ATIM-25. TEN-YEAR FOLLOW UP WITH LONG TERM REMISSION IN PATIENTS WITH NEWLY DIAGNOSED GLIOBLASTOMA (GBM) TREATED WITH ICT-107 VACCINE (PHASE I)

Abstract

BACKGROUND:We previously reported 7 patients with prolonged survival > 5 years from a phase I study of 16 newly diagnosed GBM patients (Neuro-Oncology 15(suppl3), 71, IT-015, 2013) and expression of four ICT-107 targeted antigens in pre-immunotherapy tumors correlated with prolonged OS and PFS in GBM patients (Cancer Immunol Immunother. 2013 Jan;62(1):125-35.PATIENTS AND METHODS:ICT-107 is an autologous immunotherapy consisting of patient dendritic cells pulsed with six tumor associated peptides (TAA) peptides derived from AIM-2, TRP-2, HER2/neu, IL-13Ra2 (overexpressed on CSC), gp100, MAGE1 administered intradermal three times at two week intervals to HLA-A1 and/or HLA-A2 positive GBM patients after a standard therapy with concurrent Temozolomide and radiation therapy.RESULTS:With 10-year follow up, we identified 3(19%) of 16 the GBM patients were disease free over 8 years (PFS 9.2+, 8.3+, 8.1+) and 6 patients (KPS 90%, age range 34-62 years old at age of diagnosis) survived > 7.7 years (range 7.7- 9.6 years). There were 2 HLA-A1+ and 4 HLA-A2+ and their TAA expressed at least 5 peptides including antigens overexpressed on CSC in this group. One patient with PFS >9.2 years is working full time with good quality of life, showed immune response 2.5 (>1.5 fold increase IFNg production after administration by tetramer/FACS). Six (38%) of 16 GBM patients are presently alive > 7.7 years and only one patient received active treatment for recurrence. While long term remission and survival was seen in this 16 GBM patient cohort, median PFS was 16.9 months, 5-year PFS was 37.5% (95%:15.4-60), median OS was 38.4 months and 5-year OS rate was 50% (95% CI: 24.5-71).CONCLUSION:It is unprecedented to have 19% long term remission > 8 years in this group from ICT-107 immunotherapy. This correlated with cancer-stem-associated expression, and a trend toward greater CD8 T cell cytokine responses.