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Broomfield J, Hill M, Chandler F, Crowther MJ, Godfrey J, Guglieri M, Hastie J, Larkindale J, Mumby-Croft J, Reuben E, Woodcock F, Abrams KR. Developing a Natural History Model for Duchenne Muscular Dystrophy. PHARMACOECONOMICS - OPEN 2024; 8:79-89. [PMID: 38019449 PMCID: PMC10781931 DOI: 10.1007/s41669-023-00450-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/18/2023] [Indexed: 11/30/2023]
Abstract
BACKGROUND The aim of this study was to pool multiple data sets to build a patient-centric, data-informed, natural history model (NHM) for Duchenne muscular dystrophy (DMD) to estimate disease trajectory across patient lifetime under current standard of care in future economic evaluations. The study was conducted as part of Project HERCULES, a multi-stakeholder collaboration to develop tools to support health technology assessments of new treatments for DMD. METHODS Health states were informed by a review of NHMs for DMD and input from clinicians, patients and caregivers, and defined using common outcomes in clinical trials and real-world practice. The primary source informing the NHM was the Critical Path Institute Duchenne Regulatory Science Consortium (D-RSC) database. This was supplemented with expert input obtained via an elicitation exercise, and a systematic literature review and meta-analysis of mortality data. RESULTS The NHM includes ambulatory, transfer and non-ambulatory phases, which capture loss of ambulation, ability to weight bear and upper body and respiratory function, respectively. The NHM estimates patients spend approximately 9.5 years in ambulatory states, 1.5 years in the transfer state and the remainder of their lives in non-ambulatory states. Median predicted survival is 34.8 years (95% CI 34.1-35.8). CONCLUSION The model includes a detailed disease pathway for DMD, including the clinically and economically important transfer state. The NHM may be used to estimate the current trajectory of DMD in economic evaluations of new treatments, facilitating inclusion of a lifetime time horizon, and will help identify areas for further research.
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Affiliation(s)
| | - M Hill
- GlaxoSmithKline, Middlesex, UK
| | - F Chandler
- Sanofi, Reading, UK
- Duchenne UK, London, UK
| | - M J Crowther
- Karolinska Institute, Stockholm, Sweden
- Red Door Analytics, Stockholm, Sweden
| | | | - M Guglieri
- Newcastle University and Newcastle Hospitals NHS Foundation Trust, Newcastle-upon-Tyne, UK
| | | | | | | | | | | | - K R Abrams
- University of Warwick, Coventry, UK
- University of York, York, UK
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Raghavan K, Dedeepiya VD, Srinivasan S, Pushkala S, Bharatidasan SS, Ikewaki N, Iwasaki M, Senthilkumar R, Preethy S, Abraham SJ. Beneficial immune-modulatory effects of the N-163 strain of Aureobasidium pullulans-produced 1,3-1,6 Beta glucans in Duchenne muscular dystrophy: Results of an open-label, prospective, exploratory case-control clinical study. IBRO Neurosci Rep 2023; 15:90-99. [PMID: 38053632 PMCID: PMC10694341 DOI: 10.1016/j.ibneur.2023.06.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 06/29/2023] [Indexed: 12/07/2023] Open
Abstract
Background This exploratory case-control study is to evaluate the effects of supplementation of Aureobasidium pullulans-N-163 strain produced 1,3-1,- 6 beta glucan in young patients with Duchenne muscular dystrophy (DMD). Methods Twenty-seven male subjects aged 5-19 years with DMD were included, nine in the control arm and 18 in the treatment arm to receive N-163 beta glucan along with conventional therapies for 45 days. While performing the analysis, steroid usage was also taken into consideration, those not administered steroids (Steroid -ve) (Control, n = 5; treatment, n = 9), those administered steroids (Steroid +ve) (Control, n = 4; treatment, n = 9). Results IL-6 showed a significant decrease in the treatment groups, especially the N-163 Steroid -ve group. IL-13 decreased in both treatment groups and TGF-β levels showed a significant decrease in the treatment groups, especially the N-163 Steroid -ve group, (p < 0.05). Dystrophin levels increased by up to 32% in the treatment groups compared to the control. Medical research council (MRC) grading showed slight improvement in muscle strength improvement in 12 out of 18 patients (67%) in the treatment group and four out of nine (44%) subjects in the control group. Conclusion Supplementation with the N-163 beta glucan food supplement produced beneficial effects: a significant decrease in inflammation and fibrosis markers, increase in serum dystrophin and slight improvement in muscle strength in DMD subjects over 45 days, thus making this a potential adjunct treatment for DMD after validation. Trial registration The study was registered in Clinical trials registry of India, CTRI/2021/05/033346. Registered on 5th May, 2021.
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Affiliation(s)
- Kadalraja Raghavan
- Dept of Paediatric Neurology, Jesuit Antonyraj memorial Inter-disciplinary Centre for Advanced Recovery and Education (JAICARE), Madurai, India
- Department of Paediatric Neurology, Kenmax Medical Service Private Limited, Madurai, India
- Department of Paediatric Neurology, Sarvee Integra Private Limited, Chennai, India
| | | | - Subramaniam Srinivasan
- Mary-Yoshio Translational Hexagon (MYTH), Nichi-In Centre for Regenerative Medicine (NCRM), Chennai, India
| | - Subramanian Pushkala
- Department of Immunology, The Tamil Nadu Dr. M.G.R. Medical University, Chennai 600032, India
| | - Sudhakar S. Bharatidasan
- Department of Anesthesia, Thunder Bay Regional Health Sciences Centre, Thunder Bay, Ontario, Canada
| | - Nobunao Ikewaki
- Dept. of Medical Life Science, Kyushu University of Health and Welfare, Japan
- Institute of Immunology, Junsei Educational Institute, Nobeoka, Miyazaki, Japan
| | - Masaru Iwasaki
- Centre for Advancing Clinical Research (CACR), University of Yamanashi - School of Medicine, Chuo, Japan
| | - Rajappa Senthilkumar
- Fujio-Eiji Academic Terrain (FEAT), Nichi-In Centre for Regenerative Medicine (NCRM), Chennai, India
| | - Senthilkumar Preethy
- Fujio-Eiji Academic Terrain (FEAT), Nichi-In Centre for Regenerative Medicine (NCRM), Chennai, India
| | - Samuel J.K. Abraham
- Mary-Yoshio Translational Hexagon (MYTH), Nichi-In Centre for Regenerative Medicine (NCRM), Chennai, India
- Centre for Advancing Clinical Research (CACR), University of Yamanashi - School of Medicine, Chuo, Japan
- Antony, Xavier Interdisciplinary Scholastics (AXIS), GN Corporation Co. Ltd., Kofu, Japan
- Levy-Jurgen Transdisciplinary Exploratory (LJTE), Global Niche Corp., Wilmington, DE, USA
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Filonova G, Aartsma-Rus A. Next steps for the optimization of exon therapy for Duchenne muscular dystrophy. Expert Opin Biol Ther 2023; 23:133-143. [PMID: 36655939 DOI: 10.1080/14712598.2023.2169070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
INTRODUCTION It is established that the exon-skipping approach can restore dystrophin in Duchenne muscular dystrophy (DMD) patients. However, dystrophin restoration levels are low, and the field is evolving to provide solutions for improved exon skipping. DMD is a neuromuscular disorder associated with chronic muscle tissue loss attributed to the lack of dystrophin, which causes muscle inflammation, fibrosis formation, and impaired regeneration. Currently, four antisense oligonucleotides (AONs) based on phosphorodiamidate morpholino oligomer (PMO) chemistry are approved by US Food and Drug Administration for exon skipping therapy of eligible DMD patients. AREAS COVERED This review describes a preclinical and clinical experience with approved and newly developed AONs for DMD, outlines efforts that have been done to enhance AON efficiency, reviews challenges of clinical trials, and summarizes the current state of the exon skipping approach in the DMD field. EXPERT OPINION The exon skipping approach for DMD is under development, and several chemical modifications with improved properties are under (pre)-clinical investigation. Despite existing advantages of these modifications, their safety and effectiveness have to be examined in clinical trials, which are planned or ongoing. Furthermore, we propose clinical settings using natural history controls to facilitate studying the functional effect of the therapy.
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Affiliation(s)
| | - Annemieke Aartsma-Rus
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
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Muntoni F, Signorovitch J, Sajeev G, Goemans N, Wong B, Tian C, Mercuri E, Done N, Wong H, Moss J, Yao Z, Ward SJ, Manzur A, Servais L, Niks EH, Straub V, de Groot IJM, McDonald C. Real-world and natural history data for drug evaluation in Duchenne muscular dystrophy: suitability of the North Star Ambulatory Assessment for comparisons with external controls. Neuromuscul Disord 2022; 32:271-283. [DOI: 10.1016/j.nmd.2022.02.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 02/15/2022] [Accepted: 02/18/2022] [Indexed: 10/19/2022]
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Benny Klimek ME, Vila MC, Edwards K, Boehler J, Novak J, Zhang A, Van der Meulen J, Tatum K, Quinn J, Fiorillo A, Burki U, Straub V, Lu QL, Hathout Y, van Den Anker J, Partridge TA, Morales M, Hoffman E, Nagaraju K. Effects of Chronic, Maximal Phosphorodiamidate Morpholino Oligomer (PMO) Dosing on Muscle Function and Dystrophin Restoration in a Mouse Model of Duchenne Muscular Dystrophy. J Neuromuscul Dis 2021; 8:S369-S381. [PMID: 34569970 DOI: 10.3233/jnd-210701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Phosphorodiamidate morpholino oligomer (PMO)-mediated exon skipping is currently used in clinical development to treat Duchenne muscular dystrophy (DMD), with four exon-skipping drugs achieving regulatory approval. Exon skipping elicits a truncated, but semi-functional dystrophin protein, similar to the truncated dystrophin expressed in patients with Becker Muscular dystrophy (BMD) where the disease phenotype is less severe than DMD. Despite promising results in both dystrophic animal models and DMD boys, restoration of dystrophin by exon skipping is highly variable, leading to contradictory functional outcomes in clinical trials. OBJECTIVE To develop optimal PMO dosing protocols that result in increased dystrophin and improved outcome measures in preclinical models of DMD. METHODS Tested effectiveness of multiple chronic, high dose PMO regimens using biochemical, histological, molecular, and imaging techniques in mdx mice. RESULTS A chronic, monthly regimen of high dose PMO increased dystrophin rescue in mdx mice and improved specific force in the extensor digitorum longus (EDL) muscle. However, monthly high dose PMO administration still results in variable dystrophin expression localized throughout various muscles. CONCLUSIONS High dose monthly PMO administration restores dystrophin expression and increases muscle force; however, the variability of dystrophin expression at both the inter-and intramuscular level remains. Additional strategies to optimize PMO uptake including increased dosing frequencies or combination treatments with other yet-to-be-defined therapies may be necessary to achieve uniform dystrophin restoration and increases in muscle function.
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Affiliation(s)
| | - Maria Candida Vila
- Center for Genetic Medicine, Children's National Health System, Washington, DC, USA.,The George Washington University, Institute of Biomedical Sciences, Washington, DC, USA
| | - Katie Edwards
- School of Pharmacy and Pharmaceutical Sciences, Binghamton University, Binghamton, NY, USA
| | - Jessica Boehler
- Center for Genetic Medicine, Children's National Health System, Washington, DC, USA.,The George Washington University, Institute of Biomedical Sciences, Washington, DC, USA
| | - James Novak
- Center for Genetic Medicine, Children's National Health System, Washington, DC, USA
| | - Aiping Zhang
- Center for Genetic Medicine, Children's National Health System, Washington, DC, USA
| | - Jack Van der Meulen
- Center for Genetic Medicine, Children's National Health System, Washington, DC, USA
| | - Kathleen Tatum
- Center for Genetic Medicine, Children's National Health System, Washington, DC, USA
| | - James Quinn
- Center for Genetic Medicine, Children's National Health System, Washington, DC, USA
| | - Alyson Fiorillo
- Center for Genetic Medicine, Children's National Health System, Washington, DC, USA
| | - Umar Burki
- Center for Genetic Medicine, Children's National Health System, Washington, DC, USA
| | - Volker Straub
- The John Walton Muscular Dystrophy Research Centre, MRC Centre for Neuromuscular Diseases at Newcastle, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Qi Long Lu
- McColl-Lockwood Laboratory for Muscular Dystrophy Research, Neuromuscular/ALS Center, Department of Neurology, Carolinas Medical Center, Charlotte, NC, USA
| | - Yetrib Hathout
- Center for Genetic Medicine, Children's National Health System, Washington, DC, USA.,The George Washington University, Institute of Biomedical Sciences, Washington, DC, USA.,School of Pharmacy and Pharmaceutical Sciences, Binghamton University, Binghamton, NY, USA
| | - John van Den Anker
- Center for Genetic Medicine, Children's National Health System, Washington, DC, USA.,Center for Translational Science, Children's National Health System, Washington, DC, USA
| | - Terence A Partridge
- Center for Genetic Medicine, Children's National Health System, Washington, DC, USA.,The George Washington University, Institute of Biomedical Sciences, Washington, DC, USA
| | - Melissa Morales
- School of Pharmacy and Pharmaceutical Sciences, Binghamton University, Binghamton, NY, USA
| | - Eric Hoffman
- Center for Genetic Medicine, Children's National Health System, Washington, DC, USA.,The George Washington University, Institute of Biomedical Sciences, Washington, DC, USA.,School of Pharmacy and Pharmaceutical Sciences, Binghamton University, Binghamton, NY, USA
| | - Kanneboyina Nagaraju
- Center for Genetic Medicine, Children's National Health System, Washington, DC, USA.,The George Washington University, Institute of Biomedical Sciences, Washington, DC, USA.,School of Pharmacy and Pharmaceutical Sciences, Binghamton University, Binghamton, NY, USA
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Rossi R, Falzarano MS, Osman H, Armaroli A, Scotton C, Mantuano P, Boccanegra B, Cappellari O, Schwartz E, Yuryev A, Mercuri E, Bertini E, D'Amico A, Mora M, Johansson C, Al-Khalili Szigyarto C, De Luca A, Ferlini A. Circadian Genes as Exploratory Biomarkers in DMD: Results From Both the mdx Mouse Model and Patients. Front Physiol 2021; 12:678974. [PMID: 34305639 PMCID: PMC8300012 DOI: 10.3389/fphys.2021.678974] [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: 03/10/2021] [Accepted: 06/14/2021] [Indexed: 11/21/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a rare genetic disease due to dystrophin gene mutations which cause progressive weakness and muscle wasting. Circadian rhythm coordinates biological processes with the 24-h cycle and it plays a key role in maintaining muscle functions, both in animal models and in humans. We explored expression profiles of circadian circuit master genes both in Duchenne muscular dystrophy skeletal muscle and in its animal model, the mdx mouse. We designed a customized, mouse-specific Fluidic-Card-TaqMan-based assay (Fluid-CIRC) containing thirty-two genes related to circadian rhythm and muscle regeneration and analyzed gastrocnemius and tibialis anterior muscles from both unexercised and exercised mdx mice. Based on this first analysis, we prioritized the 7 most deregulated genes in mdx mice and tested their expression in skeletal muscle biopsies from 10 Duchenne patients. We found that CSNK1E, SIRT1, and MYOG are upregulated in DMD patient biopsies, consistent with the mdx data. We also demonstrated that their proteins are detectable and measurable in the DMD patients’ plasma. We suggest that CSNK1E, SIRT1, and MYOG might represent exploratory circadian biomarkers in DMD.
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Affiliation(s)
- Rachele Rossi
- Unit of Medical Genetics, Department of Medical Sciences, University of Ferrara, Ferrara, Italy.,The Dubowitz Neuromuscular Centre, Institute of Child Health, London, United Kingdom
| | - Maria Sofia Falzarano
- Unit of Medical Genetics, Department of Medical Sciences, University of Ferrara, Ferrara, Italy
| | - Hana Osman
- Unit of Medical Genetics, Department of Medical Sciences, University of Ferrara, Ferrara, Italy.,Department of Medical Microbiology, Faculty of Medical Laboratory Sciences, University of Khartoum, Khartoum, Sudan
| | - Annarita Armaroli
- Unit of Medical Genetics, Department of Medical Sciences, University of Ferrara, Ferrara, Italy
| | - Chiara Scotton
- Unit of Medical Genetics, Department of Medical Sciences, University of Ferrara, Ferrara, Italy
| | - Paola Mantuano
- Section of Pharmacology, Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", Bari, Italy
| | - Brigida Boccanegra
- Section of Pharmacology, Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", Bari, Italy
| | - Ornella Cappellari
- Section of Pharmacology, Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", Bari, Italy
| | | | | | - Eugenio Mercuri
- Pediatric Neurology Unit, Catholic University and Nemo Center, Policlinico Universitario Gemelli, Rome, Italy
| | - Enrico Bertini
- Unit of Neuromuscular and Neurodegenerative Disorders, Department of Neurosciences, IRCCS Bambino Gesu Children's Hospital, Rome, Italy
| | - Adele D'Amico
- Unit of Neuromuscular and Neurodegenerative Disorders, Department of Neurosciences, IRCCS Bambino Gesu Children's Hospital, Rome, Italy
| | - Marina Mora
- Neuromuscular Diseases and Neuroimmunology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Camilla Johansson
- School of Chemistry, Biotechnology and Health, Royal Institute of Technology, Stockholm, Sweden
| | - Cristina Al-Khalili Szigyarto
- School of Chemistry, Biotechnology and Health, Royal Institute of Technology, Stockholm, Sweden.,Science for Life Laboratory, Royal Institute of Technology, Stockholm, Sweden
| | - Annamaria De Luca
- Section of Pharmacology, Department of Pharmacy-Drug Sciences, University of Bari "Aldo Moro", Bari, Italy
| | - Alessandra Ferlini
- Unit of Medical Genetics, Department of Medical Sciences, University of Ferrara, Ferrara, Italy.,The Dubowitz Neuromuscular Centre, Institute of Child Health, London, United Kingdom
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Biressi S, Filareto A, Rando TA. Stem cell therapy for muscular dystrophies. J Clin Invest 2021; 130:5652-5664. [PMID: 32946430 DOI: 10.1172/jci142031] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Muscular dystrophies are a heterogeneous group of genetic diseases, characterized by progressive degeneration of skeletal and cardiac muscle. Despite the intense investigation of different therapeutic options, a definitive treatment has not been developed for this debilitating class of pathologies. Cell-based therapies in muscular dystrophies have been pursued experimentally for the last three decades. Several cell types with different characteristics and tissues of origin, including myogenic stem and progenitor cells, stromal cells, and pluripotent stem cells, have been investigated over the years and have recently entered in the clinical arena with mixed results. In this Review, we do a roundup of the past attempts and describe the updated status of cell-based therapies aimed at counteracting the skeletal and cardiac myopathy present in dystrophic patients. We present current challenges, summarize recent progress, and make recommendations for future research and clinical trials.
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Affiliation(s)
- Stefano Biressi
- Department of Cellular, Computational and Integrative Biology (CIBIO) and.,Dulbecco Telethon Institute, University of Trento, Povo, Italy
| | - Antonio Filareto
- Department of Research Beyond Borders, Regenerative Medicine, Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, Conneticut, USA
| | - Thomas A Rando
- Department of Neurology and Neurological Sciences and.,Paul F. Glenn Center for the Biology of Aging, Stanford University School of Medicine, Stanford, California, USA.,Center for Tissue Regeneration, Repair and Restoration, Veterans Affairs Palo Alto Health Care System, Palo Alto, California, USA
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Effective Data Sharing as a Conduit for Advancing Medical Product Development. Ther Innov Regul Sci 2021; 55:591-600. [PMID: 33398663 PMCID: PMC7780909 DOI: 10.1007/s43441-020-00255-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 12/17/2020] [Indexed: 12/20/2022]
Abstract
INTRODUCTION Patient-level data sharing has the potential to significantly impact the lives of patients by optimizing and improving the medical product development process. In the product development setting, successful data sharing is defined as data sharing that is actionable and facilitates decision making during the development and review of medical products. This often occurs through the creation of new product development tools or methodologies, such as novel clinical trial design and enrichment strategies, predictive pre-clinical and clinical models, clinical trial simulation tools, biomarkers, and clinical outcomes assessments, and more. METHODS To be successful, extensive partnerships must be established between all relevant stakeholders, including industry, academia, research institutes and societies, patient-advocacy groups, and governmental agencies, and a neutral third-party convening organization that can provide a pre-competitive space for data sharing to occur. CONCLUSIONS Data sharing focused on identified regulatory deliverables that improve the medical product development process encounters significant challenges that are not seen with data sharing aimed at advancing clinical decision making and requires the commitment of all stakeholders. Regulatory data sharing challenges and solutions, as well as multiple examples of previous successful data sharing initiatives are presented and discussed in the context of medical product development.
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Komaki H, Takeshima Y, Matsumura T, Ozasa S, Funato M, Takeshita E, Iwata Y, Yajima H, Egawa Y, Toramoto T, Tajima M, Takeda S. Viltolarsen in Japanese Duchenne muscular dystrophy patients: A phase 1/2 study. Ann Clin Transl Neurol 2020; 7:2393-2408. [PMID: 33285037 PMCID: PMC7732240 DOI: 10.1002/acn3.51235] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 10/01/2020] [Accepted: 10/03/2020] [Indexed: 01/14/2023] Open
Abstract
Objective The novel morpholino antisense oligonucleotide viltolarsen targets exon 53 of the dystrophin gene, and could be an effective treatment for patients with Duchenne muscular dystrophy (DMD). We investigated viltolarsen’s ability to induce dystrophin expression and examined its safety in DMD patients. Methods In this open‐label, multicenter, parallel‐group, phase 1/2, exploratory study, 16 ambulant and nonambulant males aged 5–12 years with DMD received viltolarsen 40 or 80 mg/kg/week via intravenous infusion for 24 weeks. Primary endpoints were dystrophin expression and exon 53 skipping levels. Results In western blot analysis, mean changes in dystrophin expression (% normal) from baseline to Weeks 12 and 24 were − 1.21 (P = 0.5136) and 1.46 (P = 0.1636), respectively, in the 40 mg/kg group, and 0.76 (P = 0.2367) and 4.81 (P = 0.0536), respectively, in the 80 mg/kg group. The increase in mean dystrophin level at Weeks 12 and 24 was significant in the 80 mg/kg group (2.78%; P = 0.0364). Patients receiving 80 mg/kg showed a higher mean exon 53 skipping level (42.4%) than those receiving 40 mg/kg (21.8%). All adverse events were judged to be mild or moderate in intensity and none led to study discontinuation. Interpretation Treatment with viltolarsen 40 or 80 mg/kg elicited an increasing trend in dystrophin expression and exon 53 skipping levels, and was safe and well tolerated. The decline in motor function appeared less marked in patients with higher dystrophin levels; this may warrant further investigation. This study supports the potential clinical benefit of viltolarsen.
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Affiliation(s)
- Hirofumi Komaki
- Translational Medical Center, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan
| | - Yasuhiro Takeshima
- Department of Pediatrics, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - Tsuyoshi Matsumura
- Department of Neurology, National Hospital Organization Osaka Toneyama Medical Center, Toyonaka, Osaka, Japan
| | - Shiro Ozasa
- Department of Pediatrics, Kumamoto University Hospital, Kumamoto, Kumamoto, Japan
| | - Michinori Funato
- Department of Pediatrics, National Hospital Organization Nagara Medical Center, Gifu, Japan
| | - Eri Takeshita
- Department of Child Neurology, National Center of Neurology and Psychiatry, National Center Hospital, Kodaira, Tokyo, Japan
| | - Yasuyuki Iwata
- Department of Rehabilitation, National Center of Neurology and Psychiatry, National Center Hospital, Kodaira, Tokyo, Japan
| | - Hiroyuki Yajima
- Department of Rehabilitation, National Center of Neurology and Psychiatry, National Center Hospital, Kodaira, Tokyo, Japan
| | - Yoichi Egawa
- Global Clinical Development Department, Nippon Shinyaku Co., Ltd., Kyoto, Kyoto, Japan
| | - Takuya Toramoto
- Global Clinical Development Department, Nippon Shinyaku Co., Ltd., Kyoto, Kyoto, Japan
| | - Masaya Tajima
- Global Clinical Development Department, Nippon Shinyaku Co., Ltd., Kyoto, Kyoto, Japan
| | - Shinichi Takeda
- National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan
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Miller NF, Alfano LN, Iammarino MA, Connolly AM, Moore-Clingenpeel M, Powers BR, Tsao CY, Waldrop MA, Flanigan KM, Mendell JR, Lowes LP. Natural History of Steroid-Treated Young Boys With Duchenne Muscular Dystrophy Using the NSAA, 100m, and Timed Functional Tests. Pediatr Neurol 2020; 113:15-20. [PMID: 32979653 DOI: 10.1016/j.pediatrneurol.2020.08.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 08/17/2020] [Accepted: 08/19/2020] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Clinical trials targeting younger cohorts of boys with Duchenne muscular dystrophy are necessary as earlier intervention may maximize treatment effect. Boys with Duchenne muscular dystrophy often have gross motor delays very early in life, and although they gain skills, they are on a lower trajectory than typical peers. Quantifying the natural rate of motor maturation in Duchenne muscular dystrophy from an early age permits identification of deviations from the expected trajectory related to treatment effects. METHODS The purpose of our study was to define the natural history in boys aged from ≥3 to <8 years using the North Star Ambulatory Assessment (NSAA), 100-meter timed test (100m), 10-meter walk/run (10m), time to rise (Rise), and 4-stair climb (4SC). Assessments were completed as standard of care during regularly scheduled clinic visits. RESULTS One hundred sixty-two boys with DMD aged 3.1 to 7.9 years on glucocorticoids were evaluated using one or more of the following tests as appropriate for age: NSAA (N = 158; 3.1-7.9 years), 100m (N = 131; 3.4-7.9 years), 10m (N = 162; 3.1-7.9 years), Rise (N = 160; 3.1-7.9 years), and 4SC (N = 153; 3.1-7.9 years). Longitudinal data are presented by age in a subcohort (N = 64). CONCLUSIONS Our study documents the baseline function of boys with DMD who are being treated with corticosteroids. These data will be useful to compare ongoing and future therapeutic intervention(s) for DMD.
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Affiliation(s)
- Natalie F Miller
- Center for Gene Therapy, The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio.
| | - Lindsay N Alfano
- Center for Gene Therapy, The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio
| | - Megan A Iammarino
- Center for Gene Therapy, The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio
| | - Anne M Connolly
- Center for Gene Therapy, The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio; Department of Neurology, The College of Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Melissa Moore-Clingenpeel
- Biostatistics Resource, The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio
| | - Brenna R Powers
- Center for Gene Therapy, The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio
| | - Chang-Yong Tsao
- Department of Neurology, The College of Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Megan A Waldrop
- Center for Gene Therapy, The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio; Department of Pediatrics, The College of Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Kevin M Flanigan
- Center for Gene Therapy, The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio; Department of Pediatrics, The College of Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Jerry R Mendell
- Center for Gene Therapy, The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio; Department of Pediatrics, The College of Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Linda P Lowes
- Center for Gene Therapy, The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio; Department of Pediatrics, The College of Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio
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11
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Nishizawa H, Sato Y, Ishikawa M, Arakawa Y, Iijima M, Akiyama T, Takano K, Watanabe A, Kosho T. Marked motor function improvement in a 32-year-old woman with childhood-onset hypophosphatasia by asfotase alfa therapy: Evaluation based on standardized testing batteries used in Duchenne muscular dystrophy clinical trials. Mol Genet Metab Rep 2020; 25:100643. [PMID: 32983894 PMCID: PMC7494508 DOI: 10.1016/j.ymgmr.2020.100643] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 08/21/2020] [Accepted: 08/21/2020] [Indexed: 12/12/2022] Open
Abstract
Hypophosphatasia (HPP) is a rare disorder resulting from biallelic loss-of-function variants or monoallelic dominant negative variants in the ALPL gene. We herein describe the clinical outcome of a 32-year-old woman with childhood-onset HPP caused by compound heterozygous variants in ALPL. Her chief complaints were severe musculoskeletal pain, muscle weakness, and impaired daily activities necessitating assistance in housework and child-rearing in addition to a history of early tooth loss and mildly short stature. Asfotase alfa therapy produced a remarkable increase in muscle strength and daily activities and markedly reduced musculoskeletal pain. Drug efficacy was clearly demonstrated through multiple test batteries (muscle strength test using microFET®2, six-minute walking test, Stair Climb Test, rising-from-floor-time test, and number-of-steps test using Actigraph®) currently adopted as standardized evaluations in Duchenne muscular dystrophy clinical trials since no test batteries for HPP have been established to date. These tests may also be promising for the assessment of HPP.
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Affiliation(s)
- Hitomi Nishizawa
- Faculty of Health Sciences, Department of Medicine, Shinshu University, Matsumoto, Japan
| | - Yoshihiko Sato
- Department of Diabetes, Endocrinology and Metabolism, Division of Internal Medicine, Shinshu University School of Medicine, Matsumoto, Japan.,Department of Diabetes, Endocrinology and Metabolism, Matsumoto City Hospital, Matsumoto, Japan
| | - Masumi Ishikawa
- Center for Medical Genetics, Shinshu University Hospital, Matsumoto, Japan
| | - Yuko Arakawa
- Department of Dentistry and Oral Surgery, Shinshu University School of Medicine, Matsumoto, Japan
| | - Mari Iijima
- Department of Clinical Nutrition, Shinshu University Hospital, Matsumoto, Japan
| | - Tomoyuki Akiyama
- Department of Child Neurology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Science, Okayama, Japan
| | - Kyoko Takano
- Center for Medical Genetics, Shinshu University Hospital, Matsumoto, Japan.,Department of Medical Genetics, Shinshu University School of Medicine, Matsumoto, Japan
| | - Atsushi Watanabe
- Division of Clinical Genetics, Kanazawa University Hospital, Kanazawa, Japan
| | - Tomoki Kosho
- Center for Medical Genetics, Shinshu University Hospital, Matsumoto, Japan.,Department of Medical Genetics, Shinshu University School of Medicine, Matsumoto, Japan.,Research Center for Supports to Advanced Science, Shinshu University, Matsumoto, Japan.,Division of Clinical Sequence, Shinshu University School of Medicine, Matsumoto, Japan
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12
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Scaglioni D, Ellis M, Catapano F, Torelli S, Chambers D, Feng L, Sewry C, Morgan J, Muntoni F, Phadke R. A high-throughput digital script for multiplexed immunofluorescent analysis and quantification of sarcolemmal and sarcomeric proteins in muscular dystrophies. Acta Neuropathol Commun 2020; 8:53. [PMID: 32303261 PMCID: PMC7165405 DOI: 10.1186/s40478-020-00918-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 03/16/2020] [Indexed: 12/21/2022] Open
Abstract
The primary molecular endpoint for many Duchenne muscular dystrophy (DMD) clinical trials is the induction, or increase in production, of dystrophin protein in striated muscle. For accurate endpoint analysis, it is essential to have reliable, robust and objective quantification methodologies capable of detecting subtle changes in dystrophin expression. In this work, we present further development and optimisation of an automated, digital, high-throughput script for quantitative analysis of multiplexed immunofluorescent (IF) whole slide images (WSI) of dystrophin, dystrophin associated proteins (DAPs) and regenerating myofibres (fetal/developmental myosin-positive) in transverse sections of DMD, Becker muscular dystrophy (BMD) and control skeletal muscle biopsies. The script enables extensive automated assessment of myofibre morphometrics, protein quantification by fluorescence intensity and sarcolemmal circumference coverage, colocalisation data for dystrophin and DAPs and regeneration at the single myofibre and whole section level. Analysis revealed significant variation in dystrophin intensity, percentage coverage and amounts of DAPs between differing DMD and BMD samples. Accurate identification of dystrophin via a novel background subtraction method allowed differential assessment of DAP fluorescence intensity within dystrophin positive compared to dystrophin negative sarcolemma regions. This enabled surrogate quantification of molecular functionality of dystrophin in the assembly of the DAP complex. Overall, the digital script is capable of multiparametric and unbiased analysis of markers of myofibre regeneration and dystrophin in relation to key DAPs and enabled better characterisation of the heterogeneity in dystrophin expression patterns seen in BMD and DMD alongside the surrogate assessment of molecular functionality of dystrophin. Both these aspects will be of significant relevance to ongoing and future DMD and other muscular dystrophies clinical trials to help benchmark therapeutic efficacy.
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13
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Tsoumpra MK, Fukumoto S, Matsumoto T, Takeda S, Wood MJA, Aoki Y. Peptide-conjugate antisense based splice-correction for Duchenne muscular dystrophy and other neuromuscular diseases. EBioMedicine 2019; 45:630-645. [PMID: 31257147 PMCID: PMC6642283 DOI: 10.1016/j.ebiom.2019.06.036] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 05/31/2019] [Accepted: 06/18/2019] [Indexed: 12/14/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is an X-linked disorder characterized by progressive muscle degeneration, caused by the absence of dystrophin. Exon skipping by antisense oligonucleotides (ASOs) has recently gained recognition as therapeutic approach in DMD. Conjugation of a peptide to the phosphorodiamidate morpholino backbone (PMO) of ASOs generated the peptide-conjugated PMOs (PPMOs) that exhibit a dramatically improved pharmacokinetic profile. When tested in animal models, PPMOs demonstrate effective exon skipping in target muscles and prolonged duration of dystrophin restoration after a treatment regime. Herein we summarize the main pathophysiological features of DMD and the emergence of PPMOs as promising exon skipping agents aiming to rescue defective gene expression in DMD and other neuromuscular diseases. The listed PPMO laboratory findings correspond to latest trends in the field and highlight the obstacles that must be overcome prior to translating the animal-based research into clinical trials tailored to the needs of patients suffering from neuromuscular diseases.
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Key Words
- aso, antisense oligonucleotides
- cns, central nervous system
- cpp, cell penetrating peptide
- dgc, dystrophin glyco-protein complex
- dmd, duchenne muscular dystrophy
- fda, us food and drug administration
- pmo, phosphorodiamidate morpholino
- ppmo, peptide-conjugated pmos
- ps, phosphorothioate
- sma, spinal muscular atrophy
- 2ʹ-ome, 2ʹ-o-methyl
- 2ʹ-moe, 2ʹ-o-methoxyethyl
- 6mwt, 6-minute walk test
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Affiliation(s)
- Maria K Tsoumpra
- Department of Molecular Therapy, National Institute of Neuroscience, National Centre of Neurology and Psychiatry, Kodaira-shi, Tokyo, Japan
| | - Seiji Fukumoto
- Fujii Memorial Institute of Medical Sciences, University of Tokushima, Tokushima, Japan
| | - Toshio Matsumoto
- Fujii Memorial Institute of Medical Sciences, University of Tokushima, Tokushima, Japan
| | - Shin'ichi Takeda
- Department of Molecular Therapy, National Institute of Neuroscience, National Centre of Neurology and Psychiatry, Kodaira-shi, Tokyo, Japan
| | | | - Yoshitsugu Aoki
- Department of Molecular Therapy, National Institute of Neuroscience, National Centre of Neurology and Psychiatry, Kodaira-shi, Tokyo, Japan.
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14
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Next-generation muscle-directed gene therapy by in silico vector design. Nat Commun 2019; 10:492. [PMID: 30700722 PMCID: PMC6353880 DOI: 10.1038/s41467-018-08283-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Accepted: 12/28/2018] [Indexed: 01/10/2023] Open
Abstract
There is an urgent need to develop the next-generation vectors for gene therapy of muscle disorders, given the relatively modest advances in clinical trials. These vectors should express substantially higher levels of the therapeutic transgene, enabling the use of lower and safer vector doses. In the current study, we identify potent muscle-specific transcriptional cis-regulatory modules (CRMs), containing clusters of transcription factor binding sites, using a genome-wide data-mining strategy. These novel muscle-specific CRMs result in a substantial increase in muscle-specific gene transcription (up to 400-fold) when delivered using adeno-associated viral vectors in mice. Significantly higher and sustained human micro-dystrophin and follistatin expression levels are attained than when conventional promoters are used. This results in robust phenotypic correction in dystrophic mice, without triggering apoptosis or evoking an immune response. This multidisciplinary approach has potentially broad implications for augmenting the efficacy and safety of muscle-directed gene therapy. Adeno-associated viral vectors (AAV) are being developed for gene therapy of skeletal muscle, but it is a challenge to achieve robust gene expression. Here, the authors identify muscle-specific cisregulatory elements that lead to a substantial increase in micro-dystrophin and follistatin expression, resulting in a safe and sustainable rescue of the dystrophic phenotype in mouse models.
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15
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Multiple Exon Skipping in the Duchenne Muscular Dystrophy Hot Spots: Prospects and Challenges. J Pers Med 2018; 8:jpm8040041. [PMID: 30544634 PMCID: PMC6313462 DOI: 10.3390/jpm8040041] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 11/24/2018] [Accepted: 12/04/2018] [Indexed: 12/19/2022] Open
Abstract
Duchenne muscular dystrophy (DMD), a fatal X-linked recessive disorder, is caused mostly by frame-disrupting, out-of-frame deletions in the dystrophin (DMD) gene. Antisense oligonucleotide-mediated exon skipping is a promising therapy for DMD. Exon skipping aims to convert out-of-frame mRNA to in-frame mRNA and induce the production of internally-deleted dystrophin as seen in the less severe Becker muscular dystrophy. Currently, multiple exon skipping has gained special interest as a new therapeutic modality for this approach. Previous retrospective database studies represented a potential therapeutic application of multiple exon skipping. Since then, public DMD databases have become more useful with an increase in patient registration and advances in molecular diagnosis. Here, we provide an update on DMD genotype-phenotype associations using a global DMD database and further provide the rationale for multiple exon skipping development, particularly for exons 45–55 skipping and an emerging therapeutic concept, exons 3–9 skipping. Importantly, this review highlights the potential of multiple exon skipping for enabling the production of functionally-corrected dystrophin and for treating symptomatic patients not only with out-of-frame deletions but also those with in-frame deletions. We will also discuss prospects and challenges in multiple exon skipping therapy, referring to recent progress in antisense chemistry and design, as well as disease models.
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16
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Tremblay JP, Iyombe-Engembe JP, Duchêne B, Ouellet DL. Gene Editing for Duchenne Muscular Dystrophy Using the CRISPR/Cas9 Technology: The Importance of Fine-tuning the Approach. Mol Ther 2018; 24:1888-1889. [PMID: 27916992 DOI: 10.1038/mt.2016.191] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Affiliation(s)
- Jacques P Tremblay
- Centre de Recherche du CHU de Québec-Université Laval, Quebec, Quebec, Canada.
| | | | - Benjamin Duchêne
- Centre de Recherche du CHU de Québec-Université Laval, Quebec, Quebec, Canada
| | - Dominique L Ouellet
- Centre de Recherche du CHU de Québec-Université Laval, Quebec, Quebec, Canada
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17
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Zolkipli-Cunningham Z, Xiao R, Stoddart A, McCormick EM, Holberts A, Burrill N, McCormack S, Williams L, Wang X, Thompson JLP, Falk MJ. Mitochondrial disease patient motivations and barriers to participate in clinical trials. PLoS One 2018; 13:e0197513. [PMID: 29771953 PMCID: PMC5957366 DOI: 10.1371/journal.pone.0197513] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 05/03/2018] [Indexed: 01/21/2023] Open
Abstract
Background Clinical treatment trials are increasingly being designed in primary mitochondrial disease (PMD), a phenotypically and genetically heterogeneous collection of inherited multi- system energy deficiency disorders that lack effective therapy. We sought to identify motivating factors and barriers to clinical trial participation in PMD. Methods A survey study was conducted in two independent mitochondrial disease subject cohorts. A discovery cohort invited subjects with well-defined biochemical or molecularly- confirmed PMD followed at a single medical center (CHOP, n = 30/67 (45%) respondents). A replication cohort included self-identified PMD subjects in the Rare Disease Clinical Research Network (RDCRN) national contact registry (n = 290/1119 (26%) respondents). Five-point Likert scale responses were analyzed using descriptive and quantitative statistics. Experienced and prioritized symptoms for trial participation, and patient attitudes toward detailed aspects of clinical trial drug features and study design. Results PMD subjects experienced an average of 16 symptoms. Muscle weakness, chronic fatigue, and exercise intolerance were the lead symptoms encouraging trial participation. Motivating trial design factors included a self-administered study drug; vitamin, antioxidant, natural or plant-derivative; pills; daily treatment; guaranteed treatment access during and after study; short travel distances; and late-stage (phase 3) participation. Relative trial participation barriers included a new study drug; discontinuation of current medications; disease progression; daily phlebotomy; and requiring participant payment. Treatment trial type or design preferences were not influenced by population age (pediatric versus adult), prior research trial experience, or disease severity. Conclusions These data are the first to convey clear PMD subject preferences and priorities to enable improved clinical treatment trial design that cuts across the complex diversity of disease. Partnering with rare disease patient communities is essential to effectively design robust clinical trials that engage patients and enable meaningful evaluation of emerging treatment interventions.
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Affiliation(s)
- Zarazuela Zolkipli-Cunningham
- Division of Neurology, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
- Mitochondrial Medicine Frontier Program, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Rui Xiao
- Department of Biostatistics and Epidemiology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Amy Stoddart
- Mitochondrial Medicine Frontier Program, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
- Arcadia University, Glenside, Pennsylvania, United States of America
- Division of Human Genetics, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Elizabeth M. McCormick
- Mitochondrial Medicine Frontier Program, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
- Division of Human Genetics, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Amy Holberts
- Rare Diseases Clinical Research Network, Health Informatics Institute, University of South Florida, Tampa, Florida, United States of America
| | - Natalie Burrill
- Mitochondrial Medicine Frontier Program, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Shana McCormack
- Mitochondrial Medicine Frontier Program, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
- Division of Endocrinology and Diabetes, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
- University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Lauren Williams
- Department of Biostatistics, Mailman School of Public Health, Columbia University Medical Center, New York, New York, United States of America
| | - Xiaoyan Wang
- Department of Biostatistics, Mailman School of Public Health, Columbia University Medical Center, New York, New York, United States of America
| | - John L. P. Thompson
- Department of Biostatistics, Mailman School of Public Health, Columbia University Medical Center, New York, New York, United States of America
| | - Marni J. Falk
- Mitochondrial Medicine Frontier Program, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
- Division of Human Genetics, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
- Department of Biostatistics, Mailman School of Public Health, Columbia University Medical Center, New York, New York, United States of America
- * E-mail:
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18
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Eteplirsen for paediatric patients with Duchenne muscular dystrophy: A pooled-analysis. J Clin Neurosci 2017; 49:1-6. [PMID: 29254734 DOI: 10.1016/j.jocn.2017.10.082] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 10/23/2017] [Indexed: 01/09/2023]
Abstract
BACKGROUND Duchenne Muscular Dystrophy is a paediatric disorder resulting from a defective dystrophin gene. It causes progressive loss of muscle fibres, muscle weakness, and eventually loss of ambulation during adolescence, with death due to respiratory or cardiovascular complications soon afterwards. The drug eteplirsen has received support from medical experts and parents of affected children, but the FDA has delayed their decision for approval of this drug. OBJECTIVE This study analysed the results of previous studies to assess the safety and efficacy of the eteplirsen, and is the first pooled-analysis of its kind. METHODS A literature search of electronic databases was performed. Only human studies using eteplirsen were eligible. RESULTS A total of four relevant clinical studies were identified. A pooled-analysis was performed using data relating to percentage dystrophin-positive fibres obtained from muscle biopsy, and the six-minute walk test (6 MWT). The average increase in percentage dystrophin-positive fibres after treatment with eteplirsen was 24.23% (range -4 to 78; SD 24.44%). The average rate of decline in distance walked was 65metres (range -335 to 83; SD 100.08 m). CONCLUSIONS Whether or not this increase in percentage dystrophin-positive fibres and distance walked is clinically significant is unclear, and there is therefore a need for more clinical trials.
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19
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Coenen-Stass AML, Wood MJA, Roberts TC. Biomarker Potential of Extracellular miRNAs in Duchenne Muscular Dystrophy. Trends Mol Med 2017; 23:989-1001. [PMID: 28988850 DOI: 10.1016/j.molmed.2017.09.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 09/11/2017] [Accepted: 09/13/2017] [Indexed: 12/12/2022]
Abstract
miRNAs are small, noncoding RNAs that not only regulate gene expression within cells, but might also constitute promising extracellular biomarkers for a variety of pathologies, including the progressive muscle-wasting disorder Duchenne Muscular Dystrophy (DMD). A set of muscle-enriched miRNAs, the myomiRs (miR-1, miR-133, and miR-206) are highly elevated in the serum of patients with DMD and in dystrophin-deficient animal models. Furthermore, circulating myomiRs might be used as pharmacodynamic biomarkers, given that their levels can be restored towards wild-type levels following exon skipping therapy in dystrophic mice. The relationship between muscle pathology and extracellular myomiR release is complex, and incompletely understood. Here, we discuss current progress leading towards the clinical utility of extracellular miRNAs as putative DMD biomarkers, and their possible contribution to muscle physiology.
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Affiliation(s)
- Anna M L Coenen-Stass
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, OX1 3QX, UK; Institute of Neurology, Sobell Department of Motor Neuroscience and Movement Disorders, University College London, London, Queen Square, London, WC1N 3BG, UK
| | - Matthew J A Wood
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, OX1 3QX, UK.
| | - Thomas C Roberts
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, OX1 3QX, UK; Sanford Burnham Prebys Medical Discovery Institute, Development, Aging and Regeneration Program, La Jolla, CA 92037, USA.
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20
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Wilson K, Faelan C, Patterson-Kane JC, Rudmann DG, Moore SA, Frank D, Charleston J, Tinsley J, Young GD, Milici AJ. Duchenne and Becker Muscular Dystrophies: A Review of Animal Models, Clinical End Points, and Biomarker Quantification. Toxicol Pathol 2017; 45:961-976. [PMID: 28974147 DOI: 10.1177/0192623317734823] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are neuromuscular disorders that primarily affect boys due to an X-linked mutation in the DMD gene, resulting in reduced to near absence of dystrophin or expression of truncated forms of dystrophin. Some newer therapeutic interventions aim to increase sarcolemmal dystrophin expression, and accurate dystrophin quantification is critical for demonstrating pharmacodynamic relationships in preclinical studies and clinical trials. Current challenges with measuring dystrophin include the variation in protein expression within individual muscle fibers and across whole muscle samples, the presence of preexisting dystrophin-positive revertant fibers, and trace amounts of residual dystrophin. Immunofluorescence quantification of dystrophin can overcome many of these challenges, but manual quantification of protein expression may be complicated by variations in the collection of images, reproducible scoring of fluorescent intensity, and bias introduced by manual scoring of typically only a few high-power fields. This review highlights the pathology of DMD and BMD, discusses animal models of DMD and BMD, and describes dystrophin biomarker quantitation in DMD and BMD, with several image analysis approaches, including a new automated method that evaluates protein expression of individual muscle fibers.
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Affiliation(s)
- Kristin Wilson
- 1 Flagship Biosciences, Inc., Westminster, Colorado, USA
| | - Crystal Faelan
- 1 Flagship Biosciences, Inc., Westminster, Colorado, USA
| | | | | | - Steven A Moore
- 2 Department of Pathology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - Diane Frank
- 3 Sarepta Therapeutics, Inc., Cambridge, Massachusetts, USA
| | - Jay Charleston
- 3 Sarepta Therapeutics, Inc., Cambridge, Massachusetts, USA
| | - Jon Tinsley
- 4 Summit Therapeutics, Abingdon, United Kingdom
| | - G David Young
- 1 Flagship Biosciences, Inc., Westminster, Colorado, USA
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21
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McDonald CM, Campbell C, Torricelli RE, Finkel RS, Flanigan KM, Goemans N, Heydemann P, Kaminska A, Kirschner J, Muntoni F, Osorio AN, Schara U, Sejersen T, Shieh PB, Sweeney HL, Topaloglu H, Tulinius M, Vilchez JJ, Voit T, Wong B, Elfring G, Kroger H, Luo X, McIntosh J, Ong T, Riebling P, Souza M, Spiegel RJ, Peltz SW, Mercuri E. Ataluren in patients with nonsense mutation Duchenne muscular dystrophy (ACT DMD): a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial. Lancet 2017; 390:1489-1498. [PMID: 28728956 DOI: 10.1016/s0140-6736(17)31611-2] [Citation(s) in RCA: 301] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 05/09/2017] [Accepted: 05/11/2017] [Indexed: 02/07/2023]
Abstract
BACKGROUND Duchenne muscular dystrophy (DMD) is a severe, progressive, and rare neuromuscular, X-linked recessive disease. Dystrophin deficiency is the underlying cause of disease; therefore, mutation-specific therapies aimed at restoring dystrophin protein production are being explored. We aimed to assess the efficacy and safety of ataluren in ambulatory boys with nonsense mutation DMD. METHODS We did this multicentre, randomised, double-blind, placebo-controlled, phase 3 trial at 54 sites in 18 countries located in North America, Europe, the Asia-Pacific region, and Latin America. Boys aged 7-16 years with nonsense mutation DMD and a baseline 6-minute walk distance (6MWD) of 150 m or more and 80% or less of the predicted normal value for age and height were randomly assigned (1:1), via permuted block randomisation (block size of four) using an interactive voice-response or web-response system, to receive ataluren orally three times daily (40 mg/kg per day) or matching placebo. Randomisation was stratified by age (<9 years vs ≥9 years), duration of previous corticosteroid use (6 months to <12 months vs ≥12 months), and baseline 6MWD (<350 m vs ≥350 m). Patients, parents and caregivers, investigational site personnel, PTC Therapeutics employees, and all other study personnel were masked to group allocation until after database lock. The primary endpoint was change in 6MWD from baseline to week 48. We additionally did a prespecified subgroup analysis of the primary endpoint, based on baseline 6MWD, which is reflective of anticipated rates of disease progression over 1 year. The primary analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT01826487. FINDINGS Between March 26, 2013, and Aug 26, 2014, we randomly assigned 230 patients to receive ataluren (n=115) or placebo (n=115); 228 patients comprised the intention-to-treat population. The least-squares mean change in 6MWD from baseline to week 48 was -47·7 m (SE 9·3) for ataluren-treated patients and -60·7 m (9·3) for placebo-treated patients (difference 13·0 m [SE 10·4], 95% CI -7·4 to 33·4; p=0·213). The least-squares mean change for ataluren versus placebo in the prespecified subgroups was -7·7 m (SE 24·1, 95% CI -54·9 to 39·5; p=0·749) in the group with a 6MWD of less than 300 m, 42·9 m (15·9, 11·8-74·0; p=0·007) in the group with a 6MWD of 300 m or more to less than 400 m, and -9·5 m (17·2, -43·2 to 24·2; p=0·580) in the group with a 6MWD of 400 m or more. Ataluren was generally well tolerated and most treatment-emergent adverse events were mild to moderate in severity. Eight (3%) patients (n=4 per group) reported serious adverse events; all except one event in the placebo group (abnormal hepatic function deemed possibly related to treatment) were deemed unrelated to treatment. INTERPRETATION Change in 6MWD did not differ significantly between patients in the ataluren group and those in the placebo group, neither in the intention-to-treat population nor in the prespecified subgroups with a baseline 6MWD of less than 300 m or 400 m or more. However, we recorded a significant effect of ataluren in the prespecified subgroup of patients with a baseline 6MWD of 300 m or more to less than 400 m. Baseline 6MWD values within this range were associated with a more predictable rate of decline over 1 year; this finding has implications for the design of future DMD trials with the 6-minute walk test as the endpoint. FUNDING PTC Therapeutics.
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Affiliation(s)
- Craig M McDonald
- University of California Davis School of Medicine, Davis, Sacramento, CA, USA.
| | - Craig Campbell
- Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | | | - Richard S Finkel
- Children's Hospital of Philadelphia, Philadelphia, PA, USA; Nemours Children's Hospital, Orlando, FL, USA
| | | | | | | | | | - Janbernd Kirschner
- Medical Center-University of Freiburg, University of Freiberg, Freiberg, Germany
| | - Francesco Muntoni
- University College London Great Ormond Street Institute of Child Health, London, UK
| | | | - Ulrike Schara
- University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Thomas Sejersen
- Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden
| | | | | | | | - Már Tulinius
- Gothenburg University, Queen Silvia Children's Hospital, Gothenburg, Sweden
| | - Juan J Vilchez
- Hospital Universitario y Politécnico La Fe, CIBERER, Valencia, Spain
| | - Thomas Voit
- University College London Great Ormond Street Institute of Child Health, London, UK; National Institute for Health Research Great Ormond Street Hospital University College London Biomedical Research Centre, London, UK
| | - Brenda Wong
- Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | | | | | | | | | - Tuyen Ong
- PTC Therapeutics, South Plainfield, NJ, USA
| | | | | | | | | | - Eugenio Mercuri
- Department of Pediatric Neurology, Catholic University, Rome, Italy
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22
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Hakim CH, Mijailovic A, Lessa TB, Coates JR, Shin C, Rutkove SB, Duan D. Non-invasive evaluation of muscle disease in the canine model of Duchenne muscular dystrophy by electrical impedance myography. PLoS One 2017; 12:e0173557. [PMID: 28339469 PMCID: PMC5365102 DOI: 10.1371/journal.pone.0173557] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 02/23/2017] [Indexed: 02/07/2023] Open
Abstract
Dystrophin-deficient dogs are by far the best available large animal models for Duchenne muscular dystrophy (DMD), the most common lethal childhood muscle degenerative disease. The use of the canine DMD model in basic disease mechanism research and translational studies will be greatly enhanced with the development of reliable outcome measures. Electrical impedance myography (EIM) is a non-invasive painless procedure that provides quantitative data relating to muscle composition and histology. EIM has been extensively used in neuromuscular disease research in both human patients and rodent models. Recent studies suggest that EIM may represent a highly reliable and convenient outcome measure in DMD patients and the mdx mouse model of DMD. To determine whether EIM can be used as a biomarker of disease severity in the canine model, we performed the assay in fourteen young (~6.6-m-old; 6 normal and 8 affected) and ten mature (~16.9-m-old; 4 normal and 6 affected) dogs of mixed background breeds. EIM was well tolerated with good inter-rater reliability. Affected dogs showed higher resistance, lower reactance and phase. The difference became more straightforward in mature dogs. Importantly, we observed a statistically significant correlation between the EIM data and muscle fibrosis. Our results suggest that EIM is a valuable objective measurement in the canine DMD model.
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Affiliation(s)
- Chady H. Hakim
- Department of Molecular Microbiology and Immunology, School of Medicine, The University of Missouri, Columbia, MO, United States of America
| | - Alex Mijailovic
- Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA, United States of America
| | - Thais B. Lessa
- Department of Molecular Microbiology and Immunology, School of Medicine, The University of Missouri, Columbia, MO, United States of America
| | - Joan R. Coates
- Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, MO, United States of America
| | - Carmen Shin
- Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA, United States of America
| | - Seward B. Rutkove
- Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA, United States of America
| | - Dongsheng Duan
- Department of Molecular Microbiology and Immunology, School of Medicine, The University of Missouri, Columbia, MO, United States of America
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, United States of America
- Department of Neurology, School of Medicine, University of Missouri, Columbia, MO, United States of America
- Department of Bioengineering, University of Missouri, Columbia, MO, United States of America
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23
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Oligonucleotide therapies for disorders of the nervous system. Nat Biotechnol 2017; 35:249-263. [PMID: 28244991 DOI: 10.1038/nbt.3784] [Citation(s) in RCA: 117] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 01/09/2017] [Indexed: 12/14/2022]
Abstract
Oligonucleotide therapies are currently experiencing a resurgence driven by advances in backbone chemistry and discoveries of novel therapeutic pathways that can be uniquely and efficiently modulated by the oligonucleotide drugs. A quarter of a century has passed since oligonucleotides were first applied in living mammalian brain to modulate gene expression. Despite challenges in delivery to the brain, multiple oligonucleotide-based compounds are now being developed for treatment of human brain disorders by direct delivery inside the blood brain barrier (BBB). Notably, the first new central nervous system (CNS)-targeted oligonucleotide-based drug (nusinersen/Spinraza) was approved by US Food and Drug Administration (FDA) in late 2016 and several other compounds are in advanced clinical trials. Human testing of brain-targeted oligonucleotides has highlighted unusual pharmacokinetic and pharmacodynamic properties of these compounds, including complex active uptake mechanisms, low systemic exposure, extremely long half-lives, accumulation and gradual release from subcellular depots. Further work on oligonucleotide uptake, development of formulations for delivery across the BBB and relevant disease biology studies are required for further optimization of the oligonucleotide drug development process for brain applications.
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24
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Slota C, Bevans M, Yang L, Shrader J, Joe G, Carrillo N. Patient reported outcomes in GNE myopathy: incorporating a valid assessment of physical function in a rare disease. Disabil Rehabil 2017. [PMID: 28637129 DOI: 10.1080/09638288.2017.1283712] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
BACKGROUND The aim of this analysis was to evaluate the psychometric properties of three patient reported outcome (PRO) measures characterizing physical function in GNE myopathy: the Human Activity Profile, the Inclusion Body Myositis Functional Rating Scale, and the Activities-specific Balance Confidence scale. METHODS This analysis used data from 35 GNE myopathy subjects participating in a natural history study. For construct validity, correlational and known-group analyses were between the PROs and physical assessments. Reliability of the PROs between baseline and 6 months was evaluated using the intra-class correlation coefficient model; internal consistency was tested with Cronbach's alpha. RESULTS The hypothesized moderate positive correlations for construct validity were supported; the strongest correlation was between the human activity profile adjusted activity score and the adult myopathy assessment endurance subscale score (r = 0.81; p < 0.0001). The PROs were able to discriminate between known high and low functioning groups for the adult myopathy assessment tool. Internal consistency of the PROs was high (α > 0.8) and there was strong reliability (ICC >0.62). CONCLUSION The PROs are valid and reliable measures of physical function in GNE myopathy and should be incorporated in investigations to better understand the impact of progressive muscle weakness on physical function in this rare disease population. Implications for Rehabilitation GNE myopathy is a rare muscle disease that results in slow progressive muscle atrophy and weakness, ultimately leading to wheelchair use and dependence on a caregiver. There is limited knowledge on the impact of this disease on the health-related quality of life, specifically physical function, of this rare disease population. Three patient reported outcomes have been shown to be valid and reliable in GNE myopathy subjects and should be incorporated in future investigations to better understand how progressive muscle weakness impacts physical functions in this rare disease population. The patient reported outcome scores of GNE myopathy patients indicate a high risk for falls and impaired physical functioning, so it is important clinicians assess and provide interventions for these subjects to maintain their functional capacity.
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Affiliation(s)
- Christina Slota
- a Therapeutics for Rare and Neglected Diseases , National Center for Advancing Translational Sciences, National Institutes of Health , Bethesda , MD , USA.,b RTI Health Solutions , NC , USA
| | - Margaret Bevans
- c National Institutes of Health Clinical Center , Bethesda , MD , USA
| | - Li Yang
- c National Institutes of Health Clinical Center , Bethesda , MD , USA
| | - Joseph Shrader
- d Rehabilitation Medicine Department , National Institutes of Health , Bethesda , MD , USA
| | - Galen Joe
- d Rehabilitation Medicine Department , National Institutes of Health , Bethesda , MD , USA
| | - Nuria Carrillo
- a Therapeutics for Rare and Neglected Diseases , National Center for Advancing Translational Sciences, National Institutes of Health , Bethesda , MD , USA.,e National Human Genome Research Institute, National Institutes of Health , Bethesda , MD , USA
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25
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Fletcher S, Bellgard MI, Price L, Akkari AP, Wilton SD. Translational development of splice-modifying antisense oligomers. Expert Opin Biol Ther 2016; 17:15-30. [PMID: 27805416 DOI: 10.1080/14712598.2017.1250880] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
INTRODUCTION Antisense nucleic acid analogues can interact with pre-mRNA motifs and influence exon or splice site selection and thereby alter gene expression. Design of antisense molecules to target specific motifs can result in either exon exclusion or exon inclusion during splicing. Novel drugs exploiting the antisense concept are targeting rare, life-limiting diseases; however, the potential exists to treat a wide range of conditions by antisense-mediated splice intervention. Areas covered: In this review, the authors discuss the clinical translation of novel molecular therapeutics to address the fatal neuromuscular disorders Duchenne muscular dystrophy and spinal muscular atrophy. The review also highlights difficulties posed by issues pertaining to restricted participant numbers, variable phenotype and disease progression, and the identification and validation of study endpoints. Expert opinion: Translation of novel therapeutics for Duchenne muscular dystrophy and spinal muscular atrophy has been greatly advanced by multidisciplinary research, academic-industry partnerships and in particular, the engagement and support of the patient community. Sponsors, supporters and regulators are cooperating to deliver new drugs and identify and define meaningful outcome measures. Non-conventional and adaptive trial design could be particularly suited to clinical evaluation of novel therapeutics and strategies to treat serious, rare diseases that may be problematic to study using more conventional clinical trial structures.
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Affiliation(s)
- S Fletcher
- a Centre for Neuromuscular and Neurological Disorders , University of Western Australia , Nedlands , Western Australia , Australia.,b Western Australian Neuroscience Research Institute , Nedlands , Western Australia , Australia.,c Centre for Comparative Genomics , Murdoch University , Western Australia , Australia
| | - M I Bellgard
- b Western Australian Neuroscience Research Institute , Nedlands , Western Australia , Australia.,c Centre for Comparative Genomics , Murdoch University , Western Australia , Australia
| | - L Price
- a Centre for Neuromuscular and Neurological Disorders , University of Western Australia , Nedlands , Western Australia , Australia.,b Western Australian Neuroscience Research Institute , Nedlands , Western Australia , Australia.,c Centre for Comparative Genomics , Murdoch University , Western Australia , Australia
| | - A P Akkari
- b Western Australian Neuroscience Research Institute , Nedlands , Western Australia , Australia.,c Centre for Comparative Genomics , Murdoch University , Western Australia , Australia.,d Shiraz Pharmaceuticals, Inc , Chapel Hill , NC , USA
| | - S D Wilton
- a Centre for Neuromuscular and Neurological Disorders , University of Western Australia , Nedlands , Western Australia , Australia.,b Western Australian Neuroscience Research Institute , Nedlands , Western Australia , Australia.,c Centre for Comparative Genomics , Murdoch University , Western Australia , Australia
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26
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Abstract
Duchenne muscular dystrophy (DMD) is the most common form of muscular dystrophy in childhood. It is caused by mutations of the DMD gene, leading to progressive muscle weakness, loss of independent ambulation by early teens, and premature death due to cardiorespiratory complications. The diagnosis can usually be made after careful review of the history and examination of affected boys presenting with developmental delay, proximal weakness, and elevated serum creatine kinase, plus confirmation by muscle biopsy or genetic testing. Precise characterization of the DMD mutation is important for genetic counseling and individualized treatment. Current standard of care includes the use of corticosteroids to prolong ambulation and to delay the onset of secondary complications. Early use of cardioprotective agents, noninvasive positive pressure ventilation, and other supportive strategies has improved the life expectancy and health-related quality of life for many young adults with DMD. New emerging treatment includes viral-mediated microdystrophin gene replacement, exon skipping to restore the reading frame, and nonsense suppression therapy to allow translation and production of a modified dystrophin protein. Other potential therapeutic targets involve upregulation of compensatory proteins, reduction of the inflammatory cascade, and enhancement of muscle regeneration. So far, data from DMD clinical trials have shown limited success in delaying disease progression; unforeseen obstacles included immune response against the generated mini-dystrophin, inconsistent evidence of dystrophin production in muscle biopsies, and failure to demonstrate a significant improvement in the primary outcome measure, as defined by the 6-minute walk test in some studies. The long-term safety and efficacy of emerging treatments will depend on the selection of appropriate clinical end points and sensitive biomarkers to detect meaningful changes in disease progression. Correction of the underlying mutations using new gene-editing technologies and corticosteroid analogs with better safety profiles offers renewed hope for many individuals with DMD and their families.
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Affiliation(s)
- Jean K Mah
- Department of Pediatrics and Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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