Detailed Program Schedule
- Wednesday, May 28
- Thursday, May 29
- Friday, May 30
- Saturday, May 31
- Sunday, June 1
Friday, May 30
Oral Abstract Session 300
8:00 am – 10:00am
Clinical Gene Therapy Oral Abstract Session
(Abstracts 296-303)
Room 304
Chair
Malcolm K. Brenner, MD, PhD
Oral Abstract Session 301
8:00 am – 10:00am
RNA Virus Vectors: Functional Applications
(Abstracts 304-311)
Room 112
Co-Chairs
Stephen J. Russell, MD, PhD
John J. Rossi, PhD
Oral Abstract Session 302
8:00 am – 10:00am
Preclinical Applications of AAV Vectors
(Abstracts 312-319)
Room 302
Co-Chairs
Saswati Chatterjee, PhD
Cathryn S. Mah, PhD
Oral Abstract Session 303
8:00 am – 10:00am
Adenovirus: Chemically and Genetically-Engineered Vectors
(Abstracts 320-327)
Room 100
Co-Chairs
Philip Ng, PhD
Robin J. Parks, PhD
Oral Abstract Session 304
8:00 am – 10:00 am
DNA Vectorology: Non-Viral Vector Engineering
(Abstracts 328-335)
Room 312
Co-Chairs
Michele P. Calos, PhD
R. Scott McIvor, PhD
Oral Abstract Session 305
8:00 am – 10:00am
Cardiovascular Gene Therapy
(Abstracts 336-343)
Room 309
Barry J. Byrne, MD, PhD
Xiao Xiao, PhD
Oral Abstract Session 306
8:00 am – 10:00am
New Developments in Bone, Joint and Muscle Disease Gene/Cell Therapy
(Abstracts 344-351)
Room 208
Paul D Robbins, PhD
Jerry R Mendell, MD
Oral Abstract Session 307
8:00 am – 10:00am
Cancer – Immunotherapy: Suicide Genes and Immune Modulators of Tumor Microenvironment
(Abstracts 352-359)
Room 311
Co-Chairs
J. Victor Garcia-Martinez, PhD
Richard G. Vile, PhD
Oral Abstract Session 308
8:00 am – 10:00am
Cancer – Targeted Gene Therapy: Targeting Strategies
(Abstracts 360-367)
Room 207
Co-Chairs
Mary K. Danks, PhD
Gianpietro Dotti, MD
Oral Abstract Session 309
8:00 am – 10:00am
Zinc Finger Proteins & Regulatable Gene Expression
(Abstracts 368-375)
Room 210
Co-Chairs
Philip D. Gregory, PhD
David M. Spencer, PhD
Scientific Symposium 310
10:15 am - 12:15 pm
Room 309
Clinical and Regulatory Affairs: Novel Clinical and Regulatory Pathways for Clinical Development of Oncolytic Viral and Bacterial Vectors in Oncology
Co-Chairs
Barry J. Byrne, MD, PhD
Carl H. June, MD
Speakers
John J. Nemunaitis, MD
Viral Vector Immunogenicity in Man: Concurrent Immunosuppression along with a Replication Competent Oncolytic Adenoviral Vector in Subjects with Cancer
There are several mechanisms by which adenoviruses mediate antitumor activity. These include oncolytic effect, immune activation, gene delivery and combination of the above mechanisms. Local regional control has been demonstrated with several adenoviruses as monotherapy and in combination with standard therapy. Unfortunately, systemic therapeutic effect solely attributed to adenovirus has not been observed, thereby severely limiting potential application of adenoviral therapy in cancer management. Key reasons for lack of systemic activity include: insufficient virus exposure, rapid induction of neutralizing antibodies, dose limiting hepatic toxicity, and induction of TNF-α. Methods of improving potency without altering toxicity which will be reviewed in detail include: 1) reduction in viral clearance and immune inhibition; 2) enhancement in intracellular viral release, tumor cell specificity, tumor uptake, viral replication rate and oncolytic activity; 3) delivery of anticancer genes; and 4) combination with standard treatment.
David H. Kirn, MD
The Discovery and Development of Targeted Oncolytic Virotherapeutics for Cancer: A Novel Product Class
Therapeutic oncolytic viruses (virotherapeutics) constitute an emerging class of targeted anti-cancer agents with a novel primary mechanism of action. These agents infect, multiply within and ultimately destroy cancer cells; subsequently released viruses can then target and destroy other cancer cells. The concept of viral oncolysis began with descriptions of cancer remissions following virus infections. The creation of rationally-designed oncolytic virotherapeutics, however, required advances in viral and cancer cell genetics, genetic engineering, immunology, clinical trial design and manufacturing. The development of virotherapeutics evolved from the use of in vitro-passaged wildtype viruses (first generation), to engineered targeted viruses (second generation; e.g. Onyx-015) and finally to targeted and transgene expressing “armed” oncolytic viruses (third generation; e.g. JX-594, see below).
Selection of the optimal virus species and strain is critical. The virus product “pharmacophore” (wildtype backbone) should evolve to inherently spread rapidly, travel efficiently intravenously and avoid innate immune-mediated clearance. In addition, human safety data (e.g. as a vaccine) and a large therapeutic and monitoring transgene expression capacity are desirable. Poxviruses have these features due to their biology. Once the optimal virus species has been selected, rational engineering can improve cancer-selectivity, potency and monitoring. Cancer-selectivity can be achieved by deleting viral genes that are necessary for replication and spread in normal tissues but are expendable in cancer tissues. For example, deletion of the viral thymidine kinase (TK) gene in JX-594 (see below) severely attenuates the poxvirus in normal tissues, while in cancer cells there is no effect due to supra-physiologic levels of TK.
As an example of this approach, we will summarize recent clinical data with JX-594 (TK-) and preclinical data with JX-963. JX-495 is a TK- vaccinia expressing GM-CSF under control of a synthetic early/late promoter. The mechanism of action includes replication-dependent oncolysis plus tumor vascular shutdown and immunostimulation. JX-594 was administered by intratumoral injection on a Phase I dose-escalation trial in patients (n=14) with liver tumors. The treatment was generally well-tolerated; dose-limiting toxicity was hyperbilirubinemia. High-level product replication with systemic spread and distant tumor targeting was demonstrated as were high-level GM-CSF production and leukocytosis. Anti-tumor efficacy (including objective responses) was demonstrated in patients with hepatocellular carcinoma (HCC), squamous cell carcinomas of the lungs and others. Phase II HCC trials and Phase I-II intravenous clinical trials are underway.
JX-963 was derived from a more potent vaccinia virus strain and its viral gene deletions target it to cancer cells with EGF-R pathway activation. High-level cancer-selectivity and efficacy have been demonstrated in animal tumor models after IV administration and Phase I clinical trials are planned.
Thomas Dubensky, PhD
Application of Live-Attenuated Listeria Monocytogenes-Based Immunotherapies to Patients with Carcinoma
Stephen J. Russell, MD, PhD
Clinical Translation of Engineered Measles Viruses: The Legend Grows
Attenuated measles is a potent oncolytic virus that selectively fuses and kills any cell population that has a high surface density of CD46 (i.e., most human tumor cells). The virus can be engineered to redirect its attachment specificity to increase its oncolytic potency or to facilitate in vivo monitoring of its propagation. In this presentation we will discuss the clinical translation of engineered measles viruses, focusing on some of the most troublesome aspects of this process. For example: 1) how did we chose which viruses to translate; 2) how did we determine which animal models to use for preclinical efficacy and safety testing; 3) how did we determine a safe starting dose for the clinical trials; 4) how do we deal with PR issues arising from the movie “I am Legend.”
Scientific Symposium 311
10:15 am - 12:15 pm
Room 304 - 306
Clinical Trial Symposium
Chair
Kenneth G. Cornetta, MD
Speakers
Cy A. Stein, MD, PhD
G3139, a Bcl-2 Targeting Phosphorothioate Oligonucleotide, is an Angiogenesis-altering Drug
G3139 is a phosphorothioate oligonucleotide targeted to the initiation codon region of the Bcl-2 mRNA. This agent, in combination with DTIC, has shown significant activity with respect to prolongation of life in a Phase III, randomized, global (N = 771 patients) in patients with advanced melanoma whose LDH < 0.8 x upper limit of normal (N = 274; log10 P = 4). The mechanism of action of this compound is uncertain, and may relate to its ability to alter angiogenesis. Data supporting this hypothesis will be presented, in addition to data supporting a radically novel view of oligonucleotide delivery.
Manuel Grez, PhD
Gene Therapy of Chronic Granulomatous Disease: Ups and Downs after 4 Years Follow-Up
In 2004 we initiated a gene therapy trial aimed at the correction of Chronic Granulomatous Disease (CGD), a rare inherited immunodeficiency caused by a functional defect in the microbial killing activity of phagocytes. Two young adult X-CGD patients were treated with gene modified cells in combination with non-myeloablative conditioning. Successful engraftment of gene transduced cells resulted in the eradication of pre-existing life-threatening bacterial and fungal infections. One of our patients died 27 months after treatment due to a severe sepsis with multiorgan dysfunction. Although gene marking was still high at this time point, expression of the therapeutic gene, gp91phox, was severely reduced due to CpG methylation at the viral promoter. After an initial polyclonal repopulation, gene marked hematopoiesis in both patients was restricted to a few clones overexpressing MDS1/EVI1 and EVI1 leading to chromosomal instability and ultimately to hematological abnormalities. Although the treatment was initially beneficial for both patients, the side effects observed demand modifications in vector design for sustained gene expression and long term correction of the disease without side effects.
Pervin Anklesaria, PhD
Safety and Clinical Outcomes from a Phase 1/2 Study of Intraarticular Injection of AAV-TNFR:Fc in Inflammatory Arthritis
Intra-articular (IA) injection of an adeno-associated virus vector containing the cDNA for the human tumor necrosis factor receptor-immunoglobulin (IgG1) Fc fusion (TNFR:Fc) gene (rAAV2-TNFR:Fc) may be a means to provide TNFR:Fc protein into the joint of inflammatory arthritis patients with disease limited to a few joints which may not warrantuse of systemic tumor necrosis factor (TNF) antagonists or those joints unresponsive tosystemic TNF antagonists. To assess safety, local tolerability and clinical response afterIA administration of rAAV2-TNFR:Fc, 127 adults with persistent moderate or severeinflammation in a target joint (TJ) were enrolled and received a single IA injection ofeither rAAV2-TNFR:Fc [1x1011, 1x1012 or 1x1013 DNase resistant particles (DRP)/mL joint volume] or placebo, followed by open-label rAAV2-TNFR:Fc based on when the target joint met pre-determined criteria for re-injection. IA rAAV2-TNFR:Fc appears to be safe and well-tolerated in inflammatory arthritis subjects with and without systemic TNF antagonists. Patient reported outcome measures emerge as more sensitive indicators of clinical response than physical examination.
Ronald G. Crystal, MD
AAV-mediated Genetic Modification of the Central Nervous System to treat Batten Disease – From Mouse to Humans
Late infantile neuronal ceroid lipofuscinosis (LINCL), a pediatric autosomal recessive lysosomal storage disorder, manifests with blindness, progressive neurodegeneration, and death by age 8 to 12. The disease results from mutations in the CLN2 gene and deficiency in its product tripeptidyl peptidase (TPP-I), resulting in progressive loss of pigmented retinal epithelium and neurons. We demonstrated that direct central nervous system gene transfer of AAV2CUhCLN2 (a serotype 2, adeno-associated gene transfer expressing the human CLN2 cDNA) in mice, rats and non-human primates mediates long term TPP-I expression in the brain, and pre-clinical toxicology assessment in rats and non-human primates at doses scalable to humans demonstrated no significant differences in toxicology parameters between control and vector groups. Based on this data, we initiated a clinical trial to assess AAV2CUhCLN2 administration to the CNS of children with LINCL. Following administration with 2.5x1012 particle units of the AAV2CUhCLN2 vector to the brain at 12 locations through 6 burr holes, 10 children were assessed for 6 to 18 months with a LINCL neurologic rating scale and CNS MRI parameters. The data demonstrate that administration of AAV2CUhCLN2 to the CNS of children with LINCL was well tolerated. While the trial was not matched, randomized or blinded, comparison of the rate of decline of the LINCL rating scale (the 1° variable) to controls, suggests there is a slowing of progression of LINCL in the treated children. On this basis, we propose that additional studies to assess the safety and efficacy of AAV-mediated gene therapy for LINCL are warranted. In this regard, we have developed a 2nd generation strategy using a non-human primate-derived AAV vector (AAVrh.10hCLN2) that is significantly more effective in improving the abnormal phenotype of a homozygous LINCL knockout mouse and in delivering TPP-I to the non-human primate brain. In the context that the toxicity studies with AAVrh.10hCLN2 show no differences from controls, we are planning to move this vector to the clinic.
Scientific Symposium 312
10:15 am
- 12:15 pm
Room 312
Gene Therapy for Genetic Diseases: Update on Clinical Gene Therapy for Genetic Diseases
Chair
Jean Bennett, MD, PhD
Speakers
Mark A. Kay, MD, PhD
Tribute to Dr. David Schowalter
Bill Hauswirth, PhD
Retinal Gene Therapy: Leber Congenital Amaurosis Clinical Trial
The preclinical efficacy and safety basis for an recently initiated AAV vector clinical trial for LCA2 will be discussed. Included will be a discussion of efficacy studies in mouse and dog models of LCA2 in terms of vision restoration, both functionally and structurally, restoration of cortical function and improvement in visually guided behavior. Based on this data and safety/biodistribution studies in dogs, rats and nonhuman primates, the design of the trial, including the vector dosing rationale, will be discussed. Issues regarding options for follow-on studies will also be discussed. If the data permits, early-stage clinical trial results will be presented.
Jean Bennett, MD, PhD
A Phase I Trial of Subretinal Injection of AAV in Subjects with Congenital Blindness – Preliminary
Marina Cavazzana-Calvo, MD, PhD
Gene Therapy SCID-X1 Clinical Trial: Where Do We Stand?
Full correction of genetic diseases has been achieved in two different forms of severe combined immunodeficiencies, X-linked severe combined immunodeficiency (SCID-X1 γc deficiency), and adenosine deaminase (ADA) deficiency, by ex-vivo gene transfer into CD34+ hematopoietic cells. The clinical benefit of gene therapy has been tempered by the occurrence of leukemia in SCID-X1 patients in our trial as well as in the British one. These data indicate that in the context of SCID-X1 the preferential retroviral targeting of active genes in hematopoietic progenitors, can induce leukemic events. Modified vector design, notably including LTR enhancer inactivation, may thus improve safety of an otherwise efficient therapy.
Adrian J. Thrasher, MD, PhD
New Developments in Clinical Trials for SCID-X1
Scientific Symposium 313
10:15 am
- 12:15 pm
Room 311
Hemopoietic: Hematopoietic Stem Cell Niche
Chair
David A. Williams, MD
Speakers
David T. Scadden, MD
Niche Interactions Governing Stem Cell Fate
Mervin Yoder, MD
Circulating and Resident Endothelial Colony Forming Cells
During embryogenesis, blood vessels are formed de novo by the patterned assembly of angioblasts in a process termed vasculogenesis. Once an intact vascular system has been established, the development of new blood vessels primarily occurs via the sprouting of endothelial cells from postcapillary venules or the maturation and de novo growth of collateral conduits from larger diameter arteries. These two mechanisms of new blood vessel formation are termed angiogenesis and arteriogenesis, respectively. In 1997, Asahara and colleagues described a population of human circulating CD34+ cells that could differentiate ex vivo into cells with endothelial cell like characteristics. These cells were termed “endothelial progenitor cells” (EPCs), and this landmark study challenged the traditional understanding of angiogenesis to suggest that circulating cells in adult peripheral blood may also contribute to new vessel formation. Further, subsequent studies showed that these cells are derived from bone marrow, circulate in peripheral blood, and home to sites of new blood vessel formation that include ischemic tissues and tumor microenvironments in a process termed “postnatal vasculogenesis”.
Utilizing sophisticated cell marking strategies, more recent studies indicate that marrow-derived EPCs may play minimal or no role in neovascularization of tumors, vessel repair, or normal vessel growth and development. These conflicting reports have raised questions about the function of EPCs in vascular homeostasis and repair. The controversies surrounding these fundamental questions may in part originate from the heterogenous phenotypic definitions of EPCs and a lack of functional clonogenic assays to isolate and accurately describe the proliferative potential of EPCs.
We have described an approach that identifies a novel hierarchy of EPCs based on their clonogenic and proliferative potential, analogous to the hematopoietic stem/progenitor cell system. Using this approach, we have identified a population of EPCs in cord blood that give rise to colonies of endothelial cells that replate into at least secondary and tertiary colonies, and express levels of telomerase activity that correlates to the degree of cell autonomous proliferative potential. Cells with similar properties have been identified in large and small vessels from the rodent lung. Thus, these studies describe a clonogenic method to define a hierarchy of EPCs based on their proliferative potential, and identify a unique population of high proliferative potential-endothelial colony forming cells (HPP-ECFC) in human blood and rodent vessels.
Dario Campana, MD, PhD
Microenvironmental Mechanisms of Drug Resistance in Acute Leukemia
Bone marrow-derived mesenchymal cells form the microenvironment that supports leukemia cell growth. There is mounting evidence indicating that mesenchymal cells can also protect leukemic cells from cytotoxic drugs. Mechanisms described include the induction of cell cycle quiescence and the stimulation of antiapoptotic molecule expression in leukemic cells. Another recently discovered mechanism that protects acute lymphoblastic leukemia cells from asparaginase cytotoxicity is the secretion of asparagine by mesenchymal cells These mechanisms and possible ways to disrupt them will be discussed.
Paul S. Frenette, MD
Circadian Control of Stem Cell Attraction
Haematopoietic stem cells (HSCs) circulate in the bloodstream under steady state conditions, but the mechanisms controlling their physiological trafficking are unknown. We describe that circulating HSCs/progenitors exhibit robust circadian fluctuations, peaking 5 h after the initiation of light and reaching a nadir 5 h after darkness. Circadian oscillations are dramatically altered when mice are subjected to continuous light or to a jet lag defined as a shift of 12 h. We show that circulating HSCs/progenitors fluctuate in antiphase with the expression of the chemokine CXCL12 in the bone marrow (BM) microenvironment. Cyclical HSC release and Cxcl12 expression are regulated by core genes of the molecular clock through noradrenergic signals from the sympathetic nervous system. These adrenergic signals are locally delivered by nerves in the BM, transmitted to stromal cells by the β3-adrenergic receptor, leading to reduced nuclear content of Sp1 transcription factor, and rapid downregulation of Cxcl12. These data suggest that circadian, neurally driven HSC release during the animal’s resting period may promote regeneration of the stem cell niche, and possibly of other tissues.
Scientific Symposium 314
10:15 am
- 12:15 pm
Room 302
Non Viral Gene Therapy: The Widening Gyre-Non Viral Gene Delivery: Slow but Sure
Chair
James G. Hecker, MD, PhD
Speakers
Muthiah Manoharan, PhD
Delivering RNAi Therapeutics using Chemistry
RNA interference (RNAi) is a powerful biological process for specific silencing of mRNAs in diversified eukaryotic cells. By introducing chemical modifications into synthetic siRNA (small interfering RNAs) building blocks, desirable “drug-like” properties can be imparted to the siRNAs. siRNAs containing chemical modifications show enhanced resistance towards nuclease degradation, suppression of immune stimulation as well as reduced “off-target” effects. To achieve in vivo delivery, certain chemical conjugates and novel formulations are being investigated. Progress in these areas will be presented.
Esther H. Chang, PhD
An Immunolipisomal Nanodelivery System for Systemic p53 Gene Therapy: A Phase I Clinical
A platform nanodelivery system has been developed comprising a self assembled, biodegradable, cationic liposomal nanoparticle, which bears targeting molecules that home to the surface of tumor cells. When systematically administered, this nanocomplex can efficiently and selectively deliver nucleic acid-based molecular therapeutics, diagnostic MRI contrast agents, and small molecules to not only primary tumors, but also metastases in animal models of a number of human cancers. The nanodelivery of imaging agents results in a marked improvement in the sensitivity and resolution in detecting minute metastatic lesions. The tumor targeting delivery of various molecular therapeutics has also been shown to dramatically synergize with conventional radio- and chemotherapies. An immunoliposomal complex containing wtp53 gene is being evaluated in a phase 1 clinical trial for patients with advanced solid tumors.
Jason G. Fewell, PhD
Clinical Development of a Polymer-Based IL-12 Gene Therapeutic for the Treatment of Recurrent Ovarian Cancer
Interleukin-12 is a potent anti-cancer cytokine whose action is mediated through a robust immunostimulatory and antiangiogenic properties. We have developed an IL-12 therapeutic (EGEN-001) composed of an IL-12 gene expression plasmid and a lipopolymer gene carrier system, PEG-PEI-Cholesterol (PPC), designed to be delivered locally in the tumor environment. Administration of EGEN-001 is effective in treating a variety of tumor types in animal models and synergistic efficacy effects have been observed when EGEN-001 is combined with standard chemotherapeutics. Manufacturing of EGEN-001 has been achieved under cGMP and the lyophilized product has been shown to be highly stable with a -20oC storage life of over 2 years. A Phase I dose escalation trial was performed in patients with recurrent disseminated ovarian cancer. Results indicated that repeated intraperitoneal administrations of EGEN-001 are safe and well tolerated with some suggestion of dose dependent efficacy. Clinical testing has subsequently advanced into a second clinical trial using EGEN-001 in combination with taxane-platinum chemotherapy.
Stephen Hyde, PhD
Non-Viral Vector Development For Reduced Inflammation and Sustained Pulmonary Gene
The UK Cystic Fibrosis Gene Therapy Consortium (www.cfgenetherapy.org.uk) is the combined research programme of the three UK gene therapy research groups that have performed cystic fibrosis gene transfer clinical studies. In support of our next phase of clinical studies we have undertaken an extensive pre-clinical research programme to identify a non-viral gene transfer formulation that 1) directs efficient pulmonary transgene expression after delivered by clinically relevant aerosolisation devices, 2) is repeatedly administrable without loss of efficacy, 3) is minimally inflammatory / toxic, and 4) is readily manufactured under cGMP. During this evaluation we identified plasmid derived CG dinucleotides as the major source of host inflammation in response to non-viral gene delivery to the lung and thus developed a range of CG dinucleotide free expression vectors that are capable of sustained lung transgene expression in the absence of host inflammation. In parallel we also developed a regulatory agency approved device to facilitate complete, rapid and scalable mixing of plasmid DNA and non-viral gene transfer agents, and identified optimal aerosolisation conditions that allow efficient delivery of our preferred formulation to our target cells that line the conducting airways.
Scientific Symposium 315
10:15 am
- 12:15 pm
Room 100
Respiratory Tract: Update on Respiratory Tract Clinical Trials
Chair
Jay K. Kolls, MD
Speakers
Terence R. Flotte, MD
Preclinical and Phase I Trials of Recombinant Adeno-Associated Virus Vectors for Alpha-1 Antitrypsin Deficiency
Results of previous phase I clinical trials of recombinant adeno-associated virus (rAAV) vector-based gene therapy indicated an association between shortened duration of transgene expression and effector T lymphocyte responses to the AAV capsid. In this current first-in-human trial, an AAV2-ITR flanked cassette expressing normal (M) alpha-1 antitrypsin (AAT) from a CMV-beta actin hybrid (CBA) promoter was cross-packaged into AAV1 capsids and injected under ultrasound guidance into the deltoid muscle of the non-dominant arm of 9 AAT-deficient subjects. Vector administration was well tolerated and safe, with only mild local reactions related to treatment and one unrelated SAE due to an intercurrent bacterial epididymitis, while M-specific AAT expression was observed above background in 6 of 6 subjects within cohorts 2 and 3 (highest being 1 mcg/ml). Trangene expression was sustained for 90 days in 2 subjects and was continuously ongoing at the final time point tested in each of the other 4 subjects; this despite positive antibody responses to AAV1 capsid and positive gamma-interferon ELISPOT responses to AAV1 capsid at day 14 in all subjects tested. These findings suggest that immune responses to AAV capsid do not target transduced cells in this context.
Eric W.F.W. Alton, MD, FRCP
Clinical Trials of Gene Therapy for Cystic Fibrosis
More than 25 clinical studies have now been undertaken for cystic fibrosis (CF) gene therapy. This talk will briefly summarise the available data, and then focus on the efforts of the UK CF Gene Therapy Consortium. This large grouping of scientists and clinicians has just begun a clinical study to assess whether the currently available, optimal non-viral formulation is sufficient to show changes in clinically relevant assays, when administered repeatedly to CF subjects.
Steven M. Albelda, MD
Gene Transfer Clinical Trials in Mesothelioma and Lung Cancer
The treatment of thoracic malignancies has been a goal of gene therapy since its inception. A number of clinical trials using a variety of vectors have been conducted and results reported. This talk will outline the design and results of trials for malignant pleural mesothelioma and lung cancer.
Zhou Xing, MD, PhD
Gene Transfer Approaches for Vaccination against Pulmonary Tuberculosis
Pulmonary tuberculosis (TB) remains a leading infectious cause of deaths worldwide. Novel vaccination strategies are needed to improve protective immunity by BCG immunization. Over the last 15 years or so, several gene transfer vectors have been explored as genetic TB vaccine platforms and some of these genetic TB vaccines have entered or are about to enter clinical trials. However, the challenge still lies ahead.
Scientific Symposium 316
10:15 am
- 12:15 pm
Room 112
Viral: The Critical Interface between AAV Vectors and the Immune System
John T. Gray, PhD
Speakers
John D. Mountz, MD, PhD
Regulation of the Adaptive Immune Response to Viral Vectors and Transgenes
The adaptive immune response to a virus or transgene, as opposed to the innate response, can be shaped by previous immunogenic or tolerogenic antigen exposure. Such responses can be modified to enable long term expression of an adenovirus (Ad) or an AAV gene therapy transgene. Central steps to immunity or tolerance involve APC processing in presentation of the antigen in MHC-restrictive manner to CD4 T cells (class II MHC molecule) or CD8 T cells (class I MHC molecule). Immunity can be boosted by cytokines of the Th1 (IL-2, IFN-γ), Th2 (IL-4 or IL10), or Th17 (IL-17) class. Tolerance can be promoted by using transgenes to which natural tolerance has occurred or presentation under conditions of low co-stimulation or in the presence of cytokines such as TGF-β or T-regulatory cells. Similarly, adaptive B cell responses involve T cell help to promote Ig gene somatic hypermutation and class-switch recombination (CSR) by B cells to produce antibodies to viral epitopes or transgenes. This can be modulated by all of the cytokines mentioned above, whereas certain soluble factors such as BLyS and CD40L promote autoantibodies to self or foreign antigens. Specific mechanisms of antigen processing and presentation can differ depending on the site of administration, due to differences in the resident or migratory APC and can be enhanced or blocked by cytokine or anti-cytokine therapy. The recent importance of B-T cell interactions regulated by chemokines and regulators of G-protein signaling provide further options to limit the adaptive immune response to enable long-term and safe transfer of gene therapy by Ad and AAV.
Roland W. Herzog, PhD
Tolerance to the Transgene Product by Taking Advantage of Organ-Specific Immune Responses
Establishment of immune tolerance to the therapeutic transgene product is critical for the success and safety of gene replacement therapy. Distinct routes of antigen administration/expression may lead to immunity or tolerance because of tissue-specific signals. We have demonstrated that hepatic gene transfer with adeno-associated viral (AAV) vectors, which do not elicit strong innate immunity and do not efficiently transduce antigen presenting cells, can induce immune tolerance to coagulation factor IX and other transgene products. Hepatocyte-derived transgene expression leads to T cell tolerance and induction of CD4+CD25+FoxP3+ regulatory T cells, which actively suppresses antibody and CTL responses to factor IX. An improved hepatic protocol directs tolerance induction largely independent of genetic effects. Furthermore, our investigations identified mucosal surfaces as an alternative target of tolerogenic antigen administration to prevent undesired immune responses to the transgene product.
Katherine A. High, MD
Immuno Responses to AAV in Human Gene Transfer Studies
In a clinical trial of AAV-2-F.IX, we studied T cell responses to AAV capsid and to Factor IX in two subjects who developed transaminase elevation after liver-directed gene transfer, and demonstrated that both had detectable AAV capsid-specific CD8+ T cells in the circulation after AAV vector infusion. In a subsequent study, we sought to develop a mouse model of the same phenomenon (transaminase elevation accompanied by loss of transgene expression), but neither we nor other groups have been able to do so. In a reductionist approach, we sought to study capsid presentation on the surface of the transduced cell. We isolated a soluble T cell receptor specific for B*0702 loaded with an AAV-specific peptide, and used this to track peptide-MHC presentation on transduced cells in vitro and in vivo (in a mouse transgenic for human HLA B*0702). In other experiments, we analyzed the ability of PBMCs expanded from normal and AAV-infused subjects to lyse an HLA-matched hepatocyte cell line transduced with AAV-1, AAV-2, or AAV-8 vectors. Finally, we have carried out a prospective analysis of T and B cell responses to AAV and to the transgene product in a clinical trial of AAV-1 expressing lipoprotein lipase in individuals who are deficient in this enzyme. The results of this study will be reviewed.
Chengwen Li, PhD
AAV Vector and the Immune Response
Recently, a clinical trial for hemophilia B patients with adeno-associated virus (AAV) vector has suggested that capsid specific CTLs eliminate AAV2/F9 transduced hepatocytes, leading to therapeutic failure. However, capisd specific CTLs did not eliminate AAV2 transduced target tissues in mouse although AAV2 capsid was shown to induce a CTL response through both a classical MHC-Class I antigen presentation and cross-presentation pathway in animal models. Two possibilities can explain this result: 1) weak immunogenicity of capsid in mice and/or 2) alternative epitopes are responsible for immune response observed in clinical trial. To enhance capsid immunogenicity, we introduced a strong immunodomain OVA epitope SIINFEKL into AAV2 capsid and tested CTL mediated killing of AAV2 transduced target cells in vivo. Under these conditions, OVA specific CTLs decrease transgene expression in AAV vector transduced mice but followed a time course mimicking uncoating kinetics of AAV2 transduction. Since these results suggested that capsid specific CTLs could play a role in transgene elimination but did not reproduce the time course observed in Phase I clinical study, we explore alternative possibilities. Specifically, we tested epitopes derived from an alternative reading frame (ARF) of the Factor 9 transgene as a potential causative agent for inducing a CTL response. First we applied bioinformatic tools that predicted 3 epitopes within the ARF of the F9 transgene as possible antigens that would elicit a CTL response consistent with time course observed in the clinic. One of these peptides (p18) induced a strong CTL response following humanized B0702 mouse immunization. More importantly, AAV2/F9 infection also elicited a CTL response against p18. These results suggest ability to develop animal model for studying potential CTL response to AAV capsid after vector transduction, as well as role of immune response to ARF with AAV liver directed vectors. More through understanding of these gene therapy parameters should enhance our understanding for designing future clinical trials
Exhibit Hall Open
12:00 pm – 2:00 pm
Room Exhibit Hall A, Plaza Level
Lunch in the Exhibit Hall
12:15 pm
– 1:15 pm
Exhibit Hall A, Plaza Level
Special Plenary Session 320
1:30 pm – 3:30 pm
Presentation of the Top Abstracts
Room Ballroom A-C
Co-Chairs
Paul B. McCray, Jr. MD
Brian P. Sorrentino, MD
Abstract Introducers and Presenters:
Steven M. Albelda, MD
Introduces
376 - Ta-Chiang Liu, MD, PhD
Clinical Proof-Of-Concept with JX-594, a Novel Targeted Multi-Mechanistic Oncolytic Poxvirus, In Patients with Refractory Liver Tumors
Helen E. Heslop, MD
Introduces
377 - Chiara Bonini, MD
Transfer of a Suicide Gene into Donor Lymphocytes Allows Early and Effective Immune-reconstitution after Family Haploidentical Hematopoietic Stem Cell Transplantation for Leukemias: Results of the TK007 Study.
Jeffrey Chamberlain, PhD Introduces
378 - Toshifumi Yokota, PhD
Body-wide Restoration of Dystrophin Expression and Amelioration of Pathology in Dystrophic Dogs Using a Morpholino Cocktail
Bill Hauswirth, PhD Introduces
379 - Defne Amado
AAV-Mediated Delivery of Rod-Derived Cone Viability Factor: Towards A Mutation-Independent Prevention of Retinal Blindness
David M. Bodine, PhD Introduces
380 - Yashuhiro Kazuki, PhD
A Novel Human Artificial Chromosome (HAC) for Gene Therapy and Animal Transgenesis
John F. Engelhardt, PhD Introduces
381 - Li Zhong, MD
Next Generation of Recombinant Adeno-associated Virus 2 Vectors: Point Mutations in Tyrosine Residues Lead to High-efficiency Transduction at Lower Vector Doses
Break
3:30 pm – 3:45 pm
Oral Abstract Session 330
3:45 pm – 5:15 pm
HSV and Other DNA Viruses
(Abstracts 382-387)
Room 309
Co-Chairs
Joseph C. Glorioso, PhD
David Strayer, MD, PhD
Oral Abstract Session 331
3:45 pm – 5:15 pm
DNA Vectorology: In Vivo Non-Viral Delivery
(Abstracts 388-393)
Room 304
Co-Chairs
Muna I. Naash, PhD
Andrew D. Miller, PhD
Oral Abstract Session 332
3:45 pm – 5:15 pm
Advances in Non-Viral Approaches for Vaccine and Therapeutic Applications
(Abstracts 394-399)
Room 312
Co-Chairs
Richard Heller, PhD
Dexi Liu, PhD
Oral Abstract Session 333
3:45 pm – 5:15 pm
Hemophilia and Inborn Errors
(Abstracts 400-405)
Room 207
Co-Chairs
Nicola Brunetti-Pierri, MD
Paul E. Monahan, MD
Oral Abstract Session 334
3:45 pm – 5:15 pm
Targeting Viral Infection Through Gene Delivery
(Abstracts 406-411)
Room 210
Co-Chairs
Dorothee von Laer, MD
Grant D Trobridge, PhD
Oral Abstract Session 335
3:45 pm – 5:15 pm
Cancer – Apoptosis and Suicide: Mechanisms
(Abstracts 412-417)
Room 100
Co-Chairs
James S. Norris, PhD
Rajagopal Ramesh, PhD
Oral Abstract Session 336
3:45 pm – 5:15 pm
Advances in Lung Gene Therapy
(Abstracts 418-423)
Room 208
Co-Chairs
Patrick L. Sinn, PhD
Gerry McLachlan, PhD
Oral Abstract Session 337
3:45 pm – 5:15 pm
Immune Responses to Viral Vectors
(Abstracts 424-429)
Room 311
Co-Chairs
Pedro Lowenstein, MD, PhD
Katherine M. Ponder, MD
Oral Abstract Session 338
3:45 pm – 5:15 pm
Oligonucleotide Therapies for Diseases of Muscle and Nerve
(Abstracts 430-435)
Room 302
Scott Harper, PhD
Matthew H. Porteus, MD, PhD
Oral Abstract Session 339
3:45 pm – 5:15 pm
Cell Processing and Vector Production
(Abstracts 436-441)
Room 112
Co-Chairs
Gerhard Bauer, PhD
Greg Podsakoff, MD
Networking Reception and Exhibits
5:15 pm
– 8:15 pm
Room Exhibit Hall A, Plaza Level
Poster Session II
5:15 pm
– 8:15 pm
Room Exhibit Hall B, Plaza Level
Adenovirus Vectors: Cancer Therapy
(Abstracts 442 through 468)
HSV and Other DNA Vectors
(Abstracts 469 through 481)
DNA Vectorology: Non-Viral Vector Engineering
(Abstracts 482 through 4948)
Nonviral Gene Transfer – Targeting Strategies
(Abstracts 495 through 508)
Neurologic – New Approaches
(Abstracts 509 through 526; Abstracts 512 & 526 have been moved to Poster Session III after Abstract 900)
Musculoskeletal Gene and Cell Therapy: Muscular Dystrophies
(Abstracts 527 through 540)
Targeting Viral Infection Through Gene Delivery
(Abstracts 541 through 548)
Cancer – Immunotherapy: Novel Viral Therapeutics
(Abstracts 549 through 560)
Cancer – Mechanisms of Cancer Cell Killing
(Abstracts 561 through 573)
Cancer – Targeted Gene Therapy: Targeting Strategies
(Abstracts 574 through 597)
Cancer – Targeted Gene Therapy: Angiogenesis, Combination Therapies and Bioinformatics
(Abstracts 598 through 618)
Hematologic – Transduction, Engraftment and Transgene Expression
(Abstracts 619 through 635)
Growth Factors, Protein Delivery, Animal Models
(Abstracts 636 through 653)
Oligonucleotide Therapies I
(Abstracts 654 through 672)
Foundation Symposium 340
Supported by the ALS Association, Families of SMA, Fight SMA, Muscular Dystrophy Association, and SMA Foundation
7:00 pm – 10:00 pm
Room 304/306
Innovations in Gene Therapy for Neurodegenerative Diseases
Chair
Kenneth Fischbeck, MD
Speakers
Kenneth Fischbeck, MD
Introduction
Brian K. Kaspar, PhD
Translational gene delivery for motor neuron diseases
This presentation will focus on gene delivery to the CNS for SMA and ALS therapy focusing on:
(1) Cellular targets for SMA and ALS
(2) Strategies for gene delivery to the spinal cord
(3) New developments in gene delivery to motor neurons and astrocytes
Katherine W. Klinger, PhD
CNS targeted delivery for lysosomal storage diseases and Spinal Muscular Atrophy (SMA)
This presentation will cover some of the challenges and opportunities in CNS gene therapy for LSDs and SMA and will include:
(1) the inherent difference in gene therapy designed to deliver secreted protein versus a structural protein
(2) reaching the desired target cell
(3) potential requirement for both CNS and systemic delivery
Jerry Mendell, MD
Translational and clinical studies of gene delivery for neuromuscular diseases
(1) Learning from our ongoing clinical gene therapy studies
(2) Gene delivery to produce clinically meaningful outcomes
(3) Alternative strategies to gene replacement
R. Jude Samulski, PhD
Vector delivery for neuromuscular disorders: from bench to bedside
This presentation will cover three aspects of vector delivery for Phase I clinical trials:
(1) The development and testing of vectors for pre-clinical research;
(2) The production of lead candidates following regulatory guidelines for tox and biodistribution studies;
(3) The clinical production campaign; time lines, budgets, and use of common sense.