Immunotherapy for children with malignant brain tumors

The incidence of high-grade malignant gliomas (MG) ranges from 35 to 46% of all central nervous system tumors. Despite combined therapy including surgery, radiation treatment and chemotherapy, overall five-year survival does not exceed 10%. The advent of novel immunotherapeutic strategies has promoted a renewed hopes for the treatment of MG. The aim of the present study was to improve the survival rates of glioma patients. Our study included 5 pediatric patients at the median age of 7.6 years (2-16). Three pts had anaplastic astrocytoma (AA) (1st relapse, 1 pt; 2nd relapse, in 2 pts), One patient was diagnosed with glioblastoma multiforme (GBM) (3rd recurrence), and 1 child had diffuse brainstem glioma (BSG). The median time to the first relapse was 12 months (4 to 16), the second relapse occurred at a median of 5 months (1 to 8). The protocol of immunotherapy included combined administration of autologous dendritic cell-based vaccine (DV) and repeated intrathecal/intraventricular injections of donor allogeneic immunocompetent cells (alloIC) for at least 2 years. Two of 3 pts with AA experienced a progression-free interval of 67 and 71 months. One patient with 3rd GBM relapse is alive without any treatment for 13.3 years after starting the immunotherapy. The median time of follow-up was 67 months, with the 2-year overall survival rate of 58%. Two pts died from the disease progression within 6 and 7 months from the beginning of immunotherapy. Over the period of treatment, the patients received a median of 20 alloIC injections (8 to 60), and 18 DV administrations (8 to 44). No serious side-effects were observed. Immunotherapy could be an promising option for treating patients with high-grade malignant gliomas refractory to conventional therapy and, therefore, deserves further investigations.