherapy. We aimed to investigate the organ-specific response patterns among unresectable HCC patients treated with first-line atezolizumab-bevacizumab or lenvatinib.

Methods: This retrospective study included 386 patients with Child-Pugh A unresectable HCC who were treated with first-line atezolizumab-bevacizumab (n = 217) or lenvatinib (n = 169). The organ-specific response was separately evaluated according to the site of the lesions: liver, lung, lymph node (LN), and intraabdomen based on a radiological evaluation adopted from RECIST v 1.1.

Results: The median age was 60 years. Hepatitis B infection was the most common etiology (n = 270, 69.9%), and 291 (75.4%) patients had a viral etiology. The proportion of patients achieving a ≥ 30% reduction in the tumor burden for each organ category was overall higher in the atezolizumab-bevacizumab group than that in the lenvatinib group: 20.2% vs. 11.8%, 23.0% vs. 12.2%, 27.9% vs. 17.9% and 33.3% vs. 15.0% for intrahepatic, lung, LN, and intraabdominal lesions, respectively. The corresponding values for the subgroup with a viral etiology were 17.3% vs. 8.1%, 18.8% vs. 13.3%, 28.9% vs. 3.6%, and 36.0% vs. 12.5%, respectively.

Conclusion: Compared to lenvatinib, atezolizumab-bevacizumab was associated with a favorable organ-specific response regardless of the site of the tumor lesions. Unlike anti-PD-1 monotherapy, atezolizumab-bevacizumab had a comparable organ-specific response between intrahepatic and extrahepatic lesions, especially for those with viral etiology HCCs.