Adjuvant dendritic cell-based tumour vaccination for children with malignant brain tumours

Abstract

Background: A large experience with dendritic cell (DC)-based vaccination for malignant brain tumours has been gained in adults. Here we focus on the results obtained in children with relapsed malignant brain tumours.

Procedure: In total 45 children were vaccinated: 33 high grade glioma (HGG), 5 medulloblastoma (MB)/primitive neuro-ectodermal tumour (PNET), 4 ependymoma and 3 atypical teratoid-rhabdoid tumour (ATRT). Autologous, monocyte-derived DC were generated and loaded with tumour lysate, which was used as source of tumour-associated antigens.

Results: In 38 patients peripheral blood mononuclear cells (PBMC) were obtained from leukapheresis and in 7 patients from fresh blood samples. 7 HGG patients are still alive with median follow-up (FU) of 35.7 months (range: 12.1-85.6). Median overall survival (OS) was 13.5 months (range: 1.4-85.6). All patients with MB/PNET died (median OS 5.7 months; range 4.3-51.2). One patient with ependymoma is still alive at 22.3 months FU. The other three patients died at, respectively, 7.7, 30.1 and 31.5 months. Two patients with ATRT are still alive at, respectively, 34.1 and 52.6 months FU. The third patient died at 50.5 months. No severe adverse events were noticed.

Conclusions: In this exploratory study, HGG and ATRT seem to respond more favourably to vaccination than MB/PNET and ependymoma. Although preliminary, our results are promising and support further testing of DC-based immunotherapy in new treatment protocols for HGG and ATRT.