Addition of Dendritic Cell Vaccination to Conditioning Cyclophosphamide and Chemoembolization in Patients with Hepatocellular Carcinoma: The ImmunoTACE Trial

Abstract

Purpose: A previous study by our group using dendritic cells (DC) pulsed ex vivo with the lysate of the HepG2 cell line showed evidence of antigen-specific T-cell responses in some patients with advanced hepatocellular carcinoma. The ImmunoTACE trial evaluated the preliminary activity of this vaccine in combination with transarterial chemoembolization (TACE) in patients with intermediate-stage hepatocellular carcinoma. Patients and Methods: A randomized phase II trial was conducted in three tertiary referral centers in the United Kingdom. Eligible patients were randomly assigned in a 1:1 ratio to TACE + preconditioning cyclophosphamide or to TACE + preconditioning cyclophosphamide + DC infusions. The primary endpoint was progression-free survival time using RECIST v1.1 criteria. Additional endpoints included safety and immune responses. Results: Between March 2016 and October 2019, 55 patients were randomized, of whom 48 were evaluable (24 in each group). The median progression-free survival time using RECIST criteria was 18.6 months in patients treated with chemoembolization + preconditioning cyclophosphamide + DC infusions compared with 10.4 months in those treated with chemoembolization + preconditioning cyclophosphamide alone (HR = 0.43; upper value of one-sided 80% confidence interval, 0.57; P = 0.016). The addition of DC infusions did not significantly increase the incidence or severity of adverse events. An enhanced antigen (α-fetoprotein)-specific immune response was observed in patients treated with DC vaccination. Conclusions: The addition of DC infusions to TACE and preconditioning cyclophosphamide has shown promising preliminary activity and merits further investigation in a larger randomized trial.