Transarterial Chemoembolization Combined With Immune Checkpoint Inhibitors and Tyrosine Kinase Inhibitors for Unresectable Hepatocellular Carcinoma: Efficacy and Systemic Immune Response

Abstract

Background: Locoregional therapy combined with systemic therapy can further improve the prognoses for HCC. However, the efficacy of TACE combined with ICIs and TKIs for HCC and whether this triple therapy can activate systemic immune response are still unknown.

Purpose: To identify the efficacy of TACE+ICIs+TKIs for unresectable hepatocellular carcinoma (uHCC) and its effect on systemic immunity.

Materials and methods: This single-center retrospective study was approved by the Institutional Review Board. From August 1, 2019, to March 30, 2021, patients with uHCC who received the combination therapy of TACE+ICIs+TKIs were included. Peripheral blood samples were collected at baseline and once a month for 4 months after treatment. Lymphocyte subsets were measured by flow cytometry. Immunoglobulins were measured using the immune turbidimetric method. The dynamic change trend of circulating parameters was tested using simple linear regression.

Results: Fifty-three patients with a mean age of 59 ± 10.6 years were included. TTP was 8.0 months (95% CI, 5.5-10.5) and PFS was 8.5 months (95% CI, 5.4-11.5). ORR was 52.8% and DCR was 81.1%. Twenty patients had completed analysis of biomarkers in peripheral blood. For cellular immune response, the level of circulating CD8⁺, CD3⁺ T cells and NK cells increased, the frequency of CD4⁺T cells and the CD4⁺/CD8⁺ ratio decreased, and among them, CD8⁺ T cells increased significantly. For humoral immune response, there was a significant decrease in B cells and a significant increase in Ig G, Ig κ, and Ig λ. Moreover, Ig G, Ig κ, and Ig λ were related to tumor response.

Conclusion: TACE+ICIs+TKIs showed considerable efficacy in patients with uHCC. This triple therapy activated not only cell immune but also humoral immune activation. Circulating Ig G, Ig λ, and Ig κ can serve as potential biomarkers.

Keywords: B cells; TACE; hepatocellular carcinoma; humoral immune response; immune checkpoint inhibitors; tyrosine kinase inhibitors.