Abstract BACKGROUND Medical interventions for recurrent grade IV glioma and high-grade glioma, which have a median overall survival of approximately 6-9 months, remain limited. Glioma stem cells (GSCs) have shown their pivotal roles in tumor recurrence and therapeutic resistance, which are considered potential targets. Here, we report data on the early clinical responses of all ten patients with recurrent grade IV glioma in an investigator-initiated trial (IIT) to explore the feasibility of locoregional administration of newly developed bispecific CAR-T cells, armored with a truncated form of the IL7Ra intracellular domain, that target a pair of GSC-associated antigens, CD44 and CD133 (Tris-CAR-T cells). MATERIAL AND METHODS Ten patients were treated with the regimen. A 2 + 2+3 + 3 cohort was designed. The first 2 cohorts were for safety exploration (cohort 1, 2 patients, low dose; cohort 2, 2 patients, high dose). The subsequent cohorts were for therapeutic efficiency exploration and received verified dosages for weekly administration (cohort 3, 3 patients, medium dose; cohort 4, 3 patients, high dose). The primary outcome was the safety of the Tris-CAR-T cells, as determined on the basis of adverse events (AEs) and serious adverse events (SAEs). The secondary outcomes were the distribution and persistence of the Tris-CAR-T cells, cytokine concentrations, and the therapeutic effect according to the Immunotherapy Response Assessment in Neuro-Oncology (iRANO) criteria. All eligible patients had progressive disease at the time of treatment and underwent intraventricular or intracavitary Ommaya reservoir implantation. Despite clinical data (MRI and PET image, lab-test, survival follow-up, cytokine assay), CSF, CAR-T products, and PBMC samples were also collected for scRNA-seq, and the subsequent analysis was conducted. RESULTS Low-grade adverse events occurred after CAR-T injection, and were managed effectively with symptomatic treatment. On-target, off-tumor effects and dose-limiting toxicity (DLT) were not observed. No significant fluctuations of CRS-associated cytokines in both the cerebrospinal fluid (CSF) and peripheral blood were observed. Three of the all ten patients achieved a long-term partial response (30%, 95% confidence interval CI 6.7%-65.2%). The disease control rate is 70% (95% CI 34.8%-93.3%). Further proteomics and single-cell RNA sequencing unveiled immune micro-environment characteristics and signatures associated with clinical response, highlighting the pivotal role and markers of myeloid cells. This is the first clinical study of GSC-targeting CAR-T cells against recurrent grade IV glioma. CONCLUSION This is the first clinical study of GSC-targeting CAR-T cells against recurrent grade IV glioma. Our data support the safety, efficacy, and potential immune reconstitution of newly constructed Tris-CAR-T cells. (NCT05577091, NMPA CXSL2500032)
Zhai et al. (Wed,) studied this question.