Background: Glioblastoma multiforme (GBM) is the most common and most aggressive primary brain tumor. More than 300,000 new cases are diagnosed globally with over 250,000 deaths each year (Sung H, et al. CA Cancer J Clin. 2021). Patients with recurrent GBM have a poor prognosis, with limited treatment options and a median survival of less than 1 year (Gallego. Curr Oncol, 2015). While prior attempts to treat GBM with chimeric antigen receptor (CAR) T-cells have been limited by tumor heterogeneity, chlorotoxin (CLTX)-directed CAR T-cells in mice demonstrated broad anti-tumor activity and prolonged survival with no off-tumor toxicity or antigen escape (Wang, et al. Sci Transl Med, 2020). CLTX, a 36–amino acid peptide identified in scorpion venom, selectively binds to malignant glioma cells through matrix metalloproteinase-2 (MMP2) and clinical administration of CLTX-based biologics has been well tolerated in patients (Mamelak, et al. J Clin Oncol, 2005, Patil, et al. Neurosurgery, 2019). CHM 1101 is the first CAR T to utilize CLTX as its tumor targeting domain for autologous CAR T-cell therapy. A single-center first-in-human phase 1 study of CHM 1101 in patients with recurrent GBM is ongoing. Methods: Clinical Trial NCT05627323 is a phase 1b, multi-center study of CHM 1101 in adult subjects with MMP2+ recurrent or progressive GBM after standard therapy. After leukapheresis and tumor resection, pts will receive CHM 1101 at Dose Level 1 (240 × 10⁶ CAR T cells) or Dose Level 2 (440 x 10⁶d CAR T-cells), divided across 3 once-weekly intracranial (intracavitary and intraventricular) administrations; after disease assessment at 28 days, additional doses of CHM 1101 can be administered on a weekly schedule. Eligible subjects have a prior histologically confirmed diagnosis of a grade 4 GBM, a grade 2 or 3 malignant glioma with radiographic progression consistent with a grade 4 GBM (IDH wild type), grade 4 diffuse astrocytoma (IDH mutant), or a unifocal relapse of GBM. MMP2+ tumor expression is confirmed by IHC (≥20% moderate/high MMP2 score [2+ or 3+]). The primary endpoint is safety; key secondary endpoints include feasibility, progression-free survival, overall survival, response rate (RANO criteria), and cellular kinetics. Recruitment is ongoing. Clinical trial information: NCT05627323.