Importance of Atezolizumab Plus Bevacizumab Combination Treatment as First-line Therapy for Immunological Changes in Patients With Unresectable Hepatocellular Carcinoma

The atezolizumab plus bevacizumab (AteBev) therapy is recommended as first-line treatment for unresectable hepatocellular carcinoma (uHCC). However, there remains a need to examine its efficacy with and without previous chemotherapy. Therefore, in patients with uHCC who underwent AteBev therapy, we aimed to clarify the effects of previous chemotherapy by examining serum immunological changes.We retrospectively analyzed data of 29 patients with uHCC treated by AteBev therapy as part of a prospective study and divided participants into two groups depending on whether they had received prior chemotherapy. Dynamic computed tomography was performed after 6 weeks of treatment. Blood samples were collected at baseline and after 3 weeks of treatment.The group with prior treatment included 15 patients and the group without prior treatment included 14 patients. Objective response rates after six weeks of treatment were 13.3% and 28.6% in the groups with and without prior treatment, respectively. Serum levels of interleukin (IL)-6 and tumor necrosis factor-alpha showed no significant change in the group with prior treatment but increased significantly in the group without prior treatment. The percentage of regulatory T cells decreased significantly after treatment only in the group without prior treatment.In patients with uHCC, AteBev therapy can be expected to elicit an effective immune response in patients without prior treatment, but it may not do so in patients with prior treatment. Thus, AteBev appears to be more effective when used as first-line chemotherapy.