1
|
Ismail AM, Witt E, Bouwman T, Clark W, Yates B, Franco M, Fong S. The longitudinal kinetics of AAV5 vector integration profiles and evaluation of clonal expansion in mice. Mol Ther Methods Clin Dev 2024; 32:101294. [PMID: 39104575 PMCID: PMC11298592 DOI: 10.1016/j.omtm.2024.101294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Accepted: 06/24/2024] [Indexed: 08/07/2024]
Abstract
Adeno-associated virus (AAV)-based vectors are used clinically for gene transfer and persist as extrachromosomal episomes. A small fraction of vector genomes integrate into the host genome, but the theoretical risk of tumorigenesis depends on vector regulatory features. A mouse model was used to investigate integration profiles of an AAV serotype 5 (AAV5) vector produced using Sf and HEK293 cells that mimic key features of valoctocogene roxaparvovec (AAV5-hFVIII-SQ), a gene therapy for severe hemophilia A. The majority (95%) of vector genome reads were derived from episomes, and mean (± standard deviation) integration frequency was 2.70 ± 1.26 and 1.79 ± 0.86 integrations per 1,000 cells for Sf- and HEK293-produced vector. Longitudinal integration analysis suggested integrations occur primarily within 1 week, at low frequency, and their abundance was stable over time. Integration profiles were polyclonal and randomly distributed. No major differences in integration profiles were observed for either vector production platform, and no integrations were associated with clonal expansion. Integrations were enriched near transcription start sites of genes highly expressed in the liver (p = 1 × 10-4) and less enriched for genes of lower expression. We found no evidence of tumorigenesis or fibrosis caused by the vector integrations.
Collapse
Affiliation(s)
| | - Evan Witt
- BioMarin Pharmaceutical Inc., Novato, CA 94949, USA
| | | | - Wyatt Clark
- BioMarin Pharmaceutical Inc., Novato, CA 94949, USA
| | | | - Matteo Franco
- ProtaGene CGT GmbH, Heidelberg 69120, Germany
- ProtaGene Inc., Burlington, MA 01803, USA
| | - Sylvia Fong
- BioMarin Pharmaceutical Inc., Novato, CA 94949, USA
| |
Collapse
|
2
|
Bu Z, Lou J, Xu W, Zhang L, Tang Y. Human umbilical cord mesenchymal stem cell-based gene therapy for hemophilia B using scAAV-DJ/8-LP1-hFIXco transduction. Stem Cell Res Ther 2024; 15:210. [PMID: 39020429 PMCID: PMC11256413 DOI: 10.1186/s13287-024-03824-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Accepted: 07/01/2024] [Indexed: 07/19/2024] Open
Abstract
BACKGROUND Hemophilia B is an X-linked bleeding disorder caused by a mutation in the gene responsible for encoding coagulation factor IX (FIX). Gene therapy offers promising potential for curing this disease. However, the current method of relatively high dosage of virus injection carries inherent risks. The purpose of this study was to introduce a novel scAAV-DJ/8-LP1-hFIXco vector transduced human umbilical cord blood derived mesenchymal stem cells (HUCMSCs) as an alternative cell-based gene therapy to conventional gene therapy for Hemophilia B. METHODS The LP1-hFIXco gene structure was designed by us through searching the literature from NCBI and the scAAV-DJ/8-LP1-hFIXco vector was constructed by a commercial company. The HUCMSCs were cultivated in routine approach and transduced with scAAV-DJ/8-LP1-hFIXco vector. The human FIX activation system was employed for detection of hFIXco activity. The RNA and protein expression levels of the hFIXco were evaluated using PCR and western blot techniques. In animal studies, both NSG and F9-KO mice were used for the experiment, in which clotting time was utilized as a parameter for bleeding assessment. The immunohistochemical analysis was used to assess the distribution of HUCMSCs in mouse tissue sections. The safety for tumorigenicity of this cell-based gene therapy was evaluated by pathological observation after hematoxylin-eosin staining. RESULTS The transduction of HUCMSCs with the scAAV-DJ/8-LP1-hFIXco vector results in consistent and sustainable secretion of human FIXco during 5 months period both in vitro and in mouse model. The secretion level (hFIXco activity: 97.1 ± 2.3% at day 7 to 48.8 ± 4.5% at 5 months) was comparable to that observed following intravenous injection with a high dose of the viral vector (hFIXco activity: 95.2 ± 2.2% to 40.8 ± 4.3%). After a 5-month observation period, no clonal expansions of the transduced cells in tissues were observed in any of the mice studied. CONCLUSIONS We have discovered a novel and safer HUCMSCs mediated approach potentially effective for gene therapy in hemophilia B.
Collapse
Affiliation(s)
- Zibin Bu
- Division/Center of Hematology-oncology, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Zhejiang Hangzhou, 310003, PR China
| | - Jintu Lou
- Department of Clinical Laboratory, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Zhejiang Hangzhou, 310003, PR China
| | - Weiqun Xu
- Division/Center of Hematology-oncology, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Zhejiang Hangzhou, 310003, PR China
| | - Lingyan Zhang
- Division/Center of Hematology-oncology, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Zhejiang Hangzhou, 310003, PR China
| | - Yongmin Tang
- Division/Center of Hematology-oncology, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Zhejiang Hangzhou, 310003, PR China.
| |
Collapse
|
3
|
Pierce GF, Fong S, Long BR, Kaczmarek R. Deciphering conundrums of adeno-associated virus liver-directed gene therapy: focus on hemophilia. J Thromb Haemost 2024; 22:1263-1289. [PMID: 38103734 DOI: 10.1016/j.jtha.2023.12.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 11/07/2023] [Accepted: 12/01/2023] [Indexed: 12/19/2023]
Abstract
Adeno-associated virus gene therapy has been the subject of intensive investigation for monogenic disease gene addition therapy for more than 25 years, yet few therapies have been approved by regulatory agencies. Most have not progressed beyond phase 1/2 due to toxicity, lack of efficacy, or both. The liver is a natural target for adeno-associated virus since most serotypes have a high degree of tropism for hepatocytes due to cell surface receptors for the virus and the unique liver sinusoidal geometry facilitating high volumes of blood contact with hepatocyte cell surfaces. Recessive monogenic diseases such as hemophilia represent promising targets since the defective proteins are often synthesized in the liver and secreted into the circulation, making them easy to measure, and many do not require precise regulation. Yet, despite initiation of many disease-specific clinical trials, therapeutic windows are often nonexistent, resulting in excess toxicity and insufficient efficacy. Iterative progress built on these attempts is best illustrated by hemophilia, with the first regulatory approvals for factor IX and factor VIII gene therapies eventually achieved 25 years after the first gene therapy studies in humans. Although successful gene transfer may result in the production of sufficient transgenic protein to modify the disease, many emerging questions on durability, predictability, reliability, and variability of response have not been answered. The underlying biology accounting for these heterogeneous responses and the interplay between host and virus is the subject of intense investigation and the subject of this review.
Collapse
Affiliation(s)
- Glenn F Pierce
- World Federation of Hemophilia, Montreal, Quebec, Canada.
| | - Sylvia Fong
- BioMarin Pharmaceutical Inc, Research and Early Development, Novato, California, USA
| | - Brian R Long
- BioMarin Pharmaceutical Inc, Research and Early Development, Novato, California, USA
| | - Radoslaw Kaczmarek
- Department of Pediatrics, Indiana University School of Medicine, Wells Center for Pediatric Research, Indiana, USA; Laboratory of Glycobiology, Hirszfeld Institute of Immunology and Experimental Therapy, Wroclaw, Poland
| |
Collapse
|
4
|
Kasimsetty A, Sabatino DE. Integration and the risk of liver cancer-Is there a real risk? J Viral Hepat 2024; 31 Suppl 1:26-34. [PMID: 38606944 DOI: 10.1111/jvh.13915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 12/10/2023] [Accepted: 12/15/2023] [Indexed: 04/13/2024]
Abstract
Adeno-associated virus (AAV)-based gene therapies are in clinical development for haemophilia and other genetic diseases. Since the recombinant AAV genome primarily remains episomal, it provides the opportunity for long-term expression in tissues that are not proliferating and reduces the safety concerns compared with integrating viral vectors. However, AAV integration events are detected at a low frequency. Preclinical studies in mouse models have reported hepatocellular carcinoma (HCC) after systemic AAV administration in some settings, though this has not been reported in large animal models. The risk of HCC or other cancers after AAV gene therapy in clinical studies thus remains theoretical. Potential risk factors for HCC after gene therapy are beginning to be elucidated through animal studies, but their relevance to human studies remains unknown. Studies to investigate the factors that may influence the risk of oncogenesis as well as detailed investigation of cases of cancer in AAV gene therapy patients will be important to define the potential risk of AAV genotoxicity.
Collapse
Affiliation(s)
- Aradhana Kasimsetty
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Denise E Sabatino
- The Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- Division of Hematology, Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| |
Collapse
|
5
|
Ryckman AE, Deschenes NM, Quinville BM, Osmon KJ, Mitchell M, Chen Z, Gray SJ, Walia JS. Intrathecal delivery of a bicistronic AAV9 vector expressing β-hexosaminidase A corrects Sandhoff disease in a murine model: A dosage study. Mol Ther Methods Clin Dev 2024; 32:101168. [PMID: 38205442 PMCID: PMC10777117 DOI: 10.1016/j.omtm.2023.101168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Accepted: 11/30/2023] [Indexed: 01/12/2024]
Abstract
The pathological accumulation of GM2 ganglioside associated with Tay-Sachs disease (TSD) and Sandhoff disease (SD) occurs in individuals who possess mutant forms of the heterodimer β-hexosaminidase A (Hex A) because of mutation of the HEXA and HEXB genes, respectively. With a lack of approved therapies, patients experience rapid neurological decline resulting in early death. A novel bicistronic vector carrying both HEXA and HEXB previously demonstrated promising results in mouse models of SD following neonatal intravenous administration, including significant reduction in GM2 accumulation, increased levels of Hex A, and a 2-fold extension of survival. The aim of the present study was to identify an optimal dose of the bicistronic vector in 6-week-old SD mice by an intrathecal route of administration along with transient immunosuppression, to inform possible clinical translation. Three doses of the bicistronic vector were tested: 2.5e11, 1.25e11, and 0.625e11 vector genomes per mouse. The highest dose provided the greatest increase in biochemical and behavioral parameters, such that treated mice lived to a median age of 56 weeks (>3 times the lifespan of the SD controls). These results have direct implications in deciding a human equivalent dose for TSD/SD and have informed the approval of a clinical trial application (NCT04798235).
Collapse
Affiliation(s)
- Alex E. Ryckman
- Centre for Neuroscience Studies, Queen’s University, Kingston, ON K7L 3N6, Canada
| | - Natalie M. Deschenes
- Centre for Neuroscience Studies, Queen’s University, Kingston, ON K7L 3N6, Canada
| | - Brianna M. Quinville
- Centre for Neuroscience Studies, Queen’s University, Kingston, ON K7L 3N6, Canada
| | - Karlaina J.L. Osmon
- Centre for Neuroscience Studies, Queen’s University, Kingston, ON K7L 3N6, Canada
| | - Melissa Mitchell
- Medical Genetics/Departments of Pediatrics, Queen’s University, Kingston, ON K7L 2V7, Canada
| | - Zhilin Chen
- Department of Biomedical and Molecular Sciences, Queen’s University, Kingston, ON K7L 3N6, Canada
| | - Steven J. Gray
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jagdeep S. Walia
- Centre for Neuroscience Studies, Queen’s University, Kingston, ON K7L 3N6, Canada
- Department of Biomedical and Molecular Sciences, Queen’s University, Kingston, ON K7L 3N6, Canada
- Medical Genetics/Departments of Pediatrics, Queen’s University, Kingston, ON K7L 2V7, Canada
| |
Collapse
|
6
|
Symington E, Rangarajan S, Lester W, Madan B, Pierce GF, Raheja P, Robinson TM, Osmond D, Russell CB, Vettermann C, Agarwal SK, Li M, Wong WY, Laffan M. Long-term safety and efficacy outcomes of valoctocogene roxaparvovec gene transfer up to 6 years post-treatment. Haemophilia 2024; 30:320-330. [PMID: 38317480 DOI: 10.1111/hae.14936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 12/07/2023] [Accepted: 12/30/2023] [Indexed: 02/07/2024]
Abstract
INTRODUCTION Valoctocogene roxaparvovec uses an adeno-associated virus serotype 5 (AAV5) vector to transfer a factor VIII (FVIII) coding sequence to individuals with severe haemophilia A, providing bleeding protection. AIM To assess safety and efficacy of valoctocogene roxaparvovec 5-6 years post-treatment. METHODS In a phase 1/2 trial, adult male participants with severe haemophilia A (FVIII ≤1 IU/dL) without FVIII inhibitors or anti-AAV5 antibodies received valoctocogene roxaparvovec and were followed for 6 (6 × 1013 vg/kg; n = 7) and 5 (4 × 1013 vg/kg; n = 6) years. Safety, including investigation of potential associations between a malignancy and gene therapy, and efficacy are reported. RESULTS No new treatment-related safety signals emerged. During year 6, a participant in the 6 × 1013 vg/kg cohort was diagnosed with grade 2 parotid gland acinar cell carcinoma; definitive treatment was uncomplicated parotidectomy with lymph node dissection. Target enrichment sequencing of tumour and adjacent healthy tissue revealed low vector integration (8.25 × 10-5 per diploid cell). Integrations were not elevated in tumour samples, no insertions appeared to drive tumorigenesis, and no clonal expansion of integration-containing cells occurred. During all follow-ups, >90% decreases from baseline in annualised treated bleeds and FVIII infusion rates were maintained. At the end of years 6 and 5, mean FVIII activity (chromogenic assay) was 9.8 IU/dL (median, 5.6 IU/dL) and 7.6 IU/dL (median, 7.1 IU/dL) for the 6 × 1013 and 4 × 1013 vg/kg cohorts, respectively, representing proportionally smaller year-over-year declines than earlier timepoints. CONCLUSIONS Valoctocogene roxaparvovec safety and efficacy profiles remain largely unchanged; genomic investigations showed no association with a parotid tumour.
Collapse
Affiliation(s)
- Emily Symington
- Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | | | - Will Lester
- University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Bella Madan
- Guy's and St Thomas' NHS Foundation Trust, London, UK
| | | | - Priyanka Raheja
- Haemophilia Centre Royal London Hospital, Barts Health NHS Trust, London, UK
| | | | - Dane Osmond
- BioMarin Pharmaceutical Inc., Novato, California, USA
| | | | | | | | - Mingjin Li
- BioMarin Pharmaceutical Inc., Novato, California, USA
| | - Wing Yen Wong
- BioMarin Pharmaceutical Inc., Novato, California, USA
| | - Michael Laffan
- Centre for Haematology, Imperial College London, London, UK
| |
Collapse
|
7
|
Mücke MM, Fong S, Foster GR, Lillicrap D, Miesbach W, Zeuzem S. Adeno-associated viruses for gene therapy - clinical implications and liver-related complications, a guide for hepatologists. J Hepatol 2024; 80:352-361. [PMID: 37890721 DOI: 10.1016/j.jhep.2023.10.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 10/13/2023] [Accepted: 10/17/2023] [Indexed: 10/29/2023]
Abstract
Gene therapy has garnered increasing interest over recent decades. Several therapies employing gene transfer mechanisms have been developed, and, of these, adeno-associated virus (AAV) vectors have demonstrated viability for use with in vivo gene therapy. Several AAV-based therapeutics have received regulatory approval in the last few years including those for retinal disease, spinal muscular atrophy or aromatic L-amino acid decarboxylase deficiency. Lately, with the introduction of novel liver-directed AAV vector-based therapeutics for the treatment of haemophilia A and B, gene therapy has attracted significant attention in the hepatology community, with the liver increasingly recognised as a target for gene therapy. However, the introduction of foreign DNA into hepatocytes is associated with a risk of hepatic reactions, with raised ALT (alanine aminotransferase) and AST (aspartate aminotransferase) being - so far - the most commonly reported side effects. The complete mechanisms underlying the ALT flairs remain to be determined and the long-term risks associated with these new treatments is not yet known. The liver community is increasingly being asked to support liver-directed gene therapy to mitigate potential liver associated harm. In this review, we focus on AAV vector-based gene therapy, shedding light on this promising technique and its remarkable success in haemophilia, with a special focus on hepatic complications and their management in daily clinical practice.
Collapse
Affiliation(s)
- Marcus Maximilian Mücke
- Department of Internal Medicine I, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
| | - Sylvia Fong
- Research and Early Development, BioMarin Pharmaceutical. Inc, San Rafael, United States
| | - Graham R Foster
- Barts Liver Centre, Blizard Institute, QMUL, London, United Kingdom.
| | - David Lillicrap
- Department of Pathology and Molecular Medicine, Queen's University, Kingston, Canada
| | - Wolfgang Miesbach
- Department of Internal Medicine II, Haemostaseology and Haemophilia Centre, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
| | - Stefan Zeuzem
- Department of Internal Medicine I, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
| |
Collapse
|
8
|
Ago Y, Rintz E, Musini KS, Ma Z, Tomatsu S. Molecular Mechanisms in Pathophysiology of Mucopolysaccharidosis and Prospects for Innovative Therapy. Int J Mol Sci 2024; 25:1113. [PMID: 38256186 PMCID: PMC10816168 DOI: 10.3390/ijms25021113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 01/09/2024] [Accepted: 01/10/2024] [Indexed: 01/24/2024] Open
Abstract
Mucopolysaccharidoses (MPSs) are a group of inborn errors of the metabolism caused by a deficiency in the lysosomal enzymes required to break down molecules called glycosaminoglycans (GAGs). These GAGs accumulate over time in various tissues and disrupt multiple biological systems, including catabolism of other substances, autophagy, and mitochondrial function. These pathological changes ultimately increase oxidative stress and activate innate immunity and inflammation. We have described the pathophysiology of MPS and activated inflammation in this paper, starting with accumulating the primary storage materials, GAGs. At the initial stage of GAG accumulation, affected tissues/cells are reversibly affected but progress irreversibly to: (1) disruption of substrate degradation with pathogenic changes in lysosomal function, (2) cellular dysfunction, secondary/tertiary accumulation (toxins such as GM2 or GM3 ganglioside, etc.), and inflammatory process, and (3) progressive tissue/organ damage and cell death (e.g., skeletal dysplasia, CNS impairment, etc.). For current and future treatment, several potential treatments for MPS that can penetrate the blood-brain barrier and bone have been proposed and/or are in clinical trials, including targeting peptides and molecular Trojan horses such as monoclonal antibodies attached to enzymes via receptor-mediated transport. Gene therapy trials with AAV, ex vivo LV, and Sleeping Beauty transposon system for MPS are proposed and/or underway as innovative therapeutic options. In addition, possible immunomodulatory reagents that can suppress MPS symptoms have been summarized in this review.
Collapse
Affiliation(s)
- Yasuhiko Ago
- Nemours Children’s Health, 1600 Rockland Rd., Wilmington, DE 19803, USA; (Y.A.); (K.S.M.); (Z.M.)
| | - Estera Rintz
- Department of Molecular Biology, Faculty of Biology, University of Gdansk, 80-308 Gdansk, Poland;
| | - Krishna Sai Musini
- Nemours Children’s Health, 1600 Rockland Rd., Wilmington, DE 19803, USA; (Y.A.); (K.S.M.); (Z.M.)
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Zhengyu Ma
- Nemours Children’s Health, 1600 Rockland Rd., Wilmington, DE 19803, USA; (Y.A.); (K.S.M.); (Z.M.)
| | - Shunji Tomatsu
- Nemours Children’s Health, 1600 Rockland Rd., Wilmington, DE 19803, USA; (Y.A.); (K.S.M.); (Z.M.)
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
- Department of Pediatrics, Graduate School of Medicine, Gifu University, Gifu 501-1112, Japan
- Department of Pediatrics, Thomas Jefferson University, Philadelphia, PA 19144, USA
| |
Collapse
|
9
|
Chuecos MA, Lagor WR. Liver directed adeno-associated viral vectors to treat metabolic disease. J Inherit Metab Dis 2024; 47:22-40. [PMID: 37254440 PMCID: PMC10687323 DOI: 10.1002/jimd.12637] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 05/05/2023] [Accepted: 05/25/2023] [Indexed: 06/01/2023]
Abstract
The liver is the metabolic center of the body and an ideal target for gene therapy of inherited metabolic disorders (IMDs). Adeno-associated viral (AAV) vectors can deliver transgenes to the liver with high efficiency and specificity and a favorable safety profile. Recombinant AAV vectors contain only the transgene cassette, and their payload is converted to non-integrating circular double-stranded DNA episomes, which can provide stable expression from months to years. Insights from cellular studies and preclinical animal models have provided valuable information about AAV capsid serotypes with a high liver tropism. These vectors have been applied successfully in the clinic, particularly in trials for hemophilia, resulting in the first approved liver-directed gene therapy. Lessons from ongoing clinical trials have identified key factors affecting efficacy and safety that were not readily apparent in animal models. Circumventing pre-existing neutralizing antibodies to the AAV capsid, and mitigating adaptive immune responses to transduced cells are critical to achieving therapeutic benefit. Combining the high efficiency of AAV delivery with genome editing is a promising path to achieve more precise control of gene expression. The primary safety concern for liver gene therapy with AAV continues to be the small risk of tumorigenesis from rare vector integrations. Hepatotoxicity is a key consideration in the safety of neuromuscular gene therapies which are applied at substantially higher doses. The current knowledge base and toolkit for AAV is well developed, and poised to correct some of the most severe IMDs with liver-directed gene therapy.
Collapse
Affiliation(s)
- Marcel A. Chuecos
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX USA
- Translational Biology and Molecular Medicine Program, Baylor College of Medicine, Houston, TX USA
| | - William R. Lagor
- Department of Integrative Physiology, Baylor College of Medicine, Houston, TX USA
| |
Collapse
|
10
|
Seker Yilmaz B, Gissen P. Genetic Therapy Approaches for Ornithine Transcarbamylase Deficiency. Biomedicines 2023; 11:2227. [PMID: 37626723 PMCID: PMC10452060 DOI: 10.3390/biomedicines11082227] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 08/06/2023] [Accepted: 08/07/2023] [Indexed: 08/27/2023] Open
Abstract
Ornithine transcarbamylase deficiency (OTCD) is the most common urea cycle disorder with high unmet needs, as current dietary and medical treatments may not be sufficient to prevent hyperammonemic episodes, which can cause death or neurological sequelae. To date, liver transplantation is the only curative choice but is not widely available due to donor shortage, the need for life-long immunosuppression and technical challenges. A field of research that has shown a great deal of promise recently is gene therapy, and OTCD has been an essential candidate for different gene therapy modalities, including AAV gene addition, mRNA therapy and genome editing. This review will first summarise the main steps towards clinical translation, highlighting the benefits and challenges of each gene therapy approach, then focus on current clinical trials and finally outline future directions for the development of gene therapy for OTCD.
Collapse
Affiliation(s)
- Berna Seker Yilmaz
- Genetics and Genomic Medicine Department, Great Ormond Street Institute of Child Health, University College London, London WC1N 1EH, UK;
| | - Paul Gissen
- Genetics and Genomic Medicine Department, Great Ormond Street Institute of Child Health, University College London, London WC1N 1EH, UK;
- National Institute of Health Research Great Ormond Street Biomedical Research Centre, London WC1N 1EH, UK
- Metabolic Medicine Department, Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, UK
| |
Collapse
|
11
|
René CA, Parks RJ. Expanding the Availability of Onasemnogene Abeparvovec to Older Patients: The Evolving Treatment Landscape for Spinal Muscular Atrophy. Pharmaceutics 2023; 15:1764. [PMID: 37376212 DOI: 10.3390/pharmaceutics15061764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 06/06/2023] [Accepted: 06/15/2023] [Indexed: 06/29/2023] Open
Abstract
Spinal muscular atrophy (SMA) is a devastating neuromuscular disorder caused by mutations in the survival of motor neuron 1 (SMN1) gene, which leads to a reduced level in the SMN protein within cells. Patients with SMA suffer from a loss of alpha motor neurons in the spinal cord leading to skeletal muscle atrophy in addition to deficits in other tissues and organs. Patients with severe forms of the disease require ventilator assistance and typically succumb to the disease due to respiratory failure. Onasemnogene abeparvovec is an adeno-associated virus (AAV)-based gene therapeutic that has been approved for infants and young children with SMA, and it is delivered through intravenous administration using a dose based on the weight of the patient. While excellent outcomes have been observed in treated patients, the greater viral dose necessary to treat older children and adults raises legitimate safety concerns. Recently, onasemnogene abeparvovec use was investigated in older children through a fixed dose and intrathecal administration, a route that provides a more direct delivery to affected cells in the spinal cord and central nervous system. The promising results observed in the STRONG trial may support approval of onasemnogene abeparvovec for a greater proportion of patients with SMA.
Collapse
Affiliation(s)
- Charlotte A René
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
- Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
- Centre for Neuromuscular Disease, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Robin J Parks
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
- Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
- Centre for Neuromuscular Disease, University of Ottawa, Ottawa, ON K1H 8M5, Canada
- Department of Medicine, The Ottawa Hospital, Ottawa, ON K1H 8L6, Canada
| |
Collapse
|
12
|
Chen X, Dong T, Hu Y, De Pace R, Mattera R, Eberhardt K, Ziegler M, Pirovolakis T, Sahin M, Bonifacino JS, Ebrahimi-Fakhari D, Gray SJ. Intrathecal AAV9/AP4M1 gene therapy for hereditary spastic paraplegia 50 shows safety and efficacy in preclinical studies. J Clin Invest 2023; 133:e164575. [PMID: 36951961 PMCID: PMC10178841 DOI: 10.1172/jci164575] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 03/14/2023] [Indexed: 03/24/2023] Open
Abstract
Spastic paraplegia 50 (SPG50) is an ultrarare childhood-onset neurological disorder caused by biallelic loss-of-function variants in the AP4M1 gene. SPG50 is characterized by progressive spastic paraplegia, global developmental delay, and subsequent intellectual disability, secondary microcephaly, and epilepsy. We preformed preclinical studies evaluating an adeno-associated virus (AAV)/AP4M1 gene therapy for SPG50 and describe in vitro studies that demonstrate transduction of patient-derived fibroblasts with AAV2/AP4M1, resulting in phenotypic rescue. To evaluate efficacy in vivo, Ap4m1-KO mice were intrathecally (i.t.) injected with 5 × 1011, 2.5 × 1011, or 1.25 × 1011 vector genome (vg) doses of AAV9/AP4M1 at P7-P10 or P90. Age- and dose-dependent effects were observed, with early intervention and higher doses achieving the best therapeutic benefits. In parallel, three toxicology studies in WT mice, rats, and nonhuman primates (NHPs) demonstrated that AAV9/AP4M1 had an acceptable safety profile up to a target human dose of 1 × 1015 vg. Of note, similar degrees of minimal-to-mild dorsal root ganglia (DRG) toxicity were observed in both rats and NHPs, supporting the use of rats to monitor DRG toxicity in future i.t. AAV studies. These preclinical results identify an acceptably safe and efficacious dose of i.t.-administered AAV9/AP4M1, supporting an investigational gene transfer clinical trial to treat SPG50.
Collapse
Affiliation(s)
- Xin Chen
- Department of Pediatrics, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Thomas Dong
- Department of Pediatrics, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Yuhui Hu
- Department of Pediatrics, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Raffaella De Pace
- Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, Maryland, USA
| | - Rafael Mattera
- Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, Maryland, USA
| | - Kathrin Eberhardt
- Department of Neurology and F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Marvin Ziegler
- Department of Neurology and F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | | | - Mustafa Sahin
- Department of Neurology and F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Juan S. Bonifacino
- Neurosciences and Cellular and Structural Biology Division, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, Maryland, USA
| | - Darius Ebrahimi-Fakhari
- Department of Neurology and F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Steven J. Gray
- Department of Pediatrics, UT Southwestern Medical Center, Dallas, Texas, USA
| |
Collapse
|
13
|
Abstract
Gene therapy is poised to revolutionize modern medicine, with seemingly unlimited potential for treating and curing genetic disorders. For otherwise incurable indications, including most inherited metabolic liver disorders, gene therapy provides a realistic therapeutic option. In this Review, we discuss gene supplementation and gene editing involving the use of recombinant adeno-associated virus (rAAV) vectors for the treatment of inherited liver diseases, including updates on several ongoing clinical trials that are producing promising results. Clinical testing has been essential in highlighting many key translational challenges associated with this transformative therapy. In particular, the interaction of a patient's immune system with the vector raises issues of safety and the duration of treatment efficacy. Furthermore, several serious adverse events after the administration of high doses of rAAVs suggest greater involvement of innate immune responses and pre-existing hepatic conditions than initially anticipated. Finally, permanent modification of the host genome associated with rAAV genome integration and gene editing raises concerns about the risk of oncogenicity that require careful evaluation. We summarize the main progress, challenges and pathways forward for gene therapy for liver diseases.
Collapse
|
14
|
Ramamurthy RM, Atala A, Porada CD, Almeida-Porada G. Organoids and microphysiological systems: Promising models for accelerating AAV gene therapy studies. Front Immunol 2022; 13:1011143. [PMID: 36225917 PMCID: PMC9549755 DOI: 10.3389/fimmu.2022.1011143] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 09/01/2022] [Indexed: 11/24/2022] Open
Abstract
The FDA has predicted that at least 10-20 gene therapy products will be approved by 2025. The surge in the development of such therapies can be attributed to the advent of safe and effective gene delivery vectors such as adeno-associated virus (AAV). The enormous potential of AAV has been demonstrated by its use in over 100 clinical trials and the FDA’s approval of two AAV-based gene therapy products. Despite its demonstrated success in some clinical settings, AAV-based gene therapy is still plagued by issues related to host immunity, and recent studies have suggested that AAV vectors may actually integrate into the host cell genome, raising concerns over the potential for genotoxicity. To better understand these issues and develop means to overcome them, preclinical model systems that accurately recapitulate human physiology are needed. The objective of this review is to provide a brief overview of AAV gene therapy and its current hurdles, to discuss how 3D organoids, microphysiological systems, and body-on-a-chip platforms could serve as powerful models that could be adopted in the preclinical stage, and to provide some examples of the successful application of these models to answer critical questions regarding AAV biology and toxicity that could not have been answered using current animal models. Finally, technical considerations while adopting these models to study AAV gene therapy are also discussed.
Collapse
|
15
|
Sabatino DE, Bushman FD, Chandler RJ, Crystal RG, Davidson BL, Dolmetsch R, Eggan KC, Gao G, Gil-Farina I, Kay MA, McCarty DM, Montini E, Ndu A, Yuan J. Evaluating the state of the science for adeno-associated virus integration: An integrated perspective. Mol Ther 2022; 30:2646-2663. [PMID: 35690906 PMCID: PMC9372310 DOI: 10.1016/j.ymthe.2022.06.004] [Citation(s) in RCA: 78] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 06/03/2022] [Accepted: 06/06/2022] [Indexed: 12/12/2022] Open
Abstract
On August 18, 2021, the American Society of Gene and Cell Therapy (ASGCT) hosted a virtual roundtable on adeno-associated virus (AAV) integration, featuring leading experts in preclinical and clinical AAV gene therapy, to further contextualize and understand this phenomenon. Recombinant AAV (rAAV) vectors are used to develop therapies for many conditions given their ability to transduce multiple cell types, resulting in long-term expression of transgenes. Although most rAAV DNA typically remains episomal, some rAAV DNA becomes integrated into genomic DNA at a low frequency, and rAAV insertional mutagenesis has been shown to lead to tumorigenesis in neonatal mice. Currently, the risk of rAAV-mediated oncogenesis in humans is theoretical because no confirmed genotoxic events have been reported to date. However, because insertional mutagenesis has been reported in a small number of murine studies, there is a need to characterize this genotoxicity to inform research, regulatory needs, and patient care. The purpose of this white paper is to review the evidence of rAAV-related host genome integration in animal models and possible risks of insertional mutagenesis in patients. In addition, technical considerations, regulatory guidance, and bioethics are discussed.
Collapse
Affiliation(s)
- Denise E Sabatino
- The Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA; Division of Hematology, Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| | - Frederic D Bushman
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Randy J Chandler
- National Human Genome Research Institute, NIH, Bethesda, MD, USA
| | - Ronald G Crystal
- Department of Genetic Medicine, Weill Medical College of Cornell University, New York, NY, USA
| | - Beverly L Davidson
- The Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA; Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | | | | | - Guangping Gao
- Horae Gene Therapy Center, University of Massachusetts Medical School, Worcester, MA, USA
| | | | - Mark A Kay
- Departments of Pediatrics and Genetics, Stanford University, Stanford, CA, USA
| | | | - Eugenio Montini
- San Raffaele Telethon Institute for Gene Therapy, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Adora Ndu
- BridgeBio Pharma, Inc., Palo Alto, CA, USA
| | - Jing Yuan
- Drug Safety Research and Development, Pfizer Inc., Cambridge, MA, USA
| |
Collapse
|
16
|
Modern therapeutic approaches to liver-related disorders. J Hepatol 2022; 76:1392-1409. [PMID: 35589258 DOI: 10.1016/j.jhep.2021.12.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 11/30/2021] [Accepted: 12/17/2021] [Indexed: 12/19/2022]
Abstract
The liver is a key production and processing site that is essential for health. Liver dysfunction can result in both systemic and liver-specific diseases. To combat these diseases, genetic approaches have been developed that have high liver tropism and are based on gene addition/editing or gene silencing. The gene addition/editing approach has yielded encouraging clinical data on the use of viral vectors in patients with haemophilia, as well as neuromuscular diseases, and has led to trials for liver-related disorders. However, the immune response and the long-term stability of exogenous expression remain important challenges. Gene editing and mRNA therapy have yielded first in-human proof-of-concept therapeutics and vaccines, but the road to the treatment of liver-related disorders remains long. Gene silencing is accomplished primarily via antisense oligonucleotides and small-interfering RNAs (siRNAs). siRNA modification with N-acetyl galactosamine results in hepatocellular-specific targeting and catapulted the liver to the centre of siRNA research. Several siRNA drugs for liver-related disorders have recently been approved, and the pipeline of drugs under investigation is crowded. Loss-of-function mutations might also be treated with enzyme substitution therapy. This review summarises current genetic approaches as well as key enzyme substitution therapies, focusing on recently approved compounds, potential adverse effects, and future challenges. Collectively, these recent advances place the liver at the forefront of precision medicine for metabolic and genetic diseases and are expected to transform the care and treatment of patients with both liver-specific and systemic diseases.
Collapse
|
17
|
Macdonald J, Marx J, Büning H. Capsid-Engineering for Central Nervous System-Directed Gene Therapy with Adeno-Associated Virus Vectors. Hum Gene Ther 2021; 32:1096-1119. [PMID: 34662226 DOI: 10.1089/hum.2021.169] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Closing the gap in knowledge on the cause of neurodegenerative disorders is paving the way toward innovative treatment strategies, among which gene therapy has emerged as a top candidate. Both conventional gene therapy and genome editing approaches are being developed, and a great number of human clinical trials are ongoing. Already 2 years ago, the first gene therapy for a neurodegenerative disease, spinal muscular atrophy type 1 (SMA1), obtained market approval. To realize such innovative strategies, gene therapy delivery tools are key assets. Here, we focus on recombinant adeno-associated virus (AAV) vectors and report on strategies to improve first-generation vectors. Current efforts focus on the viral capsid to modify the host-vector interaction aiming at increasing the efficacy of target cell transduction, at simplifying vector administration, and at reducing the risk of vector dose-related side effects.
Collapse
Affiliation(s)
- Josephine Macdonald
- Institute of Experimental Hematology, Hannover Medical School, Hannover, Germany.,REBIRTH Research Center for Translational Regenerative Medicine, Hannover Medical School, Hannover, Germany
| | - Jennifer Marx
- Institute of Experimental Hematology, Hannover Medical School, Hannover, Germany.,REBIRTH Research Center for Translational Regenerative Medicine, Hannover Medical School, Hannover, Germany
| | - Hildegard Büning
- Institute of Experimental Hematology, Hannover Medical School, Hannover, Germany.,REBIRTH Research Center for Translational Regenerative Medicine, Hannover Medical School, Hannover, Germany
| |
Collapse
|
18
|
Bolt MW, Brady JT, Whiteley LO, Khan KN. Development challenges associated with rAAV-based gene therapies. J Toxicol Sci 2021; 46:57-68. [PMID: 33536390 DOI: 10.2131/jts.46.57] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The number of gene therapies in development continues to increase, as they represent a novel method to treat, and potentially cure, many diseases. Gene therapies can be conducted with an in vivo or ex vivo approach, to cause gene augmentation, gene suppression, or genomic editing. Adeno-associated viruses are commonly used to deliver gene therapies, but their use is associated with several manufacturing, nonclinical and clinical challenges. As these challenges emerge, regulatory agency expectations continue to evolve. Following administration of rAAV-based gene therapies, nonclinical toxicities may occur, which includes immunogenicity, hepatotoxicity, neurotoxicity, and the potential risks for insertional mutagenesis and subsequent tumorgenicity. The mechanism for these findings and translation into the clinical setting are unclear at this time but have influenced the nonclinical studies that regulatory agencies are increasingly requesting to support clinical trials and marketing authorizations. These evolving regulatory expectations and toxicities, as well as future nonclinical considerations, are discussed herein.
Collapse
Affiliation(s)
- Michael W Bolt
- Pfizer Inc., Drug Safety Research and Development, Cambridge, MA, USA
| | - Joseph T Brady
- Pfizer Inc., Drug Safety Research and Development, Cambridge, MA, USA
| | | | - K Nasir Khan
- Pfizer Inc., Drug Safety Research and Development, Groton, CA, USA
| |
Collapse
|
19
|
Hatano Y, Ideta T, Hirata A, Hatano K, Tomita H, Okada H, Shimizu M, Tanaka T, Hara A. Virus-Driven Carcinogenesis. Cancers (Basel) 2021; 13:2625. [PMID: 34071792 PMCID: PMC8198641 DOI: 10.3390/cancers13112625] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/22/2021] [Accepted: 05/25/2021] [Indexed: 12/13/2022] Open
Abstract
Cancer arises from the accumulation of genetic and epigenetic alterations. Even in the era of precision oncology, carcinogens contributing to neoplastic process are still an important focus of research. Comprehensive genomic analyses have revealed various combinations of base substitutions, referred to as the mutational signatures, in cancer. Each mutational signature is believed to arise from specific DNA damage and repair processes, including carcinogens. However, as a type of carcinogen, tumor viruses increase the cancer risk by alternative mechanisms, including insertional mutagenesis, viral oncogenes, and immunosuppression. In this review, we summarize virus-driven carcinogenesis to provide a framework for the control of malignant cell proliferation. We first provide a brief overview of oncogenic viruses and describe their implication in virus-related tumors. Next, we describe tumor viruses (HPV, Human papilloma virus; HBV, Hepatitis B virus; HCV, Hepatitis C virus; EBV, Epstein-Barr virus; Kaposi sarcoma herpesvirus; MCV, Merkel cell polyoma virus; HTLV-1, Human T-cell lymphotropic virus, type-1) and tumor virus-related cancers. Lastly, we introduce emerging tumor virus candidates, human cytomegalovirus (CMV), human herpesvirus-6 (HHV-6) and adeno-associated virus-2 (AAV-2). We expect this review to be a hub in a complex network of data for virus-associated carcinogenesis.
Collapse
Affiliation(s)
- Yuichiro Hatano
- Department of Tumor Pathology, Gifu University Graduate School of Medicine, Gifu 501-1194, Japan; (H.T.); (A.H.)
| | - Takayasu Ideta
- Department of Gastroenterology, Gifu University Graduate School of Medicine, Gifu 501-1194, Japan; (T.I.); (M.S.)
- Department of Laboratory Medicine, Gifu University Graduate School of Medicine, Gifu 501-1194, Japan
| | - Akihiro Hirata
- Laboratory of Veterinary Pathology, Joint Department of Veterinary Medicine, Faculty of Applied Biological Sciences, Gifu University, Gifu 501-1194, Japan;
| | - Kayoko Hatano
- Department of Obstetrics and Gynecology, Gifu University Hospital, Gifu 501-1194, Japan;
| | - Hiroyuki Tomita
- Department of Tumor Pathology, Gifu University Graduate School of Medicine, Gifu 501-1194, Japan; (H.T.); (A.H.)
| | - Hideshi Okada
- Department of Emergency and Disaster Medicine, Gifu University Graduate School of Medicine, Gifu 501-1194, Japan;
| | - Masahito Shimizu
- Department of Gastroenterology, Gifu University Graduate School of Medicine, Gifu 501-1194, Japan; (T.I.); (M.S.)
| | - Takuji Tanaka
- Department of Diagnostic Pathology (DDP) and Research Center of Diagnostic Pathology (RC-DiP), Gifu Municipal Hospital, Gifu 500-8513, Japan;
| | - Akira Hara
- Department of Tumor Pathology, Gifu University Graduate School of Medicine, Gifu 501-1194, Japan; (H.T.); (A.H.)
| |
Collapse
|
20
|
He X, Urip BA, Zhang Z, Ngan CC, Feng B. Evolving AAV-delivered therapeutics towards ultimate cures. J Mol Med (Berl) 2021; 99:593-617. [PMID: 33594520 PMCID: PMC7885987 DOI: 10.1007/s00109-020-02034-2] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 12/18/2020] [Accepted: 12/23/2020] [Indexed: 12/17/2022]
Abstract
Gene therapy has entered a new era after decades-long efforts, where the recombinant adeno-associated virus (AAV) has stood out as the most potent vector for in vivo gene transfer and demonstrated excellent efficacy and safety profiles in numerous preclinical and clinical studies. Since the first AAV-derived therapeutics Glybera was approved by the European Medicines Agency (EMA) in 2012, there is an increasing number of AAV-based gene augmentation therapies that have been developed and tested for treating incurable genetic diseases. In the subsequent years, the United States Food and Drug Administration (FDA) approved two additional AAV gene therapy products, Luxturna and Zolgensma, to be launched into the market. Recent breakthroughs in genome editing tools and the combined use with AAV vectors have introduced new therapeutic modalities using somatic gene editing strategies. The promising outcomes from preclinical studies have prompted the continuous evolution of AAV-delivered therapeutics and broadened the scope of treatment options for untreatable diseases. Here, we describe the clinical updates of AAV gene therapies and the latest development using AAV to deliver the CRISPR components as gene editing therapeutics. We also discuss the major challenges and safety concerns associated with AAV delivery and CRISPR therapeutics, and highlight the recent achievement and toxicity issues reported from clinical applications.
Collapse
Affiliation(s)
- Xiangjun He
- School of Biomedical Sciences, Faculty of Medicine; Institute for Tissue Engineering and Regenerative Medicine (iTERM), The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
| | - Brian Anugerah Urip
- School of Biomedical Sciences, Faculty of Medicine; Institute for Tissue Engineering and Regenerative Medicine (iTERM), The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
| | - Zhenjie Zhang
- School of Biomedical Sciences, Faculty of Medicine; Institute for Tissue Engineering and Regenerative Medicine (iTERM), The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
| | - Chun Christopher Ngan
- School of Biomedical Sciences, Faculty of Medicine; Institute for Tissue Engineering and Regenerative Medicine (iTERM), The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China
- Centre for Regenerative Medicine and Health, Hong Kong Institute of Science & Innovation, Chinese Academy of Sciences, Shatin N.T., Hong Kong SAR, China
| | - Bo Feng
- School of Biomedical Sciences, Faculty of Medicine; Institute for Tissue Engineering and Regenerative Medicine (iTERM), The Chinese University of Hong Kong, Shatin N.T., Hong Kong SAR, China.
- Centre for Regenerative Medicine and Health, Hong Kong Institute of Science & Innovation, Chinese Academy of Sciences, Shatin N.T., Hong Kong SAR, China.
- Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Guangzhou, 510320, China.
- Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China.
| |
Collapse
|
21
|
Ferla R, Alliegro M, Dell’Anno M, Nusco E, Cullen JM, Smith SN, Wolfsberg TG, O’Donnell P, Wang P, Nguyen AD, Chandler RJ, Chen Z, Burgess SM, Vite CH, Haskins ME, Venditti CP, Auricchio A. Low incidence of hepatocellular carcinoma in mice and cats treated with systemic adeno-associated viral vectors. Mol Ther Methods Clin Dev 2021; 20:247-257. [PMID: 33473358 PMCID: PMC7803627 DOI: 10.1016/j.omtm.2020.11.015] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 11/19/2020] [Indexed: 12/11/2022]
Abstract
Adeno-associated viral (AAV) vectors have emerged as the preferred platform for in vivo gene transfer because of their combined efficacy and safety. However, insertional mutagenesis with the subsequent development of hepatocellular carcinomas (HCCs) has been recurrently noted in newborn mice treated with high doses of AAV, and more recently, the association of wild-type AAV integrations in a subset of human HCCs has been documented. Here, we address, in a comprehensive, prospective study, the long-term risk of tumorigenicity in young adult mice following delivery of single-stranded AAVs targeting liver. HCC incidence in mice treated with therapeutic and reporter AAVs was low, in contrast to what has been previously documented in mice treated as newborns with higher doses of AAV. Specifically, HCCs developed in 6 out 76 of AAV-treated mice, and a pathogenic integration of AAV was found in only one tumor. Also, no evidence of liver tumorigenesis was found in juvenile AAV-treated mucopolysaccharidosis type VI (MPS VI) cats followed as long as 8 years after vector administration. Together, our results support the low risk of tumorigenesis associated with AAV-mediated gene transfer targeting juvenile/young adult livers, although constant monitoring of subjects enrolled in AAV clinical trial is advisable.
Collapse
Affiliation(s)
- Rita Ferla
- Telethon Institute of Genetics and Medicine (TIGEM), 80078 Pozzuoli, Naples, Italy
- Medical Genetics, Department of Translational Medicine, “Federico II” University, 80131 Naples, Italy
| | - Marialuisa Alliegro
- Telethon Institute of Genetics and Medicine (TIGEM), 80078 Pozzuoli, Naples, Italy
- Medical Genetics, Department of Translational Medicine, “Federico II” University, 80131 Naples, Italy
| | - Margherita Dell’Anno
- Telethon Institute of Genetics and Medicine (TIGEM), 80078 Pozzuoli, Naples, Italy
- Medical Genetics, Department of Translational Medicine, “Federico II” University, 80131 Naples, Italy
| | - Edoardo Nusco
- Telethon Institute of Genetics and Medicine (TIGEM), 80078 Pozzuoli, Naples, Italy
| | - John M. Cullen
- North Carolina College of Veterinary Medicine, Raleigh, NC 27607, USA
| | | | - Tyra G. Wolfsberg
- National Human Genome Research Institute, NIH, Bethesda, MD 20892, USA
| | - Patricia O’Donnell
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ping Wang
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Anh-Dao Nguyen
- National Human Genome Research Institute, NIH, Bethesda, MD 20892, USA
| | - Randy J. Chandler
- National Human Genome Research Institute, NIH, Bethesda, MD 20892, USA
| | - Zelin Chen
- National Human Genome Research Institute, NIH, Bethesda, MD 20892, USA
| | - Shawn M. Burgess
- National Human Genome Research Institute, NIH, Bethesda, MD 20892, USA
| | - Charles H. Vite
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Mark E. Haskins
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | | | - Alberto Auricchio
- Telethon Institute of Genetics and Medicine (TIGEM), 80078 Pozzuoli, Naples, Italy
- Medical Genetics, Department of Advanced Biomedicine, “Federico II” University, 80131 Naples, Italy
| |
Collapse
|
22
|
Ocana-Santero G, Díaz-Nido J, Herranz-Martín S. Future Prospects of Gene Therapy for Friedreich's Ataxia. Int J Mol Sci 2021; 22:1815. [PMID: 33670433 PMCID: PMC7918362 DOI: 10.3390/ijms22041815] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 02/04/2021] [Accepted: 02/06/2021] [Indexed: 12/18/2022] Open
Abstract
Friedreich's ataxia is an autosomal recessive neurogenetic disease that is mainly associated with atrophy of the spinal cord and progressive neurodegeneration in the cerebellum. The disease is caused by a GAA-expansion in the first intron of the frataxin gene leading to a decreased level of frataxin protein, which results in mitochondrial dysfunction. Currently, there is no effective treatment to delay neurodegeneration in Friedreich's ataxia. A plausible therapeutic approach is gene therapy. Indeed, Friedreich's ataxia mouse models have been treated with viral vectors en-coding for either FXN or neurotrophins, such as brain-derived neurotrophic factor showing promising results. Thus, gene therapy is increasingly consolidating as one of the most promising therapies. However, several hurdles have to be overcome, including immunotoxicity and pheno-toxicity. We review the state of the art of gene therapy in Friedreich's ataxia, addressing the main challenges and the most feasible solutions for them.
Collapse
Affiliation(s)
- Gabriel Ocana-Santero
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Departamento de Biología Molecular, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049 Madrid, Spain; (G.O.-S.); (J.D.-N.)
- Department of Physiology, Anatomy and Genetics, Sherrington Building, Parks Road, University of Oxford, Oxford OX1 3PT, UK
| | - Javier Díaz-Nido
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Departamento de Biología Molecular, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049 Madrid, Spain; (G.O.-S.); (J.D.-N.)
| | - Saúl Herranz-Martín
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Departamento de Biología Molecular, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049 Madrid, Spain; (G.O.-S.); (J.D.-N.)
| |
Collapse
|
23
|
Dalwadi DA, Torrens L, Abril-Fornaguera J, Pinyol R, Willoughby C, Posey J, Llovet JM, Lanciault C, Russell DW, Grompe M, Naugler WE. Liver Injury Increases the Incidence of HCC following AAV Gene Therapy in Mice. Mol Ther 2021; 29:680-690. [PMID: 33554867 PMCID: PMC7854305 DOI: 10.1016/j.ymthe.2020.10.018] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 08/10/2020] [Accepted: 10/19/2020] [Indexed: 02/07/2023] Open
Abstract
Adeno-associated virus (AAV) integrates into host genomes at low frequency, but when integration occurs in oncogenic hotspots it can cause hepatocellular carcinoma (HCC). Given the possibility of recombinant AAV (rAAV) integration leading to HCC, common causes of liver inflammation like non-alcoholic fatty liver disease (NAFLD) may increase the risk of rAAV-induced HCC. A rAAV targeting the oncogenic mouse Rian locus was used, and as expected led to HCC in all mice infected as neonates, likely due to growth-related hepatocyte proliferation in young mice. Mice infected with rAAV as adults did not develop HCC unless they were fed a diet leading to NAFLD, with increased inflammation and hepatocyte proliferation. Female mice were less susceptible to rAAV-induced HCC, and male mice with NAFLD treated with estrogen exhibited less inflammation and immune exhaustion associated with oncogenesis compared to those without estrogen. Adult NAFLD mice infected with a non-targeted control rAAV also developed HCC, though only half as frequently as those exposed to the Rian targeted rAAV. This study shows that adult mice exposed to rAAV gene therapy in the context of chronic liver disease developed HCC at high frequency, and thus warrants further study in humans given the high prevalence of NAFLD in the population.
Collapse
Affiliation(s)
- Dhwanil A Dalwadi
- Department of Medicine, Division of Gastroenterology and Hepatology, Oregon Health and Science University, Portland, OR 97239, USA; Papé Family, Pediatric Research Institute, Department of Pediatrics, Oregon Health and Science University, Portland, OR 97239, USA
| | - Laura Torrens
- Translational Research in Hepatic Oncology, Liver Unit, IDIBAPS-Hospital Clínic, University of Barcelona, Catalonia, Spain
| | - Jordi Abril-Fornaguera
- Translational Research in Hepatic Oncology, Liver Unit, IDIBAPS-Hospital Clínic, University of Barcelona, Catalonia, Spain
| | - Roser Pinyol
- Translational Research in Hepatic Oncology, Liver Unit, IDIBAPS-Hospital Clínic, University of Barcelona, Catalonia, Spain
| | - Catherine Willoughby
- Translational Research in Hepatic Oncology, Liver Unit, IDIBAPS-Hospital Clínic, University of Barcelona, Catalonia, Spain
| | - Jeffrey Posey
- Papé Family, Pediatric Research Institute, Department of Pediatrics, Oregon Health and Science University, Portland, OR 97239, USA
| | - Josep M Llovet
- Translational Research in Hepatic Oncology, Liver Unit, IDIBAPS-Hospital Clínic, University of Barcelona, Catalonia, Spain; Mount Sinai Liver Cancer Program, Divisions of Liver Diseases, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, NY, NY, USA; Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Catalonia, Spain
| | - Christian Lanciault
- Department of Pathology, Oregon Health and Science University, Portland, OR 97239, USA
| | - David W Russell
- Department of Medicine, University of Washington, Seattle, WA 98195, USA; Department of Biochemistry, University of Washington, Seattle, WA 98195, USA
| | - Markus Grompe
- Papé Family, Pediatric Research Institute, Department of Pediatrics, Oregon Health and Science University, Portland, OR 97239, USA
| | - Willscott E Naugler
- Department of Medicine, Division of Gastroenterology and Hepatology, Oregon Health and Science University, Portland, OR 97239, USA.
| |
Collapse
|
24
|
Nguyen GN, Everett JK, Kafle S, Roche AM, Raymond HE, Leiby J, Wood C, Assenmacher CA, Merricks EP, Long CT, Kazazian HH, Nichols TC, Bushman FD, Sabatino DE. A long-term study of AAV gene therapy in dogs with hemophilia A identifies clonal expansions of transduced liver cells. Nat Biotechnol 2021; 39:47-55. [PMID: 33199875 PMCID: PMC7855056 DOI: 10.1038/s41587-020-0741-7] [Citation(s) in RCA: 231] [Impact Index Per Article: 77.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 10/15/2020] [Indexed: 12/14/2022]
Abstract
Nine dogs with hemophilia A were treated with adeno-associated viral (AAV) gene therapy and followed for up to 10 years. Administration of AAV8 or AAV9 vectors expressing canine factor VIII (AAV-cFVIII) corrected the FVIII deficiency to 1.9-11.3% of normal FVIII levels. In two of nine dogs, levels of FVIII activity increased gradually starting about 4 years after treatment. None of the dogs showed evidence of tumors or altered liver function. Analysis of integration sites in liver samples from six treated dogs identified 1,741 unique AAV integration events in genomic DNA and expanded cell clones in five dogs, with 44% of the integrations near genes involved in cell growth. All recovered integrated vectors were partially deleted and/or rearranged. Our data suggest that the increase in FVIII protein expression in two dogs may have been due to clonal expansion of cells harboring integrated vectors. These results support the clinical development of liver-directed AAV gene therapy for hemophilia A, while emphasizing the importance of long-term monitoring for potential genotoxicity.
Collapse
Affiliation(s)
- Giang N Nguyen
- The Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - John K Everett
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Samita Kafle
- The Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Aoife M Roche
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Hayley E Raymond
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Jacob Leiby
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Christian Wood
- The Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Charles-Antoine Assenmacher
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Elizabeth P Merricks
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- UNC Blood Research Center, University of North Carolina School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - C Tyler Long
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- UNC Blood Research Center, University of North Carolina School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Haig H Kazazian
- Department of Genetic Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Timothy C Nichols
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- UNC Blood Research Center, University of North Carolina School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Frederic D Bushman
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Denise E Sabatino
- The Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, USA.
- Division of Hematology, Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| |
Collapse
|
25
|
Brommel CM, Cooney AL, Sinn PL. Adeno-Associated Virus-Based Gene Therapy for Lifelong Correction of Genetic Disease. Hum Gene Ther 2020; 31:985-995. [PMID: 32718227 PMCID: PMC7495917 DOI: 10.1089/hum.2020.138] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 07/27/2020] [Indexed: 12/27/2022] Open
Abstract
The list of successful gene therapy trials using adeno-associated virus (AAV)-based vectors continues to grow and includes a wide range of monogenic diseases. Replication incompetent AAV genomes typically remain episomal and expression dilutes as cells divide and die. Consequently, long-term transgene expression from AAV is best suited for quiescent cell types, such as retinal cells, myocytes, or neurons. For genetic diseases that involve cells with steady turnover, AAV-conferred correction may require routine readministration, where every dose carries the risk of developing an adaptive immune response that renders treatment ineffective. Here, we discuss innovative approaches to permanently modify the host genome using AAV-based platforms, thus potentially requiring only a single dose. Such approaches include using AAV delivery of DNA transposons, homologous recombination templates into safe harbors, and nucleases for targeting integration. In tissues with continual cell turnover, genetic modification of progenitor cell populations will help ensure persistent therapeutic outcomes. Combining the safety profile of AAV-based gene therapy vectors with the ability to integrate a therapeutic transgene creates novel solutions to the challenge of lifelong curative treatments for human genetic diseases.
Collapse
Affiliation(s)
| | - Ashley L. Cooney
- Department of Pediatrics, University of Iowa, Iowa City, Iowa, USA
| | - Patrick L. Sinn
- Program in Molecular Medicine, University of Iowa, Iowa City, Iowa, USA
- Department of Pediatrics, University of Iowa, Iowa City, Iowa, USA
| |
Collapse
|
26
|
Arruda VR, Doshi BS. Gene Therapy for Hemophilia: Facts and Quandaries in the 21st Century. Mediterr J Hematol Infect Dis 2020; 12:e2020069. [PMID: 32952980 PMCID: PMC7485465 DOI: 10.4084/mjhid.2020.069] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 08/19/2020] [Indexed: 01/19/2023] Open
Abstract
Therapy for hemophilia has evolved in the last 40 years from plasma-based concentrates to recombinant proteins and, more recently, to non-factor therapeutics. Along this same timeline, research in adeno-associated viral (AAV) based gene therapy vectors has provided the framework for early phase clinical trials initially for hemophilia B (HB) and now for hemophilia A. Successive lessons learned from early HB trials have paved the way for current advanced phase trials. Nevertheless, questions linger regarding 1) the optimal balance of vector dose to transgene expression, 2) amount and durability of transgene expression required, and 3) long-term safety. Some trials have demonstrated unique findings not seen previously regarding transient elevation of liver enzymes, immunogenicity of the vector capsid, and loss of transgene expression. This review will provide an update on the clinical AAV gene therapy trials in hemophilia and address the questions above. A thoughtful and rationally approached expansion of gene therapy to the clinics would certainly be a welcome addition to the arsenal of options for hemophilia therapy. Further, the global impact of gene therapy could be vastly improved by expanding eligibility to different patient populations and to developing nations. With the advances made to date, it is possible to envision a shift from the early goal of simply increasing life expectancy to a significant improvement in quality of life by reduction in spontaneous bleeding episodes and disease complications.
Collapse
Affiliation(s)
- Valder R. Arruda
- Divsion of Hematology, Children’s Hospital of Philadelphia, Philadelphia PA USA
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia PA USA
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Children’s Hospital of Philadelphia, Philadelphia PA USA
| | - Bhavya S. Doshi
- Divsion of Hematology, Children’s Hospital of Philadelphia, Philadelphia PA USA
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia PA USA
| |
Collapse
|
27
|
George LA, Ragni MV, Rasko JEJ, Raffini LJ, Samelson-Jones BJ, Ozelo M, Hazbon M, Runowski AR, Wellman JA, Wachtel K, Chen Y, Anguela XM, Kuranda K, Mingozzi F, High KA. Long-Term Follow-Up of the First in Human Intravascular Delivery of AAV for Gene Transfer: AAV2-hFIX16 for Severe Hemophilia B. Mol Ther 2020; 28:2073-2082. [PMID: 32559433 DOI: 10.1016/j.ymthe.2020.06.001] [Citation(s) in RCA: 119] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 05/26/2020] [Accepted: 06/03/2020] [Indexed: 12/26/2022] Open
Abstract
Adeno-associated virus (AAV) vectors are a leading platform for gene-based therapies for both monogenic and complex acquired disorders. The success of AAV gene transfer highlights the need to answer outstanding clinical questions of safety, durability, and the nature of the human immune response to AAV vectors. Here, we present longitudinal follow-up data of subjects who participated in the first trial of a systemically delivered AAV vector. Adult males (n = 7) with severe hemophilia B received an AAV2 vector at doses ranging from 8 × 1010 to 2 × 1012 vg/kg to target hepatocyte-specific expression of coagulation factor IX; a subset (n = 4) was followed for 12-15 years post-vector administration. No major safety concerns were observed. There was no evidence of sustained hepatic toxicity or development of hepatocellular carcinoma as assessed by liver transaminase values, serum α-fetoprotein, and liver ultrasound. Subjects demonstrated persistent, increased AAV neutralizing antibodies (NAbs) to the infused AAV serotype 2 (AAV2) as well as all other AAV serotypes tested (AAV5 and AAV8) for the duration of follow-up. These data represent the longest available longitudinal follow-up data of subjects who received intravascular AAV and support the preliminary safety of intravascular AAV administration at the doses tested in adults. Data demonstrate, for the first time, the persistence of high-titer, multi-serotype cross-reactive AAV NAbs for up to 15 years post- AAV vector administration. Our observations are broadly applicable to the development of AAV-mediated gene therapy.
Collapse
Affiliation(s)
- Lindsey A George
- Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA; Division of Hematology and Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Margaret V Ragni
- Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - John E J Rasko
- Gene & Stem Cell Therapy Program, Centenary Institute, and Faculty of Medicine and Health, The University of Sydney, Sydney, Australia; Cell and Molecular Therapies, Royal Prince Alfred Hospital, Camperdown, NSW, Australia
| | - Leslie J Raffini
- Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA; Division of Hematology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Benjamin J Samelson-Jones
- Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA; Division of Hematology and Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Margareth Ozelo
- Department of Internal Medicine, Faculty of Medical Sciences, University of Campinas, Campinas, São Paulo, Brazil; IHTC Hemophilia Unit Cláudio Luiz Pizzigatti Corrêa, INCT do Sangue Hemocentro UNICAMP, University of Campinas, Campinas, São Paulo, Brazil
| | - Maria Hazbon
- Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Alexa R Runowski
- Division of Hematology and Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | | | | | | | | | | | | | - Katherine A High
- Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA; Spark Therapeutics, Philadelphia, PA, USA.
| |
Collapse
|
28
|
Rafi MA, Luzi P, Wenger DA. Conditions for combining gene therapy with bone marrow transplantation in murine Krabbe disease. ACTA ACUST UNITED AC 2020; 10:105-115. [PMID: 32363154 PMCID: PMC7186542 DOI: 10.34172/bi.2020.13] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Accepted: 03/17/2020] [Indexed: 02/06/2023]
Abstract
Introduction: Krabbe disease (KD) is an autosomal recessive lysosomal disorder caused by mutations in the galactocerebrosidase (GALC) gene. This results in defective myelination in the peripheral and central nervous systems due to low GALC activity. Treatment at this time is limited to hematopoietic stem cell transplantation (HSCT) in pre-symptomatic individuals. While this treatment extends the lives of treated individuals, most have difficulty walking by the end of the first decade due to peripheral neuropathy. Studies in the murine model of KD, twitcher (twi) combining bone marrow transplantation (BMT) with AAVrh10-mGALC showed a great extension of life from 40 days to about 400 days, with some living a full life time. Methods: In order to find the optimum conditions for dosing and timing of this combined treatment, twi mice were injected with five doses of AAVrh10-mGALC at different times after BMT. Survival, as well as GALC expression were monitored along with studies of sciatic nerve myelination and possible liver pathology. Results: Dosing had a pronounced effect on survival and measured GALC activity. There was window of time after BMT to inject the viral vector and see similar results, however delaying both the BMT and the viral injection shortened the lifespans of the treated mice. Lowering the viral dose too much decreased the correction of the sciatic nerve myelination. There was no evidence for hepatic neoplasia. Conclusion: These studies provide the conditions optimum for successfully treating the murine model of KD. There is some flexibility in dosing and timing to obtain a satisfactory outcome. These studies are critical to the planning of a human trial combining the "standard of care", HSCT, with a single iv injection of AAVrh10-GALC.
Collapse
Affiliation(s)
- Mohammad A Rafi
- Department of Neurology, Sidney Kimmel College of Medicine, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Paola Luzi
- Department of Neurology, Sidney Kimmel College of Medicine, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - David A Wenger
- Department of Neurology, Sidney Kimmel College of Medicine, Thomas Jefferson University, Philadelphia, PA 19107, USA
| |
Collapse
|
29
|
Bioanalysis of adeno-associated virus gene therapy therapeutics: regulatory expectations. Bioanalysis 2019; 11:2011-2024. [DOI: 10.4155/bio-2019-0135] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The number of gene therapy (GTx) modality therapies in development has grown significantly in the last few years. Adeno-associated virus (AAV)-based delivery approach has become most prevalent among other virus-based GTx vectors. Several regulatory guidelines provide the industry with general considerations related to AAV GTx development including discussion and recommendations related to highly diverse bioanalytical support of the AAV-based therapeutics. This includes assessment of pre- and post-treatment immunity, evaluation of post-treatment viral shedding and infectivity, as well as detection of transgene protein expression. An overview of the current regulatory recommendations as found in currently active and published draft US FDA and EMA guidance or guideline documents is presented herein.
Collapse
|
30
|
Hudry E, Vandenberghe LH. Therapeutic AAV Gene Transfer to the Nervous System: A Clinical Reality. Neuron 2019; 101:839-862. [DOI: 10.1016/j.neuron.2019.02.017] [Citation(s) in RCA: 155] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 02/07/2019] [Accepted: 02/11/2019] [Indexed: 02/07/2023]
|
31
|
Nelson CE, Wu Y, Gemberling MP, Oliver ML, Waller MA, Bohning JD, Robinson-Hamm JN, Bulaklak K, Castellanos Rivera RM, Collier JH, Asokan A, Gersbach CA. Long-term evaluation of AAV-CRISPR genome editing for Duchenne muscular dystrophy. Nat Med 2019; 25:427-432. [PMID: 30778238 PMCID: PMC6455975 DOI: 10.1038/s41591-019-0344-3] [Citation(s) in RCA: 283] [Impact Index Per Article: 56.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 12/21/2018] [Indexed: 12/12/2022]
Abstract
Duchenne muscular dystrophy (DMD) is a monogenic disorder and a candidate for therapeutic genome editing. There have been several recent reports of genome editing in preclinical models of Duchenne muscular dystrophy1-6, however, the long-term persistence and safety of these genome editing approaches have not been addressed. Here we show that genome editing and dystrophin protein restoration is sustained in the mdx mouse model of Duchenne muscular dystrophy for 1 year after a single intravenous administration of an adeno-associated virus that encodes CRISPR (AAV-CRISPR). We also show that AAV-CRISPR is immunogenic when administered to adult mice7; however, humoral and cellular immune responses can be avoided by treating neonatal mice. Additionally, we describe unintended genome and transcript alterations induced by AAV-CRISPR that should be considered for the development of AAV-CRISPR as a therapeutic approach. This study shows the potential of AAV-CRISPR for permanent genome corrections and highlights aspects of host response and alternative genome editing outcomes that require further study.
Collapse
Affiliation(s)
- Christopher E Nelson
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
- Center for Genomic and Computational Biology, Duke University, Durham, NC, USA
| | - Yaoying Wu
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Matthew P Gemberling
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
- Center for Genomic and Computational Biology, Duke University, Durham, NC, USA
| | - Matthew L Oliver
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Matthew A Waller
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
- Center for Genomic and Computational Biology, Duke University, Durham, NC, USA
| | - Joel D Bohning
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
- Center for Genomic and Computational Biology, Duke University, Durham, NC, USA
| | - Jacqueline N Robinson-Hamm
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
- Center for Genomic and Computational Biology, Duke University, Durham, NC, USA
| | - Karen Bulaklak
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
- Center for Genomic and Computational Biology, Duke University, Durham, NC, USA
| | | | - Joel H Collier
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Aravind Asokan
- Department of Surgery, Duke University Medical Center, Durham, NC, USA
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, USA
| | - Charles A Gersbach
- Department of Biomedical Engineering, Duke University, Durham, NC, USA.
- Center for Genomic and Computational Biology, Duke University, Durham, NC, USA.
- Department of Orthopaedic Surgery, Duke University Medical Center, Durham, NC, USA.
| |
Collapse
|
32
|
Palaschak B, Herzog RW, Markusic DM. AAV-Mediated Gene Delivery to the Liver: Overview of Current Technologies and Methods. Methods Mol Biol 2019; 1950:333-360. [PMID: 30783984 DOI: 10.1007/978-1-4939-9139-6_20] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Adeno-associated virus (AAV) vectors to treat liver-specific genetic diseases are the focus of several ongoing clinical trials. The ability to give a peripheral injection of virus that will successfully target the liver is one of many attractive features of this technology. Although initial studies of AAV liver gene transfer revealed some limitations, extensive animal modeling and further clinical development have helped solve some of these issues, resulting in several successful clinical trials that have reached curative levels of clotting factor expression in hemophilia. Looking beyond gene replacement, recent technologies offer the possibility for AAV liver gene transfer to directly repair deficient genes and potentially treat autoimmune disease.
Collapse
Affiliation(s)
- Brett Palaschak
- Department of Pediatrics, University of Florida, Gainesville, FL, USA
| | - Roland W Herzog
- Department of Pediatrics, University of Florida, Gainesville, FL, USA.,Department of Pediatrics, Indiana University, Indianapolis, IN, USA
| | - David M Markusic
- Department of Pediatrics, Indiana University, Indianapolis, IN, USA.
| |
Collapse
|
33
|
Doshi BS, Arruda VR. Gene therapy for hemophilia: what does the future hold? Ther Adv Hematol 2018; 9:273-293. [PMID: 30210756 DOI: 10.1177/2040620718791933] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 07/09/2018] [Indexed: 01/19/2023] Open
Abstract
Recent phase I/II adeno-associated viral vector-mediated gene therapy clinical trials have reported remarkable success in ameliorating disease phenotype in hemophilia A and B. These trials, which highlight the challenges overcome through decades of preclinical and first in human clinical studies, have generated considerable excitement for patients and caregivers alike. Optimization of vector and transgene expression has significantly improved the ability to achieve therapeutic factor levels in these subjects. Long-term follow-up studies will guide standardization of the approach with respect to the combination of serotype, promoter, dose, and manufacturing processes and inform safety for inclusion of young patients. Certain limitations preclude universal applicability of gene therapy, including transient liver transaminase elevations due to the immune responses to vector capsids or as yet undefined mechanisms, underlying liver disease from iatrogenic viral hepatitis, and neutralizing antibodies to clotting factors. Integrating vectors show promising preclinical results, but manufacturing and safety concerns still remain. The prospect of gene editing for correction of the underlying mutation is on the horizon with considerable potential. Herein, we review the advances and limitations that have resulted in these recent successful clinical trials and outline avenues that will allow for broader applicability of gene therapy.
Collapse
Affiliation(s)
- Bhavya S Doshi
- Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Valder R Arruda
- Department of Pediatrics, The Children's Hospital of Philadelphia, 3501 Civic Center Blvd, 5056 Colket Translational Research Center, Philadelphia, PA 19104, USA
| |
Collapse
|
34
|
Abstract
Hemophilia is a congenital bleeding disorder that affects nearly half a million individuals worldwide. Joint bleeding and other co-morbidities are a significant source of debilitation for this population. Current therapies are effective but must be given lifelong at regular intervals, are costly, and are available to only about 25% of the hemophilia population living in resource-rich countries. Gene therapy for hemophilia has been in development for three decades and is now entering pivotal-stage clinical trials. While many different technology platforms exist for gene therapy, all current clinical trials for hemophilia employ adeno-associated vector (AAV)-based cell transduction. This small viral particle is capable of packaging modified F8 or F9 transgenes, can be generated robustly from cell lines, and transduces several relatively end-differentiated target tissues such as the liver with high efficiency. While pre-existing neutralizing antibodies to the AAV capsid are recognized to limit current therapy, other challenges have been identified in human studies that were not seen in preclinical studies. Both liver transaminase elevations and immune-mediated loss of transgene expression have been observed in clinical trials. Toll-like receptors, cytotoxic T cells, and other components of the immune response have been implicated in the loss of factor expression, but a full understanding of the immune response awaits clarification. Despite these challenges, many patients enrolled in gene therapy trials have attained long-term expression of factors VIII and IX. This emerging technology now represents a cure for the severe bleeding and joint damage associated with hemophilia.
Collapse
Affiliation(s)
- John C Chapin
- Shire, 650 Kendall Drive, Cambridge, MA, 02142, USA.
| | | |
Collapse
|
35
|
Abstract
In recent years, the number of clinical trials in which adeno-associated virus (AAV) vectors have been used for in vivo gene transfer has steadily increased. The excellent safety profile, together with the high efficiency of transduction of a broad range of target tissues, has established AAV vectors as the platform of choice for in vivo gene therapy. Successful application of the AAV technology has also been achieved in the clinic for a variety of conditions, including coagulation disorders, inherited blindness, and neurodegenerative diseases, among others. Clinical translation of novel and effective "therapeutic products" is, however, a long process that involves several cycles of iterations from bench to bedside that are required to address issues encountered during drug development. For the AAV vector gene transfer technology, several hurdles have emerged in both preclinical studies and clinical trials; addressing these issues will allow in the future to expand the scope of AAV gene transfer as a therapeutic modality for a variety of human diseases. In this review, we will give an overview on the biology of AAV vector, discuss the design of AAV-based gene therapy strategies for in vivo applications, and present key achievements and emerging issues in the field. We will use the liver as a model target tissue for gene transfer based on the large amount of data available from preclinical and clinical studies.
Collapse
Affiliation(s)
- Pasqualina Colella
- Genethon, INSERM U951 INTEGRARE, University of Evry, University Paris-Saclay, 91001 Evry, France
| | - Giuseppe Ronzitti
- Genethon, INSERM U951 INTEGRARE, University of Evry, University Paris-Saclay, 91001 Evry, France
| | - Federico Mingozzi
- Genethon, INSERM U951 INTEGRARE, University of Evry, University Paris-Saclay, 91001 Evry, France
- University Pierre and Marie Curie-Paris 6 and INSERM U974, 75651 Paris, France
| |
Collapse
|
36
|
Junge N, Yuan Q, Vu TH, Krooss S, Bednarski C, Balakrishnan A, Cathomen T, Manns MP, Baumann U, Sharma AD, Ott M. Homologous recombination mediates stable Fah gene integration and phenotypic correction in tyrosinaemia mouse-model. World J Hepatol 2018; 10:277-286. [PMID: 29527263 PMCID: PMC5838446 DOI: 10.4254/wjh.v10.i2.277] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 02/01/2018] [Accepted: 03/01/2018] [Indexed: 02/06/2023] Open
Abstract
AIM To stably correct tyrosinaemia in proliferating livers of fumarylacetoacetate-hydrolase knockout (Fah-/-) mice by homologous-recombination-mediated targeted addition of the Fah gene.
METHODS C57BL/6 Fah∆exon5 mice served as an animal model for human tyrosinaemia type 1 in our study. The vector was created by amplifying human Fah cDNA including the TTR promoter from a lentivirus plasmid as described. The Fah expression cassette was flanked by homologous arms (620 bp and 749 bp long) of the Rosa26 gene locus. Mice were injected with 2.1 × 108 VP of this vector (rAAV8-ROSA26.HAL-TTR.Fah-ROSA26.HAR) via the tail vein. Mice in the control group were injected with 2.1 × 108 VP of a similar vector but missing the homologous arms (rAAV8-TTR.Fah). Primary hepatocytes from Fah-/- recipient mice, treated with our vectors, were isolated and 1 × 106 hepatocytes were transplanted into secondary Fah-/- recipient mice by injection into the spleen. Upon either vector application or hepatocyte transplantation NTBC treatment was stopped in recipient mice.
RESULTS Here, we report successful HR-mediated genome editing by integration of a Fah gene expression cassette into the “safe harbour locus” Rosa26 by recombinant AAV8. Both groups of mice showed long-term survival, weight gain and FAH positive clusters as determined by immunohistochemistry analysis of liver sections in the absence of NTBC treatment. In the group of C57BL/6 Fah∆exon5 mice, which have been transplanted with hepatocytes from a mouse injected with rAAV8-ROSA26.HAL-TTR.Fah-ROSA26.HAR 156 d before, 6 out of 6 mice showed long-term survival, weight gain and FAH positive clusters without need for NTBC treatment. In contrast only 1 out 5 mice, who received hepatocytes from rAAV8-TTR.Fah treated mice, survived and showed few and smaller FAH positive clusters. These results demonstrate that homologous recombination-mediated Fah gene transfer corrects the phenotype in a mouse model of human tyrosinaemia type 1 (Fah-/- mice) and is long lasting in a proliferating state of the liver as shown by withdrawal of NTBC treatment and serial transplantation of isolated hepatocytes from primary Fah-/- recipient mice into secondary Fah-/- recipient mice. This long term therapeutic efficacy is clearly superior to our control mice treated with episomal rAAV8 gene therapy approach.
CONCLUSION HR-mediated rAAV8 gene therapy provides targeted transgene integration and phenotypic correction in Fah-/- mice with superior long-term efficacy compared to episomal rAAV8 therapy in proliferating livers.
Collapse
Affiliation(s)
- Norman Junge
- Department of Pediatric Gastroenterology and Hepatology, Hannover Medical School, Hannover 30625, Germany
| | - Qinggong Yuan
- Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hannover 30625, Germany
- TWINCORE, Centre for Experimental and Clinical Infection Research, Hannover 30625, Germany
| | - Thu Huong Vu
- Department of Pediatric Gastroenterology and Hepatology, Hannover Medical School, Hannover 30625, Germany
| | - Simon Krooss
- TWINCORE, Centre for Experimental and Clinical Infection Research, Hannover 30625, Germany
| | - Christien Bednarski
- Medical Center, University of Freiburg, Institute for Cell and Gene Therapy, Freiburg 79108, Germany
| | - Asha Balakrishnan
- Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hannover 30625, Germany
- TWINCORE, Centre for Experimental and Clinical Infection Research, Hannover 30625, Germany
| | - Toni Cathomen
- Medical Center, University of Freiburg, Institute for Cell and Gene Therapy, Freiburg 79108, Germany
| | - Michael P Manns
- Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hannover 30625, Germany
| | - Ulrich Baumann
- Department of Pediatric Gastroenterology and Hepatology, Hannover Medical School, Hannover 30625, Germany
| | - Amar Deep Sharma
- Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hannover 30625, Germany
- Research Group MicroRNA in Liver Regeneration, Cluster of Excellence REBIRTH, Hannover Medical School, Hannover 30625, Germany
| | - Michael Ott
- Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hannover 30625, Germany
- TWINCORE, Centre for Experimental and Clinical Infection Research, Hannover 30625, Germany
| |
Collapse
|
37
|
Martinez-Fernandez De La Camara C, Nanda A, Salvetti AP, Fischer MD, MacLaren RE. Gene therapy for the treatment of X-linked retinitis pigmentosa. Expert Opin Orphan Drugs 2018; 6:167-177. [PMID: 30057863 PMCID: PMC6059358 DOI: 10.1080/21678707.2018.1444476] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
INTRODUCTION X-linked retinitis pigmentosa caused by mutations in the retinitis pigmentosa GTPase regulator (RPGR) gene is the most common form of recessive RP. The phenotype is characterised by its severity and rapid disease progression. Gene therapy using adeno-associated viral vectors is currently the most promising therapeutic approach. However, the construction of a stable vector encoding the full-length RPGR transcript has previously proven to be a limiting step towards gene therapy clinical trials. Recently however, a codon optimised version of RPGR has been shown to increase the stability and fidelity of the sequence, conferring a therapeutic effect in murine and canine animal models. AREAS COVERED This manuscript reviews the natural history of X-linked retinitis pigmentosa and the research performed from the discovery of the causative gene, RPGR, to the preclinical testing of potential therapies that have led to the initiation of three clinical trials. EXPERT OPINION X-linked retinitis pigmentosa is an amenable disease to be treated by gene therapy. Codon optimisation has overcome the challenge of designing an RPGR vector without mutations, and with a therapeutic effect in different animal models. With the RPGR gene therapy clinical trials still in the early stages, the confirmation of the safety, tolerability and potency of the therapy is still ongoing.
Collapse
Affiliation(s)
| | - Anika Nanda
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, John Radcliffe Hospital, Oxford, UK
| | - Anna Paola Salvetti
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, UK
- Department of Biomedical and Clinical Sciences “Luigi Sacco”, Sacco Hospital, University of Milan, Milano, Italy
| | - M. Dominik Fischer
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, UK
- Centre for Ophthalmology Tübingen, University Eye Hospital, Tübingen, Germany
| | - Robert E. MacLaren
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, John Radcliffe Hospital, Oxford, UK
| |
Collapse
|
38
|
Torres-Torronteras J, Cabrera-Pérez R, Vila-Julià F, Viscomi C, Cámara Y, Hirano M, Zeviani M, Martí R. Long-Term Sustained Effect of Liver-Targeted Adeno-Associated Virus Gene Therapy for Mitochondrial Neurogastrointestinal Encephalomyopathy. Hum Gene Ther 2018; 29:708-718. [PMID: 29284302 DOI: 10.1089/hum.2017.133] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is caused by mutations in TYMP, the gene encoding the enzyme thymidine phosphorylase (TP). TP dysfunction results in systemic accumulation of the noxious TP substrates thymidine and deoxyuridine. Gene therapy using either a lentiviral vector or adeno-associated vector (AAV) has proven to be a feasible strategy, as both vectors restore biochemical homeostasis in a murine model of the disease. This study shows that the effect of an AAV containing the TYMP coding sequence transcriptionally targeted to the liver persists long term in mice. Although the vector copy number was diluted and AAV-mediated liver TP activity eventually reduced or lost after 21 months at the lowest vector doses, the effect was sustained (with a negligible decrease in TP activity) and fully effective on nucleoside homeostasis for at least 21 months at a dose of 2 × 1012 vg/kg. Macroscopic visual inspection of the animals' organs at completion of the study showed no adverse effects associated with the treatment. These results further support the feasibility of gene therapy for MNGIE.
Collapse
Affiliation(s)
- Javier Torres-Torronteras
- 1 Research Group on Neuromuscular and Mitochondrial Diseases, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona , Barcelona, Spain .,2 Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III , Madrid, Spain
| | - Raquel Cabrera-Pérez
- 1 Research Group on Neuromuscular and Mitochondrial Diseases, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona , Barcelona, Spain .,2 Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III , Madrid, Spain
| | - Ferran Vila-Julià
- 1 Research Group on Neuromuscular and Mitochondrial Diseases, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona , Barcelona, Spain .,2 Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III , Madrid, Spain
| | - Carlo Viscomi
- 3 MRC-Mitochondrial Biology Unit, MRC MBU, Wellcome Trust/MRC Building, Hills Road, Cambridge, United Kingdom
| | - Yolanda Cámara
- 1 Research Group on Neuromuscular and Mitochondrial Diseases, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona , Barcelona, Spain .,2 Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III , Madrid, Spain
| | - Michio Hirano
- 4 H. Houston Merritt Center, Department of Neurology, Columbia University Medical Center , New York, New York
| | - Massimo Zeviani
- 3 MRC-Mitochondrial Biology Unit, MRC MBU, Wellcome Trust/MRC Building, Hills Road, Cambridge, United Kingdom
| | - Ramon Martí
- 1 Research Group on Neuromuscular and Mitochondrial Diseases, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona , Barcelona, Spain .,2 Biomedical Network Research Centre on Rare Diseases (CIBERER), Instituto de Salud Carlos III , Madrid, Spain
| |
Collapse
|
39
|
Dogbevia GK, Töllner K, Körbelin J, Bröer S, Ridder DA, Grasshoff H, Brandt C, Wenzel J, Straub BK, Trepel M, Löscher W, Schwaninger M. Gene therapy decreases seizures in a model ofIncontinentia pigmenti. Ann Neurol 2017. [DOI: 10.1002/ana.24981] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Godwin K. Dogbevia
- Institute for Experimental and Clinical Pharmacology and Toxicology; University of Lübeck; Lübeck Germany
| | - Kathrin Töllner
- Department of Pharmacology, Toxicology, and Pharmacy; University of Veterinary Medicine and Center for Systems Neuroscience; Hannover Germany
| | - Jakob Körbelin
- University Medical Center Hamburg-Eppendorf, Hubertus Wald Cancer Center, Department of Oncology and Hematology; Hamburg Germany
| | - Sonja Bröer
- Department of Pharmacology, Toxicology, and Pharmacy; University of Veterinary Medicine and Center for Systems Neuroscience; Hannover Germany
| | - Dirk A. Ridder
- Institute of Pathology; University Medical Center Mainz; Mainz Germany
| | - Hanna Grasshoff
- Institute for Experimental and Clinical Pharmacology and Toxicology; University of Lübeck; Lübeck Germany
| | - Claudia Brandt
- Department of Pharmacology, Toxicology, and Pharmacy; University of Veterinary Medicine and Center for Systems Neuroscience; Hannover Germany
| | - Jan Wenzel
- Institute for Experimental and Clinical Pharmacology and Toxicology; University of Lübeck; Lübeck Germany
- DZHK (German Research Centre for Cardiovascular Research), partner site Hamburg/Lübeck/Kiel; Lübeck Germany
| | - Beate K. Straub
- Institute of Pathology; University Medical Center Mainz; Mainz Germany
| | - Martin Trepel
- University Medical Center Hamburg-Eppendorf, Hubertus Wald Cancer Center, Department of Oncology and Hematology; Hamburg Germany
- Augsburg Medical Center, Department of Hematology and Oncology; Augsburg Germany
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy; University of Veterinary Medicine and Center for Systems Neuroscience; Hannover Germany
| | - Markus Schwaninger
- Institute for Experimental and Clinical Pharmacology and Toxicology; University of Lübeck; Lübeck Germany
- DZHK (German Research Centre for Cardiovascular Research), partner site Hamburg/Lübeck/Kiel; Lübeck Germany
| |
Collapse
|
40
|
Chandler RJ, Sands MS, Venditti CP. Recombinant Adeno-Associated Viral Integration and Genotoxicity: Insights from Animal Models. Hum Gene Ther 2017; 28:314-322. [PMID: 28293963 DOI: 10.1089/hum.2017.009] [Citation(s) in RCA: 155] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Currently, clinical gene therapy is experiencing a renaissance, with new products for clinical use approved in Europe and clinical trials for multiple diseases reporting positive results, especially those using recombinant adeno-associated viral (rAAV) vectors. Amid this new success, it is prudent to recall that the field of gene therapy experienced tragic setbacks in 1999 and 2002 because of the serious adverse events related to retroviral and adenoviral gene delivery in two clinical trials that resulted in the death of two patients. In both cases, the toxicity observed in humans had been documented to occur in animal models. However, these toxicities were either undetected or underappreciated before they arose in humans. rAAVs have been tested extensively in animals and animal models of disease, largely without adverse events, except for transient elevation in liver enzymes in some patients. However, a small but growing number of murine studies have documented that adeno-associated viral gene delivery can result in insertional mutagenesis. Herein, the aggregate data are reviewed from multiple murine studies where genotoxicity associated with rAAV treatment has been observed. The data emphasize the need for a proactive position to evaluate the potential risks and possible solutions associated with AAV-mediated gene therapy.
Collapse
Affiliation(s)
- Randy J Chandler
- 1 Medical Genomics and Metabolic Genetics Branch, National Human Genome Research Institute, National Institutes of Health , Department of Health and Human Services, Bethesda, Maryland
| | - Mark S Sands
- 2 Department of Internal Medicine, Washington University School of Medicine , St. Louis, Missouri.,3 Department of Genetics, Washington University School of Medicine , St. Louis, Missouri
| | - Charles P Venditti
- 1 Medical Genomics and Metabolic Genetics Branch, National Human Genome Research Institute, National Institutes of Health , Department of Health and Human Services, Bethesda, Maryland
| |
Collapse
|
41
|
Abstract
There are conflicting reports that integration of the wild-type adeno-associated virus 2 (AAV2) genome is associated with induction of hepatocellular carcinoma (HCC) in a small subset of patients. However, there are several lines of evidence that contradict this assertion: (i) AAV2 has long been known to be a non-pathogenic virus, although ∼90% of the human population is seropositive for AAV2 antibodies; (ii) AAV2 has been shown to possess anticancer activity; (iii) epidemiological evidence suggests that AAV2 infection plays a protective role against cervical carcinoma; and (iv) five different AAV serotype vectors (AAV1, AAV2, AAV5, AAV8, and AAV9) have been or are currently being used in 162 Phase I/II clinical trials and one Phase III clinical trial in humans to date, and no cancer of any type has ever been observed or reported. A brief historical account of the putative role of infection by AAV in the etiology of cancer, or lack thereof, is presented.
Collapse
Affiliation(s)
- Arun Srivastava
- 1 Division of Cellular and Molecular Therapy, Departments of Pediatrics and Molecular Genetics and Microbiology, Powell Gene Therapy Center; Genetics Institute; University of Florida College of Medicine , Gainesville, Florida
| | | |
Collapse
|
42
|
Low-dose Gene Therapy Reduces the Frequency of Enzyme Replacement Therapy in a Mouse Model of Lysosomal Storage Disease. Mol Ther 2016; 24:2054-2063. [PMID: 27658524 PMCID: PMC5159621 DOI: 10.1038/mt.2016.181] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 08/29/2016] [Indexed: 12/29/2022] Open
Abstract
Enzyme replacement therapy (ERT) is the standard of care for several lysosomal storage diseases (LSDs). ERT, however, requires multiple and costly administrations and has limited efficacy. We recently showed that a single high dose administration of adeno-associated viral vector serotype 8 (AAV2/8) is at least as effective as weekly ERT in a mouse model of mucopolysaccharidosis type VI (MPS VI). However, systemic administration of high doses of AAV might result in both cell-mediated immune responses and insertional mutagenesis. Here we evaluated whether the combination of low doses of AAV2/8 with a less frequent (monthly) than canonical (weekly) ERT schedule may be as effective as the single treatments at high doses or frequent regimen. A greater reduction of both urinary glycosaminoglycans, considered a sensitive biomarker of therapeutic efficacy, and storage in the myocardium and heart valves was observed in mice receiving the combined than the single therapies. Importantly, these levels of correction were similar to those we obtained in a previous study following either high doses of AAV2/8 or weekly ERT. Our data show that low-dose gene therapy can be used as a means to rarify ERT administration, thus reducing both the risks and costs associated with either therapies.
Collapse
|
43
|
Somatic Therapy of a Mouse SMA Model with a U7 snRNA Gene Correcting SMN2 Splicing. Mol Ther 2016; 24:1797-1805. [PMID: 27456062 PMCID: PMC5112044 DOI: 10.1038/mt.2016.152] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 07/18/2016] [Indexed: 12/12/2022] Open
Abstract
Spinal Muscular Atrophy is due to the loss of SMN1 gene function. The duplicate gene SMN2 produces some, but not enough, SMN protein because most transcripts lack exon 7. Thus, promoting the inclusion of this exon is a therapeutic option. We show that a somatic gene therapy using the gene for a modified U7 RNA which stimulates this splicing has a profound and persistent therapeutic effect on the phenotype of a severe Spinal Muscular Atrophy mouse model. To this end, the U7 gene and vector and the production of pure, highly concentrated self-complementary (sc) adenovirus-associated virus 9 vector particles were optimized. Introduction of the functional vector into motoneurons of newborn Spinal Muscular Atrophy mice by intracerebroventricular injection led to a highly significant, dose-dependent increase in life span and improvement of muscle functions. Besides the central nervous system, the therapeutic U7 RNA was expressed in the heart and liver which may additionally have contributed to the observed therapeutic efficacy. This approach provides an additional therapeutic option for Spinal Muscular Atrophy and could also be adapted to treat other diseases of the central nervous system with regulatory small RNA genes.
Collapse
|
44
|
Fischer MD. On Retinal Gene Therapy. Ophthalmologica 2016; 236:1-7. [PMID: 27119148 DOI: 10.1159/000445782] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Accepted: 03/18/2016] [Indexed: 11/19/2022]
Abstract
Mutations in a large number of genes cause retinal degeneration and blindness with no cure currently available. Retinal gene therapy has evolved over the last decades to become a promising new treatment paradigm for these rare disorders. This article reflects on the ideas and concepts arising from basic science towards the translation of retinal gene therapy into the clinical realm. It describes the advances and present thinking on the efficacy of current clinical trials and discusses potential roadblocks and solutions for the future of retinal gene therapy.
Collapse
Affiliation(s)
- M Dominik Fischer
- University Eye Hospital, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| |
Collapse
|
45
|
Abstract
Recombinant AAV vectors (rAAV) are considered as very efficient tools for in vivo gene transfer. Accordingly, several preclinical and clinical gene therapy trials use these vectors to treat inherited and acquired diseases. rAAV vectors possess the capacity to persist for a long term in the transduced tissue in a transcriptionally active, extra-chromosomal (episomal) form. However, many studies have shown that a significant fraction of the rAAV genomes can also nonspecifically integrate into the host cell genome thus raising the possibility of insertional mutagenesis events. This review summarizes the current knowledge on integration of wild type and rAAV genomes and highlights the major questions which remain unresolved.
Collapse
Affiliation(s)
- Axel Rossi
- Centre international de recherche en infectiologie (CIRI), Inserm U1111, CNRS UMR5308, équipe NucléoVir, École normale supérieure de Lyon, 46, allée d'Italie, 69007 Lyon, France
| | - Anna Salvetti
- Centre international de recherche en infectiologie (CIRI), Inserm U1111, CNRS UMR5308, équipe NucléoVir, École normale supérieure de Lyon, 46, allée d'Italie, 69007 Lyon, France
| |
Collapse
|
46
|
Aronson SJ, Beuers U, Bosma PJ. Progress and challenges in gene therapy for Crigler–Najjar syndrome. Expert Opin Orphan Drugs 2015. [DOI: 10.1517/21678707.2015.1100991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
47
|
Isaacs CJ, Shinnick JE, Schadt K, Lynch DR, Lin KY. Prospects of gene and cell therapy for managing cardiac complications in Friedreich ataxia. Expert Opin Orphan Drugs 2015. [DOI: 10.1517/21678707.2015.1083854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
48
|
Chandler RJ, LaFave MC, Varshney GK, Trivedi NS, Carrillo-Carrasco N, Senac JS, Wu W, Hoffmann V, Elkahloun AG, Burgess SM, Venditti CP. Vector design influences hepatic genotoxicity after adeno-associated virus gene therapy. J Clin Invest 2015; 125:870-80. [PMID: 25607839 DOI: 10.1172/jci79213] [Citation(s) in RCA: 278] [Impact Index Per Article: 30.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 12/11/2014] [Indexed: 12/13/2022] Open
Abstract
The use of adeno-associated virus (AAV) as a gene therapy vector has been approved recently for clinical use and has demonstrated efficacy in a growing number of clinical trials. However, the safety of AAV as a vector has been challenged by a single study that documented hepatocellular carcinoma (HCC) after AAV gene delivery in mice. Most studies have not noted genotoxicity following AAV-mediated gene delivery; therefore, the possibility that there is an association between AAV and HCC is controversial. Here, we performed a comprehensive study of HCC in a large number of mice following therapeutic AAV gene delivery. Using a sensitive high-throughput integration site-capture technique and global expressional analysis, we found that AAV integration into the RNA imprinted and accumulated in nucleus (Rian) locus, and the resulting overexpression of proximal microRNAs and retrotransposon-like 1 (Rtl1) were associated with HCC. In addition, we demonstrated that the AAV vector dose, enhancer/promoter selection, and the timing of gene delivery are all critical factors for determining HCC incidence after AAV gene delivery. Together, our results define aspects of AAV-mediated gene therapy that influence genotoxicity and suggest that these features should be considered for design of both safer AAV vectors and gene therapy studies.
Collapse
|
49
|
Abstract
Adeno-associated virus (AAV) is a small, nonenveloped virus that was adapted 30 years ago for use as a gene transfer vehicle. It is capable of transducing a wide range of species and tissues in vivo with no evidence of toxicity, and it generates relatively mild innate and adaptive immune responses. We review the basic biology of AAV, the history of progress in AAV vector technology, and some of the clinical and research applications where AAV has shown success.
Collapse
Affiliation(s)
- R. Jude Samulski
- Gene Therapy Center, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Nicholas Muzyczka
- Powell Gene Therapy Center, College of Medicine, University of Florida, Gainesville, Florida 32610
| |
Collapse
|
50
|
Gao K, Li M, Zhong L, Su Q, Li J, Li S, He R, Zhang Y, Hendricks G, Wang J, Gao G. Empty Virions In AAV8 Vector Preparations Reduce Transduction Efficiency And May Cause Total Viral Particle Dose-Limiting Side-Effects. Mol Ther Methods Clin Dev 2014; 1:20139. [PMID: 25485285 PMCID: PMC4255953 DOI: 10.1038/mtm.2013.9] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Accepted: 11/12/2013] [Indexed: 02/05/2023]
Abstract
Empty virions are inadvertent by-products of recombinant adeno-associated virus (rAAV) packaging process, resulting in vector lots with mixtures of full and empty virions at variable ratios. Impact of empty virions on the efficiency and side-effects of rAAV transduction has not been well characterized. Here, we generated partially and completely empty AAV8 virions, fully packaged rAAV8 lots as well as mixtures of empty and fully packaged virions with variable ratios of empty virions (REVs). The aforementioned dosing formulations of rAAV8 expressing either cellular (EGFP or nuclear-targeted (n) LacZ) or secreted (human α1-antitrypsin, hA1AT) reporter genes were intravenously injected into two different mouse strains, followed by analyses of transgene expressions and serum alanine aminotransferase (ALT) levels at different time points. We found that addition of empty particles to the fixed doses of rAAV8 preparations repressed liver transduction up to 64% (serum hA1AT) and 44% (nLacZ) in C57BL/6 mice, respectively. The similar trend in inhibiting EGFP expression together with concurrent elevations of serum ATL levels were observed in the BALB/c mice, indicating that empty particles may also exacerbate side-effects of rAAV8EGFP transduction. Our results suggest that removal of empty particles from rAAV preparations may improve efficacy and safety of AAV in clinical applications.
Collapse
Affiliation(s)
- Kai Gao
- Gene Therapy Center, University of Massachusetts Medical School, Worcester, Massachusetts, USA
- National Institutes for Food and Drug Control, Beijing, China
| | - Mengxin Li
- Gene Therapy Center, University of Massachusetts Medical School, Worcester, Massachusetts, USA
- Viral Vector Core, University of Massachusetts Medical School, Worcester, Massachusetts, USA
- Department of Microbiology and Physiology Systems, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Li Zhong
- Gene Therapy Center, University of Massachusetts Medical School, Worcester, Massachusetts, USA
- Viral Vector Core, University of Massachusetts Medical School, Worcester, Massachusetts, USA
- Division of Hematology/Oncology, Department of Pediatrics, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Qin Su
- Gene Therapy Center, University of Massachusetts Medical School, Worcester, Massachusetts, USA
- Viral Vector Core, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Jia Li
- Gene Therapy Center, University of Massachusetts Medical School, Worcester, Massachusetts, USA
- Department of Microbiology and Physiology Systems, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Shaoyong Li
- Gene Therapy Center, University of Massachusetts Medical School, Worcester, Massachusetts, USA
- Department of Microbiology and Physiology Systems, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Ran He
- Gene Therapy Center, University of Massachusetts Medical School, Worcester, Massachusetts, USA
- Viral Vector Core, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Yu Zhang
- Gene Therapy Center, University of Massachusetts Medical School, Worcester, Massachusetts, USA
- Department of Oncology, Guizhou People’s Hospital, Guiyang, Guizhou, China
| | - Gregory Hendricks
- Department of Cell and Developmental Biology, Electron Microscopy Core Facility, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Junzhi Wang
- National Institutes for Food and Drug Control, Beijing, China
| | - Guangping Gao
- Gene Therapy Center, University of Massachusetts Medical School, Worcester, Massachusetts, USA
- Viral Vector Core, University of Massachusetts Medical School, Worcester, Massachusetts, USA
- Department of Microbiology and Physiology Systems, University of Massachusetts Medical School, Worcester, Massachusetts, USA
- Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| |
Collapse
|