Peptide-pulsed dendritic cell vaccination targeting interleukin-13 receptor α2 chain in recurrent malignant glioma patients with HLA-A*24/A*02 allele

Background aims. Dendritic cell (DC)-based vaccination targeting tumor-associated antigens is an attractive approach to overcoming the limitations of current treatments for malignant gliomas (MG). Interleukin-13 receptor alpha 2 chain (IL-13R alpha 2) is a promising target because of its abundant and specific expression in MG. We conducted a phase I trial of DC vaccination in patients with recurrent MG using two IL-13R alpha 2-derived peptides restricted to HLA-A*0201 and -A*2402. The objective was to evaluate the safety and clinical and immunologic responses. Methods. Eight recurrent MG patients were enrolled. DC were generated from peripheral blood and pulsed with HLA-matched peptide; 1 x 10(7) DC were administered every 2 weeks for a maximum of six immunizations. The T-cell response in peripheral blood was evaluated by tetramer and ELISPOT assays in HLA-A*2402 patients. Results. All enrolled patients except one completed at least four DC vaccinations. No severe adverse events were observed. A positive T-cell response was detected in two out of three evaluable HLA-A*2402 patients. One patient achieved stable disease for 16 months and another patient showed a dramatic regression for one lesion for 4 months. Conclusions. The regimen was feasible and safe, and the HLA-A*24-restricted peptide exhibited a capacity to induce immune responses. These results warrant further studies to evaluate whether add-on regimens to post-operative chemoradiotherapy delays recurrence in newly diagnosed MG patients.