Loc3CAR: Locoregional Delivery of B7-H3-CAR T Cells for Pediatric Patients With Primary CNS Tumors

Loc3CAR is a Phase I clinical trial evaluating the use of autologous B7-H3-CAR T cells for participants ≤ 21 years old with primary CNS neoplasms. B7-H3-CAR T cells will be locoregionally administered via a CNS reservoir catheter. Study participants will be divided into two cohorts: cohort A with B7-H3-positive relapsed/refractory non-brainstem primary CNS tumors, and cohort B with diffuse midline gliomas (DMG). Participants will receive four (4) B7-H3-CAR T cell infusions over a 4 week period. The purpose of this study is to find the maximum (highest) dose of B7-H3-CAR T cells that are safe to give patients with primary brain tumors. Primary objectives * To determine the safety, maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D) for the locoregional delivery of autologous B7-H3-CAR T cells in patients ≤ 21 years of age with recurrent/refractory B7-H3+ primary CNS tumors (Cohort A) or DMG (Cohort B). Secondary objectives * To assess the efficacy, defined as sustained objective response, a partial response (PR) or complete response (CR) observed anytime on active treatment with B7-H3-CAR T cells in patients with relapsed/refractory B7-H3+ primary CNS tumors (Cohort A) or DMG (Cohort B). * To characterize and monitor neurologic toxicities in patients while on study (Cohort A and B).