540 Oncolytic Properties of a Vesicular Stomatitis/Measles Virus Hybrid Molecular Therapy Volume 20, Supplement 1, May 2012 Copyright © The American Society of Gene & Cell Therapy S208 CANCER ONCOLYTI[.]
CANCER-ONCOLYTIC VIRUSES TCR mispairing might be a powerful tool for TCR gene therapy In summary, we demonstrated the feasibility of our novel “siTCR” technology with its universal effects without dependency of TCR variations: enhancing surface expression of therapeutic TCR at low proviral copy number which may reduce the risk of mutagenesis and TCR mispairing which may cause autoimmunity This novel TCR gene therapy approach using “siTCR” retroviral vectors may be promising in terms of efficacy and safety 538 A Novel Immune Receptor Expressed by T Cells for Universal Targeting of Diverse and Multiple Tumor Associated Antigens Katarzyna Urbanska,1 Evripidis Lanitis,1 Rachel Lynn,1 Mathilde Poussin,1 Nathalie Scholler,1 Daniel J Powell, Jr.1 Department of Obstetrics and Gynecology, University of Pennsylvania, Philadelphia, PA Adoptive transfer of T cells transduced to express a chimeric antigen receptor (CAR) is an attractive treatment for human malignancies CARs have fixed antigen specificity, allowing for targeting to only one tumor associated antigen (TAA), and may have limited efficacy in tumors with heterogeneous TAA expression Widespread application and efficacy of CAR therapy would thus necessitate production of a large and costly panel of CARs against an array of known TAAs We therefore sought to extend the recognition specificity potential of bioengineered lymphocytes by developing a novel and universal strategy that allows flexibility in redirecting T cells against various TAAs We designed a biotin-binding immune receptor (BBIR) composed of extracellular modified avidin linked to an intracellular T cell signaling domain BBIR T cells recognize and bind exclusively to cancer cells pretargeted with specific biotinylated molecules, including scFvs, antibodies or other reagents, that specifically bind to cancer cells according to the array of known antigens expressed on the tumor membrane In plate bound assays, where immobilized tumor antigen is secondarily bound by biotinylated reagents, binding of the BBIR to biotin triggers antigen-specific T cell effector activity Further, binding of biotinylated antibodies to mesothelin, folate binding protein or EpCAM TAAs on the tumor cell surface allows BBIR T cells to recognize various tumor cell lines with non-overlapping antigen expression and triggers their secretion of various proinflamatory cytokines and cytotoxic activity in vitro The versatility afforded by BBIRs permits sequential or simultaneous targeting of a combination of distinct antigens Furthermore, BBIR T cells possess antitumor activity in vivo against established tumor in immunodeficient mice In conclusion, we report the development of a novel system of versatile T cell specificity, the biotin binding immune receptor, which extends beyond conventional CAR approaches for the tailored generation of T cells against near infinitive number of tumor associated antigens Cancer-Oncolytic Viruses 539 Selective Targeting and Disruption of Tumor-Associated Vasculature in Humans with an Engineered Oncolytic Poxvirus Caroline J Breitbach,1 Rozanne Arulanandamn,2 Steve H Thorne,3 Naomi De Silva,2 Manijeh Daneshmand,2 Anne Moon,1 Carolina Ilkow,1,2 James Burke,1 Tae-Ho Hwang,4 Jeong Heo,4 Mong Cho,5 Hannah Chen,3 Fernando A Angarita,6 Christina Addison,2 J Andrea McCart,6 Richard Patt,7 John C Bell,1,2 David H Kirn.1 Jennerex Inc, San Francisco; 2Centre for Innovative Cancer Therapeutics, Ottawa Hospital Research Institute, Ottawa, Canada; 3Departments of Surgery and Immunology, University of Pittsburgh Cancer Institute, Pittsburgh; 4Pusan National University Hospital, Busan, Korea; 5Pusan National University Yangsan Hospital, Busan, Korea; 6Experimental Therapeutics, Toronto General Research Institute, Toronto, Canada; 7RadMD, Doylestown Efforts to selectively target and disrupt established tumor vasculature have largely failed to date We hypothesized that a vaccinia virus engineered to target cells with activation of the ras/ MAPK signaling pathway (JX-594) could specifically infect and express transgenes (hGM-CSF, β-galactosidase) in tumor-associated vascular endothelial cells in humans Efficient replication and transgene expression in normal human endothelial cells in vitro required either VEGF or FGF-2 stimulation Intravenous infusion in mice resulted in virus replication in tumor-associated endothelial cells, disruption of tumor blood flow and hypoxia within 48 hours; massive tumor necrosis ensued within five days Normal vessels were not affected In patients treated with intravenous JX-594 on a Phase clinical trial, we demonstrated dose-dependent endothelial cell infection and transgene expression in tumor biopsies of diverse histologies Finally, patients with advanced hepatocellular carcinoma, a hypervascular and VEGF-rich tumor type, were treated with JX594 on Phase clinical trials JX-594 treatment caused disruption of tumor perfusion as early as five days in both VEGF-receptor inhibitor-naïve and -refractory patients Toxicities to normal blood vessels or to wound healing were not evident clinically or on MRI scans This platform technology opens up the possibility of multifunctional engineered vaccinia products that selectively target and infect tumor-associated endothelial cells, as well as cancer cells, resulting in transgene expression, vasculature disruption and tumor destruction in humans systemically 540 Oncolytic Properties of a Vesicular Stomatitis/Measles Virus Hybrid Camilo Ayala-Breton,1 Stephen J Russell,1,2 Kah-Whye Peng.1,3 Department of Molecular Medicine, Mayo Clinic, Rochester, MN; 2Division of Hematology, Mayo Clinic, Rochester, MN; Department of Obstetrics and Gynecology, Mayo Clinic, Rochester, MN Vesicular Stomatitis Virus (VSV) is a new promising oncolytic agent due to its preferential replication in tumor cells, fast replication cycle and high burst size However, one of the main concerns with using VSV for treatment of cancer is that the virus presents broad tropism for different types of cells, including neurons Measles Virus is another important oncolytic agent that shows preferential infection and cytopathic killing of cancer cells while sparing normal cells A recombinant MV expressing the human thyroidal sodium iodide symporter (NIS) is currently undergoing clinical testing for patients with myeloma, ovarian cancer, glioma and mesothelioma To take advantage of the MV tumor selectivity and VSV rapid replication, we constructed a new hybrid virus (VSV-FH) by replacing VSV glycoprotein gene (VSV-G) with Measles Virus Hemagglutinin (MV- S208 Molecular Therapy Volume 20, Supplement 1, May 2012 Copyright © The American Society of Gene & Cell Therapy CANCER-ONCOLYTIC VIRUSES H) and Fusion (MV-F) genes In vitro analysis of VSV-FH showed that the tropism of this new oncolytic virus was restricted to those cells expressing the MV natural receptors CD46 or SLAM Since parental VSV and VSV-FH have the same replication machinery, this new hybrid virus presented a robust production and release of infectious particles into the extracellular media Moreover, due to the expression of MV glycoproteins, VSV-FH can trigger the fusion of neighbor cells to form syncytia, therefore significantly increasing intracellular viral spread In vivo, a single intravenous dose of 1E6 TCID50 of VSVFH resulted in a significant reduction in the volumes of subcutaneous human myeloma tumors compared to a ten times higher dose (1E7 TCID50) of MV-NIS The median survival was also higher (80 days) for mice treated with VSV-FH than those treated with MV-NIS (60 days, p