The immune-reinforcements of Lenvatinib plus anti-PD-1 and their rationale to unite with TACE for unresectable hepatocellular carcinoma treatment.

Résumé

BACKGROUND: Despite encouraging clinical benefits have gained by anti-PD-1 and Lenvatinib combination, in-depth characterizations about the mechanisms of action remain poorly characterized. Furthermore, although the combination of systemic anti-PD-1 or Lenvatinib treatment and locoregional transcatheter arterial chemoembolization (TACE) is widely carried out to treat unresectable HCC in clinical, the efficacies of different combination regimens are uncertain due to limited researches.METHODS: We firstly generated murine HCC models to validate the enhanced anti-tumor effects of anti-PD-1 and Lenvatinib combination therapy. Then single cell mass cytometry (CyTOF) was employed to phenotypically reveal their mechanisms of action. After that, we further compared the effectiveness of TACE plus Lenvatinib (i.e., TACE-Len) dual therapy with TACE, Lenvatinib plus anti-PD-1 (i.e., TACE-Len-PD-1) triple therapy as conversion therapy for unresectable HCC.RESULTS: Lenvatinib and anti-PD-1 combination could generate activated immune profiles not only by increasing systemic CD4, CD8T cells and B cells proportions, but also by weakening the immune-tolerance functions derived from both immunosuppressive cells (i.e., MDSCs) and co-inhibitory mediators (i.e., PD-L1 and LAG-3). Meanwhile, our study also suggested that TACE-Len-PD-1 triple therapy could achieve better clinical responses with powerful immune profiles for unresectable HCC compared to TACE-Len dual therapy.CONCLUSIONS: Our study provided a delicate immune landscape of anti-PD-1and Lenvatinib combination, and we also offered scientific evidences that TACE-Len-PD-1 triple therapy could fulfill better clinical benefits than TACE-Len dual therapy, which is anticipated to provide objective and effective evidences for clinical use.