Abstract
High-grade gliomas, such as glioblastoma (GBM) and diffuse midline gliomas (DMG), are among the most aggressive and fatal forms of brain cancer, with current therapies offering limited efficacy. Chimeric Antigen Receptor (CAR) T cell therapy holds transformative potential in treating brain cancers due to its tumor-specific targeting and ability to cross the blood-brain barrier. However, a major challenge for effective clinical application lies in the selection of optimal antigens, with only a limited number currently being explored. We employed advanced cell surface proteomics to systematically map the surface proteome of primary adult and pediatric high-grade glioma samples. This led to the identification of Ephrin type-A receptor 3 (EphA3) as a prevalently expressed target. We engineered a second-generation EphA3-targeted CAR T cell and assessed function using in vitro and in vivo models of GBM and DMG. Human EphA3-targeted CAR T cells exhibited robust, antigen-specific cytotoxicity against GBM and DMG cell lines in vitro. Using orthotopic xenograft NSG mouse models, we discovered that EphA3-targeted CAR T cells not only effectively eradicated tumors but also established a functional memory T cell population protective on rechallenge. Remarkably, mice rechallenged with a second contralateral orthotopic tumor implantation achieved complete tumor clearance and maintained a sustained complete response 6 months following initial treatment. Our findings establish EphA3-targeted CAR T cell therapy as a promising immunotherapeutic strategy for high-grade gliomas, further building upon the proven safety profile of EphA3-targeted antibodies in clinical settings. This work underscores the translational potential of EphA3-directed immunotherapy in advancing treatment options for brain cancer patients and their families, aligning with the conference’s focus on breakthrough innovations in immuno-oncology.