RESUMO
AIM: Developing effective adjuvant therapies is essential for improving the surgical outcomes in patients with hepatocellular carcinoma (HCC). Immunotherapy against HCC has become a promising strategy; however, only approximately 30% of all HCC patients respond to immunotherapy. Previously, we generated the novel therapeutic vaccine comprising multi-human leukocyte antigen-binding heat shock protein 70/glypican-3 peptides with a novel adjuvant combination of hLAG-3Ig and poly-ICLC. We also confirmed the safety of this vaccination therapy, as well as its capacity for the effective induction of immune responses in a previous clinical trial. METHODS: In this phase I study, we administered this vaccine intradermally six times before surgery, and 10 times after surgery to patients with untreated, surgically resectable HCC (stage II to IVa). The primary end-points of this study were the safety and feasibility of this treatment. We also analyzed the resected tumor specimens pathologically using hematoxylin-eosin staining and immunohistochemistry for heat shock protein 70, glypican 3, CD8 and programmed death-1. RESULTS: A total of 20 human leukocyte antigen-matched patients received this vaccination therapy with an acceptable side-effect profile. All patients underwent planned surgery without vaccination-related delay. Immunohistochemical analyses revealed that potent infiltration of CD8+ T cells into tumors with target antigen expression was observed in 12 of 20 (60%) patients. CONCLUSIONS: This novel therapeutic vaccine was safe as perioperative immunotherapy for patients with HCC, and has the potential to strongly induce CD8+ T cells infiltration into tumors.