1524 Purpose: To investigate the safety and immunological responses of personalized peptide vaccination in patients with malignant glioma. Patients and Methods: Twenty-six patients with recurrent malignant glioma entered in the phase I clinical study of personalized peptide vaccination. Peripheral blood mononuclear cells (PBMCs) and plasma prior to vaccination were provided for cellular and humoral responses in vitro to each of 31 or 36 peptides in cases of HLA-A24+ or HLA-A2+ patients, respectively, and then only the reactive peptides (maximum: 4) were allowed to in vivo administration. Post-vaccination PBMCs and plasma, and also pre-and post-vaccination cerebrospinal fluid, were provided for their reactivity to the vaccinated peptides. Expression of class 1 molecule on glioma cell was evaluated using EMR 8–5 antibody by immunohistochemical analysis. Results: The protocol was generally well tolerated, although the majority of patients developed grade 1 or 2 local redness and swelling at the injection site. Increase in cellular and humoral responses specific to at least one of the vaccinated peptides was observed in the post vaccination (6th)-PBMCs and -plasma from 62%, 73% respectively. More importantly, peptide-specific IgG were found in the post-vaccination cerebrospinal fluid of tumor sites. Clinical responses were 4 partial response, 8 stable disease, and 8 progressive disease. The clinical response was correlated to the expression of MHC class 1 on the glioma cell. The median overall survival for patients with recurrent glioblastoma multiforme in this study was 622 days. Conclusion: Personalized peptide vaccination is well tolerated and has ability to induce immune responses to the majority of malignant glioma patients along with several cases of major tumor regression. These results would encourage the phase II clinical study of personalized peptide vaccination to patients with recurrent malignant glioma. No significant financial relationships to disclose.
A phase I clinical study of a cocktail vaccine of Wilms’ tumor 1 (WT1) HLA class I and II peptides for recurrent malignant glioma