Vamorolone trial in Duchenne muscular dystrophy shows dose-related improvement of muscle function

Objective

To study vamorolone, a first-in-class steroidal anti-inflammatory drug, in Duchenne muscular dystrophy (DMD).

Methods

An open-label, multiple-ascending-dose study of vamorolone was conducted in 48 boys with DMD (age 4–<7 years, steroid-naive). Dose levels were 0.25, 0.75, 2.0, and 6.0 mg/kg/d in an oral suspension formulation (12 boys per dose level; one-third to 10 times the glucocorticoid dose in DMD). The primary goal was to define optimal doses of vamorolone. The primary outcome for clinical efficacy was time to stand from supine velocity.

Results

Oral administration of vamorolone at all doses tested was safe and well tolerated over the 24-week treatment period. The 2.0–mg/kg/d dose group met the primary efficacy outcome of improved muscle function (time to stand; 24 weeks of vamorolone treatment vs natural history controls), without evidence of most adverse effects of glucocorticoids. A biomarker of bone formation, osteocalcin, increased in vamorolone-treated boys, suggesting possible loss of bone morbidities seen with glucocorticoids. Biomarker outcomes for adrenal suppression and insulin resistance were also lower in vamorolone-treated patients with DMD relative to published studies of glucocorticoid therapy.

Conclusions

Daily vamorolone treatment suggested efficacy at doses of 2.0 and 6.0 mg/kg/d in an exploratory 24-week open-label study.

Classification of evidence

This study provides Class IV evidence that for boys with DMD, vamorolone demonstrated possible efficacy compared to a natural history cohort of glucocorticoid-naive patients and appeared to be tolerated.

Neurology Care, Diagnostics, and Emerging Therapies of the Patient With Duchenne Muscular Dystrophy

Duchenne muscular dystrophy is the most common form of childhood muscular dystrophy. A mutation in the DMD gene disrupts dystrophin (protein) production, causing damage to muscle integrity, weakness, loss of ambulation, and cardiopulmonary compromise by the second decade of life. Life expectancy has improved from mid-teenage years to mid-20s with the use of glucocorticoids and beyond the third decade with ventilator support and multidisciplinary care. However, Duchenne muscular dystrophy is associated with comorbidities and is a fatal disease. Glucocorticoids prolong ambulation, but their side effects are significant. Emerging investigational therapies have surfaced over the past decade and have rapidly been tested in clinical trials. Gene-specific strategies include nonsense readthrough, exon skipping, gene editing, utrophin modulation, and gene replacement. Other mechanisms include muscle regeneration, antioxidants, and antifibrosis and anti-inflammatory pathways. With potential therapies emerging, early diagnosis is needed to initiate treatment early enough to minimize morbidity and mortality. Newborn screening can be used to significantly improve early diagnosis, especially for gene-specific therapeutics.

Diagnosis and management of Duchenne muscular dystrophy, part 3: primary care, emergency management, psychosocial care, and transitions of care across the lifespan

Improvements in the function, quality of life, and longevity of patients with Duchenne muscular dystrophy (DMD) have been achieved through a multidisciplinary approach to management across a range of health-care specialties. In part 3 of this update of the DMD care considerations, we focus on primary care, emergency management, psychosocial care, and transitions of care across the lifespan. Many primary care and emergency medicine clinicians are inexperienced at managing the complications of DMD. We provide a guide to the acute and chronic medical conditions that these first-line providers are likely to encounter. With prolonged survival, individuals with DMD face a unique set of challenges related to psychosocial issues and transitions of care. We discuss assessments and interventions that are designed to improve mental health and independence, functionality, and quality of life in critical domains of living, including health care, education, employment, interpersonal relationships, and intimacy.

Diagnosis and management of Duchenne muscular dystrophy, part 1: diagnosis, and neuromuscular, rehabilitation, endocrine, and gastrointestinal and nutritional management

Since the publication of the Duchenne muscular dystrophy (DMD) care considerations in 2010, multidisciplinary care of this severe, progressive neuromuscular disease has evolved. In conjunction with improved patient survival, a shift to more anticipatory diagnostic and therapeutic strategies has occurred, with a renewed focus on patient quality of life. In 2014, a steering committee of experts from a wide range of disciplines was established to update the 2010 DMD care considerations, with the goal of improving patient care. The new care considerations aim to address the needs of patients with prolonged survival, to provide guidance on advances in assessments and interventions, and to consider the implications of emerging genetic and molecular therapies for DMD. The committee identified 11 topics to be included in the update, eight of which were addressed in the original care considerations. The three new topics are primary care and emergency management, endocrine management, and transitions of care across the lifespan. In part 1 of this three-part update, we present care considerations for diagnosis of DMD and neuromuscular, rehabilitation, endocrine (growth, puberty, and adrenal insufficiency), and gastrointestinal (including nutrition and dysphagia) management.

Psychometric analysis of the pediatric quality of life inventory 3.0 neuromuscular module administered to patients with duchenne muscular dystrophy: A rasch analysis

INTRODUCTION

Our objective in this study was to assess the psychometric properties of the English (UK and USA) version of the Pediatric Quality of Life Inventory 3.0 Neuromuscular Module (PedsQL NMM) administered to patients with Duchenne muscular dystrophy (DMD).

METHODS

Patients with DMD from the UK and the US completed the PedsQL NMM online. The psychometric properties of the instrument were examined using Rasch analysis.

RESULTS

A total of 278 patients completed the PedsQL NMM. Model misfit was identified for 6 of 25 items (item fit residual: mean 0.162, standard deviation [SD] 2.333), 22 of 25 items displayed disordered thresholds, and item dependency was high. The mean person fit residual was estimated at -0.183 (SD 1.475). The Person Separation Index and Cronbach's α were estimated at 0.904 and 0.915, respectively.

DISCUSSION

The English version of the PedsQL NMM may not be a valid measure of health-related quality of life in patients with DMD. Muscle Nerve 58: 367-373, 2018.

Diagnosis and management of Duchenne muscular dystrophy, part 2: respiratory, cardiac, bone health, and orthopaedic management

A coordinated, multidisciplinary approach to care is essential for optimum management of the primary manifestations and secondary complications of Duchenne muscular dystrophy (DMD). Contemporary care has been shaped by the availability of more sensitive diagnostic techniques and the earlier use of therapeutic interventions, which have the potential to improve patients' duration and quality of life. In part 2 of this update of the DMD care considerations, we present the latest recommendations for respiratory, cardiac, bone health and osteoporosis, and orthopaedic and surgical management for boys and men with DMD. Additionally, we provide guidance on cardiac management for female carriers of a disease-causing mutation. The new care considerations acknowledge the effects of long-term glucocorticoid use on the natural history of DMD, and the need for care guidance across the lifespan as patients live longer. The management of DMD looks set to change substantially as new genetic and molecular therapies become available.

Translational Research in Europe for the Assessment and Treatment for Neuromuscular Disorders (TREAT-NMD)

Translational research in Europe for the assessment and treatment of neuromuscular disorders (TREAT-NMD) is a global network of world-class experts within the neuromuscular community whose mission is to support all stages of therapy development and improve the health and quality of life of people around the world with neuromuscular disorders (NMD). Since 2007, TREAT-NMD has played a central role in bringing together the right experts, patients, advocacy organizations, scientists, healthcare professionals, and pharmaceutical companies. By uniting these experts within the neuromuscular community, TREAT-NMD has supported preclinical research in animal and cell models that has raised the potential for clinical trials. TREAT-NMD has successfully developed several key resources, including cell and animal standard operating protocols (preclinical research), global patient registries, ethical framework and care guidelines, and family guides, to help develop and extend translation research in the field, thereby making the field ready for clinical trials. This review aims to highlight key achievements of the network, which spans a decade and the successful partnership with our stakeholders who have enabled the field to identify and address challenges to therapeutic development and standard of care for patients. This review will also outline future perspectives.

Economic Evaluation in Duchenne Muscular Dystrophy: Model Frameworks for Cost-Effectiveness Analysis

BACKGROUND

Several treatments are on the horizon for Duchenne muscular dystrophy (DMD), a terminal orphan disease. In many jurisdictions, decisions regarding pricing and reimbursement of these health technologies comprise evidence of value for money.

OBJECTIVE

The objective of this study was to develop a cost-effectiveness model based on the Duchenne muscular dystrophy Functional Ability Self-Assessment Tool (DMDSAT), a new rating scale created specifically to measure disease progression in clinical practice and trials and model DMD in economic evaluations, and compare it with two alternative model structures.

METHODS

We constructed three Markov cohort state-transition models to evaluate the cost-effectiveness of a hypothetical intervention for DMD versus standard of care in a UK setting. Model I was based on the DMDSAT, model II on stages of disease as defined in the DMD clinical care guidelines and model III on patients' ventilation status. The conceptual model structures were formulated in collaboration with three DMD experts.

RESULTS

All three models were judged to have good validity with regards to the appropriateness of the choice of modelling technique, conceptual representation of the disease, model input data and model outcomes. Across frameworks, lifetime direct medical costs with standard of care ranged between £217,510 and £284,640, total costs between £624,240 and £713,840, and total number of quality-adjusted life-years between 5.96 and 7.17.

CONCLUSIONS

We present a first version of a model for the economic evaluation of treatments for DMD based on the DMDSAT, as well as two alternative frameworks encompassing conventional staging of disease progression. Our findings should be helpful to inform health technology assessments and health economic programmes of future treatments for DMD.

Why are some patients with Duchenne muscular dystrophy dying young: An analysis of causes of death in North East England

INTRODUCTION

Duchenne muscular dystrophy (DMD) is the most common inherited muscle disease in children. Recent years have seen an increase in age of survival into adulthood following the introduction of proactive standards of care. We reviewed mortality in DMD in our population in order to identify potential underlying risk factors for premature death and improve clinical care.

METHOD

A retrospective case note review of all deaths in the DMD population over the last 10 years in North East England. We identified 2 groups of patients: patients who died from underlying cardiac and/or respiratory failure (group 1) and patients who died unexpectedly in the absence of underlying cardio-respiratory failure (group 2).

RESULTS

Detailed information was available on 21 patients. Mean age of death in group 1 (17 patients) was 23.9 (14.4-39.5) years, in group 2 (4 patients) 14 (12.7-14.9) years. Causes of death in group 2 were acute pneumonia, cardiac arrest, acute respiratory distress and multi-organ failure. Across both groups we identified concerns regarding respiratory failure, inadequate nutrition, non-attendance at appointments, suboptimal coordination of care and decreased psychological wellbeing. In group 2, fat embolism, cardiac arrhythmia and adrenal insufficiency were also potential contributing factors.

CONCLUSIONS

The main cause of death in DMD in our population remains cardio-respiratory failure. Four patients (19%) died in their teenage years in the absence of severe cardiorespiratory failure. A more thorough understanding of the impact of DMD and its treatment on all organs systems is required to minimise the risk of an untimely death.

Health-related quality of life in patients with Duchenne muscular dystrophy: a multinational, cross-sectional study

AIM

To estimate health-related quality of life (HRQOL) in patients with Duchenne muscular dystrophy (DMD).

METHOD

HRQOL was assessed using the Health Utilities Index Questionnaire (HUI) and the Pediatric Quality of Life Inventory (PedsQL) neuromuscular module version 3.0 online. Results were stratified by disease stage (early/late ambulatory/non-ambulatory) and caregivers' perceptions of patients' health and mental status.

RESULTS

A total of 770 patient-caregiver pairs (173 German, 122 Italian, 191 UK, and 284 USA) participated. Most caregivers (>84%) perceived their patients as happy/somewhat happy and in excellent/very good/good health, irrespective of current ambulatory class. In contrast, mean patient utility (reflecting public preferences: 0, dead; 1, perfect health) deteriorated with disease course, from 0.75 in early ambulatory males to 0.15 in the most severely affected patients. Mean patient PedsQL scores (0-100, higher score indicating better HRQOL) decreased from 80 to 57 across ambulatory classes.

INTERPRETATION

HRQOL in DMD, measured through public preferences, is substantially impaired in relation to the general population and significantly associated with disease progression. Still, most patients are perceived as happy and in good health by their caregivers, indicating that influential domains of HRQOL remain intact through the disease progression. Our findings emphasize the challenges in measuring HRQOL in a rare, progressive childhood condition such as DMD.

Quantifying the burden of caregiving in Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is a rare pediatric neuromuscular disease associated with progressive muscle degeneration and extensive care needs. Our objective was to estimate the caregiver burden associated with DMD. We made cross-sectional assessments of caregiver health-related quality of life (HRQL) and burden using the EuroQol EQ-5D, a Visual Analogue Scale (VAS), the SF-12 Health Survey, and the Zarit Caregiver Burden Interview (ZBI) administered online. Results were stratified by disease stage (early/late ambulatory/non-ambulatory) and caregivers’ rating of patients’ health and mental status. In total, caregivers to 770 patients participated. Mean EQ-5D utility ranged between 0.85 (95 % CI 0.82–0.88) and 0.77 (0.74–0.80) across ambulatory classes and 0.88 (0.85–0.90) and 0.57 (0.39–0.74) across caregivers’ rating of patients’ health and mental status. Mean VAS score was 0.74 (0.73–0.75), mean SF-12 Mental Health Component Summary score 44 (43–45), and mean ZBI score 29 (28–30). Anxiety and depression, recorded in up to 70 % of caregivers depending on patients’ health and mental status, was significantly associated with annual household cost burden (>$5000 vs. <$1000, odds ratio 1.76, 95 % CI 1.18–2.63) and hours of leisure time devoted to informal care per week (25–50 vs. <25 h 2.01, 1.37–2.94; >50 vs. <25 h 3.35, 2.32–4.83) (p < 0.007). We show that caring for a person with DMD can be associated with a substantial burden and impaired HRQL. Our findings suggest that caregivers to patients with DMD should be screened for depression and emphasize the need for a holistic approach to family mental health in the context of chronic childhood disease.