This study showed that the targeted drug onalespib reduced the expression of cell-survival proteins such as AKT and endothelial growth factor receptor in glioma cell lines and glioma stem cells from patient tumors. This, in turn, reduced the survival, proliferation, invasion and migration of the cells. In animal models of glioblastoma the agent crossed the blood-brain barrier and showed effectiveness as a single agent and greater effectiveness in combination with temozolomide.