Human Epidermal Growth Factor Receptor 2 (HER2) -Specific Chimeric Antigen Receptor-Modified T Cells for the Immunotherapy of HER2-Positive Sarcoma.

PURPOSE: The outcome for patients with metastatic or recurrent sarcoma remains poor. Adoptive therapy with tumor-directed T cells is an attractive therapeutic option but has never been evaluated in sarcoma. PATIENTS AND METHODS: We conducted a phase I/II clinical study in which patients with recurrent/refractory human epidermal growth factor receptor 2 (HER2) -positive sarcoma received escalating doses (1 × 10(4)/m(2) to 1 × 10(8)/m(2)) of T cells expressing an HER2-specific chimeric antigen receptor with a CD28.ζ signaling domain (HER2-CAR T cells). RESULTS: We enrolled 19 patients with HER2-positive tumors (16 osteosarcomas, one Ewing sarcoma, one primitive neuroectodermal tumor, and one desmoplastic small round cell tumor). HER2-CAR T-cell infusions were well tolerated with no dose-limiting toxicity. At dose level 3 (1 × 10(5)/m(2)) and above, we detected HER2-CAR T cells 3 hours after infusion by quantitative polymerase chain reaction in 14 of 16 patients. HER2-CAR T cells persisted for at least 6 weeks in seven of the nine evaluable patients who received greater than 1 × 10(6)/m(2) HER2-CAR T cells (P = .005). HER2-CAR T cells were detected at tumor sites of two of two patients examined. Of 17 evaluable patients, four had stable disease for 12 weeks to 14 months. Three of these patients had their tumor removed, with one showing ≥ 90% necrosis. The median overall survival of all 19 infused patients was 10.3 months (range, 5.1 to 29.1 months). CONCLUSION: This first evaluation of the safety and efficacy of HER2-CAR T cells in patients with cancer shows the cells can persist for 6 weeks without evident toxicities, setting the stage for studies that combine HER2-CAR T cells with other immunomodulatory approaches to enhance their expansion and persistence.

Combinational targeting offsets antigen escape and enhances effector functions of adoptively transferred T cells in glioblastoma.

Preclinical and early clinical studies have demonstrated that chimeric antigen receptor (CAR)-redirected T cells are highly promising in cancer therapy. We observed that targeting HER2 in a glioblastoma (GBM) cell line results in the emergence of HER2-null tumor cells that maintain the expression of nontargeted tumor-associated antigens. Combinational targeting of these tumor-associated antigens could therefore offset this escape mechanism. We studied the single-cell coexpression patterns of HER2, IL-13Rα2, and EphA2 in primary GBM samples using multicolor flow cytometry and immunofluorescence, and applied a binomial routine to the permutations of antigen expression and the related odds of complete tumor elimination. This mathematical model demonstrated that cotargeting HER2 and IL-13Rα2 could maximally expand the therapeutic reach of the T cell product in all primary tumors studied. Targeting a third antigen did not predict an added advantage in the tumor cohort studied. We therefore generated bispecific T cell products from healthy donors and from GBM patients by pooling T cells individually expressing HER2 and IL-13Rα2-specific CARs and by making individual T cells to coexpress both molecules. Both HER2/IL-13Rα2-bispecific T cell products offset antigen escape, producing enhanced effector activity in vitro immunoassays (against autologous glioma cells in the case of GBM patient products) and in an orthotopic xenogeneic murine model. Further, T cells coexpressing HER2 and IL-13Rα2-CARs exhibited accentuated yet antigen-dependent downstream signaling and a particularly enhanced antitumor activity.

The miR-223/nuclear factor I-A axis regulates glial precursor proliferation and tumorigenesis in the CNS.

Contemporary views of tumorigenesis regard its inception as a convergence of genetic mutation and developmental context. Glioma is the most common and deadly malignancy in the CNS; therefore, understanding how regulators of glial development contribute to its formation remains a key question. Previously we identified nuclear factor I-A (NFIA) as a key regulator of developmental gliogenesis, while miR-223 has been shown to repress NFIA expression in other systems. Using this relationship as a starting point, we found that miR-223 can suppress glial precursor proliferation via repression of NFIA during chick spinal cord development. This relationship is conserved in glioma, as miR-223 and NFIA expression is negatively correlated in human glioma tumors, and the miR-223/NFIA axis suppresses tumorigenesis in a human glioma cell line. Subsequent analysis of NFIA function revealed that it directly represses p21 and is required for tumorigenesis in a mouse neural stem cell model of glioma. These studies represent the first characterization of miR-223/NFIA axis function in glioma and demonstrate that it is a conserved proliferative mechanism across CNS development and tumorigenesis.

TanCAR: A Novel Bispecific Chimeric Antigen Receptor for Cancer Immunotherapy.

Targeted T cells are emerging as effective non-toxic therapies for cancer. Multiple elements, however, contribute to the overall pathogenesis of cancer through both distinct and redundant mechanisms. Hence, targeting multiple cancer-specific markers simultaneously could result in better therapeutic efficacy. We created a functional chimeric antigen receptor-the TanCAR, a novel artificial molecule that mediates bispecific activation and targeting of T cells. We demonstrate the feasibility of cumulative integration of structure and docking simulation data using computational tools to interrogate the design and predict the functionality of such a complex bispecific molecule. Our prototype TanCAR induced distinct T cell reactivity against each of two tumor restricted antigens, and produced synergistic enhancement of effector functions when both antigens were simultaneously encountered. Furthermore, the TanCAR preserved the cytolytic ability of T cells upon loss of one of the target molecules and better controlled established experimental tumors by recognition of both targets in an animal disease model. This proof-of-concept approach can be used to increase the specificity of effector cells for malignant versus normal target cells, to offset antigen escape or to allow for targeting the tumor and its microenvironment.Molecular Therapy-Nucleic Acids (2013) 2, e105; doi:10.1038/mtna.2013.32; published online 9 July 2013.