Bioactivity and Safety of IL13Rα2-Redirected Chimeric Antigen Receptor CD8+ T Cells in Patients with Recurrent Glioblastoma

Purpose: A first-in-human pilot safety and feasibility trial evaluating chimeric antigen receptor (CAR)-engineered, autologous primary human CD8+ cytotoxic T lymphocytes (CTL) targeting IL13Rα2 for the treatment of recurrent glioblastoma (GBM). Experimental Design: Three patients with recurrent GBM were treated with IL13(E13Y)-zetakine CD8+ CTL targeting IL13Rα2. Patients received up to 12 local infusions at a maximum dose of 108 CAR-engineered T cells via a catheter/reservoir system. Results: We demonstrate the feasibility of manufacturing sufficient numbers of autologous CTL clones expressing an IL13 (E13Y)-zetakine CAR for redirected HLA-independent IL13Rα2- specific effector function for a cohort of patients diagnosed with GBM. Intracranial delivery of the IL13-zetakine+ CTL clones into the resection cavity of 3 patients with recurrent disease was welltolerated, with manageable temporary brain inflammation. Following infusion of IL13-zetakine+ CTLs, evidence for transient anti-glioma responses was observed in 2 of the patients. Analysis of tumor tissue from 1 patient before and after T-cell therapy suggested reduced overall IL13Rα2 expression within the tumor following treatment. MRI analysis of another patient indicated an increase in tumor necrotic volume at the site of IL13-zetakine+ Tcell administration. Conclusions: These findings provide promising first-in-human clinical experience for intracranial administration of IL13Rα2- specific CAR T cells for the treatment of GBM, establishing a foundation on which future refinements of adoptive CAR T-cell therapies can be applied. © 2015 AACR.