Locoregional delivery of IL-13Rα2-targeting CAR-T cells in recurrent high-grade glioma: a phase 1 trial.

Chimeric antigen receptor T cell (CAR-T) therapy is an emerging strategy to improve treatment outcomes for recurrent high-grade glioma, a cancer that responds poorly to current therapies. Here we report a completed phase I trial evaluating IL-13Rα2-targeted CAR-T cells in 65 patients with recurrent high-grade glioma, the majority being recurrent glioblastoma (rGBM). Primary objectives were safety and feasibility, maximum tolerated dose/maximum feasible dose and a recommended phase 2 dose plan.

Spatial organization of heterogeneous immunotherapy target antigen expression in high-grade glioma.

High-grade (WHO grades III-IV) glioma remains one of the most lethal human cancers. Adoptive transfer of tumor-targeting chimeric antigen receptor (CAR)-redirected T cells for high-grade glioma has revealed promising indications of anti-tumor activity, but objective clinical responses remain elusive for most patients. A significant challenge to effective immunotherapy is the highly heterogeneous structure of these tumors, including large variations in the magnitudes and distributions of target antigen expression, observed both within individual tumors and between patients.

Intranasally Administered L-Myc-Immortalized Human Neural Stem Cells Migrate to Primary and Distal Sites of Damage after Cortical Impact and Enhance Spatial Learning.

As the success of stem cell-based therapies is contingent on efficient cell delivery to damaged areas, neural stem cells (NSCs) have promising therapeutic potential because they inherently migrate to sites of central nervous system (CNS) damage. To explore the possibility of NSC-based therapy after traumatic brain injury (TBI), isoflurane-anesthetized adult male rats received a controlled cortical impact (CCI) of moderate severity (2.8 mm deformation at 4 m/s) or sham injury (i.

Chlorotoxin-directed CAR T cells for specific and effective targeting of glioblastoma.

Although chimeric antigen receptor (CAR) T cells have demonstrated signs of antitumor activity against glioblastoma (GBM), tumor heterogeneity remains a critical challenge. To achieve broader and more effective GBM targeting, we developed a peptide-bearing CAR exploiting the GBM-binding potential of chlorotoxin (CLTX). We find that CLTX peptide binds a great proportion of tumors and constituent tumor cells.

Long-term stability and computational analysis of migration patterns of L-MYC immortalized neural stem cells in the brain.

Background: Preclinical studies indicate that neural stem cells (NSCs) can limit or reverse central nervous system (CNS) damage through delivery of therapeutic agents for cell regeneration. Clinical translation of cell-based therapies raises concerns about long-term stability, differentiation and fate, and absence of tumorigenicity of these cells, as well as manufacturing time required to produce therapeutic cells in quantities sufficient for clinical use. Allogeneic NSC lines are in growing demand due to challenges inherent in using autologous stem cells, including production costs that limit availability to patients.

Optimization of IL13Rα2-Targeted Chimeric Antigen Receptor T Cells for Improved Anti-tumor Efficacy against Glioblastoma.

T cell immunotherapy is emerging as a powerful strategy to treat cancer and may improve outcomes for patients with glioblastoma (GBM). We have developed a chimeric antigen receptor (CAR) T cell immunotherapy targeting IL-13 receptor α2 (IL13Rα2) for the treatment of GBM. Here, we describe the optimization of IL13Rα2-targeted CAR T cells, including the design of a 4-1BB (CD137) co-stimulatory CAR (IL13BBζ) and a manufacturing platform using enriched central memory T cells.

Human Neural Stem Cell Biodistribution and Predicted Tumor Coverage by a Diffusible Therapeutic in a Mouse Glioma Model.

Engineered neural stem cells (NSCs) intrinsically migrating to brain tumors offer a promising mechanism for local therapeutic delivery. However, difficulties in quantitative assessments of NSC migration and in estimates of tumor coverage by diffusible therapeutics have impeded development and refinement of NSC-based therapies. To address this need, we developed techniques by which conventional serial-sectioned formalin-fixed paraffin-embedded (FFPE) brains can be analyzed in their entirety across multiple test animals.

Regression of Glioblastoma after Chimeric Antigen Receptor T-Cell Therapy.

A patient with recurrent multifocal glioblastoma received chimeric antigen receptor (CAR)-engineered T cells targeting the tumor-associated antigen interleukin-13 receptor alpha 2 (IL13Rα2). Multiple infusions of CAR T cells were administered over 220 days through two intracranial delivery routes - infusions into the resected tumor cavity followed by infusions into the ventricular system. Intracranial infusions of IL13Rα2-targeted CAR T cells were not associated with any toxic effects of grade 3 or higher.

L-MYC Expression Maintains Self-Renewal and Prolongs Multipotency of Primary Human Neural Stem Cells.

Pre-clinical studies indicate that neural stem cells (NSCs) can limit or reverse CNS damage through direct cell replacement, promotion of regeneration, or delivery of therapeutic agents. Immortalized NSC lines are in growing demand due to the inherent limitations of adult patient-derived NSCs, including availability, expandability, potential for genetic modifications, and costs. Here, we describe the generation and characterization of a new human fetal NSC line, immortalized by transduction with L-MYC (LM-NSC008) that in vitro displays both self-renewal and multipotent differentiation into neurons, oligodendrocytes, and astrocytes.

Planarians as a model of aging to study the interaction between stem cells and senescent cells in vivo.

The depletion of stem cell pools and the accumulation of senescent cells in animal tissues are linked to aging. Planarians are invertebrate flatworms and are unusual in that their stem cells, called neoblasts, are constantly replacing old and dying cells. By eliminating neoblasts in worms via irradiation, the biological principles of aging are exposed in the absence of wound healing and regeneration, making planaria a powerful tool for aging research.

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 10(8) CAR-engineered T cells via a catheter/reservoir system.

The histone demethylase jumonji coordinates cellular senescence including secretion of neural stem cell-attracting cytokines.

Unlabelled: Jumonji domain-containing protein 3 (JMJD3/KDM6B) demethylates lysine 27 on histone H3 (H3K27me3), a repressive epigenetic mark controlling chromatin organization and cellular senescence. To better understand the functional consequences of JMJD3 its expression was investigated in brain tumor cells. Querying patient expression profile databases confirmed JMJD3 overexpression in high-grade glioma.

Cytokine induction of VCAM-1 but not IL13Rα2 on glioma cells: a tale of two antibodies.

The interleukin-13 receptor alpha2 (IL13Rα2) is a cell surface receptor that is over-expressed by a subset of high-grade gliomas, but not expressed at significant levels by normal brain tissue. For both malignant and non-malignant cells, IL13Rα2 surface expression is reported to be induced by various cytokines such as IL-4 or IL-13 and tumor necrosis factor (TNF). Our group has developed a therapeutic platform to target IL13Rα2-positive brain tumors by engineering human cytotoxic T lymphocytes (CTLs) to express the IL13-zetakine chimeric antigen receptor.

Glioma IL13Rα2 is associated with mesenchymal signature gene expression and poor patient prognosis.

A major challenge for successful immunotherapy against glioma is the identification and characterization of validated targets. We have taken a bioinformatics approach towards understanding the biological context of IL-13 receptor α2 (IL13Rα2) expression in brain tumors, and its functional significance for patient survival. Querying multiple gene expression databases, we show that IL13Rα2 expression increases with glioma malignancy grade, and expression for high-grade tumors is bimodal, with approximately 58% of WHO grade IV gliomas over-expressing this receptor.

Neural stem cell-mediated delivery of irinotecan-activating carboxylesterases to glioma: implications for clinical use.

CPT-11 (irinotecan) has been investigated as a treatment for malignant brain tumors. However, limitations of CPT-11 therapy include low levels of the drug entering brain tumor sites and systemic toxicities associated with higher doses. Neural stem cells (NSCs) offer a novel way to overcome these obstacles because of their inherent tumor tropism and ability to cross the blood-brain barrier, which enables them to selectively target brain tumor sites.

Magnetic resonance imaging tracking of ferumoxytol-labeled human neural stem cells: studies leading to clinical use.

Numerous stem cell-based therapies are currently under clinical investigation, including the use of neural stem cells (NSCs) as delivery vehicles to target therapeutic agents to invasive brain tumors. The ability to monitor the time course, migration, and distribution of stem cells following transplantation into patients would provide critical information for optimizing treatment regimens. No effective cell-tracking methodology has yet garnered clinical acceptance.

Neural stem cell-mediated enzyme/prodrug therapy for glioma: preclinical studies.

High-grade gliomas are extremely difficult to treat because they are invasive and therefore not curable by surgical resection; the toxicity of current chemo- and radiation therapies limits the doses that can be used. Neural stem cells (NSCs) have inherent tumor-tropic properties that enable their use as delivery vehicles to target enzyme/prodrug therapy selectively to tumors. We used a cytosine deaminase (CD)-expressing clonal human NSC line, HB1.

Contact and encirclement of glioma cells in vitro is an intrinsic behavior of a clonal human neural stem cell line.

Pathotropic neural stem and/or progenitor cells (NSCs) can potentially deliver therapeutic agents to otherwise inaccessible cancers. In glioma, NSCs are found in close contact with tumor cells, raising the possibility that specificity of NSC contact with glioma targets originates in the tumor cells themselves. Alternatively, target preferences may originate, at least in part, in the tumor microenvironment.

Cellular host responses to gliomas.

Background: Glioblastoma multiforme (GBM) is the most aggressive type of malignant primary brain tumors in adults. Molecular and genetic analysis has advanced our understanding of glioma biology, however mapping the cellular composition of the tumor microenvironment is crucial for understanding the pathology of this dreaded brain cancer. In this study we identified major cell populations attracted by glioma using orthotopic rodent models of human glioma xenografts.

Stem-like tumor-initiating cells isolated from IL13Rα2 expressing gliomas are targeted and killed by IL13-zetakine-redirected T Cells.

Purpose: To evaluate IL13Rα2 as an immunotherapeutic target for eliminating glioma stem-like cancer initiating cells (GSC) of high-grade gliomas, with particular focus on the potential of genetically engineered IL13Rα2-specific primary human CD8(+) CTLs (IL13-zetakine(+) CTL) to target this therapeutically resistant glioma subpopulation.

Experimental Design: A panel of low-passage GSC tumor sphere (TS) and serum-differentiated glioma lines were expanded from patient glioblastoma specimens. These glioblastoma lines were evaluated for expression of IL13Rα2 and for susceptibility to IL13-zetakine(+) CTL-mediated killing in vitro and in vivo.

Neural stem cell targeting of glioma is dependent on phosphoinositide 3-kinase signaling.

The utility of neural stem cells (NSCs) has extended beyond regenerative medicine to targeted gene delivery, as NSCs possess an inherent tropism to solid tumors, including invasive gliomas. However, for optimal clinical implementation, an understanding of the molecular events that regulate NSC tumor tropism is needed to ensure their safety and to maximize therapeutic efficacy. We show that human NSC lines responded to multiple tumor-derived growth factors and that hepatocyte growth factor (HGF) induced the strongest chemotactic response.

Novel method for visualizing and modeling the spatial distribution of neural stem cells within intracranial glioma.

Neural stem cells (NSCs) hold great promise for glioma therapy due to their inherent tumor-tropic properties, enabling them to deliver therapeutic agents directly to invasive tumor sites. In the present study, we visualized and quantitatively analyzed the spatial distribution of tumor-tropic NSCs in a mouse model of orthotopic glioma in order to predict the therapeutic efficacy of a representative NSC-based glioma therapy. U251.

Regulation of the hyperpolarization-activated cationic current Ih in mouse hippocampal pyramidal neurones by vitronectin, a component of extracellular matrix.

Because the hyperpolarization-activated cation-selective current I(h) makes important contributions to neural excitability, we examined its long-term regulation by vitronectin, an extracellular matrix component commonly elevated at injury sites and detected immunochemically in activated microglia. Focusing on mouse hippocampal pyramidal neurones in organotypic slice cultures established at postnatal day 0 or 1 and examined after 3-4 days in vitro, we observed differences in the amplitude and activation rate of I(h) between neurones in naive and vitronectin-exposed slices (10 microg ml(-1) added to serum-free medium), and between neurones in slices derived from wild-type and vitronectin-deficient mice. The potassium inward rectifier I(K(ir)), activated at similar voltages to I(h), was not affected by vitronectin.