Bagley et al. report the results of non-prespecified interim analysis of 6 patients treated in the first 2 dose levels of an ongoing first-in-human phase 1 study with a bivalent CAR-T cell product simultaneously targeting epidermal growth factor receptor (EGFR) and IL13Rα2.6 Patients with an IDH wild-type glioblastoma that had recurred after prior radiotherapy and presence of EGFR amplification by fluorescence in situ hybridization on any prior tumor tissue specimen could be included. Here, IL13RA2 is linked to glioblastoma.