Prognostic indicators of disease progression in Duchenne muscular dystrophy: A literature review and evidence synthesis

Meta-analysis of the efficacy and safety of vamorolone in Duchenne muscular dystrophy

BACKGROUND

Duchenne muscular dystrophy (DMD) is a severe neuromuscular disorder, often leading to wheelchair dependence by age 13 with limited treatment options, largely relying on glucocorticosteroids. We assessed the efficacy and safety of vamorolone, a modified synthetic corticosteroid, for DMD.

METHODS

We performed a systematic review and meta-analysis using seven databases including prospective studies comparing vamorolone with glucocorticosteroids or placebo in DMD patients. We extracted data on efficacy and safety outcomes. We built fixed effects models to assess mean differences. (PROSPERO: CRD42023396908).

RESULTS

Out of 210 identified records, two study reports were included in meta-analysis providing data from 210 patients. Vamorolone at 2.0 mg/kg/day was associated with improvement time to climb four stairs velocity (MD = 0.05 95% CI [0.03 to 0.08] P = 0.0002), and time stand from supine velocity (MD = 0.07 95% CI [0.01 to 0.07] P = 0.007). A higher dose of 6.0 mg/kg/day was additionally associated with higher time to run/walk 10 m velocity (MD = 0.10 95% CI [-0.0.1 to 0.21] P = 0.07, I2 = 0%). Among these beneficial effects only improvement in time to climb four stairs velocity was sustained after a follow-up period of 30 months. Vamorolone did not inhibit growth but increased the risk of weight gain, suppression of adrenal function, and insulin resistance.

CONCLUSION

The results of our systematic review and meta-analyis are suggestive of improved efficacy and safety of vamorolone for DMD compared to standard glucocorticosteroids but the external validity of these findings as well as the medication's long-term effects remain to be determined.

Preventing Cardiomyopathy in Duchenne Muscular Dystrophy: Long-Term Follow-Up of Patients in the Randomised, Placebo-Controlled Drug-Trial of Perindopril and Bisoprolol

INTRODUCTION

It is uncertain whether using cardiac drugs prophylactically in combinations for DMD is better than ACE-inhibitor alone. Our previous study showed no differences in left ventricular function between perindopril-bisoprolol and matched placebo after 36 months.

METHODS

This study aimed to determine whether heart measures diverged after 60-month total follow-up. All participants had commenced open-label perindopril and bisoprolol when the original study ended. All were reconsented for access to heart measures, undertaken as part of their clinical care. The primary outcome was the change in echo-measured ventricular ejection fraction from baseline according to original randomization.

RESULTS

Of 75 participants reported originally, 65 (aged 16 ± 2.5 years) were re-recruited and had data for analysis. Adjusted primary outcomes included 44 participants (original arms: 'active' 21; 'placebo' 23), 48 for secondary outcomes, and 65 for 'headcount' analysis of those with ventricular dysfunction. Absolute LVEF% values reduced in both groups ('active': 62.5% ± 5.6% to 53.8% ± 4.0%; 'placebo': 60.6% ± 4.9% to 50.4% ± 8.5%). Despite trends favoring earlier introduction of therapy, change from baseline was similar between groups (adjusted mean difference: -7.7 (95% CI -16.4 to1.0%)). However, more in the 'placebo' arm had died, had reduced LVEF%, and were taking additional heart medications.

CONCLUSION

While some patients may have benefited from 'early' (active) as opposed to 'delayed' (placebo) initiation of perindopril and bisoprolol, group-mean ventricular function did not differ between study arms after 60 months. Small numbers, absence of a control group, insensitivity of echo-ejection fraction, and additional drug use probably prevented divergence between groups.

What's new in the pediatric spine?

Introduction

The field of pediatric spine surgery has encountered major changes and evolutions lately, with new treatment options available and the development of enabling technologies. This article aims to summarize the most relevant recent literature.

Materials and methods

The five most relevant topics were selected and assigned to one or two authors who performed a comprehensive Pubmed database search for articles published in the last 4 years (2021-2024). Only studies with a high level of evidence or clinical relevance were reported.

Results

Thirty-nine articles were selected and analyzed, covering the following subjects: treatment options in tweeners, the impact of new medical treatments in pediatric spine practice, the emergence of new surgical techniques, the development of enabling technologies in scoliosis surgery, and recent relevant randomized controlled trials.

Discussion

Many new surgical concepts and techniques have been developed lately, but their results need to be further assessed on specific subgroups of patients. Numerous significant medical improvements have been reported in the last 5 years, affecting positively the management of syndromic and neuromuscular patients.

AAV gene therapy for Duchenne muscular dystrophy: the EMBARK phase 3 randomized trial

Duchenne muscular dystrophy (DMD) is a rare, X-linked neuromuscular disease caused by pathogenic variants in the DMD gene that result in the absence of functional dystrophin, beginning at birth and leading to progressive impaired motor function, loss of ambulation and life-threatening cardiorespiratory complications. Delandistrogene moxeparvovec, an adeno-associated rh74-viral vector-based gene therapy, addresses absent functional dystrophin in DMD. Here the phase 3 EMBARK study aimed to assess the efficacy and safety of delandistrogene moxeparvovec in patients with DMD. Ambulatory males with DMD, ≥4 years to <8 years of age, were randomized and stratified by age group and North Star Ambulatory Assessment (NSAA) score to single-administration intravenous delandistrogene moxeparvovec (1.33 × 1014 vector genomes per kilogram; n = 63) or placebo (n = 62). At week 52, the primary endpoint, change from baseline in NSAA score, was not met (least squares mean 2.57 (delandistrogene moxeparvovec) versus 1.92 (placebo) points; between-group difference, 0.65; 95% confidence interval (CI), -0.45, 1.74; P = 0.2441). Secondary efficacy endpoints included mean micro-dystrophin expression at week 12: 34.29% (treated) versus 0.00% (placebo). Other secondary efficacy endpoints at week 52 (between-group differences (95% CI)) included: Time to Rise (-0.64 (-1.06, -0.23)), 10-meter Walk/Run (-0.42 (-0.71, -0.13)), stride velocity 95th centile (0.10 (0.00, 0.19)), 100-meter Walk/Run (-3.29 (-8.28, 1.70)), time to ascend 4 steps (-0.36 (-0.71, -0.01)), PROMIS Mobility and Upper Extremity (0.05 (-0.08, 0.19); -0.04 (-0.24, 0.17)) and number of NSAA skills gained/improved (0.19 (-0.67, 1.06)). In total, 674 adverse events were recorded with delandistrogene moxeparvovec and 514 with placebo. There were no deaths, discontinuations or clinically significant complement-mediated adverse events; 7 patients (11.1%) experienced 10 treatment-related serious adverse events. Delandistrogene moxeparvovec did not lead to a significant improvement in NSAA score at week 52. Some of the secondary endpoints numerically favored treatment, although no statistical significance can be claimed. Safety was manageable and consistent with previous delandistrogene moxeparvovec trials. ClinicalTrials.gov: NCT05096221.

Optimizing DMD management in Asia: Current challenges and future directions

BACKGROUND

Since 1970, advances in Duchenne muscular dystrophy (DMD) management have significantly extended the patients' life expectancy. However, DMD remains universally fatal.

OBJECTIVE

To understand the current DMD management standards and practices in Asia and to evaluate inconsistencies, unmet needs, and future directions for DMD patient management in the region.

METHODS

Clinical experts from Hong Kong, Singapore, and Taiwan convened in September 2023 to discuss DMD diagnosis, assessment, treatment, and management best practices. A pre-meeting survey was also administered to explore professional perspectives and practices and refine the discussion focus.

RESULTS

Genetic profiling has become the pivotal diagnostic tool and has been universally adopted by experts. Steroid therapy is recognized as the cornerstone of DMD care. However, there are various opinions regarding the timing of its initiation and whether it should be continued after the loss of ambulation. Gene therapy has the potential to significantly improve outcomes in patients with DMD. However, its adoption is hampered by high costs, the potential for serious adverse events, and difficulties with patient selection. Governments and manufacturers must work together to improve its affordability. Establishing a centralized DMD registry garnered strong support from the experts as it promised to provide insights into unique DMD subtypes, standardize treatment protocols, and facilitate the conduct of clinical trials. Furthermore, the introduction of gene therapy has highlighted the need for generating long-term safety and effectiveness data in patients with DMD. Lastly, a centralized patient registry can be used to inform policy decisions.

CONCLUSIONS

DMD care in Asia is characterized by substantial heterogeneity, with financial and reimbursement issues playing a major role in management decisions. A centralized patient registry has the potential to address these concerns by providing a valuable source of information.

Correction: Prognostic indicators of disease progression in Duchenne muscular dystrophy: A literature review and evidence synthesis

[This corrects the article DOI: 10.1371/journal.pone.0265879.].

Long-term course of gastrostomy nutritional management in patients with Duchenne muscular dystrophy: A retrospective cohort study

Duchenne muscular dystrophy (DMD) is a progressive neuromuscular disease that commonly requires gastrostomy due to dysphagia. This study aimed to investigate the proportion of patients with DMD requiring gastrostomy and to assess the timing and outcomes of gastrostomy in patients with DMD to optimize perioperative care and improve long-term management. We conducted a retrospective cohort study by reviewing the medical records of patients with DMD treated between March 1991 and November 2023 at Kobe University Hospital. To identify risk factors for gastrostomy, Fisher's two-tailed test and logistic analysis were used to compare the gastrostomy (group G) and comparison group without gastrostomy (group C) groups. We identified patients >18 years with DMD. We excluded those without medical records from the last decade and those on nasogastric tube feeding. Among the 135 eligible patients, five (median age, 23 years) underwent percutaneous endoscopic gastrostomy (PEG; uptake rate, 3.7 %), and their data were analyzed for perioperative outcomes. Complications included ventilatory disturbances, aspiration pneumonia, and hemorrhagic shock. Two patients experienced significant postoperative complications, underscoring the high-risk nature of PEG in this population. Participants' postoperative weight changes varied significantly. The presence or absence of ventilatory management, cardiomyopathy treatment, scoliosis, and steroid treatment were examined as risk factors between groups G and C, but no significant differences were observed. This study highlights low gastrostomy usage among patients with DMD, with varying outcomes. Meticulous planning and early consideration of gastrostomy are crucial to enhance the quality of life and nutritional outcomes in these patients.

Unleashing the full potential of digital outcome measures in clinical trials: eight questions that need attention

The use of digital health technologies to measure outcomes in clinical trials opens new opportunities as well as methodological challenges. Digital outcome measures may provide more sensitive and higher-frequency measurements but pose vital statistical challenges around how such outcomes should be defined and validated and how trials incorporating digital outcome measures should be designed and analysed. This article presents eight methodological questions, exploring issues such as the length of measurement period, choice of summary statistic and definition and handling of missing data as well as the potential for new estimands and new analyses to leverage the time series data from digital devices. The impact of key issues highlighted by the eight questions on a primary analysis of a trial are illustrated through a simulation study based on the 2019 Bellerophon INOPulse trial which had time spent in MVPA as a digital outcome measure. These eight questions present broad areas where methodological guidance is needed to enable wider uptake of digital outcome measures in trials.

Current Challenges of Using Patient-Level Claims and Electronic Health Record Data for the Longitudinal Evaluation of Duchenne Muscular Dystrophy Outcomes

INTRODUCTION

Insurance claims data and electronic health records (EHRs) have been used to characterize Duchenne muscular dystrophy (DMD) in real-world populations. The ability to assess patient-level DMD disease progression within insurance claims or EHR data infrastructures is unknown. Insurance claims and EHR data were comprehensively examined for availability and reliability of DMD outcomes that describe functional status and disease progression at the individual patient level over time.

METHODS

MarketScan Commercial and Medicaid claims, and EHR-linked Clarivate open claims datasets were examined for data measuring 54 previously identified DMD-relevant outcomes in patients with DMD. Each outcome was assigned to one of five categories: functional and clinical events, clinical measures, biomarkers, functional measures, or patient-reported outcomes (PROs). Patients were identified using published coding algorithms. Annual 5-year attrition and data availability for each outcome was determined. The ability to distinguish disease severity and identify test results was also considered where applicable.

RESULTS

A total of 1964 (MarketScan Commercial), 2007 (MarketScan Medicaid), and 10,639 (Clarivate) patients were identified. At 5 years, 31.7%, 35.1%, and 59.1% of patients remained in MarketScan Commercial, MarketScan Medicaid, and Clarivate, respectively. Claims were available for five of six functional and clinical events, with 45.5% (MarketScan Commercial), 48.0% (Clarivate), and 48.5% (MarketScan Medicaid) of patients with ≥ 1 claim for the most frequently identified clinical event (cardiomyopathy diagnosis). No data were available to describe frequency of wheelchair use or loss of ambulation. Very limited EHR data (≤ 2% of patients) were available to indicate tests were ordered for clinical measures, biomarkers, or functional assessments. No PRO notes or scores were observed. Data existed for inferring disease severity (e.g., hospitalization for cardiomyopathy); however, it was not apparent whether these events were incident.

CONCLUSION

Insurance claims and EHR-linked open claims data are of limited utility for holistically evaluating the progression and burden of DMD in individual patients.

Healthcare Stakeholder Perspectives on a Value Assessment Approach for Duchenne Muscular Dystrophy Therapies

Purpose

Traditional value assessment frameworks are challenged in comprehensively assessing the societal value new therapies bring to individuals with rare, progressive, genetic, fatal, neuromuscular diseases such as Duchenne muscular dystrophy (DMD). The objective of this study was to identify how value assessment frameworks may need to be adapted to measure the value to society of DMD therapies.

Patients and Methods

Three stakeholder groups (6 patient advocates, 4 clinicians, 3 health economists; N = 13) participated in semi-structured interviews around the International Society for Pharmacoeconomics and Outcomes Research's Value Flower, which includes elements to consider within value assessments of healthcare technologies.

Results

All stakeholders agreed that traditional value assessment frameworks based on the quality-adjusted life year (QALY) are narrow and will undervalue new DMD therapies. All stakeholders expressed some level of concern that using the QALY as a key metric of value discriminates against patients with severe progressive diseases and disabilities. Some stakeholders saw value in using the QALY for cross-disease comparisons in resource-constrained environments if the methodology was appropriate. All stakeholders recommended considering additional elements of value in decision-making around new DMD therapies. These elements reflect: economic and humanistic costs incurred by patients, caregivers, and families with Duchenne, such as indirect out-of-pocket costs, lost productivity, and family spillovers; meaningful attributes for individuals with disabilities and high unmet need, such as severity of disease, value of hope, and real option value; and factors that contribute to improvements in population health, such as insurance value, equity, and scientific spillovers.

Conclusion

These findings highlight the need to expand traditional value assessment frameworks and take a holistic approach that incorporates the perspectives of individuals with Duchenne, caregivers, clinicians, and health economists when assessing the societal value of new DMD therapies. Broadening value assessment will prevent restricted or delayed access to therapies for individuals with Duchenne.

A Voyage on the Role of Nuclear Factor Kappa B (NF-kB) Signaling Pathway in Duchenne Muscular Dystrophy: An Inherited Muscle Disorder

A recessive X-linked illness called Duchenne muscular dystrophy (DMD) is characterized by increasing muscle weakening and degradation. It primarily affects boys and is one of the most prevalent and severe forms of muscular dystrophy. Mutations in the DMD gene, which codes for the essential protein dystrophin, which aids in maintaining the stability of muscle cell membranes during contraction, are the cause of the illness. Dystrophin deficiency or malfunction damages muscle cells, resulting in persistent inflammation and progressive loss of muscular mass. The pathophysiology and genetic foundation of DMD are thoroughly examined in this review paper, focusing on the function of the NF-κB signaling system in the disease's progression. An important immune response regulator, NF-κB, is aberrantly activated in DMD, which exacerbates the inflammatory milieu in dystrophic muscles. Muscle injury and fibrosis are exacerbated and muscle regeneration is hampered by the pro-inflammatory cytokines and chemokines that are produced when NF-κB is persistently activated in muscle cells. The paper also examines our existing knowledge of treatment approaches meant to inhibit the progression of disease by modifying NF-κB signaling. These include new molecular techniques, gene treatments, and pharmacological inhibitors that are intended to lessen inflammation and improve muscle healing. Furthermore covered in the analysis is the significance of supportive care for DMD patients, including physical therapy and corticosteroid treatment, in symptom management and quality of life enhancement. The article seeks to provide a thorough understanding of the mechanisms causing DMD, possible therapeutic targets, and developing treatment options by combining recent research findings. This will provide clinicians and researchers involved in DMD care and research with invaluable insights.

Regenerative inflammation: When immune cells help to re-build tissues

Inflammation is an essential immune response critical for responding to infection, injury and maintenance of tissue homeostasis. Upon injury, regenerative inflammation promotes tissue repair by a timed and coordinated infiltration of diverse cell types and the secretion of growth factors, cytokines and lipids mediators. Remarkably, throughout evolution as well as mammalian development, this type of physiological inflammation is highly associated with immunosuppression. For instance, regenerative inflammation is the consequence of an in situ macrophage polarization resulting in a transition from pro-inflammatory to anti-inflammatory/pro-regenerative response. Immune cells are the first responders upon injury, infiltrating the damaged tissue and initiating a pro-inflammatory response depleting cell debris and necrotic cells. After phagocytosis, macrophages undergo multiple coordinated metabolic and transcriptional changes allowing the transition and dictating the initiation of the regenerative phase. Differences between a highly efficient, complete ad integrum tissue repair, such as, acute skeletal muscle injury, and insufficient regenerative inflammation, as the one developing in Duchenne Muscular Dystrophy (DMD), highlight the importance of a coordinated response orchestrated by immune cells. During regenerative inflammation, these cells interact with others and alter the niche, affecting the character of inflammation itself and, therefore, the progression of tissue repair. Comparing acute muscle injury and chronic inflammation in DMD, we review how the same cells and molecules in different numbers, concentration and timing contribute to very different outcomes. Thus, it is important to understand and identify the distinct functions and secreted molecules of macrophages, and potentially other immune cells, during tissue repair, and the contributors to the macrophage switch leveraging this knowledge in treating diseases.

Evolving Role of Viltolarsen for Treatment of Duchenne Muscular Dystrophy

Duchenne muscular dystrophy (DMD) is one of the most prevalent X-linked inherited neuromuscular disorders, with an estimated incidence between 1 in 3500 and 5000 live male births. The median life expectancy at birth is around 30 years due to a rapid and severe disease progression. Currently, there is no cure for DMD, and the standard of care is mainly palliative therapy and glucocorticoids to mitigate symptoms and improve quality of life. Recent advances in phosphorodiamidate morpholino antisense oligonucleotide (PMO) technology has proven optimistic in providing a disease-modifying therapy rather than a palliative treatment option through correcting the primary genetic defect of DMD by exon skipping. However, as a result of the high variance in mutations of the dystrophin gene causing DMD, it has been challenging to tailor an effective therapy in most patients. Viltolarsen is effective in 8% of patients and accurately skips exon 53, reestablishing the reading frame and producing a functional form of dystrophin and milder disease phenotype. Results of recently concluded preclinical and clinical trials show significantly increased dystrophin protein expression, no severe adverse effects, and stabilization of motor function. In summary, viltolarsen has provided hope for those working toward giving patients a safe and viable treatment option for managing DMD. This review summarizes an overview of the presentation, pathophysiology, genetics, and current treatment guidelines of DMD, pharmacological profile of viltolarsen, and a summary of the safety and efficacy with additional insights using recent clinical trial data.

Vamorolone: First Approval

Vamorolone (AGAMREE®) is an oral, selective, dissociative corticosteroid developed by ReveraGen BioPharma and Santhera Pharmaceuticals for the treatment of patients with muscular dystrophy. Vamorolone was approved in October 2023 for the treatment of Duchenne muscular dystrophy (DMD) in patients 2 years of age and older in the USA and received a positive opinion in the EU in October 2023 for the treatment of DMD in patients 4 years of age and older. This article summarizes the milestones in the development of vamorolone leading to this first approval for DMD.

Factors Associated with Respiratory Health and Function in Duchenne Muscular Dystrophy: A Systematic Review and Evidence Grading

BACKGROUND

Despite advances in the medical management of the disease, respiratory involvement remains a significant source of morbidity and mortality in children and adults with Duchenne muscular dystrophy (DMD).

OBJECTIVE

The objective of this systematic literature review was to synthesize and grade published evidence of factors associated with respiratory health and function in DMD.

METHODS

We searched MEDLINE, Embase, and the Cochrane Library for records of studies published from January 1, 2000 (to ensure relevance to current care practices), up until and including December 31, 2022, reporting evidence of prognostic indicators and predictors of disease progression in DMD. The quality of evidence (i.e., very low to high) was assessed using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) framework.

RESULTS

The bibliographic search strategy resulted in the inclusion of 29 articles. In total, evidence of 10 factors associated with respiratory health and function in patients with DMD was identified: glucocorticoid exposure (high- to very low-quality evidence), DMD mutations (low-quality evidence), DMD genetic modifiers (low-quality evidence), other pharmacological interventions (i.e., ataluren, eteplirsen, idebenone, and tamoxifen) (moderate- to very low-quality evidence), body mass index and weight (low-quality evidence), and functional ability (low-quality evidence).

CONCLUSIONS

In conclusion, we identified a total of 10 factors associated with respiratory health in function in DMD, encompassing both pharmacological therapies, genetic mutations and modifiers, and patient clinical characteristics. Yet, more research is needed to further delineate sources of respiratory heterogeneity, in particular the genotype-phenotype association and the impact of novel DMD therapies in a real-world setting. Our synthesis and grading should be helpful to inform clinical practice and future research of this heavily burdened patient population.

Detecting early signs in Duchenne muscular dystrophy: comprehensive review and diagnostic implications

Despite the early onset of clinical signs suggestive of Duchenne muscular dystrophy (DMD), a diagnosis is often not made until four years of age or older, with a diagnostic delay of up to two years from the appearance of the first symptoms. As disease-modifying therapies for DMD become available that are ideally started early before irreversible muscle damage occurs, the importance of avoiding diagnostic delay increases. Shortening the time to a definite diagnosis in DMD allows timely genetic counseling and assessment of carrier status, initiation of multidisciplinary standard care, timely initiation of appropriate treatments, and precise genetic mutation characterization to assess suitability for access to drugs targeted at specific mutations while reducing the emotional and psychological family burden of the disease. This comprehensive literature review describes the early signs of impairment in DMD and highlights the bottlenecks related to the different diagnostic steps. In summary, the evidence suggests that the best mitigation strategy for improving the age at diagnosis is to increase awareness of the early symptoms of DMD and encourage early clinical screening with an inexpensive and sensitive serum creatine kinase test in all boys who present signs of developmental delay and specific motor test abnormality at routine pediatrician visits.

Safety and Efficacy of DT-DEC01 Therapy in Duchenne Muscular Dystrophy Patients: A 12 - Month Follow-Up Study After Systemic Intraosseous Administration

Duchenne Muscular Dystrophy (DMD) is a progressive and fatal muscle-wasting disease with no known cure. We previously reported the preliminary safety and efficacy up to six months after the administration of DT-DEC01, a novel Dystrophin Expressing Chimeric (DEC) cell therapy created by fusion of myoblasts of DMD patient and the normal donor. In this 12-month follow-up study, we report on the safety and functional outcomes of three DMD patients after the systemic intraosseous administration of DT-DEC01. The safety of DT-DEC01 was confirmed by the absence of Adverse Events (AE) and Severe Adverse Events (SAE) up to 21 months after intraosseous DT-DEC01 administration. The lack of presence of anti-HLA antibodies and Donors Specific Antibodies (DSA) further confirmed DT-DEC01 therapy safety. Functional assessments in ambulatory patients revealed improvements in 6-Minute Walk Test (6MWT) and timed functions of North Star Ambulatory Assessment (NSAA). Additionally, improvements in PUL2.0 test and grip strength correlated with increased Motor Unit Potentials (MUP) duration recorded by Electromyography (EMG) in both ambulatory and non-ambulatory patients. DT-DEC01 systemic effect was confirmed by improved cardiac and pulmonary parameters and daily activity recordings. This follow-up study confirmed the safety and preliminary efficacy of DT-DEC01 therapy in DMD-affected patients up to 12 months after intraosseous administration. DT-DEC01 introduces a novel concept of personalized myoblast-based cellular therapy that is irrespective of the mutation type, does not require immunosuppression or the use of viral vectors, and carries no risk of off target mutations. This establishes DT-DEC01 as a promising and universally effective treatment option for all DMD patients.

Prognostic factors, disease course, and treatment efficacy in Duchenne muscular dystrophy: A systematic review and meta-analysis

INTRODUCTION/AIMS

Prognostic factors in Duchenne muscular dystrophy (DMD) predict the disease course and may help individualize patient care. The aim was to summarize the evidence on prognostic factors that may support treatment decisions.

METHODS

We searched six databases for prospective studies that each included ≥50 DMD patients with a minimum follow-up of 1 y. Primary outcomes were age at loss of ambulation (LoA), pulmonary function (forced vital capacity percent of predicted, FVC%p), and heart failure.

RESULTS

Out of 5074 references, 59 studies were analyzed. Corticosteroid use was associated with a delayed LoA (pooled effect hazard ratio [HR] 0.42, 95% confidence interval [CI] 0.23-0.75, I2 94%), better pulmonary function tests (higher peak FVC%, prolonged time with FVC%p > 50%, and reduced need for assisted ventilation) and delayed cardiomyopathy. Longer corticosteroid treatment was associated with later LoA (>1 y compared to <1 y; pooled HR: 0.50, 95% CI 0.27-0.90) and early treatment start (aged <5 y) may be associated with early cardiomyopathy and higher fracture risk. Genotype appeared to be an independent driver of LoA in some studies. Higher baseline physical function tests (e.g., 6-minute walk test) were associated with delayed LoA. Left ventricular dysfunction and FVC <1 L increased and the use of angiotensin-converting enzyme (ACE) inhibitors reduced the risk of heart failure and death. Fusion surgery in scoliosis may potentially preserve pulmonary function.

DISCUSSION

Prognostic factors that may inform clinical decisions include age at corticosteroid treatment initiation and treatment duration, ACE-inhibitor use, baseline physical function tests, pulmonary function, and cardiac dysfunction.