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Purpose A first-in-human pilot safety and feasibility trial evaluating chimeric antigen receptor (CAR) engineered, autologous primary human CD8+ cytolytic T lymphocytes (CTLs) 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 twelve 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 three patients with recurrent disease was well-tolerated, with manageable temporary CNS inflammation. Following infusion of IL13-zetakine+ CTLs, evidence for transient anti-glioma responses was observed in two of the patients. Analysis of tumor tissue from one 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+ T cell administration. Conclusion 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.

Fibrodysplasia ossificans progressiva (FOP) is an autosomal dominant human disorder of bone formation that causes developmental skeletal defects and extensive debilitating bone formation within soft connective tissues (heterotopic ossification) during childhood. All patients with classic clinical features of FOP (great toe malformations and progressive heterotopic ossification) have previously been found to carry the same heterozygous mutation (c.617G>A; p.R206H) in the GS activation domain of activin A type I receptor/activin-like kinase 2 (ACVR1/ALK2), a bone morphogenetic protein (BMP) type I receptor. Among patients with FOP-like heterotopic NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript ossification and/or toe malformations, we identified patients with clinical features unusual for FOP. These atypical FOP patients form two classes: FOP-plus (classic defining features of FOP plus one or more atypical features) and FOP variants (major variations in one or both of the two classic defining features of FOP). All patients examined have heterozygous ACVR1 missense mutations in conserved amino acids. While the recurrent c.617G>A; p.R206H mutation was found in all cases of classic FOP and most cases of FOP-plus, novel ACVR1 mutations occur in the FOP variants and two cases of FOP-plus. Protein structure homology modeling predicts that each of the amino acid substitutions activates the ACVR1 protein to enhance receptor signaling. We observed genotype-phenotype correlation between some ACVR1 mutations and the age of onset of heterotopic ossification or on embryonic skeletal development.