%0 Journal Article
%T P06.10 Dose-response relationship of ALECSAT immunotherapy in autologous patient-derived glioblastoma stem cell cultures
%J Archive of "Neuro-Oncology".
%D 2017
%R 10.1093/neuonc/nox036.184
%X Introduction: Glioblastoma (GBM) is a highly malignant brain tumor with dismal prognosis in which few treatment modalities have been proven efficacious. ALECSAT (Autologous Lymphoid Effector Cells Specific Against Tumour Cells) is a novel type of immunotherapy based on adoptively transferred autologous lymphocytes expanded and activated in vitro. ALECSAT is produced and kindly provided by the Danish biotech company CytoVac A/S. In an ongoing clinical phase II randomized trial we are investigating the efficacy and safety of ALECSAT treatment in newly diagnosed GBM. In a parallel preclinical study we aim to further investigate the rationale for ALECSAT in GBM, with focus on better understanding the underlying mechanisms of action and potential of predicting response to treatment using matched patient-derived GBM cancer stem cells. MATERIAL AND METHODS: For patients randomized to ALECSAT-treatment in the clinical study we established patient-derived cell cultures from fresh tumor tissue, collected at the patients¡¯ diagnostic neurosurgical tumor resection. The cells were cultured adherently in serum-free neural stem cell media, thus selecting for stem cells, which was verified by immunocytochemistry staining of the cells. The autologous GBM cancer stem cells were treated in vitro for 24 hours with ALECSAT produced for the specific patient with an ALECSAT to cancer stem cells ratio between 0.1:1 and 20:1 and a control, with triplicates for each condition. The effect on the autologous cancer stem cells was evaluated with a cell count after 24 hours of treatment (using DAPI staining). Results: So far we have established cell lines for four patients randomized to ALECSAT-treatment in the clinical study. The cells were proliferative as indicated by positive EdU staining and expressed the stem cell markers Nestin, SOX2 and Vimentin. ALECSAT had an effect on all autologous patient-derived cell lines with a very high cell death of the cancer stem cells at the highest doses already after 24 hours. We observed cases with >90% cell death. Further, for all patients there was a dose-response relationship with increased dose of ALECSAT corresponding to higher cell death of the GBM cancer stem cells. Conclusions: ALECSAT was highly effective in vitro killing most of the autologous GBM cancer stem cells within 24 hours at high doses. As cancer stem cells are considered more resistant to treatments this result is encouraging. We observed a strong dose-response relationship when patient-derived GBM cancer stem cells were co-cultured with autologous ALECSAT, thus suggesting
%U https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5463958/