Progression Of Duchenne Muscular Dystrophy Research Articles

Definition of diaphragmatic sleep disordered breathing and clinical meaning in Duchenne muscular dystrophy

BackgroundDiaphragmatic sleep disordered breathing (dSDB) has been recently identified as sleep dysfunction secondary to diaphragmatic weakness in Duchenne muscular dystrophy (DMD). However, scoring criteria for the identification of dSDB are...

Identifying hub genes and dysregulated pathways in Duchenne muscular dystrophy

Purpose The aim of this study was to identify the hub genes and dysregulated pathways in the progression of duchenne muscular dystrophy (DMD) and to unveil detailedly the cellular and molecular mechanisms associated with DMD for developing efficacious treatments in the future. Material and methods Three mRNA microarray datasets (GSE13608, GSE38417 and GSE109178) were downloaded from Gene Expression Omnibus (GEO). The differentially expressed genes (DEGs) between DMD and normal tissues were obtained via R package. Function enrichment analyses were implemented respectively using DAVID online database. The network analysis of protein-protein interaction network (PPI) was conducted using String. Cytoscape and String were used to analyse modules and screen hub genes. The expression of the identified hub genes was confirmed in mdx mice through using qRT-PCR. Results In total, 519 DEGs were identified, consisting of 393 upregulated genes and 126 downregulated genes. The enriched functions and pathways of the DEGs mainly involve extracellular matrix organization, collagen fibril organization, interferon-gamma-mediated signaling pathway, muscle contraction, endoplasmic reticulum lumen, MHC class II receptor activity, phagosome, graft-versus-host disease, cardiomyocytes, calcium signaling pathway. Twelve hub genes were discovered and biological process analysis proved that these genes were mainly enriched cell cycle, cell division. The result of qRT-PCR suggested that increase in expression of CD44, ECT2, TYMS, MAGEL2, HLA-DMA, SERPINH1, TNNT2 was confirmed in mdx mice and the downregulation of ASB2 and LEPREL1 was also observed. Conclusion In conclusion, DEGs and hub genes identified in the current research help us probe the molecular mechanisms underlying the pathogenesis and progression of DMD, and provide candidate targets for diagnosis and treatment of DMD.

Estimating health state utilities in Duchenne muscular dystrophy using the health utilities index and EQ-5D-5L

BackgroundThe progression of Duchenne muscular dystrophy (DMD) is characterized by loss of ambulation, respiratory insufficiency, cardiomyopathy, and early mortality. DMD profoundly impacts health-related quality-of-life (HRQoL). However, few health state utility data exist; published utilities tend to be derived from small samples for a limited number of health states and are often based on caregiver-reported patient health status. This study estimated utility values for varied clinical and functional health states in DMD, based on patient-reported health status.MethodsIndividuals with DMD in the US aged 12–40 years completed the EQ-5D (5-level) and Health Utilities Index (HUI) preference-based instruments. Based on responses to a clinical questionnaire, participants self-classified into functional health states according to level of lower and upper limb function, use of respiratory support, and presence of cardiomyopathy. Mean [standard deviation (SD)] utility and EQ-5D visual analogue scale (VAS) scores were estimated according to health state; and median (interquartile range) attribute levels calculated to understand which domains of health are most severely affected in DMD.ResultsOf 63 males with DMD, mean (SD) age was 19.8 (6.1) years and 11 (17.5%) were ambulatory. Mean (SD) utility values were 0.92 (0.08; HUI2), 0.84 (0.20; HUI3), and 0.84 (0.13; EQ-5D) for ambulatory patients without cardiomyopathy (n = 10). For non-ambulatory patients with moderately impaired upper limb function, night and daytime ventilation without cardiomyopathy, mean (SD) utilities were 0.49 (0.07) for the HUI2, 0.16 (0.15) for the HUI3 and 025 (0.14) for the EQ-5D. Mean (SD) VAS scores for the same health states were 91 (9) and 83 (21), respectively. In addition to impairments in mobility/ambulation, and self-care, attributes like usual activities and pain also showed notable effects of DMD.ConclusionsIn DMD, although a relationship between disease progression and HRQoL is observed, there is large variability in utility within functional health states, and across instruments. Utility values for less severe non-ambulatory health states described by level of upper limb function are novel. These utility values, derived based on direct patient feedback rather than from caregiver report, are relevant to individuals of varying functional statuses and augment scarce DMD-specific utility data.

Proteome Profiling of the Dystrophic mdx Mice Diaphragm.

Mdx mice with a spontaneous mutation in exon 23 of the Dmd gene represent the most common model to investigate the pathophysiology of Duchenne muscular dystrophy (DMD). The disease, caused by the lack of functional dystrophin, is characterized by irreversible impairment of muscle functions, with the diaphragm affected earlier and more severely than other skeletal muscles. We applied a label-free (LF) method and the more thorough tandem mass tag (TMT)-based method to analyze differentially expressed proteins in the diaphragm of 6-week-old mdx mice. The comparison of both methods revealed 88 commonly changed proteins. A more in-depth analysis of the TMT-based method showed 953 significantly changed proteins, with 867 increased and 86 decreased in dystrophic animals (q-value < 0.05, fold-change threshold: 1.5). Consequently, several dysregulated processes were demonstrated, including the immune response, fibrosis, translation, and programmed cell death. Interestingly, in the dystrophic diaphragm, we found a significant decrease in the expression of enzymes generating hydrogen sulfide (H2S), suggesting that alterations in the metabolism of this gaseous mediator could modulate DMD progression, which could be a potential target for pharmacological intervention.

Early Cost-Utility Analysis of Ataluren and Eteplirsen in the Treatment of Duchenne Muscular Dystrophy in Egypt

ObjectivesAtaluren and eteplirsen are orphan drugs that delay progression of Duchenne muscular dystrophy in mutation-specific subgroups. They have yet to be approved in Egypt but are expected to reach the market soon. This study describes 2 cost-utility models comparing the drugs with the standard of care. MethodsWe used a partition-survival model with 5 states based on the ambulatory status to model a cohort of ambulatory patients at the age of 5 years. Baseline curves were obtained from a published model; then the ambulation loss curve was updated using the Kaplan-Meier curve of the standard of care from a study by McDonald et al. Other curves were updated by calibration to this curve. Costs and utilities were from a local study. Deterministic and probabilistic sensitivity analyses were conducted. Prices were estimated based on other orphan drugs’ prices. ResultsIn the base case, ataluren 1000 mg and eteplirsen 50 mg/mL resulted in an incremental cost-effectiveness ratio of EGP 51 745 605 and EGP 69 652 533/quality-adjusted life-year, respectively, at their hypothetical prices of EGP 308 600 for ataluren 30-sachet pack and EGP 62 800 for eteplirsen 10 mL vial. The incremental cost-effectiveness ratio was sensitive to health state utilities but not to state costs. At EGP 911 719/quality-adjusted life-year threshold, the value-based prices were EGP 4680 for ataluren 1000 mg and EGP 733 for eteplirsen 10 mL vial. ConclusionsBased on these models, there is a huge gap between the prices of orphan drugs and their value-based prices, which highlights the need for major policy reforms in the assessment and pricing of orphan drugs.

Cardiac and Muscular Pathology on Autopsy in a Man with Duchenne Muscular Dystrophy

Duchenne muscular dystrophy (DMD) is a degenerative muscle disease characterized by a progressive decline in muscular function, with cardiomyopathy in the later stages. We report the autopsy findings of a 29-year-old man with DMD. He had been stable with the assistance of mechanical ventilation until he was found unconscious, without known cause. External examination confirmed generalized muscular atrophy and contracture consistent with his clinical history. Histopathology revealed varying degrees of fibrofatty changes in the muscles, with the calf muscles being the most extensively affected, followed by the diaphragm and heart. The cardiac muscle showed the least involvement and the pathology was confined to the left ventricular wall and the interventricular septum, exhibiting a unique morphology of fibrosis resembling stretched springs. The cause of death was attributed to cardiac failure due to DMD progression. This case highlights the clinical course of DMD, emphasizing the need for thorough examination of both skeletal and non-skeletal muscles, including the cardiac muscles, to obtain a better understanding of the disease.

Amniotic Membrane-Derived Stromal Cells Release Extracellular Vesicles That Favor Regeneration of Dystrophic Skeletal Muscles.

Duchenne muscular dystrophy (DMD) is a muscle disease caused by mutations in the dystrophin gene characterized by myofiber fragility and progressive muscle degeneration. The genetic defect results in a reduced number of self-renewing muscle stem cells (MuSCs) and an impairment of their activation and differentiation, which lead to the exhaustion of skeletal muscle regeneration potential and muscle replacement by fibrotic and fatty tissue. In this study, we focused on an unexplored strategy to improve MuSC function and to preserve their niche based on the regenerative properties of mesenchymal stromal cells from the amniotic membrane (hAMSCs), that are multipotent cells recognized to have a role in tissue repair in different disease models. We demonstrate that the hAMSC secretome (CM hAMSC) and extracellular vesicles (EVs) isolated thereof directly stimulate the in vitro proliferation and differentiation of human myoblasts and mouse MuSC from dystrophic muscles. Furthermore, we demonstrate that hAMSC secreted factors modulate the muscle stem cell niche in dystrophic-mdx-mice. Interestingly, local injection of EV hAMSC in mdx muscles correlated with an increase in the number of activated Pax7+/Ki67+ MuSCs and in new fiber formation. EV hAMSCs also significantly reduced muscle collagen deposition, thus counteracting fibrosis and MuSCs exhaustion, two hallmarks of DMD. Herein for the first time we demonstrate that CM hAMSC and EVs derived thereof promote muscle regeneration by supporting proliferation and differentiation of resident muscle stem cells. These results pave the way for the development of a novel treatment to counteract DMD progression by reducing fibrosis and enhancing myogenesis in dystrophic muscles.

EE401 Characterizing the Impact on Work Productivity in Patients with Duchenne Muscular Dystrophy and Caregivers: An Economic Analysis

Duchenne muscular dystrophy (DMD) is a rare degenerative neuromuscular disease resulting in progressive muscle weakness, loss of functional ability, and premature death. Disease progression, especially loss of ambulation, impacts work productivity for patients with DMD and caregivers, particularly in relation to loss of income and work years. The objective of this study was to quantify the lifetime loss of income and work years for patients with DMD and their caregivers based on the natural history progression of DMD.

Preliminary Results of a Genetic Study of Children with Duchenne Myodystrophy in Aktobe, Kazakhstan.

Duchenne muscular dystrophy (DMD) is an X-linked recessive neuromuscular illness with a progressive course caused by mutations in the gene encoding the protein dystrophin (DMD; locus Xp21. 2). This study aimed to investigate the clinical aspects of DMD progression according to the mutation type. Included in the study were 38 boys aged 3 to 11 years. Laboratory (biochemical evaluation of the level of creatinine phosphokinase, multiplex ligation-dependent probe amplification [MLPA], and next-generation sequencing [NGS] analysis of the DMD gene), genealogical, and clinical approaches were utilized (including adapted Hammersmith Functional Motor Scale, the study of auditory-speech memory by the "Memorizing 10 words" method, and a general neurological assessment). The MLPA revealed deletion in 22 cases (57.8%), duplication in 6 (15.7%), and negative results in 11 (26.5%). To discover point mutations, 11 infants with negative MLPA results were sequenced. According to the results of the NGS, point mutations were identified in six boys (four single-nucleotide deletions and two single-nucleotide duplications), and five boys lacked mutations. Due to the high proportion of neuro-hereditary diseases in the general structure of neurological pathology, the profound disability of patients with progressive mental and physical disadaptation, as well as the generally fatal course of these incurable afflictions, molecular genetics research is of particular importance.

Assessing the value of delandistrogene moxeparvovec (SRP-9001) gene therapy in patients with Duchenne muscular dystrophy in the United States

ABSTRACT Background: Delandistrogene moxeparvovec (SRP-9001) is an investigational gene therapy that may delay progression of Duchenne muscular dystrophy (DMD), a severe, rare neuromuscular disease caused by DMD gene mutations. Early cost-effectiveness analyses are important to help contextualize the value of gene therapies for reimbursement decision making. Objective: To determine the potential value of delandistrogene moxeparvovec using a cost-effectiveness analysis. Study design: A simulation calculated lifetime costs and equal value of life years gained (evLYG). Inputs included extrapolated clinical trial results and published utilities/costs. As a market price for delandistrogene moxeparvovec has not been established, threshold analyses established maximum treatment costs as they align with value, including varying willingness-to-pay up to $500,000, accounting for severity/rarity. Setting: USA, healthcare system perspective Patients: Boys with DMD Intervention: Delandistrogene moxeparvovec plus standard of care (SoC; corticosteroids) versus SoC alone Main outcome measure: Maximum treatment costs at a given willingness-to-pay threshold Results: Delandistrogene moxeparvovec added 10.30 discounted (26.40 undiscounted) evLYs. The maximum treatment cost was approximately $5 M, assuming $500,000/evLYG. Varying the benefit discount rate to account for the single administration increased the estimated value to >$5M, assuming $500,000/evLYG. Conclusion: In this early economic model, delandistrogene moxeparvovec increases evLYs versus SoC and begins to inform its potential value from a healthcare perspective.

Modeling Early Heterogeneous Rates of Progression in Boys with Duchenne Muscular Dystrophy.

Duchenne muscular dystrophy (DMD) exhibits substantial variability in rates of disease progression and response to treatment. This has hindered treatment development and complicated interpretation of drug effects in clinical trials. We hypothesized that a multivariate combination of early-age clinical outcome measurements can explain differential disease progression. Data on boys with DMD (ages 4-<10 years), both treated with steroidal anti-inflammatories and untreated, were obtained from CINRG Duchenne Natural History Study (n = 209) and vamorolone VBP15-002/003/LTE (n = 46) studies. Velocities from three timed function tests (TFTs; stand from supine, run/walk 10 meters, and climb 4 stairs) were simultaneously modeled in a longitudinal latent class analysis. Three classes of differentially progressing early age DMD motor trajectories were identified. Quicker decline/progression was associated with lower baseline TFT velocities, earlier loss of ability to finish a TFT, and lower predicted velocities. Earlier substantial steroid exposure was associated with greater TFT velocities while the moderate progression class was observed to have the largest difference in performance between boys treated early with steroids vs. not. Sample size calculations with the class showing the largest treatment response showed a large reduction in required sample size as compared to using summaries from all participants. Gene mutations were also investigated in post-hoc analyses, with mutations near the beginning of the DMD gene (Dp427 absent and Dp140/Dp71 present) found to be enriched in the slowest progressing class. This study provides insight into the variation in DMD progression through a latent class analysis. Our findings show class-related trajectories of motor outcomes and pharmacological response to corticosteroids, and suggest that enrichment strategies and/or subgroup analyses could be considered further in design of therapeutic interventions in DMD.

Leveraging homologous recombination repair deficiency in sarcoma.

Personalised oncology is at the forefront of cancer research. The goal of personalised oncology is to selectively kill cancer cells while minimising side effects on normal tissue. This can be achieved by identifying and targeting cancer vulnerabilities that distinguish it from normal cells. Many cancers are deficient in high-fidelity DNA repair pathways that maintain genomic stability, such as homologous recombination (HR). Such cancers are highly sensitive to targeted therapies that induce DNA damage or inhibit DNA repair pathways. A notable example and a poster child of personalised oncology are PARP1/2 inhibitors (PARPi) that selectively kill HR-deficient (HRD) cancer cells by preventing repair of DNA gaps or single-strand breaks (SSBs) (Slade, 2020). Inhibitors of cell cycle checkpoints such as CHK1 and WEE1 can also eliminate HRD cancers by pushing cancer cells through the cell cycle despite unrepaired DNA damage and causing death by mitotic catastrophe (Groelly etal, 2022). PARPi have been approved for the treatment of ovarian, breast, pancreatic, and prostate cancer but other cancer types with an HRD signature (HRDness) may also respond to PARPi treatment. Planas-Paz etal (2023) now show that many sarcomas show HRDness and respond to PARP1/2 and WEE1 inhibitors, thus offering a new personalised oncology approach for this treatment-refractory cancer.

Analysis of Long Noncoding RNAs-Related Regulatory Mechanisms in Duchenne Muscular Dystrophy Using a Disease-Related lncRNA-mRNA Pathway Network.

This study aimed to investigate the molecular regulatory mechanisms underpinning Duchenne muscular dystrophy (DMD). Using microarray data, differentially expressed long noncoding RNAs (DELs) and DMD-related differentially expressed mRNAs (DEMs) were screened based on the comparative toxicogenomics database, using a cutoff of |log2 fold change| > 1 and false discovery rate (FDR) < 0.05. Then, protein-protein interaction (PPI), coexpression network of lncRNA-mRNA, and DMD-related lncRNA-mRNA pathway networks were constructed, and functional analyses of the genes in the network were performed. Finally, the proportions of immune cells infiltrating the muscle tissues in DMD were analyzed, and the correlation between the immune cells and expression of the DELs/DEMs was studied. A total of 46 DELs and 313 DMD-related DEMs were identified. The PPI network revealed STAT1, VEGFA, and CCL2 to be the top three hub genes. The DMD-related lncRNA-mRNA pathway network comprising two pathways, nine DELs, and nine DMD-related DEMs showed that PYCARD, RIPK2, and CASP1 were significantly enriched in the NOD-like receptor signaling pathway, whereas MAP2K2, LUM, RPS6, PDCD4, TWIST1, and HIF1A were significantly enriched with proteoglycans in cancers. The nine DELs in this network were DBET, MBNL1-AS1, MIR29B2CHG, CCDC18-AS1, FAM111A-DT, GAS5, LINC01290, ATP2B1-AS1, and PSMB8-AS1. The nine DMD-related DEMs and DELs identified in this study may play important roles in the occurrence and progression of DMD through the two pathways of the NOD-like receptor signaling pathway and proteoglycans in cancers.

Longitudinal study of multi-parameter quantitative magnetic resonance imaging in Duchenne muscular dystrophy: hyperresponsiveness of gluteus maximus and detection of subclinical disease progression in functionally stable patients.

To describe the disease progression of Duchenne muscular dystrophy (DMD) in the pelvic and thigh muscles over 1-year using multiple-parameter quantitative magnetic resonance imaging (qMRI), and to determine the most responsive muscle and predict subclinical disease progression in functionally stable patients. Fifty-four DMD patients (mean age 8.9 ± 2.5, range 5-15years) completed baseline and 1-year follow-up qMRI examinations/biomarkers [3-point Dixon/fat fraction (FF); T1 mapping/T1; T2 mapping/T2]. Meanwhile, clinical assessments [NorthStar ambulatory assessment (NSAA) score] and timed function tests were performed in DMD patients. Twenty-four healthy male controls (range 5-15years) accomplished baseline qMRI examinations. Group differences were compared using the Wilcoxon test. The standardized response mean (SRM) was taken as the responsiveness to the disease progression index. FF, T1, and T2 in all DMD age subgroups changed significantly over 1-year (P < 0.05). Even in functionally stable patients (NSAA score increased, unchanged, or decreased by 1-point) over 1-year, significant increases in FF and T2 and decreases in T1 were observed in gluteus maximus (GMa), gluteus medius, vastus lateralis, and adductor magnus (P < 0.05). Overall, the SRM of FF, T1, and T2 was all the highest in GMa, which were 1.25, - 0.92, and 0.93, respectively. qMRI biomarkers are responsive to disease progression and can also detect subclinical disease progression in functionally stable DMD patients over 1-year. GMa is the most responsive to disease progression of all the muscles analyzed. Chinese Clinical Trial Registry ( http://www.chictr.org.cn/index.aspx ) ChiCTR1800018340, 09/12/2018, prospectively registered.

P.68 Validation of a composite prognostic score for time to loss of ambulation in Duchenne muscular dystrophy

Loss of ambulation (LoA) is a critical milestone in the progression of Duchenne muscular dystrophy (DMD) that usually occurs by the early teens, with significant variation across individuals. Accurate individualized predictions of time to LoA are valuable for DMD drug development (e.g., enrichment of trial populations and benchmarking of long-term treatment outcomes), as well as for counseling of patients and caregivers (e.g., advance ordering of a power wheelchair, preparing home modifications for accessibility). A composite prognostic score for LoA was previously developed based data from 608 boys and 1,240 years of follow-up across multiple DMD natural history and placebo-arm data sources. Timed function tests, steroid type, height and weight were identified as the most important predictors of LoA. We independently validated this score using data from 226 patients with 819 years of follow-up in the CINRG Duchenne natural history study, which was not used for score development. The previously-defined prognostic groups showed excellent risk stratification in the validation data, with median times to LoA of 1.8, 3.8, 7.8 and >9.0 years across groups, compared with medians of 1.1, 2.1, 4.1 and >9.0 years in the training data. Risk groups were well-differentiated despite the use of different LoA definitions in the training data (inability to walk 10 meters or complete the 6-minute walk test) and validation data (full-time wheelchair dependence), but shifted to later median ages in the validation data. Simplified prognostic scores were also explored using classification and regression trees to identify functional thresholds that best predicted time to LoA. Individualized prediction of time to LoA is possible in DMD, and is most accurate when based on a composite profile of motor function. Calibration of prognostic scores to specific definitions of LoA is important for quantitative accuracy, and for applications in clinical management and drug development.

Patient-led development of digital endpoints and the use of computer vision analysis in assessment of motor function in rare diseases.

Digital health technologies are transforming the way health outcomes are captured and measured. Digital biomarkers may provide more objective measurements than traditional approaches as they encompass continuous and longitudinal data collection and use of automated analysis for data interpretation. In addition, the use of digital health technology allows for home-based disease assessments, which in addition to reducing patient burden from on-site hospital visits, provides a more holistic picture of how the patient feels and functions in the real world. Tools that can robustly capture drug efficacy based on disease-specific outcomes that are meaningful to patients, are going to be key to the successful development of new treatments. This is particularly important for people living with rare and chronic complex conditions, where therapeutic options are limited and need to be developed using a patient-focused approach to achieve the biggest impact. Working in partnership with patient Organisation Duchenne UK, we co-developed a video-based approach, delivered through a new mobile health platform (DMD Home), to assess motor function in patients with Duchenne muscular dystrophy (DMD), a genetic, rare, muscular disease characterized by the progressive loss of muscle function and strength. Motor function tasks were selected to reflect the “transfer stage” of the disease, when patients are no longer able to walk independently but can stand and weight-bear to transfer. This stage is important for patients and families as it represents a significant milestone in the progression of DMD but it is not routinely captured and/or scored by standard DMD clinical and physiotherapy assessments. A total of 62 videos were submitted by eight out of eleven participants who onboarded the app and were analysed with pose estimation software (OpenPose) that led to the extraction of objective, quantitative measures, including time, pattern of movement trajectory, and smoothness and symmetry of movement. Computer vision analysis of video tasks to identify voluntary or compensatory movements within the transfer stage merits further investigation. Longitudinal studies to validate DMD home as a new methodology to predict progression to the non-ambulant stage will be pursued.

'Our time is precious': An exploration of parental feeding behaviours for boys with Duchenne muscular dystrophy.

Due to the increased risk of obesity for boys with Duchenne muscular dystrophy (DMD), recent guidelines recommend that dietary intake is carefully managed. Parents play an important role in the development of their child's eating behaviours and patterns. However, despite what is known about the increased risk of obesity for children with DMD, little is known about parental feeding behaviours in this population. The objective of this study was to qualitatively explore the experiences of parents of children with DMD around their child's weight management and understand what influences their feeding behaviours. This paper reports a secondary data analysis. Semi-structured, individual interviews were conducted and analysed using qualitative description. Thirteen parents were interviewed for the study. Three themes were developed: (1) parent responses to healthcare provider interactions, (2) mixed emotions contributing to feeding approach and (3) variable parenting feeding styles. Within the third theme, two subthemes arose including (1) control and preoccupation and (2) striking a balance. Given the potential impact of higher weights on the progression of DMD, it is important that healthcare providers explore feeding behaviours with families. However, it is essential that healthcare providers consider the impact of these conversations on parents, as well as the broader issues that may place additional pressure on the lives of families.

Mitochondrial stress responses in Duchenne muscular dystrophy: metabolic dysfunction or adaptive reprogramming?

Mitochondrial stress may be a secondary contributor to muscle weakness in inherited muscular dystrophies. Duchenne muscular dystrophy has received the majority of attention, whereby most discoveries suggest mitochondrial ATP synthesis may be reduced. However, not all studies support this finding. Furthermore, some studies have reported increased mitochondrial reactive oxygen species and propensity for permeability transition pore formation as an inducer of apoptosis, although divergent findings have also been described. A closer examination of the literature suggests the degree and direction of mitochondrial stress responses may depend on the progression of the disease, the muscle type examined, the mouse model used with regard to preclinical research, the precise metabolic pathways in consideration, and in some cases, the in vitro technique used to assess a given mitochondrial bioenergetic function. One intent of this review is to provide careful considerations for future experimental designs to resolve the heterogeneous nature of mitochondrial stress during the progression of Duchenne muscular dystrophy. Such considerations have implications for other muscular dystrophies as well which are addressed briefly herein. A renewed perspective of the term "mitochondrial dysfunction" is presented whereby stress responses might be re-explored in future investigations as direct contributors to myopathy versus an adaptive "reprogramming" intended to maintain homeostasis in the face of disease stressors themselves. In so doing, the prospective development of mitochondrial enhancement therapies can be driven by advances in perspectives as much as experimental approaches when resolving the precise relationships between mitochondrial remodeling and muscle weakness in Duchenne and, indeed, other muscular dystrophies.

PCR105 The Impact of Key Health State Transitions on Health-Related Quality of Life (HRQOL) in Duchenne Muscular Dystrophy (DMD): A Qualitative Study

The progression of DMD is characterized by loss of ambulation (LOA) and upper limb function, cardiorespiratory impairment, and early mortality. While much attention is focused on LOA, the impact of other aspects of progression on HRQoL is less clear. Understanding patient perspectives on these aspects is important to provide context to clinical health states in DMD, and link changes in DMD symptoms to patient experiences. The objective of this study was to obtain insights on how key health state transitions affect HRQoL among individuals with DMD.

Long-Term Protective Effect of Human Dystrophin Expressing Chimeric (DEC) Cell Therapy on Amelioration of Function of Cardiac, Respiratory and Skeletal Muscles in Duchenne Muscular Dystrophy

Duchenne Muscular Dystrophy (DMD) is a lethal disease caused by mutations in dystrophin encoding gene, causing progressive degeneration of cardiac, respiratory, and skeletal muscles leading to premature death due to cardiac and respiratory failure. Currently, there is no cure for DMD. Therefore, novel therapeutic approaches are needed for DMD patients.We have previously reported functional improvements which correlated with increased dystrophin expression following administration of dystrophin expressing chimeric (DEC) cells of myoblast origin to the mdx mouse models of DMD.In the current study, we confirmed dose-dependent protective effect of human DEC therapy created from myoblasts of normal and DMD-affected donors, on restoration of dystrophin expression and amelioration of cardiac, respiratory, and skeletal muscle function at 180 days after systemic-intraosseous DEC administration to mdx/scid mouse model of DMD. Functional improvements included maintenance of ejection fraction and fractional shortening levels on echocardiography, reduced enhanced pause and expiration time on plethysmography and improved grip strength and maximum stretch induced contraction of skeletal muscles. Improved function was associated with amelioration of mdx muscle pathology revealed by reduced muscle fibrosis, reduced inflammation and improved muscle morphology confirmed by reduced number of centrally nucleated fibers and normalization of muscle fiber diameters. Our findings confirm the long-term systemic effect of DEC therapy in the most severely affected by DMD organs including heart, diaphragm, and long skeletal muscles.These encouraging preclinical data introduces human DEC as a novel therapeutic modality of Advanced Therapy Medicinal Product (ATMP) with the potential to improve or halt the progression of DMD and enhance quality of life of DMD patients.Graphical Human DEC as a novel therapeutic modality with the potential to improve or halt progression of the DMD disease and enhance quality of life of DMD patients. Graphical abstract represents manufacturing process of the human DEC therapy for the future clinical applications. 1. We report the long-term efficacy of human DEC therapy resulting in increased dystrophin expression and reduced mdx muscle pathology after systemic-intraosseous administration of human Dystrophin Expressing Chimeric (DEC) Cells to the mdx/scid mouse model of DMD. 2. Systemic administration of human DEC therapy resulted in amelioration of cardiac, respiratory and skeletal muscle function as confirmed by echocardiography, plethysmography and standard muscle strength tests respectively. 3. We introduce human DEC as a novel Advanced Therapy Medicinal Product (ATMP) for future clinical application in DMD patients.