10021-IMT-1 A ROLE OF DENDRITIC CELL IMMUNOTHERAPY AS A MODALITY IN MULTIDISCIPLINARY THERAPY FOR GLIOBLASTOMA

Abstract We are conducting a clinical study of immunotherapy using tumor-fused dendritic cells (TFDC) as a modality of multidisciplinary treatment for patients with glioblastoma (GBM). In this study, we analyzed the additional effect of TFDC-immunotherapy for standard therapy. Newly diagnose GBM patients who treated at four of Jikei University Hospitals were analyzed in this study. Adjuvant therapy after tumor removal surgery was maintained according to the Supp's regimen. Bevacizumab (10 mg/kg, every 2 weeks) was added when a recurred tumor was confirmed. TFDC vaccine was generated from cultured tumor cells derived from autologous surgical specimen and dendritic cells from peripheral blood, and were subcutaneously administered in the cervical region for 3-14 times. All patients who had not participated in any other immunotherapy-related clinical studies were compared as a control group in a Propensity score matching analysis. The number of analyzed patients was 55 in the immunotherapy group and 35 in the control group. The 2-year survival rate and 5-year survival rate were 20.9% and 0% in the control group, respectively, while the immunotherapy group was 45.7% and 22.7%, respectively. A statistically significant difference in overall survival was observed between them (p=0.0045). There was no difference in the observed adverse events in the two groups. Specific adverse events for TFDC-immunotherapy was not observed. In the biomarker analysis, low HLA-A expression and lack of CCDC88A, KRT4, TACC2, and TONSL mutations in tumor cells were suggested as biomarkers of better prognosis. We are currently analyzing IDH profile in those patients for further analysis. TFDC-immunotherapy should be adopted as one of the modality of multidisciplinary treatments for GBM because it is expected to have some additional effects for standard therapeutic reagents without adversely affecting them. Since there are a certain number of poor responders for this immunotherapy, predictive biomarkers of therapeutic efficacy are awaited.