Impact of immune-related adverse events in patients with hepatocellular carcinoma treated with atezolizumab plus bevacizumab.

Abstract

Immune checkpoint inhibitors pose the risk of immune-related adverse events (irAEs). Recent data suggest that irAEs may be associated with a favorable prognosis. This study aimed to investigate and analyze the association between these adverse events and the clinical benefits in patients with unresectable hepatocellular carcinoma. The study enrolled 130 patients with advanced hepatocellular carcinoma treated with atezolizumab plus bevacizumab between November 2020 and January 2023 at a single center. The relationship between irAEs and both response rate and post-treatment outcomes was investigated. Out of the 130 patients, irAEs developed in 36 (27.7%) patients. The irAE group exhibited a significantly longer progression-free survival (PFS) than the non-irAE group, with a median PFS of 8.9 compared with 4.6months (P<0.01). No difference was found in the overall survival between the irAE and non-irAE groups. The irAE group demonstrated significantly higher disease control rate (DCR) than the non-irAE group (97.0% vs 65.5%, P<0.01). The analysis by irAE severity revealed that the grade 1/2 group exhibited significantly longer PFS (7.9 vs 4.6months, P=0.007) and higher DCR (100% vs 65.5%, P<0.01) than the non-irAE group. Furthermore, hypothyroidism correlated with a favorable PFS (8.9 vs 5.4months, P=0.02), DCR (100% vs 71.3%, P=0.03), and overall response rate (58.3% vs 18.5%, P=0.005). The presence of irAEs is associated with prolonged PFS and higher DCR. Specifically, mild irAEs (grade 1/2) and hypothyroidism displayed prolonged PFS and higher DCR.