Next-generation CAR-T therapy for malignant brain tumors: latest updates from the 2026 AACR Annual Meeting

The 2026 AACR Annual Meeting showcased rapid progress in chimeric antigen receptor (CAR) T-cell therapy for malignant brain tumors. This correspondence synthesizes 12 clinical and translational abstracts addressing early efficacy, resistance mechanisms, target discovery, and next-generation engineering. Phase I studies in glioblastoma demonstrated feasibility, manageable toxicity, cellular persistence, and preliminary radiographic activity, while revealing antigen loss and treatment-associated myeloid suppression. Longitudinal and spatial analyses further identified limited CAR T-cell persistence, anti-CAR immune responses, and remodeling of suppressive tumor niches. Preclinical strategies sought to overcome these barriers through programmable antigen recognition, alternative KIR/DAP12 signaling, stress-granule modulation, inducible metabolic support, membrane-tethered cytokine agonists, resistance to transforming growth factor beta, and dual targeting of tumor cells and immunosuppressive macrophages. Surfaceome profiling and affinity-guided receptor optimization also identified promising targets in glioblastoma and medulloblastoma. Collectively, these findings support mechanism-informed CAR T-cell platforms, while emphasizing that durability, neurotoxicity, trafficking, immunogenicity, and patient selection require validation in larger clinical studies.