To assess the current use of glucocorticoids (GCs) in Duchenne muscular dystrophy in the UK, and compare the benefits and the adverse events of daily versus intermittent prednisolone regimens.
A ...prospective longitudinal observational study across 17 neuromuscular centres in the UK of 360 boys aged 3-15 years with confirmed Duchenne muscular dystrophy who were treated with daily or intermittent (10 days on/10 days off) prednisolone for a mean duration of treatment of 4 years.
The median loss of ambulation was 12 years in intermittent and 14.5 years in daily treatment; the HR for intermittent treatment was 1.57 (95% CI 0.87 to 2.82). A fitted multilevel model comparing the intermittent and daily regiments for the NorthStar Ambulatory Assessment demonstrated a divergence after 7 years of age, with boys on an intermittent regimen declining faster (p<0.001). Moderate to severe side effects were more commonly reported and observed in the daily regimen, including Cushingoid features, adverse behavioural events and hypertension. Body mass index mean z score was higher in the daily regimen (1.99, 95% CI 1.79 to 2.19) than in the intermittent regimen (1.51, 95% CI 1.27 to 1.75). Height restriction was more severe in the daily regimen (mean z score -1.77, 95% CI -1.79 to -2.19) than in the intermittent regimen (mean z score -0.70, 95% CI -0.90 to -0.49).
Our study provides a framework for providing information to patients with Duchenne muscular dystrophy and their families when introducing GC therapy. The study also highlights the importance of collecting longitudinal natural history data on patients treated according to standardised protocols, and clearly identifies the benefits and the side-effect profile of two treatment regimens, which will help with informed choices and implementation of targeted surveillance.
•This study contributes to the natural history of DMD, linking the ambulant and non-ambulant phases.•Respiratory measurements, upper limb function, pinch and grip force are reported.•A composite ...score combining respiratory outcomes, upper limb function and strength is explored.
The field of translational research in Duchenne muscular dystrophy (DMD) has been transformed in the last decade by a number of therapeutic targets, mostly studied in ambulant patients. A paucity of studies focus on measures that capture the non-ambulant stage of the disease, and the transition between the ambulant and non-ambulant phase. In this prospective natural history study, we report the results of a comprehensive assessment of respiratory, upper limb function and upper limb muscle strength in a group of 89 DMD boys followed in 3 European countries, 81 receiving corticosteroids, spanning a wide age range (5–18 years) and functional abilities, from ambulant (n = 60) to non-ambulant (n = 29). Respiratory decline could be detected in the early ambulatory phase using Peak Expiratory Flow percentage predicted (PEF%), despite glucocorticoid use (mean annual decline: 4.08, 95% CI −7.44,−0.72, p = 0.02 in ambulant; 4.81, 95% CI −6.79,−2.82, p < 0.001 in non-ambulant). FVC% captured disease progression in non-ambulant DMD subjects, with an annual loss of 5.47% (95% CI −6.48,−4.45, p < 0.001). Upper limb function measured with the Performance of Upper Limb (PUL 1.2) showed an annual loss of 4.13 points (95% CI −4.79,3.47, p < 0.001) in the non-ambulant cohort. Measures of upper limb strength (MyoGrip and MyoPinch) showed a continuous decline independent of the ambulatory status, when reported as percentage predicted (grip force −5.51%, 95% CI −6.54,−4.48, p < 0.001 in ambulant and a slower decline −2.86%; 95% CI −3.29,−2.43, p < 0.001, in non-ambulant; pinch force: −2.66%, 95% CI −3.82,−1.51, p < 0.001 in ambulant and −2.23%, 95% CI −2.92,−1.53, p < 0.001 in non-ambulant). Furthermore, we also explored the novel concept of a composite endpoint by combining respiratory, upper limb function and force domains: we were able to identify clear clinical progression in patients in whom an isolated measurement of only one of these domains failed to appreciate the yearly change. Our study contributes to the field of natural history of DMD, linking the ambulant and non-ambulant phases of the disease, and suggests that composite scores should be explored further.
Abstract Cognitive and behavioral difficulties occur in approximately a third of patients with Duchenne muscular dystrophy. The aim of our study was to assess the prevalence of epilepsy in a cohort ...of 222 DMD patients. Epileptic seizures were found in 14 of the 222 DMD patients (6.3%). The age of onset ranged from 3 months to 16 years (mean 7.8). Seizures were more often focal epilepsy ( n = 6), generalized tonic–clonic seizures ( n = 4) or absences ( n = 4). They were present in 12 of the 149 boys with normal IQ (8.1%) and in two of the 73 with mental retardation (2.7%). In two cases the parents did not report any past or present history of seizures but only ‘staring episodes’ interpreted as a sign of ‘poor attention’. In both patients EEG showed the typical pattern observed in childhood absence epilepsy. Our results suggest that the prevalence of epilepsy in our study (6.3%) is higher than in the general pediatric population (0.5–1%). The risk of epilepsy does not appear to increase in patients with mental retardation.
Haploinsufficiency of the gene encoding for transcription factor 4 (TCF4) was recently identified as the underlying cause of Pitt-Hopkins syndrome (PTHS), an underdiagnosed mental-retardation ...syndrome characterised by a distinct facial gestalt, breathing anomalies and severe mental retardation.
TCF4 mutational analysis was performed in 117 patients with PTHS-like features.
In total, 16 novel mutations were identified. All of these proven patients were severely mentally retarded and showed a distinct facial gestalt. In addition, 56% had breathing anomalies, 56% had microcephaly, 38% had seizures and 44% had MRI anomalies.
This study provides further evidence of the mutational and clinical spectrum of PTHS and confirms its important role in the differential diagnosis of severe mental retardation.
The continual expression of utrophin protein by pharmacological maintenance of utrophin transcription in dystrophin deficient muscle fibres is a potential disease modifying treatment for Duchenne ...muscular dystrophy (DMD). SMT C1100 is a small molecule utrophin modulator demonstrating significant benefit on the muscular dystrophy in the dystrophin deficient mdx mouse. Assessment of the in vitro and in vivo pharmacology plus the clean toxicology and safety data from the pre-clinical work led to the nomination of SMT C1100 as the first candidate for evaluation in DMD clinical trials. We previously reported that SMT C1100 successfully completed a Phase 1 healthy volunteer trial in which an oral paediatric formulation was deemed safe and well tolerated with plasma levels above those determined to be effective to modulate utrophin levels ex-vivo in DMD myoblasts and dystrophin deficient mdx mice. The first DMD paediatric patient trials of SMT C1100 started with an open-label, single and multiple oral dose finding Phase 1b study in DMD boys earlier this year. The purpose of the study was to determine whether increasing doses of SMT C1100 were safe, well tolerated and to understand the pharmacokinetic properties in patients with DMD. The boys were studied in 3 groups (Groups A to C), with each group consisting of 4 patients aged between 5 to 11 years. The doses for Groups A to C were administered in an escalating manner after safety review for each dose group. We will present the summary data from this trial.
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