Immunological evaluation of vaccination of peptides derived from epithelial cancer-related antigens in two patients with hematological malignancy.

Recent advances in tumor immunology have resulted in identification of many epithelial cancer-related antigens and peptides applicable to specific immunotherapy. We and others have reported that several epithelial cancer-related antigens are also expressed in hematological malignancies. Two patients with hematological malignancy (multiple myeloma and chronic lymphocytic leukemia) were vaccinated with peptides derived from epithelial cancer-related antigens to evaluate the immune responses to peptides under a personalized peptide vaccination regimen. There was no adverse event except for local skin reaction at the injection site. The peptide vaccination augmented both peptide-specific CTLs cytotoxic to hematological malignant cells in post-vaccination peripheral blood mononuclear cells and peptide-specific IgG in post-vaccination sera. A transient but obvious decrease of malignant cells was observed at the early phase of the vaccination in both cases. Vaccines consisting of peptides derived from epithelial cancer antigens safely increased anti-tumor cell activity in patients with hematological malignancies. These results may provide a scientific rationale in use of epithelial cancer-related antigens for specific immunotherapy to patients with hematological malignancies.