A phase I/IIa study of adjuvant immunotherapy with tumour antigen-pulsed dendritic cells in patients with hepatocellular carcinoma.

Background: To date, no adjuvant treatment has been shown to have a clear benefit in patients with hepatocellular carcinoma (HCC). In this prospective phase I/IIa study, we evaluated the safety and efficacy of adjuvant dendritic cell (DC) therapy in HCC patients who received primary treatment for HCC.

Methods: Twelve HCC patients who had no viable tumour after primary treatments were included. Dendritic cell vaccines pulsed with cytoplasmic transduction peptide-attached alpha-fetoprotein, glypican-3 and melanoma-associated antigen 1 recombinant fusion proteins were injected subcutaneously near to inguinal lymph nodes. Adverse effects, time to progression (TTP), and associated immune responses were evaluated after DC vaccination.

Results: Nine of 12 patients had no tumour recurrence up to 24 weeks after DC vaccination. Among a total of 144 adverse events, 129 events (89.6%) were regarded as adverse drug reactions, all of which were grade 1 or 2. The majority of patients showed enhanced anti-tumour immune responses after DC vaccination. Recurrence-free patients exhibited relatively stronger anti-tumour immune responses than patients who developed recurrence after DC vaccination, as evidenced by lymphocyte proliferation and IFN-γ ELISPOT assays. The median time of TTP was 36.6 months in the DC-vaccination group and 11.8 months in the control group (hazard ratio, 0.41; 95% confidence interval, 0.18-0.95; P=0.0031 by log-rank test).

Conclusions: Adjuvant DC vaccine for HCC was safe and well tolerated in phase I/IIa study, and preliminary efficacy data are encouraging to warrant further clinical study in patients with HCC after primary treatments.