11 AAV Mediated CNS Gene Transfer of Bevacizumab Reduces Human Glioblastoma Growth and Increases Survival in Mice Molecular Therapy Volume 21, Supplement 1, May 2013 Copyright © The American Society o[.]
CANCER - IMMUNOTHERAPY I evasion from immunological control including apoptosis resistance, insensitivity to anti-growth signals, downregulation of MHC, NK cell evasion, immune suppression among others Consequently, it is essential to develop innovative cancer strategies to address immune obstacles to generate more effective immune therapies Myeloidderived suppressor cells (MDSCs) are a mixture of immune cells composed of immature macrophages, granulocytes, dendritic cells, and myeloid cells These cells possess a remarkable ability to suppress immune responses, and as part of tumor immune suppression MDSCs are able to expand, facilitating tumor growth, and immune escape These cells represent an important area of research as MDSCs may serve as a target for preventing tumor progression and could affect immune responses to anti-cancer vaccines In mice, we investigated the mechanisms of MDSCs expansion and characterized the role of MDSCs in T cell immune suppression in an antigen specific B16 melanoma tumor model utilizing a novel Tyrosinase DNA vaccine Using this potent cellular response-driving Tyr-DNA vaccine with electroporation (EP), we showed the immunogenicity of Tyr vaccine as a prophylactic measure The vaccine increased the magnitude and broadened the immune response by strengthening CD8+ T-cell infiltration at the tumor site in part by blocking MDSCs expansion This blocking was through regulating a potent angiogenic factor for MDSC expansion, MCP-1 production Combining DNA vaccines with blocking of MCP-1 production may prove important for treatment of Melanoma by immune therapy Further studies in this area are warranted 10 First-in-Human Application of Sleeping Beauty System for Gene Therapy Partow Kebriaei,1 Helen Huls,2 Harjeet Singh,2 Simon Olivares,2 Matthew J Figliola,2 Margaret Dawson,2 Bipulendu Jena,2 Rineka Jackson,2 Doyle Bosque,1 Ian McNiece,1 Gabriela Rondon,1 Perry B Hackett,3 Elizabeth J Shpall,1 Richard E Champlin,1 Laurence J N Cooper.2 Stem Cell Transplantation and Cellular Therapy, MD Anderson Cancer Center, Houston, TX; 2Pediatrics, MD Anderson Cancer Center, Houston, TX; 3Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN T cells can be genetically modified ex vivo to redirect specificity upon enforced expression of a chimeric antigen receptor (CAR) that recognizes tumor-associated antigen (TAA) independent of human leukocyte antigen (HLA) We report a new approach to non-viral gene transfer using the Sleeping Beauty (SB) transposon/ transposase system to stably express a 2nd generation CD19-specific CAR (designated CD19RCD28 that signals through chimeric CD28/CD3-) in autologous and allogeneic T cells manufactured in compliance with current good manufacturing practice (cGMP) for Phase I/II trials T cells were electroporated using a Nucleofector device to synchronously introduce plasmids carrying an SB transposon (CD19RCD28) and encoding a hyperactive SB transposase (SB11) T cells stably expressing the CAR were retrieved over 28 days of co-culture by recursive additions of g-irradiated artificial antigen presenting cells (aAPC) in presence of soluble recombinant interleukin (IL)-2 and IL-21 The aAPC (designated clone #4) were derived from K562 cells and genetically modified to co-express the TAA CD19 as well as the co-stimulatory molecules CD86, CD137L and a membrane-bound protein of IL-15 Using the dual platforms (Figure) of SB system and aAPC to date we have enrolled patients with multiple relapsed ALL (n=4) or B-cell lymphoma (n=5) on three investigator-initiated trials to infuse thawed patient- and donor-derived CD19-specific T cells after autologous (n=2), and allogeneic adult (n=6) and umbilical cord (n=1) hematopoietic stemcell transplantation (HSCT) Each T-cell product was subjected to a battery of in-process testing to complement release testing The first research participant was successfully treated in May of 2012 We have S4 administered infusions to date in patients receiving adult allogeneic HSCT, beginning at a dose of 106 and escalating to 5x107 T cells/m2 No toxicities have been noted These HSCT trials continue to accrue and pave the way for our next trials infusing autologous CAR+ T cells (including T cells activated via chimeric CD137/CD3-) after lympho-depleting chemotherapy We note that the purified plasmids can be produced in bulk at a fraction of the cost of clinical grade virus, which enhances the translational appeal of electroporation and propagation of T cells in compliance with cGMP This is the first report of the first human application of the SB system to genetically modify clinical-grade cells and provides investigators with a new approach to gene therapy 11 AAV-Mediated CNS Gene Transfer of Bevacizumab Reduces Human Glioblastoma Growth and Increases Survival in Mice Martin J Hicks,1 Kosuke Funato,3 Lan Wang,1 Eric Aronowitz,2 Jonathan P Dyke,2 Douglas J Ballon,2 Vivianne S Tabar,3 David F Havlicek,1 Esther Z Frenk,1 Bishnu P De,1 Maria J Chiuchiolo,1 Dolan Sondhi,1 Neil R Hackett,1 Stephen M Kaminsky,1 Ronald G Crystal.1 Department of Genetic Medicine, Weill Cornell Medical College, New York, NY; 2Department of Radiology, Weill Cornell Medical College, New York, NY; 3Department of Surgery, Memorial SloanKettering Cancer Center, New York, NY Glioblastoma multiforme (GBM) accounts for approximately 54% of all primary brain and CNS gliomas It is distinguished by prominent vascular proliferation, and rapid and invasive growth Despite increases in the molecular and physiological characterization of GBM, the median overall survival of GBM patients remains little more than one year Current therapies to reduce disease progression are typically administered systemically and thus, are limited by the blood-brain barrier We have developed a method to deliver the genetic message for therapeutic monoclonal antibodies (mAB) directly to the CNS via adeno-associated virus (AAV) gene transfer vectors such that expression is persistent and local to the milieu of the tumor To measure the efficacy of this strategy, either the U87MG cell line or patient-derived early passage GBM cells were administered to the striatum of NOD/SCID immunodeficient mice Quantification of GBM tumors was assessed by MRI and immunohistochemical analyses AAVrh.10BevMab, an AAVrh.10-based vector coding for bevacizumab (Avastin®), an anti-human vascular endothelial growth factor (VEGF) monoclonal, was delivered to the area of the GBM xenograft, either wk post-xenograft administration or simultaneous with xenograft administration Localized expression of the mAB was confirmed by ELISA, and Western and immunohistochemical analyses Administration of AAVrh.10BevMab to the CNS wk after GBM xenograft reduced the growth (as measured by MRI) of the U87MG tumor by 3.6-fold at wk (p