Safety and efficacy of givinostat in boys with Duchenne muscular dystrophy (EPIDYS): a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial

BACKGROUND

Duchenne muscular dystrophy, the most common childhood muscular dystrophy, is caused by dystrophin deficiency. Preclinical and phase 2 study data have suggested that givinostat, a histone deacetylase inhibitor, might help to counteract the effects of this deficiency. We aimed to evaluate the safety and efficacy of givinostat in the treatment of Duchenne muscular dystrophy.

METHODS

This multicentre, randomised, double-blind, placebo-controlled, phase 3 trial was done at 41 tertiary care sites in 11 countries. Eligible participants were ambulant, male, and aged at least 6 years, had a genetically confirmed diagnosis of Duchenne muscular dystrophy, completed two four-stair climb assessments with a mean of 8 s or less (≤1 s variance), had a time-to-rise of at least 3 s but less than 10 s, and had received systemic corticosteroids for at least 6 months. Participating boys were randomly assigned (2:1, allocated according to a list generated by the interactive response technology provider) to receive either oral givinostat or matching placebo twice a day for 72 weeks, stratified by concomitant steroid use. Boys, investigators, and site and sponsor staff were masked to treatment assignment. The dose was flexible, based on weight, and was reduced if not tolerated. Boys were divided into two groups on the basis of their baseline vastus lateralis fat fraction (VLFF; measured by magnetic resonance spectroscopy): group A comprised boys with a VLFF of more than 5% but no more than 30%, whereas group B comprised boys with a VLFF of 5% or less, or more than 30%. The primary endpoint compared the effects of givinostat and placebo on the change in results of the four-stair climb assessment between baseline and 72 weeks, in the intention-to-treat, group A population. Safety was assessed in all randomly assigned boys who received at least one dose of study drug. When the first 50 boys in group A completed 12 months of treatment, an interim futility assessment was conducted, after which the sample size was adapted using masked data from the four-stair climb assessments. Furthermore, the starting dose of givinostat was reduced following a protocol amendment. This trial is registered with ClinicalTrials.gov, NCT02851797, and is complete.

FINDINGS

Between June 6, 2017, and Feb 22, 2022, 359 boys were assessed for eligibility. Of these, 179 were enrolled into the study (median age 9·8 years [IQR 8·1-11·0]), all of whom were randomly assigned (118 to receive givinostat and 61 to receive placebo); 170 (95%) boys completed the study. Of the 179 boys enrolled, 120 (67%) were in group A (81 givinostat and 39 placebo); of these, 114 (95%) completed the study. For participants in group A, comparing the results of the four-stair climb assessment at 72 weeks and baseline, the geometric least squares mean ratio was 1·27 (95% CI 1·17-1·37) for boys receiving givinostat and 1·48 (1·32-1·66) for those receiving placebo (ratio 0·86, 95% CI 0·745-0·989; p=0·035). The most common adverse events in the givinostat group were diarrhoea (43 [36%] of 118 boys vs 11 [18%] of 61 receiving placebo) and vomiting (34 [29%] vs 8 [13%]); no treatment-related deaths occurred.

INTERPRETATION

Among ambulant boys with Duchenne muscular dystrophy, results of the four-stair climb assessment worsened in both groups over the study period; however, the decline was significantly smaller with givinostat than with placebo. The dose of givinostat was reduced after an interim safety analysis, but no new safety signals were reported. An ongoing extension study is evaluating the long-term safety and efficacy of givinostat in patients with Duchenne muscular dystrophy.

FUNDING

Italfarmaco.

Efficacy and Safety of Vamorolone Over 48 Weeks in Boys With Duchenne Muscular Dystrophy: A Randomized Controlled Trial

BACKGROUND AND OBJECTIVES

Vamorolone is a dissociative agonist of the glucocorticoid receptor that has shown similar efficacy and reduced safety concerns in comparison with prednisone in Duchenne muscular dystrophy (DMD). This study was conducted to determine the efficacy and safety of vamorolone over 48 weeks and to study crossover participants (prednisone to vamorolone; placebo to vamorolone).

METHODS

A randomized, double-blind, placebo-controlled and prednisone-controlled clinical trial of 2 doses of vamorolone was conducted in participants with DMD, in the ages from 4 years to younger than 7 years at baseline. The interventions were 2 mg/kg/d of vamorolone and 6 mg/kg/d of vamorolone for 48 weeks (period 1: 24 weeks + period 2: 24 weeks) and 0.75 mg/kg/d of prednisone and placebo for the first 24 weeks (before crossover). Efficacy was evaluated through gross motor outcomes and safety through adverse events, growth velocity, body mass index (BMI), and bone turnover biomarkers. This analysis focused on period 2.

RESULTS

A total of 121 participants with DMD were randomized. Vamorolone at a dose of 6 mg/kg/d showed maintenance of improvement for all motor outcomes to week 48 (e.g., for primary outcome, time to stand from supine [TTSTAND] velocity, week 24 least squares mean [LSM] [SE] 0.052 [0.0130] rises/s vs week 48 LSM [SE] 0.0446 [0.0138]). After 48 weeks, vamorolone at a dose of 2 mg/kg/d showed similar improvements as 6 mg/kg/d for North Star Ambulatory Assessment (NSAA) (vamorolone 6 mg/kg/d-vamorolone 2 mg/kg/d LSM [SE] 0.49 [1.14]; 95% CI -1.80 to 2.78, p = 0.67), but less improvement for other motor outcomes. The placebo to vamorolone 6 mg/kg/d group showed rapid improvements after 20 weeks of treatment approaching benefit seen with 48-week 6 mg/kg/d of vamorolone treatment for TTSTAND, time to run/walk 10 m, and NSAA. There was significant improvement in linear growth after crossover in the prednisone to vamorolone 6 mg/kg/d group, and rapid reversal of prednisone-induced decline in bone turnover biomarkers in both crossover groups. There was an increase in BMI after 24 weeks of treatment that then stabilized for both vamorolone groups.

DISCUSSION

Improvements of motor outcomes seen with 6 mg/kg/d of vamorolone at 24 weeks of treatment were maintained to 48 weeks of treatment. Vamorolone at a dose of 6 mg/kg/d showed better maintenance of effect compared with vamorolone at a dose of 2 mg/kg/d for most (3/5) motor outcomes. Bone morbidities of prednisone (stunting of growth and declines in serum bone biomarkers) were reversed when treatment transitioned to vamorolone.

TRIAL REGISTRATION INFORMATION

ClinicalTrials.gov Identifier: NCT03439670.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that for boys with DMD, the efficacy of vamorolone at a dose of 6 mg/kg/d was maintained over 48 weeks.

A Study on the Incidence and Prevalence of 5q Spinal Muscular Atrophy in Canada Using Multiple Data Sources

OBJECTIVES

Spinal muscular atrophy (SMA) is a leading genetic cause of infant death and represents a significant burden of care. An improved understanding of the epidemiology of SMA in Canada may help inform strategies to improve the standard of care for individuals living with SMA.

METHODS

We employed a multisource approach to estimate the minimal incidence and prevalence of 5q SMA and to gain greater insight into recent clinical practices and treatment trends for the Canadian SMA population. Data sources included the Canadian Paediatric Surveillance Program (CPSP), Canadian Neuromuscular Disease Registry (CNDR), and molecular genetics laboratories in Canada.

RESULTS

The estimated annual minimum incidence of 5q SMA was 4.38, 3.44, and 7.99 cases per 100,000 live births in 2020 and 2021, based on CPSP, CNDR, and molecular genetics laboratories data, respectively, representing approximately 1 in 21,472 births (range 12,516-29,070) in Canada. SMA prevalence was estimated to be 0.85 per 100,000 persons aged 0-79 years. Delay in diagnosis exists across all SMA subtypes. Most common presenting symptoms were delayed milestones, hypotonia, and muscle weakness. Nusinersen was the most common disease-modifying treatment received. Most patients utilized multidisciplinary clinics for management of SMA.

CONCLUSION

This study provides data on the annual minimum incidence of pediatric 5q SMA in Canada. Recent therapeutic advances and newborn screening have the potential to drastically alter the natural history of SMA. Findings underline the importance of ongoing surveillance of the epidemiology and long-term health outcomes of SMA in the Canadian population.

Alberta Spinal Muscular Atrophy Newborn Screening-Results from Year 1 Pilot Project

Spinal muscular atrophy (SMA) is a progressive neuromuscular disease caused by biallelic pathogenic/likely pathogenic variants of the survival motor neuron 1 (SMN1) gene. Early diagnosis via newborn screening (NBS) and pre-symptomatic treatment are essential to optimize health outcomes for affected individuals. We developed a multiplex quantitative polymerase chain reaction (qPCR) assay using dried blood spot (DBS) samples for the detection of homozygous absence of exon 7 of the SMN1 gene. Newborns who screened positive were seen urgently for clinical evaluation. Confirmatory testing by multiplex ligation-dependent probe amplification (MLPA) revealed SMN1 and SMN2 gene copy numbers. Six newborns had abnormal screen results among 47,005 newborns screened during the first year and five were subsequently confirmed to have SMA. Four of the infants received SMN1 gene replacement therapy under 30 days of age. One infant received an SMN2 splicing modulator due to high maternally transferred AAV9 neutralizing antibodies (NAb), followed by gene therapy at 3 months of age when the NAb returned negative in the infant. Early data show that all five infants made excellent developmental progress. Based on one year of data, the incidence of SMA in Alberta was estimated to be 1 per 9401 live births.

Efficacy and Safety of Viltolarsen in Boys With Duchenne Muscular Dystrophy: Results From the Phase 2, Open-Label, 4-Year Extension Study

Background: Duchenne muscular dystrophy (DMD) is caused by DMD gene mutations, resulting in absence of functional dystrophin protein. Viltolarsen, an exon 53 skipping therapy, significantly increased dystrophin levels in patients with DMD. Presented here are completed study results of >4 years of functional outcomes in viltolarsen-treated patients compared to a historical control group (Cooperative International Neuromuscular Research Group Duchenne Natural History Study [CINRG DNHS]). Objective: To evaluate the efficacy and safety of viltolarsen for an additional 192 weeks in boys with DMD. Methods: This phase 2, open-label, 192-week long-term extension (LTE) study (NCT03167255) evaluated the efficacy and safety of viltolarsen in participants aged 4 to <10 years at baseline with DMD amenable to exon 53 skipping. All 16 participants from the initial 24-week study enrolled into this LTE. Timed function tests were compared to the CINRG DNHS group. All participants received glucocorticoid treatment. The primary efficacy outcome was time to stand from supine (TTSTAND). Secondary efficacy outcomes included additional timed function tests. Safety was continuously assessed. Results: For the primary efficacy outcome (TTSTAND), viltolarsen-treated patients showed stabilization of motor function over the first two years and significant slowing of disease progression over the following two years compared with the CINRG DNHS control group which declined. Viltolarsen was well tolerated, with most reported treatment-emergent adverse events being mild or moderate. No participants discontinued drug during the study. Conclusions: Based on the results of this 4-year LTE, viltolarsen can be an important treatment strategy for DMD patients amenable to exon 53 skipping.

Understanding the experiences of lung volume recruitment among boys with Duchenne muscular dystrophy: A multicenter qualitative study

BACKGROUND

Despite recommendations for regular lung volume recruitment (LVR) use in clinical practice guidelines for children with neuromuscular disease, adherence to LVR is poor. We aimed to describe the experience of LVR by boys with Duchenne muscular dystrophy (DMD), their families, and healthcare providers (HCPs), as well as to identify the barriers and facilitators to LVR use.

METHODS

This multicenter, qualitative study evaluated boys with DMD (n = 11) who used twice-daily LVR as part of a randomized controlled trial, as well as their parents (n = 11), and HCPs involved in the clinical use of LVR (n = 9). Semistructured interviews were conducted to identify participants' understanding of LVR therapy and their beliefs, barriers and facilitators to its use. Thematic analysis was conducted using an inductive approach. A subanalysis compared adherent and nonadherent children.

RESULTS

Seven themes were identified related to participants' beliefs and experiences with LVR: emotional impact, adaptation to LVR, perceived benefits of LVR, routine, family engagement, clinical resources, and equipment-related factors. Strategies to improve adherence were also identified, including education, reinforcement and demonstration of LVR benefit, as well as clinician support. There were no thematic differences between adherent and nonadherent children.

DISCUSSION

Despite the benefits of LVR and positive experiences with it by many families, there remain barriers to adherence to treatment. HCPs need to balance the need for early introduction to give families time to adapt to LVR while ensuring that the benefit of LVR outweighs the burden. Clinician support is important for family engagement.

Corneal nerve and nerve conduction abnormalities in children with type 1 diabetes

OBJECTIVE

In vivo corneal confocal microscopy (CCM) is a novel, rapid, and non-invasive technique that identifies early small fiber damage and can predict the progression and development of clinical neuropathy in adults with type 1 diabetes. However, its usefulness in children is not well established. This study compared corneal confocal microscopy with neuropathic symptoms, signs, and objective measures of neuropathy for the diagnosis of diabetic neuropathy in children with type 1 diabetes.

RESEARCH DESIGN AND METHODS

A total of 83 children with type 1 diabetes and 83 healthy participants of similar age underwent assessment of neuropathy symptoms, signs, nerve conduction studies, quantitative sensory and autonomic function testing, and in vivo CCM.

RESULTS

Only of 3/83 (4%) children with type 1 diabetes had subclinical neuropathy. However, corneal nerve fiber density (p = 0.001), branch density (p = 0.006), fiber length (p = 0.002), tibial motor nerve amplitude and conduction velocity, and sural sensory nerve amplitude and conduction velocity (all p < 0.004) were lower in participants with type 1 diabetes than in the controls. Vibration, cooling, and warm perception thresholds and deep breathing heart rate variability were not found to be different (all p > 0.05) between children with type 1 diabetes and healthy controls. Multivariate regression analysis identified a possible association between body mass index and decreased corneal nerves.

CONCLUSIONS

Decreased corneal nerves and abnormal nerve conduction were found in children with type 1 diabetes. CCM may allow rapid objective detection of subclinical diabetic neuropathy in children and adolescents with type 1 diabetes.

Dual-energy X-ray absorptiometry measures of lean body mass as a biomarker for progression in boys with Duchenne muscular dystrophy

We evaluated whether whole-body dual-energy X-ray absorptiometry (DXA) measures of lean body mass can be used as biomarkers for disease progression and treatment effects in patients with Duchenne muscular dystrophy. This post hoc analysis utilized data from a randomized, 2-period study of domagrozumab versus placebo in 120 ambulatory boys with DMD. DXA measures of lean body mass were obtained from the whole body (excluding head), arms, legs and appendicular skeleton at baseline and every 16 weeks. Treatment effects on DXA measures for domagrozumab versus placebo were assessed at Week 49. At Week 49, domagrozumab statistically significantly increased lean body mass versus placebo in the appendicular skeleton (p = 0.050) and arms (p < 0.001). The relationship between lean body mass at Week 49 and functional endpoints at Week 97 was evaluated. Changes in lean body mass at Week 49 in all regions except arms were significantly correlated with percent change from baseline in 4-stair climb (4SC) at Week 97. DXA-derived percent lean mass at Week 49 also correlated with 4SC and North Star Ambulatory Assessment at Week 97. These data indicate that whole-body DXA measures can be used as biomarkers for treatment effects and disease progression in patients with DMD, and warrant further investigation.Trial registration: ClinicalTrials.gov, NCT02310763; registered 8 December 2014.

Efficacy and Safety of Vamorolone vs Placebo and Prednisone Among Boys With Duchenne Muscular Dystrophy: A Randomized Clinical Trial

Question

For steroidal anti-inflammatory drugs, can efficacy be retained while safety concerns are reduced among boys with Duchenne muscular dystrophy (DMD) with the novel partial receptor agonist vamorolone?

Findings

A randomized, double-blind, placebo- and prednisone-controlled trial of vamorolone (2 dose groups) was carried out in 121 patients with DMD. The trial met the primary (time to stand velocity after 24 weeks for vamorolone, 6 mg/kg per day vs placebo) and first 4 sequential secondary motor function end points; vamorolone showed loss of bone morbidities compared with prednisone, with no stunting of growth and no deleterious changes in bone biomarkers.

Meaning

This study found that vamorolone, a dissociative steroidal anti-inflammatory, was able to reduce bone morbidities while retaining efficacy.

Importance

Corticosteroidal anti-inflammatory drugs are widely prescribed but long-term use shows adverse effects that detract from patient quality of life.

Objective

To determine if vamorolone, a structurally unique dissociative steroidal anti-inflammatory drug, is able to retain efficacy while reducing safety concerns with use in Duchenne muscular dystrophy (DMD).

Design, Setting, and Participants

Randomized, double-blind, placebo- and prednisone-controlled 24-week clinical trial, conducted from June 29, 2018, to February 24, 2021, with 24 weeks of follow-up. This was a multicenter study (33 referral centers in 11 countries) and included boys 4 to younger than 7 years of age with genetically confirmed DMD not previously treated with corticosteroids.

Interventions

The study included 4 groups: placebo; prednisone, 0.75 mg/kg per day; vamorolone, 2 mg/kg per day; and vamorolone, 6 mg/kg per day.

Main Outcomes and Measures

Study outcomes monitored (1) efficacy, which included motor outcomes (primary: time to stand from supine velocity in the vamorolone, 6 mg/kg per day, group vs placebo; secondary: time to stand from supine velocity [vamorolone, 2 mg/kg per day], 6-minute walk distance, time to run/walk 10 m [vamorolone, 2 and 6 mg/kg per day]; exploratory: NorthStar Ambulatory Assessment, time to climb 4 stairs) and (2) safety, which included growth, bone biomarkers, and a corticotropin (ACTH)–challenge test.

Results

Among the 133 boys with DMD enrolled in the study (mean [SD] age, 5.4 [0.9] years), 121 were randomly assigned to treatment groups, and 114 completed the 24-week treatment period. The trial met the primary end point for change from baseline to week 24 time to stand velocity for vamorolone, 6 mg/kg per day (least-squares mean [SE] velocity, 0.05 [0.01] m/s vs placebo −0.01 [0.01] m/s; 95% CI, 0.02-0.10; P = .002) and the first 4 sequential secondary end points: time to stand velocity, vamorolone, 2 mg/kg per day, vs placebo; 6-minute walk test, vamorolone, 6 mg/kg per day, vs placebo; 6-minute walk test, vamorolone, 2 mg/kg per day, vs placebo; and time to run/walk 10 m velocity, vamorolone, 6 mg/kg per day, vs placebo. Height percentile declined in prednisone-treated (not vamorolone-treated) participants (change from baseline [SD]: prednisone, −1.88 [8.81] percentile vs vamorolone, 6 mg/kg per day, +3.86 [6.16] percentile; P = .02). Bone turnover markers declined with prednisone but not with vamorolone. Boys with DMD at baseline showed low ACTH-stimulated cortisol and high incidence of adrenal insufficiency. All 3 treatment groups led to increased adrenal insufficiency.

Conclusions and Relevance

In this pivotal randomized clinical trial, vamorolone was shown to be effective and safe in the treatment of boys with DMD over a 24-week treatment period. Vamorolone may be a safer alternative than prednisone in this disease, in which long-term corticosteroid use is the standard of care.

Trial Registration

ClinicalTrials.gov Identifier: NCT03439670

Novel approaches to analysis of the North Star Ambulatory Assessment (NSAA) in Duchenne muscular dystrophy (DMD): Observations from a phase 2 trial

Introduction

The North Star Ambulatory Assessment (NSAA) tool is a key instrument for measuring clinical outcomes in patients with Duchenne muscular dystrophy (DMD). To gain a better understanding of the longitudinal utility of the NSAA, we evaluated NSAA data from a phase II trial of 120 patients with DMD treated with domagrozumab or placebo.

Methods

The NSAA exploratory analyses included assessment of individual skills gained/lost, total skills gained/lost, cumulative loss of function, and the impact of transient loss of function due to a temporary disability on NSAA total score (temporary zero score).

Results

There was no significant difference in the total number of NSAA skills gained (mean 1.41 and 1.04, respectively; p = 0.3314) or lost (3.90 vs. 5.0; p = 0.0998) between domagrozumab- vs. placebo-treated patients at week 49. However, domagrozumab-treated patients were less likely to lose the ability to perform a NSAA item (hazard ratio 0.80, 95% confidence interval [CI]: 0.65–0.98, p = 0.029) over 48-weeks vs. placebo-treated patients. When temporary zero scores were changed to “not obtainable” (8 values from 7 patients), domagrozumab-treated patients scored higher on the NSAA total score versus placebo-treated patients (difference at week 49: 2.0, 95% CI: 0.1–3.9, p = 0.0359).

Conclusions

These exploratory analyses reveal additional approaches to interpreting the NSAA data beyond just change in NSAA total score. These observations also highlight the importance of reporting items as “not obtainable” for a patient with a temporary/transient physical disability that impacts their ability to perform the NSAA test.

ClinicalTrials.gov identifier

NCT02310763.

Machine learning classification of multiple sclerosis in children using optical coherence tomography

BACKGROUND

In children, multiple sclerosis (MS) is the ultimate diagnosis in only 1/5 to 1/3 of cases after a first episode of central nervous system (CNS) demyelination. As the visual pathway is frequently affected in MS and other CNS demyelinating disorders (DDs), structural retinal imaging such as optical coherence tomography (OCT) can be used to differentiate MS.

OBJECTIVE

This study aimed to investigate the utility of machine learning (ML) based on OCT features to identify distinct structural retinal features in children with DDs.

METHODS

This study included 512 eyes from 187 (n_eyes = 374) children with demyelinating diseases and 69 (n_eyes = 138) controls. Input features of the analysis comprised of 24 auto-segmented OCT features.

RESULTS

Random Forest classifier with recursive feature elimination yielded the highest predictive values and identified DDs with 75% and MS with 80% accuracy, while multiclass distinction between MS and monophasic DD was performed with 64% accuracy. A set of eight retinal features were identified as the most important features in this classification.

CONCLUSION

This study demonstrates that ML based on OCT features can be used to support a diagnosis of MS in children.

Quantitative magnetic resonance imaging measures as biomarkers of disease progression in boys with Duchenne muscular dystrophy: a phase 2 trial of domagrozumab

Duchenne muscular dystrophy (DMD) is a progressive, neuromuscular disorder caused by mutations in the DMD gene that results in a lack of functional dystrophin protein. Herein, we report the use of quantitative magnetic resonance imaging (MRI) measures as biomarkers in the context of a multicenter phase 2, randomized, placebo-controlled clinical trial evaluating the myostatin inhibitor domagrozumab in ambulatory boys with DMD (n = 120 aged 6 to < 16 years). MRI scans of the thigh to measure muscle volume, muscle volume index (MVI), fat fraction, and T2 relaxation time were obtained at baseline and at weeks 17, 33, 49, and 97 as per protocol. These quantitative MRI measurements appeared to be sensitive and objective biomarkers for evaluating disease progression, with significant changes observed in muscle volume, MVI, and T2 mapping measures over time. To further explore the utility of quantitative MRI measures as biomarkers to inform longer term functional changes in this cohort, a regression analysis was performed and demonstrated that muscle volume, MVI, T2 mapping measures, and fat fraction assessment were significantly correlated with longer term changes in four-stair climb times and North Star Ambulatory Assessment functional scores. Finally, less favorable baseline measures of MVI, fat fraction of the muscle bundle, and fat fraction of lean muscle were significant risk factors for loss of ambulation over a 2-year monitoring period. These analyses suggest that MRI can be a valuable tool for use in clinical trials and may help inform future functional changes in DMD.Trial registration: ClinicalTrials.gov identifier, NCT02310763; registered December 2014.

Long-Term Functional Efficacy and Safety of Viltolarsen in Patients with Duchenne Muscular Dystrophy

Background: Duchenne muscular dystrophy (DMD) is a rare, genetic disease caused by mutations in the DMD gene resulting in an absence of functional dystrophin protein. Viltolarsen, an exon 53 skipping therapy, has been shown to increase endogenous dystrophin levels. Herein, long-term (>2 years) functional outcomes in viltolarsen treated patients were compared to a matched historical control group. Objective: To evaluate long-term efficacy and safety of the anti-sense oligonucleotide viltolarsen in the treatment of patients with DMD amenable to exon 53 skipping therapy. Methods: This trial (NCT03167255) is the extension of a previously published 24-week trial in North America (NCT02740972) that examined dystrophin levels, timed function tests compared to a matched historical control group (Cooperative International Neuromuscular Research Group Duchenne Natural History Study, CINRG DNHS), and safety in boys 4 to <  10 years (N = 16) with DMD amenable to exon 53 skipping who were treated with viltolarsen. Both groups were treated with glucocorticoids. All 16 participants elected to enroll in this long-term trial (up to 192 weeks) to continue evaluation of motor function and safety. Results: Time to stand from supine and time to run/walk 10 meters showed stabilization from baseline through week 109 for viltolarsen-treated participants whereas the historical control group showed decline (statistically significant differences for multiple timepoints). Safety was similar to that observed in the previous 24-week trial, which was predominantly mild. There have been no treatment-related serious adverse events and no discontinuations. Conclusions: Based on these results at over 2 years, viltolarsen can be a new treatment option for patients with DMD amenable to exon 53 skipping.

Progressive retinal changes in pediatric multiple sclerosis

Objectives To determine to what extent acute demyelinating episodes versus chronic degenerative phenomena drive retinal neuroaxonal damage in pediatric acquired demyelinating syndromes (ADS). Methods We acquired optical coherence tomography (OCT) data (follow-up range: 2 weeks - 5 years, at variable intervals from presentation) in pediatric participants who had multiple sclerosis (MS), monophasic ADS, or were healthy. Multivariable mixed effects models were used to assess the association of the number of demyelinating episodes (either optic neuritis [ON], or non-ON relapses) with changes in retinal nerve fiber layer (RNFL) or ganglion cell layer-inner plexiform layer (GCIPL) thickness. Results 64 OCT sans from 23 MS, and 33 scans from 12 monophasic ADS participants were compared with 68 scans from 62 healthy participants. The first ON episode had the biggest impact on RNFL or GCIPL thickness in monophasic ADS (RNFL: -7.9 µm, CI=5.5, p = 0.0056; GCIPL: -8.4 µm, CI=4.4, p = 0.0002) and MS (RNFL: -16 µm, CI = 3.7, p < 10^-6; GCIPL: -15 µm, CI = 2.6, p < 10^-6). Non-ON relapses were also associated with small but significant retinal thickness reductions in MS (RNFL: -2.6 µm/relapse, CI = 1.4, p = 0.0003; GCIPL: -2.8 µm/relapse, CI = 0.89, p < 10^-6). MS participants showed progressive GCIPL thinning independent of acute demyelinating episodes (-2.7 µm/year, CI = 1.9, p = 0.0058). Conclusions We showed a prominent impact of early ON episodes on OCT measures of neuroaxonal structure in patients with ADS. We also demonstrated negative effects of non-ON relapses, and the presence of chronic retinal neurodegenerative changes, in youth with MS.

Routine lung volume recruitment in boys with Duchenne muscular dystrophy: a randomised clinical trial

BACKGROUND

Impaired cough results in airway secretion retention, atelectasis and pneumonia in individuals with Duchenne muscular dystrophy (DMD). Lung volume recruitment (LVR) stacks breaths to inflate the lungs to greater volumes than spontaneous effort. LVR is recommended in DMD clinical care guidelines but is not well studied. We aimed to determine whether twice-daily LVR, compared with standard of care alone, attenuates the decline in FVC at 2 years in boys with DMD.

METHODS

In this multicentre, assessor-blinded, randomised controlled trial, boys with DMD, aged 6-16 years with FVC >30% predicted, were randomised to receive conventional treatment or conventional treatment plus manual LVR twice daily for 2 years. The primary outcome was FVC % predicted at 2 years, adjusted for baseline FVC % predicted, age and ambulatory status. Secondary outcomes included change in chest wall distensibility (maximal insufflation capacity minus FVC) and peak cough flow.

RESULTS

Sixty-six boys (36 in LVR group, 30 in control) were evaluated (median age (IQR): 11.5 years (9.5-13.5), median baseline FVC (IQR): 85% predicted (73-96)). Adjusted mean difference in FVC between groups at 2 years was 1.9% predicted (95% CI -6.9% to 10.7%; p=0.68) in the direction of treatment benefit. We found no differences in secondary outcomes.

CONCLUSION

There was no difference in decline in FVC % predicted with use of twice-daily LVR for boys with DMD and relatively normal lung function. The burden associated with routine LVR may outweigh the benefit. Benefits of LVR to maintain lung health in boys with worse baseline lung function still need to be clarified.

TRIAL REGISTRATION NUMBER

NCT01999075.

Efficacy and Safety of Vamorolone in Duchenne Muscular Dystrophy: A 30-Month Nonrandomized Controlled Open-Label Extension Trial

IMPORTANCE

Vamorolone is a synthetic steroidal drug with potent anti-inflammatory properties. Initial open-label, multiple ascending dose-finding studies of vamorolone among boys with Duchenne muscular dystrophy (DMD) found significant motor function improvement after 6 months treatment in higher-dose (ie, ≥2.0 mg/kg/d) groups.

OBJECTIVE

To investigate outcomes after 30 months of open-label vamorolone treatment.

DESIGN, SETTING, AND PARTICIPANTS

This nonrandomized controlled trial was conducted by the Cooperative International Neuromuscular Research Group at 11 US and non-US study sites. Participants were 46 boys ages 4.5 to 7.5 years with DMD who completed the 6-month dose-finding study. Data were analyzed from July 2020 through November 2021.

INTERVENTIONS

Participants were enrolled in a 24-month, long-term extension (LTE) study with vamorolone dose escalated to 2.0 or 6.0 mg/kg/d.

MAIN OUTCOMES AND MEASURES

Change in time-to-stand (TTSTAND) velocity from dose-finding baseline to end of LTE study was the primary outcome. Efficacy assessments included timed function tests, 6-minute walk test, and NorthStar Ambulatory Assessment (NSAA). Participants with DMD treated with glucocorticoids from the Duchenne Natural History Study (DNHS) and NorthStar United Kingdom (NSUK) Network were matched and compared with participants in the LTE study receiving higher doses of vamorolone.

RESULTS

Among 46 boys with DMD who completed the dose-finding study, 41 boys (mean [SD] age, 5.33 [0.96] years) completed the LTE study. Among 21 participants treated with higher-dose (ie, ≥2.0 mg/kg/d) vamorolone consistently throughout the 6-month dose-finding and 24-month LTE studies with data available at 30 months, there was a decrease in mean (SD) TTSTAND velocity from baseline to 30 months (0.206 [0.070] rises/s vs 0.189 (0.124) rises/s), which was not a statistically significant change (-0.011 rises/s; CI, -0.068 to 0.046 rises/s). There were no statistically significant differences between participants receiving higher-dose vamorolone and matched participants in the historical control groups receiving glucocorticoid treatment (75 patients in DNHS and 110 patients in NSUK) over a 2-year period in NSAA total score change (0.22 units vs NSUK; 95% CI, -4.48 to 4.04]; P = .92), body mass index z score change (0.002 vs DNHS SD/mo; 95% CI, -0.006 to 0.010; P = .58), or timed function test change. Vamorolone at doses up to 6.0 mg/kg/d was well tolerated, with 5 of 46 participants discontinuing prematurely and for reasons not associated with study drug. Participants in the DNHS treated with glucocorticoids had significant growth delay in comparison with participants treated with vamorolone who had stable height percentiles (0.37 percentile/mo; 95% CI, 0.23 to 0.52 percentile/mo) over time.

CONCLUSIONS AND RELEVANCE

This study found that vamorolone treatment was not associated with a change in TTSTAND velocity from baseline to 30 months among boys with DMD aged 4 to 7 years at enrollment. Vamorolone was associated with maintenance of muscle strength and function up to 30 months, similar to standard of care glucocorticoid therapy, and improved height velocity compared with growth deceleration associated with glucocorticoid treatment, suggesting that vamorolone may be an attractive candidate for treatment of DMD.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03038399.

Corneal Confocal Microscopy Predicts the Development of Diabetic Neuropathy: A Longitudinal Diagnostic Multinational Consortium Study

OBJECTIVE

Corneal nerve fiber length (CNFL) has been shown in research studies to identify diabetic peripheral neuropathy (DPN). In this longitudinal diagnostic study, we assessed the ability of CNFL to predict the development of DPN.

RESEARCH DESIGN AND METHODS

From a multinational cohort of 998 participants with type 1 and type 2 diabetes, we studied the subset of 261 participants who were free of DPN at baseline and completed at least 4 years of follow-up for incident DPN. The predictive validity of CNFL for the development of DPN was determined using time-dependent receiver operating characteristic (ROC) curves.

RESULTS

A total of 203 participants had type 1 and 58 had type 2 diabetes. Mean follow-up time was 5.8 years (interquartile range 4.2-7.0). New-onset DPN occurred in 60 participants (23%; 4.29 events per 100 person-years). Participants who developed DPN were older and had a higher prevalence of type 2 diabetes, higher BMI, and longer duration of diabetes. The baseline electrophysiology and corneal confocal microscopy parameters were in the normal range but were all significantly lower in participants who developed DPN. The time-dependent area under the ROC curve for CNFL ranged between 0.61 and 0.69 for years 1-5 and was 0.80 at year 6. The optimal diagnostic threshold for a baseline CNFL of 14.1 mm/mm² was associated with 67% sensitivity, 71% specificity, and a hazard ratio of 2.95 (95% CI 1.70-5.11; P < 0.001) for new-onset DPN.

CONCLUSIONS

CNFL showed good predictive validity for identifying patients at higher risk of developing DPN ∼6 years in the future.

Longitudinally extensive transverse myelitis with positive aquaporin-4 IgG associated with dengue infection: a case report and systematic review of cases

BACKGROUND

Neuromyelitis Optica Spectrum Disorder can be associated with parainfectious and post-infectious triggers. Dengue virus infection is one of the most common arbovirus infections in the world, and may present with neurological manifestations.

OBJECTIVES

We present a case of DENV-associated with LETM and positive aquaporin-4 IgG, and a systematic review of published cases.

METHODS

Medline (Ovid) and PubMed were search through June 2021, for case reports, series and observational studies that described patients with DENV-associated LETM and/or NMOSD.

RESULTS

An adolescent girl who had recently immigrated from a Dengue-endemic region presented with a LETM with high positive AQP4-IgG titer and seropositive DENV IgM/IgG antibodies. She responded well to steroids and subsequently started maintenance rituximab for her NMOSD diagnosis.

LITERATURE REVIEW

22 publications describing 27 patients met inclusion criteria. In addition to this case, three published cases met current criteria for NMOSD with serological evidence of acute DENV infection.

CONCLUSIONS

It is unknown whether there is a pathophysiological association between DENV infection and NMOSD. Regardless, if an immune-mediated event is suspected, particularly NMOSD, appropriate immunotherapy should be considered early. Decision regarding long term immunotherapy may depend on index of suspicion of true NMOSD, and this is where AQP4-IgG status and follow-up is helpful.

Safety, Tolerability, and Efficacy of Viltolarsen in Boys With Duchenne Muscular Dystrophy Amenable to Exon 53 Skipping: A Phase 2 Randomized Clinical Trial

Question

What are the safety, tolerability, and efficacy of viltolarsen in boys with Duchenne muscular dystrophy (DMD) amenable to exon 53 skipping?

Findings

Results of this 4-week randomized clinical trial for safety followed by a 20-week open-label treatment period in 16 patients with DMD indicated significant drug-induced dystrophin production in both viltolarsen groups (40 mg/kg per week and 80 mg/kg week) after 20 to 24 weeks of treatment. Timed function tests provided supportive evidence of treatment-related clinical improvement, and viltolarsen was well tolerated.

Meaning

Viltolarsen may provide a new therapeutic option for patients with DMD amenable to exon 53 skipping.

Importance

An unmet need remains for safe and efficacious treatments for Duchenne muscular dystrophy (DMD). To date, there are limited agents available that address the underlying cause of the disease.

Objective

To evaluate the safety, tolerability, and efficacy of viltolarsen, a novel antisense oligonucleotide, in participants with DMD amenable to exon 53 skipping.

Design, Setting, and Participants

This phase 2 study was a 4-week randomized clinical trial for safety followed by a 20-week open-label treatment period of patients aged 4 to 9 years with DMD amenable to exon 53 skipping. To enroll 16 participants, with 8 participants in each of the 2 dose cohorts, 17 participants were screened. Study enrollment occurred between December 16, 2016, and August 17, 2017, at sites in the US and Canada. Data were collected from December 2016 to February 2018, and data were analyzed from April 2018 to May 2019.

Interventions

Participants received 40 mg/kg (low dose) or 80 mg/kg (high dose) of viltolarsen administered by weekly intravenous infusion.

Main Outcomes and Measures

Primary outcomes of the trial included safety, tolerability, and de novo dystrophin protein production measured by Western blot in participants’ biceps muscles. Secondary outcomes included additional assessments of dystrophin mRNA and protein production as well as clinical muscle strength and function.

Results

Of the 16 included boys with DMD, 15 (94%) were white, and the mean (SD) age was 7.4 (1.8) years. After 20 to 24 weeks of treatment, significant drug-induced dystrophin production was seen in both viltolarsen dose cohorts (40 mg/kg per week: mean [range] 5.7% [3.2-10.3] of normal; 80 mg/kg per week: mean [range] 5.9% [1.1-14.4] of normal). Viltolarsen was well tolerated; no treatment-emergent adverse events required dose reduction, interruption, or discontinuation of the study drug. No serious adverse events or deaths occurred during the study. Compared with 65 age-matched and treatment-matched natural history controls, all 16 participants treated with viltolarsen showed significant improvements in timed function tests from baseline, including time to stand from supine (viltolarsen: −0.19 s; control: 0.66 s), time to run/walk 10 m (viltolarsen: 0.23 m/s; control: −0.04 m/s), and 6-minute walk test (viltolarsen: 28.9 m; control: −65.3 m) at the week 25 visit.

Conclusions and Relevance

Systemic treatment of participants with DMD with viltolarsen induced de novo dystrophin production, and clinical improvement of timed function tests was observed.

Trial Registration

ClinicalTrials.gov Identifier: NCT02740972

Reldesemtiv in Patients with Spinal Muscular Atrophy: a Phase 2 Hypothesis-Generating Study

This phase 2, double-blind, placebo-controlled, hypothesis-generating study evaluated the effects of oral reldesemtiv, a fast skeletal muscle troponin activator, in patients with spinal muscular atrophy (SMA). Patients ≥ 12 years of age with type II, III, or IV SMA were randomized into 2 sequential, ascending reldesemtiv dosing cohorts (cohort 1: 150 mg bid or placebo [2:1]; cohort 2: 450 mg bid or placebo [2:1]). The primary objective was to determine potential pharmacodynamic effects of reldesemtiv on 8 outcome measures in SMA, including 6-minute walk distance (6MWD) and maximum expiratory pressure (MEP). Changes from baseline to weeks 4 and 8 were determined. Pharmacokinetics and safety were also evaluated. Patients were randomized to reldesemtiv 150 mg, 450 mg, or placebo (24, 20, and 26, respectively). The change from baseline in 6MWD was greater for reldesemtiv 450 mg than for placebo at weeks 4 and 8 (least squares [LS] mean difference, 35.6 m [p = 0.0037] and 24.9 m [p = 0.058], respectively). Changes from baseline in MEP at week 8 on reldesemtiv 150 and 450 mg were significantly greater than those on placebo (LS mean differences, 11.7 [p = 0.038] and 13.2 cm H2O [p = 0.03], respectively). For 6MWD and MEP, significant changes from placebo were seen in the highest reldesemtiv peak plasma concentration quartile (Cmax > 3.29 μg/mL; LS mean differences, 43.3 m [p = 0.010] and 28.8 cm H2O [p = 0.0002], respectively). Both dose levels of reldesemtiv were well tolerated. Results suggest reldesemtiv may offer clinical benefit and support evaluation in larger SMA patient populations.

The Canadian Neuromuscular Disease Registry 2010-2019: A Decade of Facilitating Clinical Research Througha Nationwide, Pan-NeuromuscularDisease Registry

We report the recruitment activities and outcomes of a multi-disease neuromuscular patient registry in Canada. The Canadian Neuromuscular Disease Registry (CNDR) registers individuals across Canada with a confirmed diagnosis of a neuromuscular disease. Diagnosis and contact information are collected across all diseases and detailed prospective data is collected for 5 specific diseases: Amyotrophic Lateral Sclerosis (ALS), Duchenne Muscular Dystrophy (DMD), Myotonic Dystrophy (DM), Limb Girdle Muscular Dystrophy (LGMD), and Spinal Muscular Atrophy (SMA). Since 2010, the CNDR has registered 4306 patients (1154 pediatric and 3148 adult) with 91 different neuromuscular diagnoses and has facilitated 125 projects (73 academic, 3 not-for-profit, 3 government, and 46 commercial) using registry data. In conclusion, the CNDR is an effective and productive pan-neuromuscular registry that has successfully facilitated a substantial number of studies over the past 10 years.

CHRNB1-associated congenital myasthenia syndrome: Expanding the clinical spectrum

CHRNB1 encodes the β subunit of the acetylcholine receptor (AChR) at the neuromuscular junction. Inherited defects in the neuromuscular junction can lead to congenital myasthenia syndrome (CMS), a clinically and genetically heterogeneous group of disorders which includes fetal akinesia deformation sequence (FADS) on the severe end of the spectrum. Here, we report two unrelated families with biallelic CHRNB1 variants, and in each family, one child presented with lethal FADS. We contrast the diagnostic odysseys in the two families, one of which lasted 16 years while the other, utilizing rapid exome sequencing, led to specific treatment in the first 2 weeks of life. Furthermore, we note that CHRNB1 variants may be under-recognized because in both families, one of the variants is a single exon deletion that has been previously described but may not easily be detected in clinically available genetic testing.

Cost-effectiveness of fingolimod versus interferon-β1a for the treatment of pediatric-onset multiple sclerosis in Canada

AIMS

To evaluate the cost-effectiveness of fingolimod versus interferon (IFN)-β1a at a dose of 30 μg per week for the treatment of relapsing pediatric-onset multiple sclerosis (POMS) in Canada.

MATERIAL AND METHODS

A discrete-time Markov model was developed to compare fingolimod with IFN β-1a over a time horizon of two years representing patients followed up to mean age of 18 years from a Canadian health care system perspective. Twenty-one health states based on the Expanded Disability Status Scale (EDSS) were considered: EDSS 0‒9 for relapsing multiple sclerosis (MS), EDSS 0‒9 for secondary progressive MS, and "Death." Relative treatment efficacy for fingolimod versus IFN-β1a was estimated from the PARADIGMS study. Costs and resource use were obtained from published literature and Canadian sources. Utilities were estimated by mapping the Pediatric Quality of Life inventory data onto the Child Health Utility Index-9 Dimension using a published mapping algorithm. Future costs and benefits were discounted at 1.5% per annum.

RESULTS

Compared with IFN β-1a, fingolimod led to an increase in quality-adjusted life-years (QALYs) (0.125) with incremental costs (Canadian dollars [CAD] 2,977) and to an incremental cost-effectiveness ratio (ICER) of CAD 23,886/QALY over a time horizon of two years representing patients followed up to mean age of 18 years. The monetary benefits of fingolimod treatment versus IFN β-1a at a willingness-to-pay (WTP) threshold of CAD 50,000 per QALY gained were higher than the costs. One-way sensitivity analysis and probabilistic sensitivity analysis (PSA) both confirmed the robustness of the results.

LIMITATIONS

The main limitations of this analysis primarily stem from the limited data availability in POMS.

CONCLUSIONS

Fingolimod is cost effective compared with IFN β-1a for the treatment of POMS over a time horizon of two years representing patients followed up to a mean age of 18 years in Canada.

Multi-Omics Identifies Circulating miRNA and Protein Biomarkers for Facioscapulohumeral Dystrophy

The development of therapeutics for muscle diseases such as facioscapulohumeral dystrophy (FSHD) is impeded by a lack of objective, minimally invasive biomarkers. Here we identify circulating miRNAs and proteins that are dysregulated in early-onset FSHD patients to develop blood-based molecular biomarkers. Plasma samples from clinically characterized individuals with early-onset FSHD provide a discovery group and are compared to healthy control volunteers. Low-density quantitative polymerase chain reaction (PCR)-based arrays identify 19 candidate miRNAs, while mass spectrometry proteomic analysis identifies 13 candidate proteins. Bioinformatic analysis of chromatin immunoprecipitation (ChIP)-seq data shows that the FSHD-dysregulated DUX4 transcription factor binds to regulatory regions of several candidate miRNAs. This panel of miRNAs also shows ChIP signatures consistent with regulation by additional transcription factors which are up-regulated in FSHD (FOS, EGR1, MYC, and YY1). Validation studies in a separate group of patients with FSHD show consistent up-regulation of miR-100, miR-103, miR-146b, miR-29b, miR-34a, miR-454, miR-505, and miR-576. An increase in the expression of S100A8 protein, an inflammatory regulatory factor and subunit of calprotectin, is validated by Enzyme-Linked Immunosorbent Assay (ELISA). Bioinformatic analyses of proteomics and miRNA data further support a model of calprotectin and toll-like receptor 4 (TLR4) pathway dysregulation in FSHD. Moving forward, this panel of miRNAs, along with S100A8 and calprotectin, merit further investigation as monitoring and pharmacodynamic biomarkers for FSHD.

Meta-analyses of ataluren randomized controlled trials in nonsense mutation Duchenne muscular dystrophy

Aim: Assess the totality of efficacy evidence for ataluren in patients with nonsense mutation Duchenne muscular dystrophy (nmDMD). Materials & methods: Data from the two completed randomized controlled trials (ClinicalTrials.gov: NCT00592553; NCT01826487) of ataluren in nmDMD were combined to examine the intent-to-treat (ITT) populations and two patient subgroups (baseline 6-min walk distance [6MWD] ≥300–<400 or <400 m). Meta-analyses examined 6MWD change from baseline to week 48. Results: Statistically significant differences in 6MWD change with ataluren versus placebo were observed across all three meta-analyses. Least-squares mean difference (95% CI): ITT (n = 342), +17.2 (0.2–34.1) m, p = 0.0473; ≥300–<400 m (n = 143), +43.9 (18.2–69.6) m, p = 0.0008; <400 m (n = 216), +27.7 (6.4–49.0) m, p = 0.0109. Conclusion: These meta-analyses support previous evidence for ataluren in slowing disease progression versus placebo in patients with nmDMD over 48 weeks. Treatment benefit was most evident in patients with a baseline 6MWD ≥300–<400 m (the ambulatory transition phase), thereby informing future trial design.

Efficacy and safety of vamorolone in Duchenne muscular dystrophy: An 18-month interim analysis of a non-randomized open-label extension study

BACKGROUND

Treatment with corticosteroids is recommended for Duchenne muscular dystrophy (DMD) patients to slow the progression of weakness. However, chronic corticosteroid treatment causes significant morbidities. Vamorolone is a first-in-class anti-inflammatory investigational drug that has shown evidence of efficacy in DMD after 24 weeks of treatment at 2.0 or 6.0 mg/kg/day. Here, open-label efficacy and safety experience of vamorolone was evaluated over a period of 18 months in trial participants with DMD.

METHODS AND FINDINGS

A multicenter, open-label, 24-week trial (VBP15-003) with a 24-month long-term extension (VBP15-LTE) was conducted by the Cooperative International Neuromuscular Research Group (CINRG) and evaluated drug-related effects of vamorolone on motor outcomes and corticosteroid-associated safety concerns. The study was carried out in Canada, US, UK, Australia, Sweden, and Israel, from 2016 to 2019. This report covers the initial 24-week trial and the first 12 months of the VBP15-LTE trial (total treatment period 18 months). DMD trial participants (males, 4 to <7 years at entry) treated with 2.0 or 6.0 mg/kg/day vamorolone for the full 18-month period (n = 23) showed clinical improvement of all motor outcomes from baseline to month 18 (time to stand velocity, p = 0.012 [95% CI 0.010, 0.068 event/second]; run/walk 10 meters velocity, p < 0.001 [95% CI 0.220, 0.491 meters/second]; climb 4 stairs velocity, p = 0.001 [95% CI 0.034, 0.105 event/second]; 6-minute walk test, p = 0.001 [95% CI 31.14, 93.38 meters]; North Star Ambulatory Assessment, p < 0.001 [95% CI 2.702, 6.662 points]). Outcomes in vamorolone-treated DMD patients (n = 46) were compared to group-matched participants in the CINRG Duchenne Natural History Study (corticosteroid-naïve, n = 19; corticosteroid-treated, n = 68) over a similar 18-month period. Time to stand was not significantly different between vamorolone-treated and corticosteroid-naïve participants (p = 0.088; least squares [LS] mean 0.042 [95% CI -0.007, 0.091]), but vamorolone-treated participants showed significant improvement compared to group-matched corticosteroid-naïve participants for run/walk 10 meters velocity (p = 0.003; LS mean 0.286 [95% CI 0.104, 0.469]) and climb 4 stairs velocity (p = 0.027; LS mean 0.059 [95% CI 0.007, 0.111]). The vamorolone-related improvements were similar in magnitude to corticosteroid-related improvements. Corticosteroid-treated participants showed stunting of growth, whereas vamorolone-treated trial participants did not (p < 0.001; LS mean 15.86 [95% CI 8.51, 23.22]). Physician-reported incidences of adverse events (AEs) for Cushingoid appearance, hirsutism, weight gain, and behavior change were less for vamorolone than published incidences for prednisone and deflazacort. Key limitations to the study were the open-label design, and use of external comparators.

CONCLUSIONS

We observed that vamorolone treatment was associated with improvements in some motor outcomes as compared with corticosteroid-naïve individuals over an 18-month treatment period. We found that fewer physician-reported AEs occurred with vamorolone than have been reported for treatment with prednisone and deflazacort, and that vamorolone treatment did not cause the stunting of growth seen with these corticosteroids. This Phase IIa study provides Class III evidence to support benefit of motor function in young boys with DMD treated with vamorolone 2.0 to 6.0 mg/kg/day, with a favorable safety profile. A Phase III RCT is underway to further investigate safety and efficacy.

TRIAL REGISTRATION

Clinical trials were registered at www.clinicaltrials.gov, and the links to each trial are as follows (as provided in manuscript text): VBP15-002 [NCT02760264] VBP15-003 [NCT02760277] VBP15-LTE [NCT03038399].

The CINRG Becker Natural History Study: Baseline characteristics

We performed an observational, natural history study of males with in-frame dystrophin gene deletions causing Becker muscular dystrophy (BMD). A prospective natural history study collected longitudinal medical, strength, and timed function assessments. Eighty-three participants with genetically confirmed BMD were enrolled (age range 5.6-75.4 years). Lower extremity function and the percentage of participants who retained ambulation declined across the age span. The largest single group of participants had in-frame deletions that corresponded to an out-of-frame deletion treated with an exon 45 skip to restore the reading frame. This group of 54 participants showed similarities in baseline motor functional assessments when compared to the group of all others in the study. A prospective natural history cohort with in-frame dystrophin gene deletions offers the potential to contribute to clinical trial readiness for BMD and to analyze therapeutic benefit of exon skipping for Duchenne muscular dystrophy.

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.

Phase IIa trial in Duchenne muscular dystrophy shows vamorolone is a first-in-class dissociative steroidal anti-inflammatory drug

We report a first-in-patient study of vamorolone, a first-in-class dissociative steroidal anti-inflammatory drug, in Duchenne muscular dystrophy. This 2-week, open-label Phase IIa multiple ascending dose study (0.25, 0.75, 2.0, and 6.0 mg/kg/day) enrolled 48 boys with Duchenne muscular dystrophy (4 to <7 years), with outcomes including clinical safety, pharmacokinetics and pharmacodynamic biomarkers. The study design included pharmacodynamic biomarkers in three contexts of use: 1. Secondary outcomes for pharmacodynamic safety (insulin resistance, adrenal suppression, bone turnover); 2. Exploratory outcomes for drug mechanism of action; 3. Exploratory outcomes for expanded pharmacodynamic safety. Vamorolone was safe and well-tolerated through the highest dose tested (6.0 mg/kg/day) and pharmacokinetics of vamorolone were similar to prednisolone. Using pharmacodynamic biomarkers, the study demonstrated improved safety of vamorolone versus glucocorticoids as shown by reduction of insulin resistance, beneficial changes in bone turnover (loss of increased bone resorption and decreased bone formation only at the highest dose level), and a reduction in adrenal suppression. Exploratory biomarkers of pharmacodynamic efficacy showed an anti-inflammatory mechanism of action and a beneficial effect on plasma membrane stability, as demonstrated by a dose-responsive decrease in serum creatine kinase activity. With an array of pre-selected biomarkers in multiple contexts of use, we demonstrate the development of the first dissociative steroid that preserves anti-inflammatory efficacy and decreases steroid-associated safety concerns. Ongoing extension studies offer the potential to bridge exploratory efficacy biomarkers to clinical outcomes.

Corneal confocal microscopy for identification of diabetic sensorimotor polyneuropathy: a pooled multinational consortium study

AIMS/HYPOTHESIS

Small cohort studies raise the hypothesis that corneal nerve abnormalities (including corneal nerve fibre length [CNFL]) are valid non-invasive imaging endpoints for diabetic sensorimotor polyneuropathy (DSP). We aimed to establish concurrent validity and diagnostic thresholds in a large cohort of participants with and without DSP.

METHODS

Nine hundred and ninety-eight participants from five centres (516 with type 1 diabetes and 482 with type 2 diabetes) underwent CNFL quantification and clinical and electrophysiological examination. AUC and diagnostic thresholds were derived and validated in randomly selected samples using receiver operating characteristic analysis. Sensitivity analyses included latent class models to address the issue of imperfect reference standard.

RESULTS

Type 1 and type 2 diabetes subcohorts had mean age of 42 ± 19 and 62 ± 10 years, diabetes duration 21 ± 15 and 12 ± 9 years and DSP prevalence of 31% and 53%, respectively. Derivation AUC for CNFL was 0.77 in type 1 diabetes (p < 0.001) and 0.68 in type 2 diabetes (p < 0.001) and was approximately reproduced in validation sets. The optimal threshold for automated CNFL was 12.5 mm/mm² in type 1 diabetes and 12.3 mm/mm² in type 2 diabetes. In the total cohort, a lower threshold value below 8.6 mm/mm² to rule in DSP and an upper value of 15.3 mm/mm² to rule out DSP were associated with 88% specificity and 88% sensitivity.

CONCLUSIONS/INTERPRETATION

We established the diagnostic validity and common diagnostic thresholds for CNFL in type 1 and type 2 diabetes. Further research must determine to what extent CNFL can be deployed in clinical practice and in clinical trials assessing the efficacy of disease-modifying therapies for DSP.

Current and Emerging Therapies for Duchenne Muscular Dystrophy

PURPOSE OF REVIEW

The purpose of this review is to summarize the current and emerging therapies for Duchenne muscular dystrophy (DMD).

RECENT FINDINGS

Coinciding with new standardized care guidelines, there are a growing number of therapeutic options to treat males with DMD. Treatment of the underlying pathobiology, such as micro-dystrophin gene replacement, exon skipping, stop codon read-through agents, and utrophin modulators showed variable success in animal and human studies. Symptomatic therapies to target muscle ischemia, enhance muscle regeneration, prevent muscle fibrosis, inhibit myostatin, and reduce inflammation are also under investigation. DMD is a complex, heterogeneous degenerative disease. The pharmacological and technological achievements made in recent years, plus timely supportive interventions will likely lead to an improved quality of life for many individuals with DMD.

A checklist for clinical trials in rare disease: obstacles and anticipatory actions-lessons learned from the FOR-DMD trial

Background

Trials in rare diseases have many challenges, among which are the need to set up multiple sites in different countries to achieve recruitment targets and the divergent landscape of clinical trial regulations in those countries. Over the past years, there have been initiatives to facilitate the process of international study set-up, but the fruits of these deliberations require time to be operationally in place. FOR-DMD (Finding the Optimum Steroid Regimen for Duchenne Muscular Dystrophy) is an academic-led clinical trial which aims to find the optimum steroid regimen for Duchenne muscular dystrophy, funded by the National Institutes of Health (NIH) for 5 years (July 2010 to June 2015), anticipating that all sites (40 across the USA, Canada, the UK, Germany and Italy) would be open to recruitment from July 2011. However, study start-up was significantly delayed and recruitment did not start until January 2013.

Method

The FOR-DMD study is used as an example to identify systematic problems in the set-up of international, multi-centre clinical trials. The full timeline of the FOR-DMD study, from funding approval to site activation, was collated and reviewed. Systematic issues were identified and grouped into (1) study set-up, e.g. drug procurement; (2) country set-up, e.g. competent authority applications; and (3) site set-up, e.g. contracts, to identify the main causes of delay and suggest areas where anticipatory action could overcome these obstacles in future studies.

Results

Time from the first contact to site activation across countries ranged from 6 to 24 months. Reasons of delay were universal (sponsor agreement, drug procurement, budgetary constraints), country specific (complexity and diversity of regulatory processes, indemnity requirements) and site specific (contracting and approvals). The main identified obstacles included (1) issues related to drug supply, (2) NIH requirements regarding contracting with non-US sites, (3) differing regulatory requirements in the five participating countries, (4) lack of national harmonisation with contracting and the requirement to negotiate terms and contract individually with each site and (5) diversity of languages needed for study materials. Additionally, as with many academic-led studies, the FOR-DMD study did not have access to the infrastructure and expertise that a contracted research organisation could provide, organisations often employed in pharmaceutical-sponsored studies. This delay impacted recruitment, challenged the clinical relevance of the study outcomes and potentially delayed the delivery of the best treatment to patients.

Conclusion

Based on the FOR-DMD experience, and as an interim solution, we have devised a checklist of steps to not only anticipate and minimise delays in academic international trial initiation but also identify obstacles that will require a concerted effort on the part of many stakeholders to mitigate.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2645-0) contains supplementary material, which is available to authorized users.

A multinational study on motor function in early-onset FSHD

OBJECTIVES

To investigate motor function associations with age, sex, and D4Z4 repeats among participants with early-onset facioscapulohumeral muscular dystrophy (FSHD) type 1 as defined by weakness onset before 10 years of age.

METHODS

We collected standardized motor assessments, including manual muscle testing (MMT), quantitative muscle testing, functional motor evaluations, and clinical severity scores (CSSs), at 12 Cooperative International Neuromuscular Research Group centers. To measure associations, we used linear regression models adjusted for sex, evaluation age, age at onset of weakness, and D4Z4 repeats.

RESULTS

Among 52 participants (60% female, mean age 22.9 ± 14.7 years), weakness was most pronounced in the shoulder and abdominal musculature. Older enrollment age was associated with greater CSSs (p = 0.003). When adjusted for enrollment age, sex, and D4Z4 repeats, younger age at onset of facial weakness was associated with greater CSSs, slower velocities in timed function tests, and lower MMT scores (p < 0.05).

CONCLUSION

Significant clinical variability was observed in early-onset FSHD. Earlier age at onset of facial weakness was associated with greater disease severity. Longitudinal assessments are needed to determine the rate of disease progression in this population.

An Overview of Congenital Myopathies

PURPOSE OF REVIEW

This article uses a case-based approach to highlight the clinical features as well as recent advances in molecular genetics, muscle imaging, and pathophysiology of the congenital myopathies.

RECENT FINDINGS

Congenital myopathies refer to a heterogeneous group of genetic neuromuscular disorders characterized by early-onset muscle weakness, hypotonia, and developmental delay. Congenital myopathies are further classified into core myopathies, centronuclear myopathies, nemaline myopathies, and congenital fiber-type disproportion based on the key pathologic features found in muscle biopsies. Genotype and phenotype correlations are hampered by the diverse clinical variability of the genes responsible for congenital myopathies, ranging from a severe neonatal course with early death to mildly affected adults with late-onset disease. An increasing number of genes have been identified, which, in turn, are associated with overlapping morphologic changes in the myofibers. Precise genetic diagnosis has important implications for disease management, including family counseling; avoidance of anesthetic-related muscle injury for at-risk individuals; monitoring for potential cardiac, respiratory, or orthopedic complications; as well as for participation in clinical trials or potential genetic therapies.

SUMMARY

Collaboration with neuromuscular experts, geneticists, neuroradiologists, neuropathologists, and other specialists is needed to ensure accurate and timely diagnosis based on clinical and pathologic features. An integrated multidisciplinary model of care based on expert-guided standards will improve quality of care and optimize outcomes for patients and families with congenital myopathies.

Echocardiographic Image Quality Deteriorates with Age in Children and Young Adults with Duchenne Muscular Dystrophy

Background

Advances in medical care for patients with Duchenne muscular dystrophy (DMD) have resulted in improved survival and an increased prevalence of cardiomyopathy. Serial echocardiographic surveillance is recommended to detect early cardiac dysfunction and initiate medical therapy. Clinical anecdote suggests that echocardiographic quality diminishes over time, impeding accurate assessment of left ventricular systolic function. Furthermore, evidence-based guidelines for the use of cardiac imaging in DMD, including cardiac magnetic resonance imaging (CMR), are limited. The objective of our single-center, retrospective study was to quantify the deterioration in echocardiographic image quality with increasing patient age and identify an age at which CMR should be considered.

Methods

We retrospectively reviewed and graded the image quality of serial echocardiograms obtained in young patients with DMD. The quality of 16 left ventricular segments in two echocardiographic views was visually graded using a binary scoring system. An endocardial border delineation percentage (EBDP) score was calculated by dividing the number of segments with adequate endocardial delineation in each imaging window by the total number of segments present in that window and multiplying by 100. Linear regression analysis was performed to model the relationship between the EBDP scores and patient age.

Results

Fifty-five echocardiograms from 13 patients (mean age 11.6 years, range 3.6–19.9) were systematically reviewed. By 13 years of age, 50% of the echocardiograms were classified as suboptimal with ≥30% of segments inadequately visualized, and by 15 years of age, 78% of studies were suboptimal. Linear regression analysis revealed a negative correlation between patient age and EBDP score (r = −2.49, 95% confidence intervals −4.73, −0.25; p = 0.032), with the score decreasing by 2.5% for each 1 year increase in age.

Conclusion

Echocardiographic image quality declines with increasing age in DMD. Alternate imaging modalities may play a role in cases of poor echocardiographic image quality.

The Canadian Neuromuscular Disease Registry: Connecting patients to national and international research opportunities

Introduction

Patient registries serve an important role in rare disease research, particularly for the recruitment and planning of clinical trials. The Canadian Neuromuscular Disease Registry was established with the primary objective of improving the future for neuromuscular (NM) patients through the enablement and support of research into potential treatments.

Methods

In this report, we discuss design and utilization of the Canadian Neuromuscular Disease Registry with special reference to the paediatric cohort currently enrolled in the registry.

Results

As of July 25, 2017, there are 658 paediatric participants enrolled in the registry, 249 are dystrophinopathies (229 are Duchenne muscular dystrophy), 57 are myotonic dystrophy participants, 98 spinal muscular atrophy participants and 65 are limb girdle muscular dystrophy. A total of 175 patients have another NM diagnosis. The registry has facilitated 20 clinical trial inquiries, 5 mail-out survey studies and 5 other studies in the paediatric population.

Discussion

The strengths of the registry are discussed. The registry has proven to be an invaluable tool to NM disease research and has increased Canada's visibility as a competitive location for the conduct of clinical trials for NM therapies.

Early onset facioscapulohumeral dystrophy - a systematic review using individual patient data

Infantile or early onset is estimated to occur in around 10% of all facioscapulohumeral dystrophy (FSHD) patients. Although small series of early onset FSHD patients have been reported, comprehensive data on the clinical phenotype is missing. We performed a systematic literature search on the clinical features of early onset FSHD comprising a total of 43 articles with individual data on 227 patients. Additional data from four cohorts was provided by the authors. Mean age at reporting was 18.8 years, and 40% of patients were wheelchair-dependent at that age. Half of the patients had systemic features, including hearing loss (40%), retinal abnormalities (37%) and developmental delay (8%). We found an inverse correlation between repeat size and disease severity, similar to adult-onset FSHD. De novo FSHD1 mutations were more prevalent than in adult-onset FSHD. Compared to adult FSHD, our findings indicate that early onset FSHD is overall characterized by a more severe muscle phenotype and a higher prevalence of systemic features. However, similar as in adults, a significant clinical heterogeneity was observed. Based on this, we consider early onset FSHD to be on the severe end of the FSHD disease spectrum. We found natural history studies and treatment studies to be very scarce in early onset FSHD, therefore longitudinal studies are needed to improve prognostication, clinical management and trial-readiness.

Impact of an electronic monitoring device and behavioral feedback on adherence to multiple sclerosis therapies in youth: results of a randomized trial

PURPOSE

To report the results of a randomized controlled trial using an electronic monitoring device (EM) plus a motivational interviewing (MI) intervention to enhance adherence to disease-modifying therapies (DMT) in pediatric MS.

METHODS

Fifty-two youth with MS (16.03 ± 2.2 years) were randomized to receive either MI (n = 25) (target intervention) or a MS medication video (n = 27) (attention control). Primary endpoint was change in adherence. Secondary outcomes included changes in quality of life, well-being and self-efficacy. Random effects modeling and Cohen's effect size computation evaluated intervention impact.

RESULTS

Longitudinal random effect models revealed that the MI group decreased their EM adherence (GroupxTime interaction = -0.19), while increasing frequency of parental DMT reminder (26.01)/administration (11.69). We found decreased EM use in the MI group at 6 months (Cohen's d = -0.61), but increased pharmacy refill adherence (d = 0.23). Parental reminders about medication increased in MI subjects vs controls (d = 0.59 at 3 months; d = 0.70 at 6 months). We found increases in self-reported adherence (d = 0.21) at 3 but not 6 months, fewer barriers to adherence at three (d = -0.58) and six months (d = -0.31), better physical (d = 0.23 at 3 months; d = 0.45 at 6 months), emotional (d = 0.25 at 3 months) and self-efficacy function (d = 0.55 at 3 months; 0.48 at 6 months), but worse well-being, including self-acceptance (d = -0.53 at 6 months) and environmental mastery (d = -0.42 at 3 and 6 months) in intervention as compared to control patients.

CONCLUSIONS

Participants receiving MI + EM experienced worsening on objective measures of adherence and increased parental involvement, but improved on some self- and parent-reported measures. MI participants reported improvements in quality of life and self-efficacy, but worsened well-being.

A Pediatric Review of Facioscapulohumeral Muscular Dystrophy

Facioscapulohumeral dystrophy is one of the most common forms of muscular dystrophies worldwide. It is a complex and heterogeneous disease secondary to insufficient epigenetic repression of D4Z4 repeats and aberrant expression of DUX4 in skeletal muscles. Type 1 facioscapulohumeral muscular dystrophy (FSHD) is caused by contraction of D4Z4 repeats on 4q35, whereas type 2 FSHD is associated with mutations of the SMCHD1 or DNMT3B gene in the presence of a disease-permissive 4qA haplotype. Classical FSHD is a slowly progressive disorder with gradual-onset of muscle atrophy and a descending pattern of muscle weakness. In contrast, early-onset FSHD is associated with a large deletion of D4Z4 repeats and a more severe disease phenotype, including early loss of independent ambulation as well as extramuscular manifestations, such as retinal vasculopathy, hearing loss, and central nervous system (CNS) involvement. However, the correlation between D4Z4 repeats and disease severity remains imprecise. The current standard of care guidelines offers comprehensive assessment and symptomatic management of secondary complications. Several clinical trials are currently underway for FSHD. New and emerging treatments focus on correcting the transcriptional misregulation of D4Z4 and reversing the cytotoxic effects of DUX4. Other potential therapeutic targets include reduction of inflammation, improving muscle mass, and activating compensatory molecular pathways. The utility of disease-modifying treatments will depend on selection of sensitive clinical endpoints as well as validation of muscle magnetic resonance imaging (MRI) and other biomarkers to detect meaningful changes in disease progression. Correction of the epigenetic defects using new gene editing as well as other DUX4 silencing technologies offers potential treatment options for many individuals with FSHD.

Developing standardized corticosteroid treatment for Duchenne muscular dystrophy

Despite corticosteroids being the only treatment documented to improve strength and function in boys with Duchenne muscular dystrophy (DMD) corticosteroid prescription is inconsistent and in some countries, corticosteroids are not prescribed. We are conducting a clinical trial that (1) compares the 3 most frequently prescribed corticosteroid regimes; (2) standardizes treatment of DMD complications; and (3) standardizes prevention of corticosteroid side effects. Investigators at 38 sites in 5 countries plan to recruit 300 boys aged 4-7 who are randomly assigned to one of three regimens: daily prednisone; daily deflazacort; or intermittent prednisone (10days on/10days off). Boys are followed for a minimum of 3years to assess the relative effectiveness and adverse event profiles of the different regimens. The primary outcome is a 3-dimensional variable consisting of log-transformed time to rise from the floor, forced vital capacity, and subject/parent satisfaction with treatment, each averaged over all post-baseline visits. The study protocol includes evidence- and consensus-based treatment of DMD complications and of corticosteroid side effects. This study seeks to establish a standard corticosteroid regimen for DMD. Since all new interventions for DMD are being developed as add-on therapies to corticosteroids, defining the optimum regimen is of importance for all new treatments.

Longitudinal Outcomes in the 2014 Acute Flaccid Paralysis Cluster in Canada

We describe the presenting features and long-term outcome of an unusual cluster of pediatric acute flaccid paralysis cases that occurred in Canada during the 2014 enterovirus D68 outbreak. Children (n = 25; median age 7.8 years) presenting to Canadian centers between July 1 and October 31, 2014, and who met diagnostic criteria for acute flaccid paralysis were evaluated retrospectively. The predominant presenting features included prodromal respiratory illness (n = 22), cerebrospinal fluid lymphocytic pleocytosis (n = 18), pain in neck/back (n = 14) and extremities (n = 10), bowel/bladder dysfunction (n = 9), focal central gray matter lesions found in all regions of the spinal cord within the cohort (n = 16), brain stem lesions (n = 8), and bulbar symptoms (n = 5). Enterovirus D68 was detectable in nasopharyngeal specimens (n = 7) but not in cerebrospinal fluid. Acute therapies (corticosteroids, intravenous immunoglobulins, plasmapheresis) were well tolerated with few side effects. Fourteen of 16 patients who were followed beyond 12 months post onset had neurologic deficits but showed ongoing clinical improvement and motor recovery.

Risk factors for non-adherence to disease-modifying therapy in pediatric multiple sclerosis

BACKGROUND

Adherence to disease-modifying therapies (DMTs) in pediatric multiple sclerosis (MS) is not well understood. We examined the prevalence and risk factors for poor adherence in pediatric MS.

METHODS

This cross-sectional study recruited youth with MS from 12 North American pediatric MS clinics. In addition to pharmacy-refill data, patients and parents completed self-report measures of adherence and quality of life. Additionally, patients completed measures of self-efficacy and well-being. Factor analysis and linear regression methods were used.

RESULTS

A total of 66 youth (mean age, 15.7 years) received MS DMTs (33% oral, 66% injectable). Estimates of poor adherence (i.e. missing >20% of doses) varied by source: pharmacy 7%, parent 14%, and patient 41%. Factor analysis yielded two composites: adherence summary and parental involvement in adherence. Regressions revealed that patients with better self-reported physical functioning were more adherent. Parents were more likely to be involved in adherence when their child had worse parent-reported PedsQL School Functioning and lower MS Self-Efficacy Control. Oral DMTs were associated with lesser parental involvement in adherence.

CONCLUSION

Rates of non-adherence varied by information source. Better self-reported physical functioning was the strongest predictor of adherence. Parental involvement in adherence was associated with worse PedsQL School Functioning and lower MS Self-Efficacy-measured confidence in controlling MS.

Myostatin inhibitor ACE-031 treatment of ambulatory boys with Duchenne muscular dystrophy: Results of a randomized, placebo-controlled clinical trial

INTRODUCTION

ACE-031 is a fusion protein of activin receptor type IIB and IgG1-Fc, which binds myostatin and related ligands. It aims to disrupt the inhibitory effect on muscle development and provide potential therapy for myopathies like Duchenne muscular dystrophy (DMD).

METHODS

ACE-031 was administered subcutaneously every 2-4 weeks to DMD boys in a randomized, double-blind, placebo-controlled, ascending-dose trial. The primary objective was safety evaluation. Secondary objectives included characterization of pharmacokinetics and pharmacodynamics.

RESULTS

ACE-031 was not associated with serious or severe adverse events. The study was stopped after the second dosing regimen due to potential safety concerns of epistaxis and telangiectasias. A trend for maintenance of the 6-minute walk test (6MWT) distance in the ACE-031 groups compared with a decline in the placebo group (not statistically significant) was noted, as was a trend for increased lean body mass and bone mineral density (BMD) and reduced fat mass.

CONCLUSION

ACE-031 use demonstrated trends for pharmacodynamic effects on lean mass, fat mass, BMD, and 6MWT. Non-muscle-related adverse events contributed to the decision to discontinue the study. Myostatin inhibition is a promising therapeutic approach for DMD. Muscle Nerve 55: 458-464, 2017.

The Role of PIEZO2 in Human Mechanosensation

BACKGROUND

The senses of touch and proprioception evoke a range of perceptions and rely on the ability to detect and transduce mechanical force. The molecular and neural mechanisms underlying these sensory functions remain poorly defined. The stretch-gated ion channel PIEZO2 has been shown to be essential for aspects of mechanosensation in model organisms.

METHODS

We performed whole-exome sequencing analysis in two patients who had unique neuromuscular and skeletal symptoms, including progressive scoliosis, that did not conform to standard diagnostic classification. In vitro and messenger RNA assays, functional brain imaging, and psychophysical and kinematic tests were used to establish the effect of the genetic variants on protein function and somatosensation.

RESULTS

Each patient carried compound-inactivating variants in PIEZO2, and each had a selective loss of discriminative touch perception but nevertheless responded to specific types of gentle mechanical stimulation on hairy skin. The patients had profoundly decreased proprioception leading to ataxia and dysmetria that were markedly worse in the absence of visual cues. However, they had the ability to perform a range of tasks, such as walking, talking, and writing, that are considered to rely heavily on proprioception.

CONCLUSIONS

Our results show that PIEZO2 is a determinant of mechanosensation in humans. (Funded by the National Institutes of Health Intramural Research Program.).

Serum pharmacodynamic biomarkers for chronic corticosteroid treatment of children

Corticosteroids are extensively used in pediatrics, yet the burden of side effects is significant. Availability of a simple, fast, and reliable biochemical read out of steroidal drug pharmacodynamics could enable a rapid and objective assessment of safety and efficacy of corticosteroids and aid development of corticosteroid replacement drugs. To identify potential corticosteroid responsive biomarkers we performed proteome profiling of serum samples from DMD and IBD patients with and without corticosteroid treatment using SOMAscan aptamer panel testing 1,129 proteins in <0.1 cc of sera. Ten pro-inflammatory proteins were elevated in untreated patients and suppressed by corticosteroids (MMP12, IL22RA2, CCL22, IGFBP2, FCER2, LY9, ITGa1/b1, LTa1/b2, ANGPT2 and FGG). These are candidate biomarkers for anti-inflammatory efficacy of corticosteroids. Known safety concerns were validated, including elevated non-fasting insulin (insulin resistance), and elevated angiotensinogen (salt retention). These were extended by new candidates for metabolism disturbances (leptin, afamin), stunting of growth (growth hormone binding protein), and connective tissue remodeling (MMP3). Significant suppression of multiple adrenal steroid hormones was also seen in treated children (reductions of 17-hydroxyprogesterone, corticosterone, 11-deoxycortisol and testosterone). A panel of new pharmacodynamic biomarkers for corticosteroids in children was defined. Future studies will need to bridge specific biomarkers to mechanism of drug action, and specific clinical outcomes.

Facioscapulohumeral dystrophy in children: design of a prospective, observational study on natural history, predictors and clinical impact (iFocus FSHD)

Background

Facioscapulohumeral muscular dystrophy (FSHD; OMIM 158900 & 158901) is a progressive skeletal muscle dystrophy, characterized by an autosomal dominant inheritance pattern. One of the major unsolved questions in FSHD is the marked clinical heterogeneity, ranging from asymptomatic individuals to severely affected patients with an early onset. An estimated 10 % of FSHD patients have an early onset (onset before 10 years of age) and are traditionally classified as infantile FSHD. This subgroup is regarded as severely affected and extra-muscular symptoms, such as hearing loss and retinopathy, are frequently described. However, information on the prevalence, natural history and clinical management of early onset FSHD is currently lacking, thereby hampering adequate patient counselling and management. Therefore, a population-based prospective cohort study on FSHD in children is highly needed.

Methods/design

This explorative study aims to recruit all children (aged 0–17 years) with a genetically confirmed diagnosis of FSHD in The Netherlands. The children will be assessed at baseline and at 2-year follow-up. The general aim of the study is the description of the clinical features and genetic characteristics of this paediatric cohort. The primary outcome is the motor function as measured by the Motor Function Measure. Secondary outcomes include quantitative and qualitative description of the clinical phenotype, muscle imaging, genotyping and prevalence estimations. The ultimate objective will be a thorough description of the natural history, predictors of disease severity and quality of life in children with FSHD.

Discussion

The results of this population-based study are vital for adequate patient management and clinical trial-readiness. Furthermore, this study is expected to provide additional insight in the epigenetic and environmental disease modifying factors. In addition to improve counselling, this could contribute to unravelling the aetiology of FSHD.

Trial registration

clinicaltrials.gov NCT02625662.