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Bao N, Wang Z, Fu J, Dong H, Jin Y. RNA structure in alternative splicing regulation: from mechanism to therapy. Acta Biochim Biophys Sin (Shanghai) 2024. [PMID: 39034824 DOI: 10.3724/abbs.2024119] [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: 07/23/2024] Open
Abstract
Alternative splicing is a highly intricate process that plays a crucial role in post-transcriptional regulation and significantly expands the functional proteome of a limited number of coding genes in eukaryotes. Its regulation is multifactorial, with RNA structure exerting a significant impact. Aberrant RNA conformations lead to dysregulation of splicing patterns, which directly affects the manifestation of disease symptoms. In this review, the molecular mechanisms of RNA secondary structure-mediated splicing regulation are summarized, with a focus on the complex interplay between aberrant RNA conformations and disease phenotypes resulted from splicing defects. This study also explores additional factors that reshape structural conformations, enriching our understanding of the mechanistic network underlying structure-mediated splicing regulation. In addition, an emphasis has been placed on the clinical role of targeting aberrant splicing corrections in human diseases. The principal mechanisms of action behind this phenomenon are described, followed by a discussion of prospective development strategies and pertinent challenges.
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Wilton-Clark H, Yan E, Yokota T. Preparing for Patient-Customized N-of-1 Antisense Oligonucleotide Therapy to Treat Rare Diseases. Genes (Basel) 2024; 15:821. [PMID: 39062600 PMCID: PMC11275492 DOI: 10.3390/genes15070821] [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: 05/29/2024] [Revised: 06/15/2024] [Accepted: 06/19/2024] [Indexed: 07/28/2024] Open
Abstract
The process of developing therapies to treat rare diseases is fraught with financial, regulatory, and logistical challenges that have limited our ability to build effective treatments. Recently, a novel type of therapy called antisense therapy has shown immense potential for the treatment of rare diseases, particularly through single-patient N-of-1 trials. Several N-of-1 antisense therapies have been developed recently for rare diseases, including the landmark study of milasen. In response to the success of N-of-1 antisense therapy, the Food and Drug Administration (FDA) has developed unique guidelines specifically for the development of antisense therapy to treat N-of-1 rare diseases. This policy change establishes a strong foundation for future therapy development and addresses some of the major limitations that previously hindered the development of therapies for rare diseases.
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Affiliation(s)
- Harry Wilton-Clark
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2R3, Canada;
| | - Eric Yan
- Department of Biological Sciences, Faculty of Science, University of Alberta, Edmonton, AB T6G 2R3, Canada;
| | - Toshifumi Yokota
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2R3, Canada;
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3
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Nguyen CQ, Kariyawasam DST, Ngai TSJ, Nguyen J, Alba-Concepcion K, Grattan SE, Palmer EE, Hetherington K, Wakefield CE, Dale RC, Woolfenden S, Mohammad S, Farrar MA. 'High hopes for treatment': Australian stakeholder perspectives of the clinical translation of advanced neurotherapeutics for rare neurological diseases. Health Expect 2024; 27:e14063. [PMID: 38711219 DOI: 10.1111/hex.14063] [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: 04/12/2023] [Revised: 03/08/2024] [Accepted: 04/22/2024] [Indexed: 05/08/2024] Open
Abstract
INTRODUCTION Advanced therapies offer unprecedented opportunities for treating rare neurological disorders (RNDs) in children. However, health literacy, perceptions and understanding of novel therapies need elucidation across the RND community. This study explored healthcare professionals' and carers' perspectives of advanced therapies in childhood-onset RNDs. METHODS In this mixed-methodology cross-sectional study, 20 healthcare professionals (clinicians, genetic counsellors and scientists) and 20 carers completed qualitative semistructured interviews and custom-designed surveys. Carers undertook validated psychosocial questionnaires. Thematic and quantitative data analysis followed. RESULTS Participants described high positive interest in advanced therapies, but low knowledge of, and access to, reliable information. The substantial 'therapeutic gap' and 'therapeutic odyssey' common to RNDs were recognised in five key themes: (i) unmet need and urgency for access; (ii) seeking information; (iii) access, equity and sustainability; (iv) a multidisciplinary and integrated approach to care and support and (v) difficult decision-making. Participants were motivated to intensify RND clinical trial activity and access to advanced therapies; however, concerns around informed consent, first-in-human trials and clinical trial procedures were evident. There was high-risk tolerance despite substantial uncertainties and knowledge gaps. RNDs with high mortality, increased functional burdens and no alternative therapies were consistently prioritised for the development of advanced therapies. However, little consensus existed on prioritisation to treatment access. CONCLUSIONS This study highlights the need to increase clinician and health system readiness for the clinical translation of advanced therapeutics for RNDs. Co-development and use of educational and psychosocial resources to support clinical decision-making, set therapeutic expectations and promotion of equitable, effective and safe delivery of advanced therapies are essential. PATIENT OR PUBLIC CONTRIBUTION Participant insights into the psychosocial burden and information need to enhance the delivery of care in this formative study are informing ongoing partnerships with families, including co-production and dissemination of psychoeducational resources featuring their voices hosted on the Sydney Children's Hospitals Network website SCHN Brain-Aid Resources.
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Affiliation(s)
- Christina Q Nguyen
- Discipline of Paediatrics and Child Health, University of New South Wales Medicine and Health, Sydney, New South Wales, Australia
| | - Didu S T Kariyawasam
- Discipline of Paediatrics and Child Health, University of New South Wales Medicine and Health, Sydney, New South Wales, Australia
- Department of Neurology, Sydney Children's Hospital Network, Sydney, New South Wales, Australia
| | - Tsz Shun Jason Ngai
- Discipline of Paediatrics and Child Health, University of New South Wales Medicine and Health, Sydney, New South Wales, Australia
| | - James Nguyen
- Discipline of Paediatrics and Child Health, University of New South Wales Medicine and Health, Sydney, New South Wales, Australia
| | - Kristine Alba-Concepcion
- Discipline of Paediatrics and Child Health, University of New South Wales Medicine and Health, Sydney, New South Wales, Australia
- Department of Neurology, Sydney Children's Hospital Network, Sydney, New South Wales, Australia
| | - Sarah E Grattan
- Discipline of Paediatrics and Child Health, University of New South Wales Medicine and Health, Sydney, New South Wales, Australia
- Department of Neurology, Sydney Children's Hospital Network, Sydney, New South Wales, Australia
| | - Elizabeth E Palmer
- Discipline of Paediatrics and Child Health, University of New South Wales Medicine and Health, Sydney, New South Wales, Australia
- Centre for Clinical Genetics, Sydney Children's Hospital Network, Sydney, New South Wales, Australia
| | - Kate Hetherington
- Discipline of Paediatrics and Child Health, University of New South Wales Medicine and Health, Sydney, New South Wales, Australia
- Behavioural Science Unit, Kids Cancer Centre, Sydney Children's Hospital, Sydney, New South Wales, Australia
| | - Claire E Wakefield
- Discipline of Paediatrics and Child Health, University of New South Wales Medicine and Health, Sydney, New South Wales, Australia
- Behavioural Science Unit, Kids Cancer Centre, Sydney Children's Hospital, Sydney, New South Wales, Australia
| | - Russell C Dale
- Department of Neurology, Sydney Children's Hospital Network, Sydney, New South Wales, Australia
- Children's Hospital Westmead Clinical School, Faculty of Medicine and Health, Sydney Medical School, University of Sydney, Sydney, Australia
| | - Sue Woolfenden
- Children's Hospital Westmead Clinical School, Faculty of Medicine and Health, Sydney Medical School, University of Sydney, Sydney, Australia
- Population Child Health Research Group, University of New South Wales, Sydney, New South Wales, Australia
- Sydney Institute for Women, Children and their Families, Sydney Local Health District, Sydney, New South Wales, Australia
| | - Shekeeb Mohammad
- Department of Neurology, Sydney Children's Hospital Network, Sydney, New South Wales, Australia
- Children's Hospital Westmead Clinical School, Faculty of Medicine and Health, Sydney Medical School, University of Sydney, Sydney, Australia
| | - Michelle A Farrar
- Discipline of Paediatrics and Child Health, University of New South Wales Medicine and Health, Sydney, New South Wales, Australia
- Department of Neurology, Sydney Children's Hospital Network, Sydney, New South Wales, Australia
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4
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Hamdan A, Hooker AC, Chen X, Traschütz A, Schüle R, Synofzik M, Karlsson MO. Item performance of the scale for the assessment and rating of ataxia in rare and ultra-rare genetic ataxias. CPT Pharmacometrics Syst Pharmacol 2024. [PMID: 38769902 DOI: 10.1002/psp4.13162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 03/28/2024] [Accepted: 05/02/2024] [Indexed: 05/22/2024] Open
Abstract
The Scale for the Assessment and Rating of Ataxia (SARA) is widely used for assessing the severity and progression of genetic cerebellar ataxias. SARA is now considered a primary end point in several ataxia treatment trials, but its underlying composite item measurement model has not yet been tested. This work aimed to evaluate the composite properties of SARA and its items using item response theory (IRT) and to demonstrate its applicability across even ultra-rare genetic ataxias. Leveraging SARA subscores data from 1932 visits from 990 patients of the Autosomal Recessive Cerebellar Ataxias (ARCA) registry, we assessed the performance of SARA using IRT methodology. The item characteristics were evaluated over the ataxia severity range of the entire ataxia population as well as the assessment validity across 115 genetic ARCA subpopulations. A unidimensional IRT model was able to describe SARA item data, indicating that SARA captures one single latent variable. All items had high discrimination values (1.5-2.9) indicating the effectiveness of the SARA in differentiating between subjects with different disease statuses. Each item contributed between 7% and 28% of the total assessment informativeness. There was no evidence for differences between the 115 genetic ARCA subpopulations in SARA applicability. These results show the good discrimination ability of SARA with all of its items adding informational value. The IRT framework provides a thorough description of SARA on the item level, and facilitates its utilization as a clinical outcome assessment in upcoming longitudinal natural history or treatment trials, across a large number of ataxias, including ultra-rare ones.
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Affiliation(s)
- Alzahra Hamdan
- Pharmacometrics Research Group, Department of Pharmacy, Uppsala University, Uppsala, Sweden
| | - Andrew C Hooker
- Pharmacometrics Research Group, Department of Pharmacy, Uppsala University, Uppsala, Sweden
| | - Xiaomei Chen
- Pharmacometrics Research Group, Department of Pharmacy, Uppsala University, Uppsala, Sweden
| | - Andreas Traschütz
- Department of Neurodegenerative Diseases, Center for Neurology and Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
- German Center for Neurodegenerative Diseases (DZNE) Tübingen, Tübingen, Germany
| | - Rebecca Schüle
- Department of Neurodegenerative Diseases, Center for Neurology and Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
- Division of Neurodegenerative Diseases, Department of Neurology, Heidelberg University Hospital, Heidelberg, Germany
| | - Matthis Synofzik
- Department of Neurodegenerative Diseases, Center for Neurology and Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
- German Center for Neurodegenerative Diseases (DZNE) Tübingen, Tübingen, Germany
| | - Mats O Karlsson
- Pharmacometrics Research Group, Department of Pharmacy, Uppsala University, Uppsala, Sweden
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5
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Hendrickx N, Mentré F, Traschütz A, Gagnon C, Schüle R, Synofzik M, Comets E. Prediction of Individual Disease Progression Including Parameter Uncertainty in Rare Neurodegenerative Diseases: The Example of Autosomal-Recessive Spastic Ataxia Charlevoix Saguenay (ARSACS). AAPS J 2024; 26:57. [PMID: 38689016 DOI: 10.1208/s12248-024-00925-7] [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: 01/26/2024] [Accepted: 04/16/2024] [Indexed: 05/02/2024] Open
Abstract
The aim of this study was to develop a model to predict individual subject disease trajectories including parameter uncertainty and accounting for missing data in rare neurological diseases, showcased by the ultra-rare disease Autosomal-Recessive Spastic Ataxia Charlevoix Saguenay (ARSACS). We modelled the change in SARA (Scale for Assessment and Rating of Ataxia) score versus Time Since Onset of symptoms using non-linear mixed effect models for a population of 173 patients with ARSACS included in the prospective real-world multicenter Autosomal Recessive Cerebellar Ataxia (ARCA) registry. We used the Multivariate Imputation Chained Equation (MICE) algorithm to impute missing covariates, and a covariate selection procedure with a pooled p-value to account for the multiply imputed data sets. We then investigated the impact of covariates and population parameter uncertainty on the prediction of the individual trajectories up to 5 years after their last visit. A four-parameter logistic function was selected. Men were estimated to have a 25% lower SARA score at disease onset and a moderately higher maximum SARA score, and time to progression (T50) was estimated to be 35% lower in patients with age of onset over 15 years. The population disease progression rate started slowly at 0.1 points per year peaking to a maximum of 0.8 points per year (at 36.8 years since onset of symptoms). The prediction intervals for SARA scores 5 years after the last visit were large (median 7.4 points, Q1-Q3: 6.4-8.5); their size was mostly driven by individual parameter uncertainty and individual disease progression rate at that time.
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Affiliation(s)
- Niels Hendrickx
- Université Paris Cité, IAME, Inserm, F-75018, Paris, France.
| | - France Mentré
- Université Paris Cité, IAME, Inserm, F-75018, Paris, France
| | - Andreas Traschütz
- Division Translational Genomics of Neurodegenerative Diseases, Hertie Institute for Clinical Brain Research (HIH), University of Tübingen, Tübingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Cynthia Gagnon
- Centre de Recherche du CHUS Et du Centre de Santé Et Des Services Sociaux du Saguenay-Lac-St-Jean, Faculté de Médecine, Université de Sherbrooke, Québec, Canada
| | - Rebecca Schüle
- Division Translational Genomics of Neurodegenerative Diseases, Hertie Institute for Clinical Brain Research (HIH), University of Tübingen, Tübingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Matthis Synofzik
- Division Translational Genomics of Neurodegenerative Diseases, Hertie Institute for Clinical Brain Research (HIH), University of Tübingen, Tübingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Emmanuelle Comets
- Université Paris Cité, IAME, Inserm, F-75018, Paris, France
- Univ Rennes, Inserm, EHESP, Irset - UMR_S 1085, 35000, Rennes, France
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Belgrad J, Fakih HH, Khvorova A. Nucleic Acid Therapeutics: Successes, Milestones, and Upcoming Innovation. Nucleic Acid Ther 2024; 34:52-72. [PMID: 38507678 DOI: 10.1089/nat.2023.0068] [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] [Indexed: 03/22/2024] Open
Abstract
Nucleic acid-based therapies have become the third major drug class after small molecules and antibodies. The role of nucleic acid-based therapies has been strengthened by recent regulatory approvals and tremendous clinical success. In this review, we look at the major obstacles that have hindered the field, the historical milestones that have been achieved, and what is yet to be resolved and anticipated soon. This review provides a view of the key innovations that are expanding nucleic acid capabilities, setting the stage for the future of nucleic acid therapeutics.
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Affiliation(s)
- Jillian Belgrad
- RNA Therapeutics Institute, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
| | - Hassan H Fakih
- RNA Therapeutics Institute, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
| | - Anastasia Khvorova
- RNA Therapeutics Institute, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
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7
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Hostiuc M, Scafa A, Iancu B, Iancu D, Isailă OM, Ion OM, Stroe A, Diaconu C, Epistatu D, Hostiuc S. Ethical implications of developing RNA-based therapies for cardiovascular disorders. Front Bioeng Biotechnol 2024; 12:1370403. [PMID: 38558789 PMCID: PMC10978717 DOI: 10.3389/fbioe.2024.1370403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Accepted: 02/21/2024] [Indexed: 04/04/2024] Open
Abstract
The awareness concerning RNA-based therapies was boosted significantly after the successful development of COVID-19 vaccines. However, they can potentially lead to significant advances in other areas of medicine, such as oncology or chronic diseases. In recent years, there has been an exponential increase in the number of RNA-based therapies that were evaluated as potential treatments for cardiovascular disorders. One of the areas that was not explicitly assessed about these therapies is represented by their overall ethical framework. Some studies evaluate ethical issues of RNA-based treatments in general or targeting specific disorders (especially neurodegenerative) or interventions for developing RNA-based vaccines. Much less information is available regarding the ethical issues associated with developing these therapeutic strategies for cardiovascular disorders, which is the main aim of this study. We will focus our analysis on three main topics: risk-benefit analysis (including the management of public awareness about these technologies), and justice (in both research and clinical medicine).
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Affiliation(s)
- Mihaela Hostiuc
- Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
| | - Alexandru Scafa
- Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
| | | | - Daniela Iancu
- Wessex Clinical Genetics Service, Southampton, United Kingdom
- University College London, London, United Kingdom
| | - Oana-Maria Isailă
- Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
| | - Oana Mihaela Ion
- Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
| | - Ana Stroe
- Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
| | - Camelia Diaconu
- Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
| | - Dragos Epistatu
- Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
| | - Sorin Hostiuc
- Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
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8
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Jaarsma D, Birkisdóttir MB, van Vossen R, Oomen DWGD, Akhiyat O, Vermeij WP, Koekkoek SKE, De Zeeuw CI, Bosman LWJ. Different Purkinje cell pathologies cause specific patterns of progressive gait ataxia in mice. Neurobiol Dis 2024; 192:106422. [PMID: 38286390 DOI: 10.1016/j.nbd.2024.106422] [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: 09/19/2023] [Revised: 01/24/2024] [Accepted: 01/24/2024] [Indexed: 01/31/2024] Open
Abstract
Gait ataxia is one of the most common and impactful consequences of cerebellar dysfunction. Purkinje cells, the sole output neurons of the cerebellar cortex, are often involved in the underlying pathology, but their specific functions during locomotor control in health and disease remain obfuscated. We aimed to describe the effect of gradual adult-onset Purkinje cell degeneration on gaiting patterns in mice, and to determine whether two different mechanisms that both lead to Purkinje cell degeneration cause different patterns in the development of gait ataxia. Using the ErasmusLadder together with a newly developed limb detection algorithm and machine learning-based classification, we subjected mice to a challenging locomotor task with detailed analysis of single limb parameters, intralimb coordination and whole-body movement. We tested two Purkinje cell-specific mouse models, one involving stochastic cell death due to impaired DNA repair mechanisms (Pcp2-Ercc1-/-), the other carrying the mutation that causes spinocerebellar ataxia type 1 (Pcp2-ATXN1[82Q]). Both mouse models showed progressive gaiting deficits, but the sequence with which gaiting parameters deteriorated was different between mouse lines. Our longitudinal approach revealed that gradual loss of Purkinje cell function can lead to a complex pattern of loss of function over time, and that this pattern depends on the specifics of the pathological mechanisms involved. We hypothesize that this variability will also be present in disease progression in patients, and that our findings will facilitate the study of therapeutic interventions in mice, as subtle changes in locomotor abilities can be quantified by our methods.
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Affiliation(s)
- Dick Jaarsma
- Department of Neuroscience, Erasmus MC, 3015 CA, Rotterdam, the Netherlands.
| | - Maria B Birkisdóttir
- Department of Neuroscience, Erasmus MC, 3015 CA, Rotterdam, the Netherlands; Princess Máxima Center for Pediatric Oncology, 3584 CS, Utrecht, the Netherlands
| | - Randy van Vossen
- Department of Neuroscience, Erasmus MC, 3015 CA, Rotterdam, the Netherlands
| | - Demi W G D Oomen
- Department of Neuroscience, Erasmus MC, 3015 CA, Rotterdam, the Netherlands
| | - Oussama Akhiyat
- Department of Neuroscience, Erasmus MC, 3015 CA, Rotterdam, the Netherlands
| | - Wilbert P Vermeij
- Princess Máxima Center for Pediatric Oncology, 3584 CS, Utrecht, the Netherlands; Oncode Institute, 3521 AL, Utrecht, the Netherlands
| | | | - Chris I De Zeeuw
- Department of Neuroscience, Erasmus MC, 3015 CA, Rotterdam, the Netherlands; Netherlands Institute for Neuroscience, Royal Dutch Academy of Arts & Science, 1105 BA, Amsterdam, the Netherlands
| | - Laurens W J Bosman
- Department of Neuroscience, Erasmus MC, 3015 CA, Rotterdam, the Netherlands.
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9
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Chen S, Heendeniya SN, Le BT, Rahimizadeh K, Rabiee N, Zahra QUA, Veedu RN. Splice-Modulating Antisense Oligonucleotides as Therapeutics for Inherited Metabolic Diseases. BioDrugs 2024; 38:177-203. [PMID: 38252341 PMCID: PMC10912209 DOI: 10.1007/s40259-024-00644-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/03/2024] [Indexed: 01/23/2024]
Abstract
The last decade (2013-2023) has seen unprecedented successes in the clinical translation of therapeutic antisense oligonucleotides (ASOs). Eight such molecules have been granted marketing approval by the United States Food and Drug Administration (US FDA) during the decade, after the first ASO drug, fomivirsen, was approved much earlier, in 1998. Splice-modulating ASOs have also been developed for the therapy of inborn errors of metabolism (IEMs), due to their ability to redirect aberrant splicing caused by mutations, thus recovering the expression of normal transcripts, and correcting the deficiency of functional proteins. The feasibility of treating IEM patients with splice-switching ASOs has been supported by FDA permission (2018) of the first "N-of-1" study of milasen, an investigational ASO drug for Batten disease. Although for IEM, owing to the rarity of individual disease and/or pathogenic mutation, only a low number of patients may be treated by ASOs that specifically suppress the aberrant splicing pattern of mutant precursor mRNA (pre-mRNA), splice-switching ASOs represent superior individualized molecular therapeutics for IEM. In this work, we first summarize the ASO technology with respect to its mechanisms of action, chemical modifications of nucleotides, and rational design of modified oligonucleotides; following that, we precisely provide a review of the current understanding of developing splice-modulating ASO-based therapeutics for IEM. In the concluding section, we suggest potential ways to improve and/or optimize the development of ASOs targeting IEM.
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Affiliation(s)
- Suxiang Chen
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Murdoch, WA, 6150, Australia
- Precision Nucleic Acid Therapeutics, Perron Institute for Neurological and Translational Science, Nedlands, WA, 6009, Australia
| | - Saumya Nishanga Heendeniya
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Murdoch, WA, 6150, Australia
- Precision Nucleic Acid Therapeutics, Perron Institute for Neurological and Translational Science, Nedlands, WA, 6009, Australia
| | - Bao T Le
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Murdoch, WA, 6150, Australia
- Precision Nucleic Acid Therapeutics, Perron Institute for Neurological and Translational Science, Nedlands, WA, 6009, Australia
- ProGenis Pharmaceuticals Pty Ltd, Bentley, WA, 6102, Australia
| | - Kamal Rahimizadeh
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Murdoch, WA, 6150, Australia
- Precision Nucleic Acid Therapeutics, Perron Institute for Neurological and Translational Science, Nedlands, WA, 6009, Australia
| | - Navid Rabiee
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Murdoch, WA, 6150, Australia
- Precision Nucleic Acid Therapeutics, Perron Institute for Neurological and Translational Science, Nedlands, WA, 6009, Australia
| | - Qurat Ul Ain Zahra
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Murdoch, WA, 6150, Australia
- Precision Nucleic Acid Therapeutics, Perron Institute for Neurological and Translational Science, Nedlands, WA, 6009, Australia
| | - Rakesh N Veedu
- Centre for Molecular Medicine and Innovative Therapeutics, Health Futures Institute, Murdoch University, Murdoch, WA, 6150, Australia.
- Precision Nucleic Acid Therapeutics, Perron Institute for Neurological and Translational Science, Nedlands, WA, 6009, Australia.
- ProGenis Pharmaceuticals Pty Ltd, Bentley, WA, 6102, Australia.
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10
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Godbole NP, Haxton E, Rowe OE, Locascio JJ, Schmahmann JD, Eichler FS, Ratai E, Stephen CD. Clinical and imaging predictors of late-onset GM2 gangliosidosis: A scoping review. Ann Clin Transl Neurol 2024; 11:207-224. [PMID: 38009419 PMCID: PMC10791033 DOI: 10.1002/acn3.51947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Accepted: 11/03/2023] [Indexed: 11/28/2023] Open
Abstract
OBJECTIVE Late-onset GM2 gangliosidosis (LOGG) subtypes late-onset Tay-Sachs (LOTS) and Sandhoff disease (LOSD) are ultra-rare neurodegenerative lysosomal storage disorders presenting with weakness, ataxia, and neuropsychiatric symptoms. Previous studies considered LOTS and LOSD clinically indistinguishable; recent studies have challenged this. We performed a scoping review to ascertain whether imaging and clinical features may differentiate these diseases. METHODS We examined MEDLINE/non-MEDLINE databases up to May 2022. Articles reporting brain imaging findings in genetically/enzymatically confirmed LOGG, symptom onset at age ≥ 10 years (or evaluated at least once ≥18 years) were included, yielding 170 LOGG patients (LOTS = 127, LOSD = 43) across 68 papers. We compared LOTS versus LOSD and performed regression analyses. Results were corrected for multiple comparisons. RESULTS Age of onset was lower in LOTS versus LOSD (17.9 ± 8.2 vs. 23.9 ± 14.4 years, p = 0.017), although disease duration was similar (p = 0.34). LOTS more commonly had psychosis/bipolar symptoms (35.0% vs. 9.30%, p = 0.011) but less frequent swallowing problems (4.10% vs. 18.60%, p = 0.041). Cerebellar atrophy was more common in LOTS (89.0%) versus LOSD (60.5%), p < 0.0001, with more severe atrophy in LOTS (p = 0.0005). Brainstem atrophy was documented only in LOTS (14.2%). Independent predictors of LOTS versus LOSD (odds ratio [95% confidence interval]) included the presence of psychosis/bipolar symptoms (4.95 [1.59-19.52], p = 0.011), no swallowing symptoms (0.16 [0.036-0.64], p = 0.011), and cerebellar atrophy (5.81 [2.10-17.08], p = 0.0009). Lower age of onset (0.96 [0.93-1.00], p = 0.075) and tremor (2.50 [0.94-7.43], p = 0.078) were marginally statistically significant but felt relevant to include in the model. INTERPRETATION These data suggest significant differences in symptomatology, disease course, and imaging findings between LOTS and LOSD.
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Affiliation(s)
- Neha P. Godbole
- Center for Rare Neurological Diseases, Department of NeurologyMassachusetts General Hospital and Harvard Medical SchoolBostonMassachusettsUSA
| | - Elizabeth Haxton
- Center for Rare Neurological Diseases, Department of NeurologyMassachusetts General Hospital and Harvard Medical SchoolBostonMassachusettsUSA
| | - Olivia E. Rowe
- Athinoula A. Martinos Center for Biomedical Imaging, Division of Neuroradiology, Department of RadiologyMassachusetts General Hospital and Harvard Medical SchoolCharlestownMassachusettsUSA
| | - Joseph J. Locascio
- Department of NeurologyMassachusetts General Hospital and Harvard Medical SchoolBostonMassachusettsUSA
- Harvard Catalyst Biostatistical Consulting Group, Harvard Medical SchoolBostonMassachusettsUSA
| | - Jeremy D. Schmahmann
- Department of NeurologyMassachusetts General Hospital and Harvard Medical SchoolBostonMassachusettsUSA
- Laboratory for Neuroanatomy and Cerebellar Neurobiology, Department of NeurologyMassachusetts General Hospital and Harvard Medical SchoolBostonMassachusettsUSA
| | - Florian S. Eichler
- Center for Rare Neurological Diseases, Department of NeurologyMassachusetts General Hospital and Harvard Medical SchoolBostonMassachusettsUSA
- Department of NeurologyMassachusetts General Hospital and Harvard Medical SchoolBostonMassachusettsUSA
| | - Eva‐Maria Ratai
- Athinoula A. Martinos Center for Biomedical Imaging, Division of Neuroradiology, Department of RadiologyMassachusetts General Hospital and Harvard Medical SchoolCharlestownMassachusettsUSA
| | - Christopher D. Stephen
- Center for Rare Neurological Diseases, Department of NeurologyMassachusetts General Hospital and Harvard Medical SchoolBostonMassachusettsUSA
- Department of NeurologyMassachusetts General Hospital and Harvard Medical SchoolBostonMassachusettsUSA
- Laboratory for Neuroanatomy and Cerebellar Neurobiology, Department of NeurologyMassachusetts General Hospital and Harvard Medical SchoolBostonMassachusettsUSA
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11
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Le BT, Chen S, Veedu RN. Evaluation of Chemically Modified Nucleic Acid Analogues for Splice Switching Application. ACS OMEGA 2023; 8:48650-48661. [PMID: 38162739 PMCID: PMC10753547 DOI: 10.1021/acsomega.3c07618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 10/30/2023] [Accepted: 11/21/2023] [Indexed: 01/03/2024]
Abstract
In recent years, several splice switching antisense oligonucleotide (ASO)-based therapeutics have gained significant interest, and several candidates received approval for clinical use for treating rare diseases, in particular, Duchenne muscular dystrophy and spinal muscular atrophy. These ASOs are fully modified; in other words, they are composed of chemically modified nucleic acid analogues instead of natural RNA oligomers. This has significantly improved drug-like properties of these ASOs in terms of efficacy, stability, pharmacokinetics, and safety. Although chemical modifications of oligonucleotides have been discussed previously for numerous applications including nucleic acid aptamers, small interfering RNA, DNAzyme, and ASO, to the best of our knowledge, none of them have solely focused on the analogues that have been utilized for splice switching applications. To this end, we present here a comprehensive review of different modified nucleic acid analogues that have been explored for developing splice switching ASOs. In addition to the antisense chemistry, we also endeavor to provide a brief historical overview of the approved spice switching ASO drugs, including a list of drugs that have entered human clinical trials. We hope this work will inspire further investigations into expanding the potential of novel nucleic acid analogues for constructing splice switching ASOs.
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Affiliation(s)
- Bao T. Le
- Centre
for Molecular Medicine and Innovative Therapeutics, Health Futures
Institute, Murdoch University, Murdoch, Western Australia 6150, Australia
- Precision
Nucleic Acid Therapeutics, Perron Institute
for Neurological and Translational Science, Nedlands, Western Australia 6009, Australia
- ProGenis
Pharmaceuticals Pty Ltd., Bentley, Western Australia 6102, Australia
| | - Suxiang Chen
- Centre
for Molecular Medicine and Innovative Therapeutics, Health Futures
Institute, Murdoch University, Murdoch, Western Australia 6150, Australia
- Precision
Nucleic Acid Therapeutics, Perron Institute
for Neurological and Translational Science, Nedlands, Western Australia 6009, Australia
| | - Rakesh N. Veedu
- Centre
for Molecular Medicine and Innovative Therapeutics, Health Futures
Institute, Murdoch University, Murdoch, Western Australia 6150, Australia
- Precision
Nucleic Acid Therapeutics, Perron Institute
for Neurological and Translational Science, Nedlands, Western Australia 6009, Australia
- ProGenis
Pharmaceuticals Pty Ltd., Bentley, Western Australia 6102, Australia
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12
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Seemann J, Traschütz A, Ilg W, Synofzik M. 4-Aminopyridine improves real-life gait performance in SCA27B on a single-subject level: a prospective n-of-1 treatment experience. J Neurol 2023; 270:5629-5634. [PMID: 37439944 PMCID: PMC10576659 DOI: 10.1007/s00415-023-11868-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 07/05/2023] [Accepted: 07/06/2023] [Indexed: 07/14/2023]
Affiliation(s)
- Jens Seemann
- Section Computational Sensomotorics, Hertie Institute for Clinical Brain Research, Otfried-Müller-Straße 25, 72076, Tübingen, Germany
- Centre for Integrative Neuroscience (CIN), Tübingen, Germany
| | - Andreas Traschütz
- Division Translational Genomics of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research and Center of Neurology, University of Tübingen, Tübingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Winfried Ilg
- Section Computational Sensomotorics, Hertie Institute for Clinical Brain Research, Otfried-Müller-Straße 25, 72076, Tübingen, Germany.
- Centre for Integrative Neuroscience (CIN), Tübingen, Germany.
| | - Matthis Synofzik
- Division Translational Genomics of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research and Center of Neurology, University of Tübingen, Tübingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
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13
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Wilpert NM, Tonduti D, Vaia Y, Krude H, Sarret C, Schuelke M. Establishing Patient-Centered Outcomes for MCT8 Deficiency: Stakeholder Engagement and Systematic Literature Review. Neuropsychiatr Dis Treat 2023; 19:2195-2216. [PMID: 37881807 PMCID: PMC10595182 DOI: 10.2147/ndt.s379703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 10/07/2023] [Indexed: 10/27/2023] Open
Abstract
Introduction The SCL16A2 gene encodes the thyroid hormone (TH) transporter MCT8. Pathogenic variants result in a reduced TH uptake into the CNS despite high serum T3 concentrations. Patients suffer from severe neurodevelopmental delay and require multidisciplinary care. Since a first compassionate use study in 2008, the development of therapies has recently gained momentum. Treatment strategies range from symptom-based approaches, supplementation with TH or TH-analogs, to gene therapy. All these studies have mainly used surrogate endpoints and clinical outcomes. However, the EMA and FDA strongly encourage researchers to involve patients and their advocacy groups in the design of clinical trials. This should strengthen the patients' perspective and identify clinical endpoints that are clinically relevant to their daily life. Methods We involved patient families to define patient-relevant outcomes for MCT8 deficiency. In close collaboration with patient families, we designed a questionnaire asking for their five most preferred therapeutic goals, which, if achieved at least, make a difference in their lives. In addition, we performed a systematic review according to Cochrane recommendations of the published treatment trials. Results We obtained results from 15 families with completed questionnaires from 14 mothers and 8 fathers. Improvement in development, especially in gross motor skills, was most important to the parents. 59% wished for head control and 50% for sitting ability. Another 36% wished for weight gain, 32% for improvement of expressive language skills, and 18% for a reduction of dystonia/spasticity, less dysphagia, and reflux. Paraclinical aspects were least important (5-9%). In a treatment trial (n=46) and compassionate use cases (n=83), the results were mainly inconclusive, partly due to a lack of predefined patient-centered clinical endpoints. Discussion We recommend that future trials should define a relevant improvement in "development" and/or other patient-relevant outcomes compared to natural history as treatment goals.
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Affiliation(s)
- Nina-Maria Wilpert
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health (BIH), Department of Pediatric Neurology, Berlin, Germany
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität Zu Berlin, and Berlin Institute of Health (BIH), Center for Chronically Sick Children, Berlin, Germany
| | - Davide Tonduti
- Unit of Pediatric Neurology, C.O.A.L.A. (Center for Diagnosis and Treatment of Leukodystrophies), V. Buzzi Children’s Hospital, Università Degli Studi Di Milano, Milan, Italy
| | - Ylenia Vaia
- Unit of Pediatric Neurology, C.O.A.L.A. (Center for Diagnosis and Treatment of Leukodystrophies), V. Buzzi Children’s Hospital, Università Degli Studi Di Milano, Milan, Italy
| | - Heiko Krude
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health (BIH), Institute of Experimental Pediatric Endocrinology, Berlin, Germany
| | - Catherine Sarret
- Centre de Compétence des Leucodystrophies et Leucoencéphalopathies de Cause Rare, Centre Hospitalier Universitaire de Clermont-Ferrand, Clermont-Ferrand, France
| | - Markus Schuelke
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health (BIH), Department of Pediatric Neurology, Berlin, Germany
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität Zu Berlin, and Berlin Institute of Health (BIH), Center for Chronically Sick Children, Berlin, Germany
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health (BIH), NeuroCure Clinical Research Center, Berlin, Germany
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14
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Wilke C, Pellerin D, Mengel D, Traschütz A, Danzi MC, Dicaire MJ, Neumann M, Lerche H, Bender B, Houlden H, Züchner S, Schöls L, Brais B, Synofzik M. GAA-FGF14 ataxia (SCA27B): phenotypic profile, natural history progression and 4-aminopyridine treatment response. Brain 2023; 146:4144-4157. [PMID: 37165652 DOI: 10.1093/brain/awad157] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 04/08/2023] [Accepted: 05/01/2023] [Indexed: 05/12/2023] Open
Abstract
Ataxia due to an autosomal dominant intronic GAA repeat expansion in FGF14 [GAA-FGF14 ataxia, spinocerebellar ataxia 27B (SCA27B)] has recently been identified as one of the most common genetic late-onset ataxias. We here aimed to characterize its phenotypic profile, natural history progression, and 4-aminopyridine (4-AP) treatment response. We conducted a multi-modal cohort study of 50 GAA-FGF14 patients, comprising in-depth phenotyping, cross-sectional and longitudinal progression data (up to 7 years), MRI findings, serum neurofilament light (sNfL) levels, neuropathology, and 4-AP treatment response data, including a series of n-of-1 treatment studies. GAA-FGF14 ataxia consistently presented as late-onset [60.0 years (53.5-68.5), median (interquartile range)] pancerebellar syndrome, partly combined with afferent sensory deficits (55%) and dysautonomia (28%). Dysautonomia increased with duration while cognitive impairment remained infrequent, even in advanced stages. Cross-sectional and longitudinal assessments consistently indicated mild progression of ataxia [0.29 Scale for the Assessment and Rating of Ataxia (SARA) points/year], not exceeding a moderate disease severity even in advanced stages (maximum SARA score: 18 points). Functional impairment increased relatively slowly (unilateral mobility aids after 8 years in 50% of patients). Corresponding to slow progression and low extra-cerebellar involvement, sNfL was not increased relative to controls. Concurrent second diseases (including progressive supranuclear palsy neuropathology) represented major individual aggravators of disease severity, constituting important caveats for planning future GAA-FGF14 trials. A treatment response to 4-AP with relevance for everyday living was reported by 86% of treated patients. A series of three prospective n-of-1 treatment experiences with on/off design showed marked reduction in daily symptomatic time and symptom severity on 4-AP. Our study characterizes the phenotypic profile, natural history progression, and 4-AP treatment response of GAA-FGF14 ataxia. It paves the way towards large-scale natural history studies and 4-AP treatment trials in this newly discovered, possibly most frequent, and treatable late-onset ataxia.
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Affiliation(s)
- Carlo Wilke
- Division Translational Genomics of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research and Center of Neurology, University of Tübingen, 72076 Tübingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), 72076 Tübingen, Germany
| | - David Pellerin
- Department of Neurology and Neurosurgery, Montreal Neurological Hospital and Institute, McGill University, Montreal, Quebec H3A 1A1, Canada
| | - David Mengel
- Division Translational Genomics of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research and Center of Neurology, University of Tübingen, 72076 Tübingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), 72076 Tübingen, Germany
| | - Andreas Traschütz
- Division Translational Genomics of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research and Center of Neurology, University of Tübingen, 72076 Tübingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), 72076 Tübingen, Germany
| | - Matt C Danzi
- Dr. John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Marie-Josée Dicaire
- Department of Neurology and Neurosurgery, Montreal Neurological Hospital and Institute, McGill University, Montreal, Quebec H3A 1A1, Canada
| | - Manuela Neumann
- German Center for Neurodegenerative Diseases (DZNE), 72076 Tübingen, Germany
- Department of Neuropathology, University of Tübingen, 72076 Tübingen, Germany
| | - Holger Lerche
- Department of Neurology and Epileptology, Hertie-Institute for Clinical Brain Research, University of Tübingen, 72076 Tübingen, Germany
| | - Benjamin Bender
- Department of Diagnostic and Interventional Neuroradiology, University of Tübingen, 72016 Tübingen, Germany
| | - Henry Houlden
- Department of Neuromuscular Disorders, UCL London, Institute of Neurology, University College London, London WC1N 3BG, UK
| | - Stephan Züchner
- Dr. John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Ludger Schöls
- German Center for Neurodegenerative Diseases (DZNE), 72076 Tübingen, Germany
- Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research and Center of Neurology, University of Tübingen, 72076 Tübingen, Germany
| | - Bernard Brais
- Department of Neurology and Neurosurgery, Montreal Neurological Hospital and Institute, McGill University, Montreal, Quebec H3A 1A1, Canada
| | - Matthis Synofzik
- Division Translational Genomics of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research and Center of Neurology, University of Tübingen, 72076 Tübingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), 72076 Tübingen, Germany
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15
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Defelippe VM, J M W van Thiel G, Otte WM, Schutgens REG, Stunnenberg B, Cross HJ, O'Callaghan F, De Giorgis V, Jansen FE, Perucca E, Brilstra EH, Braun KPJ. Toward responsible clinical n-of-1 strategies for rare diseases. Drug Discov Today 2023; 28:103688. [PMID: 37356616 DOI: 10.1016/j.drudis.2023.103688] [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: 01/17/2023] [Revised: 06/08/2023] [Accepted: 06/20/2023] [Indexed: 06/27/2023]
Abstract
N-of-1 strategies can provide high-quality evidence of treatment efficacy at the individual level and optimize evidence-based selection of off-label treatments for patients with rare diseases. Given their design characteristics, n-of-1 strategies are considered to lay at the intersection between medical research and clinical care. Therefore, whether n-of-1 strategies should be governed by research or care regulations remains a debated issue. Here, we delineate differences between medical research and optimized clinical care, and distinguish the regulations which apply to either. We also set standards for responsible optimized clinical n-of-1 strategies with (off-label) treatments for rare diseases. Implementing clinical n-of-1 strategies as defined here could aid in optimized treatment selection for such diseases.
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Affiliation(s)
- Victoria M Defelippe
- Department of Child Neurology, UMCU Brain Center, University Medical Center Utrecht, Universiteitsweg 100, 3584 CG Utrecht, the Netherlands; European Reference Network for Rare and Complex Epilepsies (EpiCare), Department of Paediatric Clinical Epileptology, Sleep Disorders and Functional Neurology, c/o Pr Arzimanoglou, Hôpital Femme Mère Enfant, 59 Boulevard Pinel, 69677 Bron, France.
| | - Ghislaine J M W van Thiel
- Department of Medical Humanities, Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Universiteitsweg 100, 3584 CG Utrecht, the Netherlands
| | - Willem M Otte
- Department of Child Neurology, UMCU Brain Center, University Medical Center Utrecht, Universiteitsweg 100, 3584 CG Utrecht, the Netherlands
| | - Roger E G Schutgens
- Van Creveldkliniek, Benign Hematology Center, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, the Netherlands; European Reference Network for Oncological and non-oncological Rare Hematological Diseases (EuroBloodNet), Hôpital St Louis / Université Paris 7, 1 Avenue Claude Vellefaux, 75475 Paris, France
| | - Bas Stunnenberg
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Donders Center for Medical Neuroscience, Radboud University Medical Center, Thomas van Aquinostraat 4, 6525 GD Nijmegen, the Netherlands
| | - Helen J Cross
- European Reference Network for Rare and Complex Epilepsies (EpiCare), Department of Paediatric Clinical Epileptology, Sleep Disorders and Functional Neurology, c/o Pr Arzimanoglou, Hôpital Femme Mère Enfant, 59 Boulevard Pinel, 69677 Bron, France; University College London (UCL) Great Ormond Street, Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - Finbar O'Callaghan
- European Reference Network for Rare and Complex Epilepsies (EpiCare), Department of Paediatric Clinical Epileptology, Sleep Disorders and Functional Neurology, c/o Pr Arzimanoglou, Hôpital Femme Mère Enfant, 59 Boulevard Pinel, 69677 Bron, France; Paediatric Neuroscience, UCL Great Ormond Street, Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
| | - Valentina De Giorgis
- European Reference Network for Rare and Complex Epilepsies (EpiCare), Department of Paediatric Clinical Epileptology, Sleep Disorders and Functional Neurology, c/o Pr Arzimanoglou, Hôpital Femme Mère Enfant, 59 Boulevard Pinel, 69677 Bron, France; Fondazione Mondino National Institute of Neurology, University of Pavia, Via Mondino 2, 27100 Pavia, Italy
| | - Floor E Jansen
- Department of Child Neurology, UMCU Brain Center, University Medical Center Utrecht, Universiteitsweg 100, 3584 CG Utrecht, the Netherlands; European Reference Network for Rare and Complex Epilepsies (EpiCare), Department of Paediatric Clinical Epileptology, Sleep Disorders and Functional Neurology, c/o Pr Arzimanoglou, Hôpital Femme Mère Enfant, 59 Boulevard Pinel, 69677 Bron, France
| | - Emilio Perucca
- European Reference Network for Rare and Complex Epilepsies (EpiCare), Department of Paediatric Clinical Epileptology, Sleep Disorders and Functional Neurology, c/o Pr Arzimanoglou, Hôpital Femme Mère Enfant, 59 Boulevard Pinel, 69677 Bron, France; Department of Medicine, University of Melbourne (Austin Health), Heidelberg, VIC 3084, Australia; Department of Neuroscience, Monash University, Melbourne, VIC, Australia
| | - Eva H Brilstra
- European Reference Network for Rare and Complex Epilepsies (EpiCare), Department of Paediatric Clinical Epileptology, Sleep Disorders and Functional Neurology, c/o Pr Arzimanoglou, Hôpital Femme Mère Enfant, 59 Boulevard Pinel, 69677 Bron, France; Department of Genetics, Center for Molecular Medicine, University Medical Center Utrecht, Universiteitsweg 100, 3584 CG Utrecht, the Netherlands
| | - Kees P J Braun
- European Reference Network for Rare and Complex Epilepsies (EpiCare), Department of Paediatric Clinical Epileptology, Sleep Disorders and Functional Neurology, c/o Pr Arzimanoglou, Hôpital Femme Mère Enfant, 59 Boulevard Pinel, 69677 Bron, France; Department of Child Neurology, UMCU Brain Center, University Medical Center Utrecht, Universiteitsweg 100, 3584 CG Utrecht, the Netherlands
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16
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Traschütz A, Adarmes-Gómez AD, Anheim M, Baets J, Brais B, Gagnon C, Gburek-Augustat J, Doss S, Hanağası HA, Kamm C, Klivenyi P, Klockgether T, Klopstock T, Minnerop M, Münchau A, Renaud M, Santorelli FM, Schöls L, Thieme A, Vielhaber S, van de Warrenburg BP, Zanni G, Hilgers RD, Synofzik M. Responsiveness of the Scale for the Assessment and Rating of Ataxia and Natural History in 884 Recessive and Early Onset Ataxia Patients. Ann Neurol 2023; 94:470-485. [PMID: 37243847 DOI: 10.1002/ana.26712] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 04/04/2023] [Accepted: 05/22/2023] [Indexed: 05/29/2023]
Abstract
OBJECTIVE The Scale for the Assessment and Rating of Ataxia (SARA) is the most widely applied clinical outcome assessment (COA) for genetic ataxias, but presents metrological and regulatory challenges. To facilitate trial planning, we characterize its responsiveness (including subitem-level relations to ataxia severity and patient-focused outcomes) across a large number of ataxias, and provide first natural history data for several of them. METHODS Subitem-level correlation and distribution-based analysis of 1,637 SARA assessments in 884 patients with autosomal recessive/early onset ataxia (370 with 2-8 longitudinal assessments) were complemented by linear mixed effects modeling to estimate progression and sample sizes. RESULTS Although SARA subitem responsiveness varied between ataxia severities, gait/stance showed a robust granular linear scaling across the broadest range (SARA < 25). Responsiveness was diminished by incomplete subscale use at intermediate or upper levels, nontransitions ("static periods"), and fluctuating decreases/increases. All subitems except nose-finger showed moderate-to-strong correlations to activities of daily living, indicating that metric properties-not content validity-limit SARA responsiveness. SARA captured mild-to-moderate progression in many genotypes (eg, SYNE1-ataxia: 0.55 points/yr, ataxia with oculomotor apraxia type 2: 1.14 points/yr, POLG-ataxia: 1.56 points/yr), but no change in others (autosomal recessive spastic ataxia of Charlevoix-Saguenay, COQ8A-ataxia). Whereas sensitivity to change was optimal in mild ataxia (SARA < 10), it substantially deteriorated in advanced ataxia (SARA > 25; 2.7-fold sample size). Use of a novel rank-optimized SARA without subitems finger-chase and nose-finger reduces sample sizes by 20 to 25%. INTERPRETATION This study comprehensively characterizes COA properties and annualized changes of the SARA across and within a large number of ataxias. It suggests specific approaches for optimizing its responsiveness that might facilitate regulatory qualification and trial design. ANN NEUROL 2023;94:470-485.
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Affiliation(s)
- Andreas Traschütz
- Research Division "Translational Genomics of Neurodegenerative Diseases," Hertie Institute for Clinical Brain Research and Center of Neurology, University of Tübingen, Tübingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Astrid D Adarmes-Gómez
- Movement Disorders Unit, Department of Neurology and Clinical Neurophysiology, Institute of Biomedicine of Seville, Virgen del Rocío University Hospital/CSIC/University of Seville, Seville, Spain
- Center for Biomedical Research Network on Neurodegenerative Diseases, Madrid, Spain
| | - Mathieu Anheim
- Department of Neurology, Hautepierre Hospital, University Hospitals of Strasbourg, Strasbourg, France
- Federation of Translational Medicine of Strasbourg, University of Strasbourg, Strasbourg, France
- Institute of Genetics and Molecular and Cellular Biology, INSERM-U964/CNRS-UMR7104/University of Strasbourg, Illkirch, France
| | - Jonathan Baets
- Translational Neurosciences, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
- Laboratory of Neuromuscular Pathology, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
- Neuromuscular Reference Center, Department of Neurology, Antwerp University Hospital, Antwerp, Belgium
| | - Bernard Brais
- Department of Neurology, McGill University, Montreal Neurological Institute, Montreal, Quebec, Canada
| | - Cynthia Gagnon
- CHUS Research Center and Health and Social Services Center of Saguenay-Lac-Saint-Jean, Faculty of Medicine, University of Sherbrooke, Quebec, Quebec, Canada
| | - Janina Gburek-Augustat
- Division of Neuropediatrics, Hospital for Children and Adolescents, University of Leipzig, Leipzig, Germany
| | - Sarah Doss
- Department of Neurology, Charité-Universitätsmedizin Berlin, corporate member of Free University of Berlin, Humboldt University of Berlin, Berlin, Germany
- Department of Neurological Sciences, University of Nebraska Medical Center, Omaha, NE, USA
| | - Haşmet A Hanağası
- Behavioral Neurology and Movement Disorders Unit, Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Christoph Kamm
- Department of Neurology, University of Rostock, Rostock, Germany
| | - Peter Klivenyi
- Interdisciplinary Excellence Center, Department of Neurology, Faculty of Medicine, Albert Szent-Györgyi Clinical Center, University of Szeged, Szeged, Hungary
| | - Thomas Klockgether
- Department of Neurology, University Hospital Bonn, Bonn, Germany
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Thomas Klopstock
- Department of Neurology, Friedrich Baur Institute, Ludwig Maximilian University of Munich, Munich, Germany
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
- Munich Cluster for Systems Neurology, Munich, Germany
| | - Martina Minnerop
- Institute of Neuroscience and Medicine, Research Center Jülich, Jülich, Germany
- Department of Neurology, Center for Movement Disorders and Neuromodulation, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
- Institute of Clinical Neuroscience and Medical Psychology, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
| | - Alexander Münchau
- Institute of Systems Motor Science, Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
| | - Mathilde Renaud
- Clinical Genetics Service, CHRU of Nancy, Nancy, France
- INSERM-U1256 NGERE, University of Lorraine, Nancy, France
| | | | - Ludger Schöls
- Research Division "Translational Genomics of Neurodegenerative Diseases," Hertie Institute for Clinical Brain Research and Center of Neurology, University of Tübingen, Tübingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Andreas Thieme
- Department of Neurology and Center for Translational Neuro and Behavioral Sciences, Essen University Hospital, University of Duisburg-Essen, Essen, Germany
| | - Stefan Vielhaber
- Department of Neurology, Otto von Guericke University, Magdeburg, Germany
- German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany
- Center for Behavioral Brain Sciences, Otto von Guericke University Magdeburg, Magdeburg, Germany
| | - Bart P van de Warrenburg
- Department of Neurology, Donders Institute for Brain, Cognition, and Behavior, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Ginevra Zanni
- Unit of Neuromuscular and Neurodegenerative Disorders, Department of Neurosciences, Bambino Gesù Childrens' Hospital, IRCCS, Rome, Italy
| | | | - Matthis Synofzik
- Research Division "Translational Genomics of Neurodegenerative Diseases," Hertie Institute for Clinical Brain Research and Center of Neurology, University of Tübingen, Tübingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
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17
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Mortberg MA, Gentile JE, Nadaf N, Vanderburg C, Simmons S, Dubinsky D, Slamin A, Maldonado S, Petersen C, Jones N, Kordasiewicz H, Zhao H, Vallabh S, Minikel E. A single-cell map of antisense oligonucleotide activity in the brain. Nucleic Acids Res 2023; 51:7109-7124. [PMID: 37188501 PMCID: PMC10415122 DOI: 10.1093/nar/gkad371] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 04/19/2023] [Accepted: 04/27/2023] [Indexed: 05/17/2023] Open
Abstract
Antisense oligonucleotides (ASOs) dosed into cerebrospinal fluid (CSF) distribute broadly throughout the central nervous system (CNS). By modulating RNA, they hold the promise of targeting root molecular causes of disease and hold potential to treat myriad CNS disorders. Realization of this potential requires that ASOs must be active in the disease-relevant cells, and ideally, that monitorable biomarkers also reflect ASO activity in these cells. The biodistribution and activity of such centrally delivered ASOs have been deeply characterized in rodent and non-human primate (NHP) models, but usually only in bulk tissue, limiting our understanding of the distribution of ASO activity across individual cells and across diverse CNS cell types. Moreover, in human clinical trials, target engagement is usually monitorable only in a single compartment, CSF. We sought a deeper understanding of how individual cells and cell types contribute to bulk tissue signal in the CNS, and how these are linked to CSF biomarker outcomes. We employed single nucleus transcriptomics on tissue from mice treated with RNase H1 ASOs against Prnp and Malat1 and NHPs treated with an ASO against PRNP. Pharmacologic activity was observed in every cell type, though sometimes with substantial differences in magnitude. Single cell RNA count distributions implied target RNA suppression in every single sequenced cell, rather than intense knockdown in only some cells. Duration of action up to 12 weeks post-dose differed across cell types, being shorter in microglia than in neurons. Suppression in neurons was generally similar to, or more robust than, the bulk tissue. In macaques, PrP in CSF was lowered 40% in conjunction with PRNP knockdown across all cell types including neurons, arguing that a CSF biomarker readout is likely to reflect ASO pharmacodynamic effect in disease-relevant cells in a neuronal disorder. Our results provide a reference dataset for ASO activity distribution in the CNS and establish single nucleus sequencing as a method for evaluating cell type specificity of oligonucleotide therapeutics and other modalities.
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Affiliation(s)
- Meredith A Mortberg
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Juliana E Gentile
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Naeem M Nadaf
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Charles Vanderburg
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Sean Simmons
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Dan Dubinsky
- Genomics Platform, Broad Institute of MIT and Harvard, Cambridge, MA 02141, USA
| | - Adam Slamin
- Genomics Platform, Broad Institute of MIT and Harvard, Cambridge, MA 02141, USA
| | - Salome Maldonado
- Genomics Platform, Broad Institute of MIT and Harvard, Cambridge, MA 02141, USA
| | - Caroline L Petersen
- Genomics Platform, Broad Institute of MIT and Harvard, Cambridge, MA 02141, USA
| | - Nichole Jones
- Genomics Platform, Broad Institute of MIT and Harvard, Cambridge, MA 02141, USA
| | | | - Hien T Zhao
- Ionis Pharmaceuticals, Carlsbad, CA 92010, USA
| | - Sonia M Vallabh
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- McCance Center for Brain Health and Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
- Department of Neurology, Harvard Medical School, Boston, MA02115, USA
- Prion Alliance, Cambridge, MA 02139, USA
| | - Eric Vallabh Minikel
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
- McCance Center for Brain Health and Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
- Department of Neurology, Harvard Medical School, Boston, MA02115, USA
- Prion Alliance, Cambridge, MA 02139, USA
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18
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Aartsma-Rus A, van Roon-Mom W, Lauffer M, Siezen C, Duijndam B, Coenen-de Roo T, Schüle R, Synofzik M, Graessner H. Development of tailored splice-switching oligonucleotides for progressive brain disorders in Europe: development, regulation, and implementation considerations. RNA (NEW YORK, N.Y.) 2023; 29:446-454. [PMID: 36669889 PMCID: PMC10019362 DOI: 10.1261/rna.079540.122] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 01/12/2023] [Indexed: 06/01/2023]
Abstract
Splice-modulating antisense oligonucleotides (ASOs) offer treatment options for rare neurological diseases, including those with very rare mutations, where patient-specific, individualized ASOs have to be developed. Inspired by the development of milasen, the 1 Mutation 1 Medicine (1M1M) and Dutch Center for RNA Therapeutics (DCRT) aim to develop patient-specific ASOs and treat eligible patients within Europe and the Netherlands, respectively. Treatment will be provided under a named patient setting. Our initiatives benefited from regulatory advice from the European Medicines Agency (EMA) with regard to preclinical proof-of-concept studies, safety studies, compounding and measuring benefit and safety in treated patients. We here outline the most important considerations from these interactions and how we implemented this advice into our plan to develop and treat eligible patients within Europe.
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Affiliation(s)
- Annemieke Aartsma-Rus
- Dutch Center for RNA Therapeutics and Department of Human Genetics, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
- 1 Mutation 1 Medicine, 72076 Tübingen, Germany
| | - Willeke van Roon-Mom
- Dutch Center for RNA Therapeutics and Department of Human Genetics, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
- 1 Mutation 1 Medicine, 72076 Tübingen, Germany
| | - Marlen Lauffer
- Dutch Center for RNA Therapeutics and Department of Human Genetics, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
| | | | - Britt Duijndam
- Medicines Evaluation Board, 3531 AH Utrecht, The Netherlands
| | - Tineke Coenen-de Roo
- Dutch Center for RNA Therapeutics and Department of Human Genetics, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
- Animal and Transgenesis Facility, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands
| | - Rebecca Schüle
- 1 Mutation 1 Medicine, 72076 Tübingen, Germany
- Division of Neurodegenerative Diseases, Department of Neurology, University of Heidelberg Medical Center, 69120 Heidelberg, Germany
- Center for Neurology and Hertie Institute for Clinical Brain Research, University of Tübingen, 72076 Tübingen, Germany
- European Reference Network for Rare Neurological Diseases
| | - Matthis Synofzik
- 1 Mutation 1 Medicine, 72076 Tübingen, Germany
- Center for Neurology and Hertie Institute for Clinical Brain Research, University of Tübingen, 72076 Tübingen, Germany
- Division of Translational Genomics of Neurodegenerative Diseases, Hertie-Institute of Clinical Brain Research & Center of Neurology, 72076 Tübingen, Germany
- German Center for Neurodegenerative Diseases (DZNE), 72076 Tübingen, Germany
- European Reference Network for Rare Neurological Diseases
| | - Holm Graessner
- 1 Mutation 1 Medicine, 72076 Tübingen, Germany
- Institute for Medical Genetics and Applied Genomics, University of Tübingen, 72076 Tübingen, Germany
- Center for Rare Diseases, University Hospital Tübingen, 72076 Tübingen, Germany
- European Reference Network for Rare Neurological Diseases
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19
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Harel T. Rare disease informs mechanism and possible treatment of statin-associated myopathy. Proc Natl Acad Sci U S A 2023; 120:e2300988120. [PMID: 36848568 PMCID: PMC10013738 DOI: 10.1073/pnas.2300988120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2023] Open
Affiliation(s)
- Tamar Harel
- Department of Genetics, Hadassah Medical Center, Jerusalem91120, Israel
- Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem91120, Israel
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20
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Vockley J, Aartsma-Rus A, Cohen JL, Cowsert LM, Howell RR, Yu TW, Wasserstein MP, Defay T. Whole-genome sequencing holds the key to the success of gene-targeted therapies. AMERICAN JOURNAL OF MEDICAL GENETICS. PART C, SEMINARS IN MEDICAL GENETICS 2023; 193:19-29. [PMID: 36453229 DOI: 10.1002/ajmg.c.32017] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 10/12/2022] [Accepted: 11/15/2022] [Indexed: 12/02/2022]
Abstract
Rare genetic disorders affect as many as 3%-5% of all babies born. Approximately 10,000 such disorders have been identified or hypothesized to exist. Treatment is supportive except in a limited number of instances where specific therapies exist. Development of new therapies has been hampered by at least two major factors: difficulty in diagnosing diseases early enough to enable treatment before irreversible damage occurs, and the high cost of developing new drugs and getting them approved by regulatory agencies. Whole-genome sequencing (WGS) techniques have become exponentially less expensive and more rapid since the beginning of the human genome project, such that return of clinical data can now be achieved in days rather than years and at a cost that is comparable to other less expansive genetic testing. Thus, it is likely that WGS will ultimately become a mainstream, first-tier NBS technique at least for those disorders without appropriate high-throughput functional tests. However, there are likely to be several steps in the evolution to this end. The clinical implications of these advances are profound but highlight the bottlenecks in drug development that still limit transition to treatments. This article summarizes discussions arising from a recent National Institute of Health conference on nucleic acid therapy, with a focus on the impact of WGS in the identification of diagnosis and treatment of rare genetic disorders.
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Affiliation(s)
- Jerry Vockley
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Department of Human Genetics, University of Pittsburgh School of Public Health, Pittsburgh, Pennsylvania, USA
| | | | - Jennifer L Cohen
- Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, USA
| | - Lex M Cowsert
- National Phenylketonuria Alliance, Eau Claire, Wisconsin, USA
| | - R Rodney Howell
- Miller School of Medicine, University of Miami, Miami, Florida, USA
| | - Timothy W Yu
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
| | - Melissa P Wasserstein
- Department of Pediatrics, Albert Einstein College of Medicine and the Children's Hospital at Montefiore, Bronx, New York, USA
| | - Thomas Defay
- Alexion AstraZeneca Rare Diseases, Boston, Massachusetts, USA
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21
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Lekstrom-Himes J, Brooks PJ, Koeberl DD, Brower A, Goldenberg A, Green RC, Morris JA, Orsini JJ, Yu TW, Augustine EF. Moving away from one disease at a time: Screening, trial design, and regulatory implications of novel platform technologies. AMERICAN JOURNAL OF MEDICAL GENETICS. PART C, SEMINARS IN MEDICAL GENETICS 2023; 193:30-43. [PMID: 36738469 PMCID: PMC10038900 DOI: 10.1002/ajmg.c.32031] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 12/16/2022] [Accepted: 01/04/2023] [Indexed: 02/06/2023]
Abstract
Most rare diseases are caused by single-gene mutations, and as such, lend themselves to a host of new gene-targeted therapies and technologies including antisense oligonucleotides, phosphomorpholinos, small interfering RNAs, and a variety of gene delivery and gene editing systems. Early successes are encouraging, however, given the substantial number of distinct rare diseases, the ability to scale these successes will be unsustainable without new development efficiencies. Herein, we discuss the need for genomic newborn screening to match pace with the growing development of targeted therapeutics and ability to rapidly develop individualized therapies for rare variants. We offer approaches to move beyond conventional "one disease at a time" preclinical and clinical drug development and discuss planned regulatory innovations that are necessary to speed therapy delivery to individuals in need. These proposals leverage the shared properties of platform classes of therapeutics and innovative trial designs including master and platform protocols to better serve patients and accelerate drug development. Ultimately, there are risks to these novel approaches; however, we believe that close partnership and transparency between health authorities, patients, researchers, and drug developers present the path forward to overcome these challenges and deliver on the promise of gene-targeted therapies for rare diseases.
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Affiliation(s)
| | - P J Brooks
- Division of Rare Diseases Research Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, Maryland, USA
| | - Dwight D Koeberl
- Division of Medical Genetics, Department of Pediatrics, Duke University School of Medicine, Durham, North Carolina, USA
| | - Amy Brower
- American College of Medical Genetics and Genomics, Bethesda, Maryland, USA
| | - Aaron Goldenberg
- Department of Bioethics, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - Robert C Green
- Mass General Brigham, Broad Institute, Ariadne Labs and Harvard Medical School, Boston, MA, USA
| | - Jill A Morris
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Joseph J Orsini
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - Timothy W Yu
- Division of Genetics and Genomics, Harvard Medical School, Boston, Massachusetts, USA
| | - Erika F Augustine
- Department of Neurology and Neurodevelopmental Medicine, Kennedy Krieger Institute, Baltimore, Maryland, USA
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22
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Gasser T. [Introduction to Gene Therapy]. FORTSCHRITTE DER NEUROLOGIE-PSYCHIATRIE 2023; 91:129-134. [PMID: 36806179 DOI: 10.1055/a-2002-5176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
After many years of research and numerous setbacks, there are now undeniable success stories of gene therapies, namely the direct modification of genetic information on the DNA or RNA level. Both "ex vivo" strategies, i. e. the genetic manipulation of patient cells in a dish, as well as "in vivo" approaches are being used successfully. In addition to the supplementation of defective genes, the use of the CRISPR-Cas9 system to alter nuclear DNA sequences and the sequence-specific interference with the transcriptional process on the RNA level can be designated as gene therapies in a broad sense.
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Affiliation(s)
- Thomas Gasser
- Zentrum für Neurologie, Hertie-Institut für klinische Hirnforschung, Abteilung Neurodegenerative Erkrankungen, Tübingen
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23
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Mortberg MA, Gentile JE, Nadaf N, Vanderburg C, Simmons S, Dubinsky D, Slamin A, Maldonado S, Petersen CL, Jones N, Kordasiewicz HB, Zhao HT, Vallabh SM, Minikel EV. A single-cell map of antisense oligonucleotide activity in the brain. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.14.528473. [PMID: 36824749 PMCID: PMC9948956 DOI: 10.1101/2023.02.14.528473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Antisense oligonucleotides (ASOs) dosed into cerebrospinal fluid (CSF) distribute broadly throughout the brain and hold the promise of treating myriad brain diseases by modulating RNA. CNS tissue is not routinely biopsied in living individuals, leading to reliance on CSF biomarkers to inform on drug target engagement. Animal models can link CSF biomarkers to brain parenchyma, but our understanding of how individual cells contribute to bulk tissue signal is limited. Here we employed single nucleus transcriptomics on tissue from mice treated with RNase H1 ASOs against Prnp and Malat1 and macaques treated with an ASO against PRNP . Activity was observed in every cell type, though sometimes with substantial differences in magnitude. Single cell RNA count distributions implied target suppression in every single sequenced cell, rather than intense knockdown in only some cells. Duration of action up to 12 weeks post-dose differed across cell types, being shorter in microglia than in neurons. Suppression in neurons was generally similar to, or more robust than, the bulk tissue. In macaques, PrP in CSF was lowered 40% in conjunction with PRNP knockdown across all cell types including neurons, arguing that a CSF biomarker readout is likely to reflect disease-relevant cells in a neuronal disorder.
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Affiliation(s)
- Meredith A Mortberg
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard,Cambridge, MA, 02142, USA
| | - Juliana E Gentile
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard,Cambridge, MA, 02142, USA
| | - Naeem Nadaf
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard,Cambridge, MA, 02142, USA
| | - Charles Vanderburg
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard,Cambridge, MA, 02142, USA
| | - Sean Simmons
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard,Cambridge, MA, 02142, USA
| | - Dan Dubinsky
- Genomics Platform, Broad Institute of MIT and Harvard, Cambridge, MA, 02141, USA
| | - Adam Slamin
- Genomics Platform, Broad Institute of MIT and Harvard, Cambridge, MA, 02141, USA
| | - Salome Maldonado
- Genomics Platform, Broad Institute of MIT and Harvard, Cambridge, MA, 02141, USA
| | - Caroline L Petersen
- Genomics Platform, Broad Institute of MIT and Harvard, Cambridge, MA, 02141, USA
| | - Nichole Jones
- Genomics Platform, Broad Institute of MIT and Harvard, Cambridge, MA, 02141, USA
| | | | - Hien T Zhao
- Ionis Pharmaceuticals, Carlsbad, CA, 92010, USA
| | - Sonia M Vallabh
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard,Cambridge, MA, 02142, USA
- McCance Center for Brain Health and Department of Neurology, Massachusetts GeneralHospital, Boston, MA, 02114, USA
- Department of Neurology, Harvard Medical School, Boston, MA, 02115, USA
- Prion Alliance, Cambridge, MA, 02139, USA
| | - Eric Vallabh Minikel
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard,Cambridge, MA, 02142, USA
- McCance Center for Brain Health and Department of Neurology, Massachusetts GeneralHospital, Boston, MA, 02114, USA
- Department of Neurology, Harvard Medical School, Boston, MA, 02115, USA
- Prion Alliance, Cambridge, MA, 02139, USA
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24
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Aartsma-Rus A, Garanto A, van Roon-Mom W, McConnell EM, Suslovitch V, Yan WX, Watts JK, Yu TW. Consensus Guidelines for the Design and In Vitro Preclinical Efficacy Testing N-of-1 Exon Skipping Antisense Oligonucleotides. Nucleic Acid Ther 2023; 33:17-25. [PMID: 36516128 PMCID: PMC9940807 DOI: 10.1089/nat.2022.0060] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Antisense oligonucleotides (ASOs) can modulate pre-mRNA splicing. This offers therapeutic opportunities for numerous genetic diseases, often in a mutation-specific and sometimes even individual-specific manner. Developing therapeutic ASOs for as few as even a single patient has been shown feasible with the development of Milasen for an individual with Batten disease. Efforts to develop individualized ASOs for patients with different genetic diseases are ongoing globally. The N = 1 Collaborative (N1C) is an umbrella organization dedicated to supporting the nascent field of individualized medicine. N1C recently organized a workshop to discuss and advance standards for the rigorous design and testing of splice-switching ASOs. In this study, we present guidelines resulting from that meeting and the key recommendations: (1) dissemination of standardized experimental designs, (2) use of standardized reference ASOs, and (3) a commitment to data sharing and exchange.
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Affiliation(s)
- Annemieke Aartsma-Rus
- Dutch Center for RNA Therapeutics, the Netherlands.,Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands.,N = 1 Collaborative
| | - Alejandro Garanto
- Dutch Center for RNA Therapeutics, the Netherlands.,Department of Pediatrics and Department of Human Genetics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Willeke van Roon-Mom
- Dutch Center for RNA Therapeutics, the Netherlands.,Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands
| | | | - Victoria Suslovitch
- N = 1 Collaborative.,Department of Genetics and Genomics, Boston Children's Hospital, Boston, Massachusetts, USA
| | | | - Jonathan K Watts
- RNA Therapeutics Institute, UMass Chan Medical School, Worcester, Massachusetts, USA
| | - Timothy W Yu
- N = 1 Collaborative.,Department of Genetics and Genomics, Boston Children's Hospital, Boston, Massachusetts, USA.,Harvard Medical School, Division of Genetics and Genomics, Boston, Massachusetts, USA
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25
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Shirakaki S, Roshmi RR, Yokota T. Genetic Approaches for the Treatment of Giant Axonal Neuropathy. J Pers Med 2022; 13:jpm13010091. [PMID: 36675752 PMCID: PMC9865904 DOI: 10.3390/jpm13010091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 12/18/2022] [Accepted: 12/23/2022] [Indexed: 01/01/2023] Open
Abstract
Giant axonal neuropathy (GAN) is a pediatric, hereditary, neurodegenerative disorder that affects both the central and peripheral nervous systems. It is caused by mutations in the GAN gene, which codes for the gigaxonin protein. Gigaxonin plays a role in intermediate filament (IF) turnover hence loss of function of this protein leads to IF aggregates in various types of cells. These aggregates can lead to abnormal cellular function that manifests as a diverse set of symptoms in persons with GAN including nerve degeneration, cognitive issues, skin diseases, vision loss, and muscle weakness. GAN has no cure at this time. Currently, an adeno-associated virus (AAV) 9-mediated gene replacement therapy is being tested in a phase I clinical trial for the treatment of GAN. This review paper aims to provide an overview of giant axonal neuropathy and the current efforts at developing a treatment for this devastating disease.
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26
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Amanat M, Nemeth CL, Fine AS, Leung DG, Fatemi A. Antisense Oligonucleotide Therapy for the Nervous System: From Bench to Bedside with Emphasis on Pediatric Neurology. Pharmaceutics 2022; 14:2389. [PMID: 36365206 PMCID: PMC9695718 DOI: 10.3390/pharmaceutics14112389] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 10/26/2022] [Accepted: 11/02/2022] [Indexed: 09/05/2023] Open
Abstract
Antisense oligonucleotides (ASOs) are disease-modifying agents affecting protein-coding and noncoding ribonucleic acids. Depending on the chemical modification and the location of hybridization, ASOs are able to reduce the level of toxic proteins, increase the level of functional protein, or modify the structure of impaired protein to improve function. There are multiple challenges in delivering ASOs to their site of action. Chemical modifications in the phosphodiester bond, nucleotide sugar, and nucleobase can increase structural thermodynamic stability and prevent ASO degradation. Furthermore, different particles, including viral vectors, conjugated peptides, conjugated antibodies, and nanocarriers, may improve ASO delivery. To date, six ASOs have been approved by the US Food and Drug Administration (FDA) in three neurological disorders: spinal muscular atrophy, Duchenne muscular dystrophy, and polyneuropathy caused by hereditary transthyretin amyloidosis. Ongoing preclinical and clinical studies are assessing the safety and efficacy of ASOs in multiple genetic and acquired neurological conditions. The current review provides an update on underlying mechanisms, design, chemical modifications, and delivery of ASOs. The administration of FDA-approved ASOs in neurological disorders is described, and current evidence on the safety and efficacy of ASOs in other neurological conditions, including pediatric neurological disorders, is reviewed.
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Affiliation(s)
- Man Amanat
- Moser Center for Leukodystrophies, Kennedy Krieger Institute, Baltimore, MD 21205, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Christina L. Nemeth
- Moser Center for Leukodystrophies, Kennedy Krieger Institute, Baltimore, MD 21205, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Amena Smith Fine
- Moser Center for Leukodystrophies, Kennedy Krieger Institute, Baltimore, MD 21205, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Doris G. Leung
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Center for Genetic Muscle Disorders, Kennedy Krieger Institute, Baltimore, MD 21205, USA
| | - Ali Fatemi
- Moser Center for Leukodystrophies, Kennedy Krieger Institute, Baltimore, MD 21205, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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27
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Thakur S, Sinhari A, Jain P, Jadhav HR. A perspective on oligonucleotide therapy: Approaches to patient customization. Front Pharmacol 2022; 13:1006304. [PMID: 36339619 PMCID: PMC9626821 DOI: 10.3389/fphar.2022.1006304] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 10/05/2022] [Indexed: 09/12/2023] Open
Abstract
It is estimated that the human genome encodes 15% of proteins that are considered to be disease-modifying. Only 2% of these proteins possess a druggable site that the approved clinical candidates target. Due to this disparity, there is an immense need to develop therapeutics that may better mitigate the disease or disorders aroused by non-druggable and druggable proteins or enzymes. The recent surge in approved oligonucleotide therapeutics (OT) indicates the imminent potential of these therapies. Oligonucleotide-based therapeutics are of intermediate size with much-improved selectivity towards the target and fewer off-target effects than small molecules. The OTs include Antisense RNAs, MicroRNA (MIR), small interfering RNA (siRNA), and aptamers, which are currently being explored for their use in neurodegenerative disorders, cancer, and even orphan diseases. The present review is a congregated effort to present the past and present of OTs and the current efforts to make OTs for plausible future therapeutics. The review provides updated literature on the challenges and bottlenecks of OT and recent advancements in OT drug delivery. Further, this review deliberates on a newly emerging approach to personalized treatment for patients with rare and fatal diseases with OT.
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Affiliation(s)
- Shikha Thakur
- Pharmaceutical Chemistry Laboratory, Department of Pharmacy, Birla Institute of Technology and Sciences Pilani, Pilani, RJ, India
| | - Apurba Sinhari
- Pharmaceutical Chemistry Laboratory, Department of Pharmacy, Birla Institute of Technology and Sciences Pilani, Pilani, RJ, India
| | - Priti Jain
- Department of Pharmaceutical Chemistry, School of Pharmaceutical Sciences, Delhi Pharmaceutical Sciences and Research University, New Delhi, India
| | - Hemant R. Jadhav
- Pharmaceutical Chemistry Laboratory, Department of Pharmacy, Birla Institute of Technology and Sciences Pilani, Pilani, RJ, India
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28
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Variable Expression of GABAA Receptor Subunit Gamma 2 Mutation in a Nuclear Family Displaying Developmental and Encephalopathic Phenotype. Int J Mol Sci 2022; 23:ijms23179683. [PMID: 36077081 PMCID: PMC9456057 DOI: 10.3390/ijms23179683] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 08/13/2022] [Accepted: 08/23/2022] [Indexed: 12/17/2022] Open
Abstract
Mutations in GABAA receptor subunit genes (GABRs) are a major etiology for developmental and epileptic encephalopathies (DEEs). This article reports a case of a genetic abnormality in GABRG2 and updates the pathophysiology and treatment development for mutations in DEEs based on recent advances. Mutations in GABRs, especially in GABRA1, GABRB2, GABRB3, and GABRG2, impair GABAergic signaling and are frequently associated with DEEs such as Dravet syndrome and Lennox-Gastaut syndrome, as GABAergic signaling is critical for early brain development. We here present a novel association of a microdeletion of GABRG2 with a diagnosed DEE phenotype. We characterized the clinical phenotype and underlying mechanisms, including molecular genetics, EEGs, and MRI. We then compiled an update of molecular mechanisms of GABR mutations, especially the mutations in GABRB3 and GABRG2 attributed to DEEs. Genetic therapy is also discussed as a new avenue for treatment of DEEs through employing antisense oligonucleotide techniques. There is an urgent need to define treatment targets and explore new treatment paradigms for the DEEs, as early deployment could alleviate long-term disabilities and improve quality of life for patients. This study highlights biomolecular targets for future therapeutic interventions, including via both pharmacological and genetic approaches.
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Helm J, Schöls L, Hauser S. Towards Personalized Allele-Specific Antisense Oligonucleotide Therapies for Toxic Gain-of-Function Neurodegenerative Diseases. Pharmaceutics 2022; 14:pharmaceutics14081708. [PMID: 36015334 PMCID: PMC9416334 DOI: 10.3390/pharmaceutics14081708] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 08/11/2022] [Accepted: 08/12/2022] [Indexed: 11/29/2022] Open
Abstract
Antisense oligonucleotides (ASOs) are single-stranded nucleic acid strings that can be used to selectively modify protein synthesis by binding complementary (pre-)mRNA sequences. By specific arrangements of DNA and RNA into a chain of nucleic acids and additional modifications of the backbone, sugar, and base, the specificity and functionality of the designed ASOs can be adjusted. Thereby cellular uptake, toxicity, and nuclease resistance, as well as binding affinity and specificity to its target (pre-)mRNA, can be modified. Several neurodegenerative diseases are caused by autosomal dominant toxic gain-of-function mutations, which lead to toxic protein products driving disease progression. ASOs targeting such mutations—or even more comprehensively, associated variants, such as single nucleotide polymorphisms (SNPs)—promise a selective degradation of the mutant (pre-)mRNA while sparing the wild type allele. By this approach, protein expression from the wild type strand is preserved, and side effects from an unselective knockdown of both alleles can be prevented. This makes allele-specific targeting strategies a focus for future personalized therapies. Here, we provide an overview of current strategies to develop personalized, allele-specific ASO therapies for the treatment of neurodegenerative diseases, such Huntington’s disease (HD) and spinocerebellar ataxia type 3 (SCA3/MJD).
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Affiliation(s)
- Jacob Helm
- German Center for Neurodegenerative Diseases (DZNE), 72076 Tübingen, Germany
- Hertie Institute for Clinical Brain Research and Department of Neurology, University of Tübingen, 72076 Tübingen, Germany
- Graduate School of Cellular and Molecular Neuroscience, University of Tübingen, 72076 Tübingen, Germany
| | - Ludger Schöls
- German Center for Neurodegenerative Diseases (DZNE), 72076 Tübingen, Germany
- Hertie Institute for Clinical Brain Research and Department of Neurology, University of Tübingen, 72076 Tübingen, Germany
| | - Stefan Hauser
- German Center for Neurodegenerative Diseases (DZNE), 72076 Tübingen, Germany
- Hertie Institute for Clinical Brain Research and Department of Neurology, University of Tübingen, 72076 Tübingen, Germany
- Correspondence:
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Klockgether T, Ashizawa T, Brais B, Chuang R, Durr A, Fogel B, Greenfield J, Hagen S, Jardim LB, Jiang H, Onodera O, Pedroso JL, Soong BW, Szmulewicz D, Graessner H, Synofzik M. Paving the Way Toward Meaningful Trials in Ataxias: An Ataxia Global Initiative Perspective. Mov Disord 2022; 37:1125-1130. [PMID: 35475582 DOI: 10.1002/mds.29032] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 03/31/2022] [Indexed: 01/22/2023] Open
Affiliation(s)
- Thomas Klockgether
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.,Department of Neurology, University Hospital Bonn, Bonn, Germany
| | - Tetsuo Ashizawa
- Houston Methodist Research Institute and Weil Cornell Medical College at Houston Methodist, Houston, Texas, USA
| | | | | | - Alexandra Durr
- Sorbonne Université, Paris Brain Institute, Paris Brain Institute - ICM, INSERM, CNRS, APHP, University Hospital de la Pitié-Salpêtrière Paris, Paris, France
| | - Brent Fogel
- Departments of Neurology and Human Genetics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | | | - Sue Hagen
- National Ataxia Foundation, Minneapolis, Minnesota, USA
| | - Laura Bannach Jardim
- Hospital de Clinicas de Porto Alegre, Porto Alegre, Brazil.,Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Hong Jiang
- Xiangya Hospital, Central South University, Changsha, China
| | - Osamu Onodera
- Brain Research Institute, Niigata University, Niigata, Japan
| | - José Luiz Pedroso
- Ataxia Unit, Department of Neurology, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Bin-Weng Soong
- National Yang-Ming Chiao Tung University, Taipei, Taiwan.,Taipei Neurologic Institute, Taipei Medical University, Taipei, Taiwan
| | | | - Holm Graessner
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany.,Center for Rare Diseases, University Hospital Tübingen, Tübingen, Germany
| | - Matthis Synofzik
- Division Translational Genomics of Neurodegenerative Diseases, Center for Neurology and Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.,German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
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Therapeutic Prospects of Exon Skipping for Epidermolysis Bullosa. Int J Mol Sci 2021; 22:ijms222212222. [PMID: 34830104 PMCID: PMC8621297 DOI: 10.3390/ijms222212222] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 11/03/2021] [Accepted: 11/08/2021] [Indexed: 12/12/2022] Open
Abstract
Epidermolysis bullosa is a group of genetic skin conditions characterized by abnormal skin (and mucosal) fragility caused by pathogenic variants in various genes. The disease severity ranges from early childhood mortality in the most severe types to occasional acral blistering in the mildest types. The subtype and severity of EB is linked to the gene involved and the specific variants in that gene, which also determine its mode of inheritance. Current treatment is mainly focused on symptomatic relief such as wound care and blister prevention, because truly curative treatment options are still at the preclinical stage. Given the current level of understanding, the broad spectrum of genes and variants underlying EB makes it impossible to develop a single treatment strategy for all patients. It is likely that many different variant-specific treatment strategies will be needed to ultimately treat all patients. Antisense-oligonucleotide (ASO)-mediated exon skipping aims to counteract pathogenic sequence variants by restoring the open reading frame through the removal of the mutant exon from the pre-messenger RNA. This should lead to the restored production of the protein absent in the affected skin and, consequently, improvement of the phenotype. Several preclinical studies have demonstrated that exon skipping can restore protein production in vitro, in skin equivalents, and in skin grafts derived from EB-patient skin cells, indicating that ASO-mediated exon skipping could be a viable strategy as a topical or systemic treatment. The potential value of exon skipping for EB is supported by a study showing reduced phenotypic severity in patients who carry variants that result in natural exon skipping. In this article, we review the substantial progress made on exon skipping for EB in the past 15 years and highlight the opportunities and current challenges of this RNA-based therapy approach. In addition, we present a prioritization strategy for the development of exon skipping based on genomic information of all EB-involved genes.
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