CAR T cell therapy for glioblastoma: A review of the first decade of clinical trials

Glioblastoma (GBM) is an aggressive primary brain tumor with a poor prognosis and few effective treatment options. Focus has shifted toward using immunotherapies, such as chimeric antigen receptor (CAR) T cells, to selectively target tumor antigens and mediate cytotoxic activity within an otherwise immunosuppressive tumor microenvironment. Between 2015 and 2024, the results of eight completed and two ongoing phase I clinical trials have been published. The majority of studies have treated recurrent GBM patients, although the inter- and intra-patient tumor heterogeneity has been historically challenging to overcome. Molecular targets have included EGFR, HER2, and IL13Ra2 and there has been continued development in improving receptor constructs, identifying novel targets, and adding adjuvant enhancers to increase efficacy. CAR T cells have been safely administered through both peripheral and locoregional routes but with variable clinical and radiographic efficacy. Most trials utilized autologous T cell products to avoid immune rejection yet were unable to consistently show robust engraftment and persistence within patients. Nonetheless, targeted immunotherapies such as CAR T cell therapy remain the next frontier for GBM treatment, and the popularity and complexity of this undertaking is evident in the past, present, and future landscape of clinical trials.