Infiltration of T Cells and Programmed Cell Death Ligand 1-expressing Macrophages as a Potential Predictor of Lenvatinib Response in Hepatocellular Carcinoma.

Background/Aims Lenvatinib was recently proven to be non-inferior to sorafenib in treating unresectable hepatocellular carcinoma (HCC) in a phase-3 randomized controlled trial. In this study, we investigated whether the response to lenvatinib was affected by tumor immunogenicity. Methods Between May 2019 and April 2020, nine patients with intermediate-to-advanced HCC, who were treated with lenvatinib after liver biopsy, were enrolled. Immunohistochemical staining and multi-color flow cytometry were performed on specimens obtained from liver biopsy. Results Among the nine patients enrolled, four showed objective responses (complete responses+partial responses). Immunohistochemical staining for CD3, CD68, and programmed cell death ligand 1 (PD-L1) demonstrated that patients with objective responses showed marked infiltration of T cells and PD-L1-expressing macrophages in intra-tumoral and peri-tumoral tissues compared to those without objective responses. A significant difference in the numbers of infiltrated T cells, both in the intra-tumoral (P<0.01) and peri-tumoral regions (P<0.05), were identified between responders and non-responders. Regarding the number of infiltrated macrophages, no significant difference was found between the responders and non-responders, although the number of PD-L1-expressing tumor-associated macrophages was significantly higher in responders than that in non-responders (P<0.05). Conclusions Tumor immunogenicity, as indicated by T cell and PD-L1-positive macrophage infiltration, affects lenvatinib response in unresectable HCC.