First clinical trial of cancer vaccine therapy with artificially synthesized helper/ killer-hybrid epitope long peptide of MAGE-A4 cancer antigen.

A patient with pulmonary metastasis of colon cancer was treated with artificially synthesized helper/killer-hybrid epitope long peptide (H/K-HELP) of MAGE-A4 cancer antigen. The patient was vaccinated with MAGE-A4-H/K-HELP combined with OK432 and Montanide ISA-51. There were no severe side-effects except for a skin reaction at the injection site. MAGE-A4-H/K-HELP induced MAGE-A4-specific Th1 and Tc1 immune responses and the production of MAGE-A4-specific complement-fixing IgG antibodies. Tumor growth and carcinoembryonic antigen tumor marker were significantly decreased in the final diagnosis. This is the first report that artificially synthesized MAGE-A4-H/K-HELP induces Th1-dependent cellular and humoral immune responses in a human cancer patient.