ABSTRACT
Background: Dilated cardiomyopathy (DCM) is a major complication of, and leading cause of mortality in Duchenne muscular dystrophy (DMD). Its severity, age at onset, and rate of progression display wide variability, whose molecular bases have been scarcely elucidated. Potential DCM-modifying factors include glucocorticoid (GC) and cardiological treatments, DMD mutation type and location, and variants in other genes. Methods and Results: We retrospectively collected 3138 echocardiographic measurements of left ventricular ejection fraction (EF), shortening fraction (SF), and end-diastolic volume (EDV) from 819 DMD participants, 541 from an Italian multicentric cohort and 278 from the Cooperative International Neuromuscular Group Duchenne Natural History Study (CINRG-DNHS). Using generalized estimating equation (GEE) models, we estimated the yearly rate of decrease of EF (-0.80%) and SF (-0.41%), while EDV increase was not significantly associated with age. Utilizing a multivariate generalized estimating equation (GEE) model we observed that mutations preserving the expression of the C-terminal Dp71 isoform of dystrophin were correlated with decreased EDV (-11.01âmL/m2, pâ=â0.03) while for dp116 were correlated with decreased EF (-4.14%, pâ=â<0.001). The rs10880 genotype in the LTBP4 gene, previously shown to prolong ambulation, was also associated with increased EF and decreased EDV (+3.29%, pâ=â0.002, and -10.62âmL/m2, pâ=â0.008) with a recessive model. Conclusions: We quantitatively describe the progression of systolic dysfunction progression in DMD, confirm the effect of distal dystrophin isoform expression on the dystrophin-deficient heart, and identify a strong effect of LTBP4 genotype of DCM in DMD.
Subject(s)
Cardiomyopathies , Muscular Dystrophy, Duchenne , Humans , Dystrophin/genetics , Dystrophin/metabolism , Haplotypes , Retrospective Studies , Stroke Volume , Ventricular Function, Left , Muscular Dystrophy, Duchenne/genetics , Muscular Dystrophy, Duchenne/complications , Cardiomyopathies/etiology , Cardiomyopathies/genetics , Protein Isoforms/genetics , Latent TGF-beta Binding Proteins/geneticsABSTRACT
OBJECTIVE: Strategic Targeting of Registries and International Database of Excellence (STRIDE) is an ongoing, international, multicenter registry of real-world ataluren use in individuals with nonsense mutation Duchenne muscular dystrophy (nmDMD) in clinical practice. This updated interim report (data cut-off: January 31, 2022), describes STRIDE patient characteristics and ataluren safety data, as well as the effectiveness of ataluren plus standard of care (SoC) in STRIDE versus SoC alone in the Cooperative International Neuromuscular Research Group (CINRG) Duchenne Natural History Study (DNHS). METHODS: Patients are followed up from enrollment for at least 5 years or until study withdrawal. Propensity score matching was performed to identify STRIDE and CINRG DNHS patients who were comparable in established predictors of disease progression. RESULTS: As of January 31, 2022, 307 patients were enrolled from 14 countries. Mean (standard deviation [SD]) ages at first symptoms and at genetic diagnosis were 2.9 (1.7) years and 4.5 (3.7) years, respectively. Mean (SD) duration of ataluren exposure was 1671 (56.8) days. Ataluren had a favorable safety profile; most treatment-emergent adverse events were mild or moderate and unrelated to ataluren. Kaplan-Meier analyses demonstrated that ataluren plus SoC significantly delayed age at loss of ambulation by 4 years (p < 0.0001) and age at decline to %-predicted forced vital capacity of < 60% and < 50% by 1.8 years (p = 0.0021) and 2.3 years (p = 0.0207), respectively, compared with SoC alone. CONCLUSION: Long-term, real-world treatment with ataluren plus SoC delays several disease progression milestones in individuals with nmDMD. NCT02369731; registration date: February 24, 2015.
Subject(s)
Codon, Nonsense , Muscular Dystrophy, Duchenne , Humans , Muscular Dystrophy, Duchenne/drug therapy , Muscular Dystrophy, Duchenne/genetics , Registries , Disease ProgressionABSTRACT
Genetic modifiers of Duchenne muscular dystrophy (DMD) are variants located in genes different from the disease-causing gene DMD, but associated with differences in disease onset, progression, or response to treatment. Modifiers described so far have been tested mainly for associations with ambulatory function, while their effect on upper limb function, which is especially relevant for quality of life and independence in non-ambulatory patients, is unknown. We tested genotypes at several known modifier loci (SPP1, LTBP4, CD40, ACTN3) for association with Performance Upper Limb version 1.2 score in an Italian multicenter cohort, and with Brooke scale score in the Cooperative International Neuromuscular Group Duchenne Natural History Study (CINRG-DNHS), using generalized estimating equation (GEE) models of longitudinally collected data, with age and glucocorticoid treatment as covariates. CD40 rs1883832, previously linked to earlier loss of ambulation, emerged as a modifier of upper limb function, negatively affecting shoulder and distal domains of PUL (p = 0.023 and 0.018, respectively) in the Italian cohort, as well as of Brooke score (p = 0.018) in the CINRG-DNHS. These findings will be useful for the design and interpretation of clinical trials in DMD, especially for non-ambulatory populations.
Subject(s)
Muscular Dystrophy, Duchenne , Actinin/genetics , Cohort Studies , Genotype , Humans , Muscular Dystrophy, Duchenne/genetics , Quality of Life , Upper ExtremityABSTRACT
Aim: We investigated the effect of ataluren plus standard of care (SoC) on age at loss of ambulation (LoA) and respiratory decline in patients with nonsense mutation Duchenne muscular dystrophy (nmDMD) versus patients with DMD on SoC alone. Patients & methods: Study 019 was a long-term Phase III study of ataluren safety in nmDMD patients with a history of ataluren exposure. Propensity score matching identified Study 019 and CINRG DNHS patients similar in disease progression predictors. Results & conclusion: Ataluren plus SoC was associated with a 2.2-year delay in age at LoA (p = 0.0006), and a 3.0-year delay in decline of predicted forced vital capacity to <60% in nonambulatory patients (p = 0.0004), versus SoC. Ataluren plus SoC delays disease progression and benefits ambulatory and nonambulatory patients with nmDMD. ClinicalTrials.gov registration: NCT01557400.
Subject(s)
Codon, Nonsense , Muscular Dystrophy, Duchenne , Humans , Muscular Dystrophy, Duchenne/genetics , Oxadiazoles/therapeutic use , WalkingABSTRACT
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].
Subject(s)
Motor Activity/drug effects , Muscular Dystrophy, Duchenne/drug therapy , Pregnadienediols/therapeutic use , Adrenal Cortex Hormones/adverse effects , Child , Child, Preschool , Disease Progression , Glucocorticoids/adverse effects , Humans , Male , Prednisone/therapeutic use , Pregnadienediols/metabolism , Treatment Outcome , Walking/physiologyABSTRACT
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.
Subject(s)
Dystrophin/genetics , Muscular Dystrophy, Duchenne/diagnosis , Adolescent , Adult , Aged , Child , Child, Preschool , Disease Progression , Gene Deletion , Humans , Longitudinal Studies , Male , Middle Aged , Muscular Dystrophy, Duchenne/genetics , Muscular Dystrophy, Duchenne/physiopathology , Phenotype , Prospective Studies , Symptom Assessment , Young AdultABSTRACT
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.
Subject(s)
Dystrophin/metabolism , Muscular Dystrophy, Duchenne/drug therapy , Muscular Dystrophy, Duchenne/metabolism , Oligonucleotides, Antisense/pharmacology , Oligonucleotides/pharmacology , Outcome Assessment, Health Care , Child , Child, Preschool , Double-Blind Method , Exons , Humans , Male , Muscular Dystrophy, Duchenne/genetics , Oligonucleotides/administration & dosage , Oligonucleotides/adverse effects , Oligonucleotides, Antisense/administration & dosage , Oligonucleotides, Antisense/adverse effectsABSTRACT
OBJECTIVE: Respiratory insufficiency is a major complication of Duchenne muscular dystrophy (DMD). Its progression shows considerable interindividual variability, which has been less thoroughly characterized and understood than in skeletal muscle. We collected pulmonary function testing (PFT) data from a large retrospective cohort followed at Centers collaborating in the Italian DMD Network. Furthermore, we analyzed PFT associations with different DMD mutation types, and with genetic variants in SPP1, LTBP4, CD40, and ACTN3, known to modify skeletal muscle weakness in DMD. Genetic association findings were independently validated in the Cooperative International Neuromuscular Research Group Duchenne Natural History Study (CINRG-DNHS). METHODS AND RESULTS: Generalized estimating equation analysis of 1852 PFTs from 327 Italian DMD patients, over an average follow-up time of 4.5 years, estimated that forced vital capacity (FVC) declined yearly by -4.2%, forced expiratory volume in 1 sec by -5.0%, and peak expiratory flow (PEF) by -2.9%. Glucocorticoid (GC) treatment was associated with higher values of all PFT measures (approximately + 15% across disease stages). Mutations situated 3' of DMD intron 44, thus predicted to alter the expression of short dystrophin isoforms, were associated with lower (approximately -6%) PFT values, a finding independently validated in the CINRG-DNHS. Deletions amenable to skipping of exon 51 and 53 were independently associated with worse PFT outcomes. A meta-analysis of the two cohorts identified detrimental effects of SPP1 rs28357094 and CD40 rs1883832 minor alleles on both FVC and PEF. INTERPRETATION: These findings support GC efficacy in delaying respiratory insufficiency, and will be useful for the design and interpretation of clinical trials focused on respiratory endpoints in DMD.
Subject(s)
Glucocorticoids/pharmacology , Muscular Dystrophy, Duchenne/genetics , Respiratory Function Tests , Respiratory Insufficiency/genetics , Adolescent , Adult , CD40 Antigens/genetics , Child , Child, Preschool , Dystrophin/genetics , Follow-Up Studies , Humans , Male , Muscular Dystrophy, Duchenne/complications , Muscular Dystrophy, Duchenne/drug therapy , Osteopontin/genetics , Respiratory Insufficiency/drug therapy , Respiratory Insufficiency/etiology , Respiratory Insufficiency/physiopathology , Retrospective Studies , Vital Capacity , Young AdultABSTRACT
Aim: Strategic Targeting of Registries and International Database of Excellence (STRIDE) is an ongoing, multicenter registry providing real-world evidence regarding ataluren use in patients with nonsense mutation Duchenne muscular dystrophy (nmDMD). We examined the effectiveness of ataluren + standard of care (SoC) in the registry versus SoC alone in the Cooperative International Neuromuscular Research Group (CINRG) Duchenne Natural History Study (DNHS), DMD genotype-phenotype/-ataluren benefit correlations and ataluren safety. Patients & methods: Propensity score matching was performed to identify STRIDE and CINRG DNHS patients who were comparable in established disease progression predictors (registry cut-off date, 9 July 2018). Results & conclusion: Kaplan-Meier analyses demonstrated that ataluren + SoC significantly delayed age at loss of ambulation and age at worsening performance in timed function tests versus SoC alone (p ≤ 0.05). There were no DMD genotype-phenotype/ataluren benefit correlations. Ataluren was well tolerated. These results indicate that ataluren + SoC delays functional milestones of DMD progression in patients with nmDMD in routine clinical practice. ClinicalTrials.gov identifier: NCT02369731. ClinicalTrials.gov identifier: NCT02369731.
Subject(s)
Codon, Nonsense/genetics , Dystrophin/genetics , Muscular Dystrophy, Duchenne/drug therapy , Oxadiazoles/therapeutic use , Humans , Muscular Dystrophy, Duchenne/genetics , Oxadiazoles/adverse effects , Registries , Treatment OutcomeABSTRACT
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.
Subject(s)
Anti-Inflammatory Agents/therapeutic use , Glucocorticoids/therapeutic use , Muscular Dystrophy, Duchenne/drug therapy , Treatment Outcome , Administration, Oral , Biomarkers/analysis , Child , Child, Preschool , Humans , Male , Prednisone/therapeutic useABSTRACT
Duchenne muscular dystrophy is the most common form of childhood muscular dystrophy. A mutation in the DMD gene disrupts dystrophin (protein) production, causing damage to muscle integrity, weakness, loss of ambulation, and cardiopulmonary compromise by the second decade of life. Life expectancy has improved from mid-teenage years to mid-20s with the use of glucocorticoids and beyond the third decade with ventilator support and multidisciplinary care. However, Duchenne muscular dystrophy is associated with comorbidities and is a fatal disease. Glucocorticoids prolong ambulation, but their side effects are significant. Emerging investigational therapies have surfaced over the past decade and have rapidly been tested in clinical trials. Gene-specific strategies include nonsense readthrough, exon skipping, gene editing, utrophin modulation, and gene replacement. Other mechanisms include muscle regeneration, antioxidants, and antifibrosis and anti-inflammatory pathways. With potential therapies emerging, early diagnosis is needed to initiate treatment early enough to minimize morbidity and mortality. Newborn screening can be used to significantly improve early diagnosis, especially for gene-specific therapeutics.
Subject(s)
Muscular Dystrophy, Duchenne/therapy , Adolescent , Child , Child, Preschool , Genetic Therapy/methods , Glucocorticoids/therapeutic use , Humans , Molecular Targeted Therapy/methods , Muscular Dystrophy, Duchenne/diagnosis , NeurologyABSTRACT
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.
Subject(s)
Anti-Inflammatory Agents/pharmacology , Anti-Inflammatory Agents/therapeutic use , Muscular Dystrophy, Duchenne/drug therapy , Pregnadienediols/pharmacology , Pregnadienediols/therapeutic use , Administration, Oral , Anti-Inflammatory Agents/blood , Biomarkers/blood , Blood Glucose/analysis , Child , Child, Preschool , Humans , Hydrocortisone/blood , Insulin/blood , Male , Muscular Dystrophy, Duchenne/metabolism , Pregnadienediols/bloodABSTRACT
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.
Subject(s)
Motor Activity , Muscle Weakness , Muscular Dystrophy, Facioscapulohumeral/physiopathology , Age of Onset , Cross-Sectional Studies , DNA Repeat Expansion , Female , Humans , Male , Muscle Weakness/epidemiology , Muscle Weakness/genetics , Muscle Weakness/physiopathology , Muscular Dystrophy, Facioscapulohumeral/epidemiology , Muscular Dystrophy, Facioscapulohumeral/genetics , Range of Motion, Articular , Severity of Illness Index , Young AdultABSTRACT
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.
Subject(s)
Adrenal Cortex Hormones/therapeutic use , Anti-Inflammatory Agents/therapeutic use , Inflammatory Bowel Diseases/blood , Inflammatory Bowel Diseases/drug therapy , Muscular Dystrophy, Duchenne/blood , Muscular Dystrophy, Duchenne/drug therapy , Adolescent , Adrenal Cortex Hormones/adverse effects , Adrenal Cortex Hormones/blood , Anti-Inflammatory Agents/adverse effects , Biomarkers/blood , Blood Proteins/metabolism , Case-Control Studies , Child , Child, Preschool , Cross-Sectional Studies , Female , Humans , Inflammation Mediators/blood , Longitudinal Studies , Male , Proteome/metabolismABSTRACT
[This corrects the article DOI: 10.1371/journal.pone.0153461.].
ABSTRACT
OBJECTIVE: To correlate time to loss of ambulation (LoA) and different truncating DMD gene mutations in a large, prospective natural history study of Duchenne muscular dystrophy (DMD), with particular attention to mutations amenable to emerging molecular treatments. METHODS: We analyzed data from the Cooperative International Neuromuscular Research Group Duchenne Natural History Study for participants with DMD single- or multi-exon deletions or duplications with defined exon boundaries (n = 186), or small mutations identified by sequencing (n = 26, including 16 nonsense point mutations). We performed a time-to-event analysis of LoA, a strong indicator of overall disease severity, adjusting for glucocorticoid treatment and genetic modifiers. RESULTS: Participants with deletions amenable to skipping of exon 44 had later LoA (median 14.8 years, hazard ratio 0.31, 95% confidence interval 0.14-0.69, p = 0.004). Age at LoA did not differ significantly in participants with deletions amenable to exon 45, 51, and 53 skipping, duplications, and small rearrangements. Nonsense mutation DMD also showed a typical median age at LoA (11.1 years), with a few outliers (ambulatory around or after 16 years of age) carrying stop codons within in-frame exons, more often situated in the rod domain. CONCLUSIONS: As exon 44 skipping-amenable DMD has a later LoA, mutation-specific randomization and selection of placebo groups are essential for the success of clinical trials.
Subject(s)
Dystrophin/genetics , Gait Disorders, Neurologic/genetics , Gait Disorders, Neurologic/physiopathology , Muscular Dystrophy, Duchenne/genetics , Muscular Dystrophy, Duchenne/physiopathology , Adolescent , Codon/genetics , Codon, Nonsense/genetics , Cohort Studies , Disease Progression , Exons/genetics , Female , Gene Deletion , Gene Duplication/genetics , Glucocorticoids/therapeutic use , Humans , Kaplan-Meier Estimate , Male , Muscular Dystrophy, Duchenne/drug therapy , Mutation/genetics , Prospective StudiesABSTRACT
PURPOSE: Clinical trials in Duchenne muscular dystrophy (DMD) are increasing due to technical advances in genetics, muscle biology and muscle imaging, and translational science. Yet the ability to achieve and measure progress in clinical trials in DMD is severely constrained by recruitment difficulties and low levels of patient and family participation. Clinical trials that do not have full inclusion of patients may affect how well new therapies perform in clinical practice. METHODS: This study qualitatively investigated family-centered and clinician-based knowledge, attitudes, and perceptions of engagement in clinical research in DMD. Thirteen focus-group sessions (8 parent based and 5 clinician based) were held at 5 demographically and geographically diverse sites (Houston, Texas; Minneapolis, Minnesota; Pittsburgh, Pennsylvania; Sacramento, California; and Washington, DC). Thematic analysis was used for identifying patterns of meaning across the dataset. FINDINGS: Totals of 28 parents and 33 clinicians participated in innovative and thoughtful discussions regarding clinical research in DMD and approaches to eliciting family engagement. Five overarching themes emerged from our qualitative data. The theme of Information discussed the lack of accessible and coherent information, as well as the overabundance of fragmented information. The theme of Conversation demonstrated the importance of having open and in-depth dialogue about research with families in eliciting trust and obligation toward the research process. The Barriers and Incentives themes presented the parents' and clinicians' views of the life-altering sacrifices that families make to participate in research and ways to reduce these burdens. Under the Solutions theme, parents and clinicians also suggested innovative ways to incentivize families and clinics and thoughtful solutions to increase family engagement in research. IMPLICATIONS: Effective recruitment for clinical studies in rare diseases requires a truly committed and engaged study team, as well as the necessary resources to overcome the multitude of barriers that families face. A clearly delineated recruitment plan, developed together with families, should be the standard operating procedure during clinical trial development. Protocols utilizing direct family-centered strategies for providing information and for recruiting research participants in studies in rare diseases are essential.
Subject(s)
Clinical Trials as Topic/psychology , Muscular Dystrophy, Duchenne , Rare Diseases , Communication Barriers , Focus Groups , Health Knowledge, Attitudes, Practice , Humans , Motivation , Patient Selection , Qualitative ResearchABSTRACT
Serum metabolite profiling in Duchenne muscular dystrophy (DMD) may enable discovery of valuable molecular markers for disease progression and treatment response. Serum samples from 51 DMD patients from a natural history study and 22 age-matched healthy volunteers were profiled using liquid chromatography coupled to mass spectrometry (LC-MS) for discovery of novel circulating serum metabolites associated with DMD. Fourteen metabolites were found significantly altered (1% false discovery rate) in their levels between DMD patients and healthy controls while adjusting for age and study site and allowing for an interaction between disease status and age. Increased metabolites included arginine, creatine and unknown compounds at m/z of 357 and 312 while decreased metabolites included creatinine, androgen derivatives and other unknown yet to be identified compounds. Furthermore, the creatine to creatinine ratio is significantly associated with disease progression in DMD patients. This ratio sharply increased with age in DMD patients while it decreased with age in healthy controls. Overall, this study yielded promising metabolic signatures that could prove useful to monitor DMD disease progression and response to therapies in the future.
Subject(s)
Biomarkers/metabolism , Blood Chemical Analysis , Muscular Dystrophy, Duchenne/metabolism , Muscular Dystrophy, Duchenne/pathology , Adolescent , Adult , Biomarkers/analysis , Biomarkers/blood , Blood Chemical Analysis/methods , Case-Control Studies , Child , Child, Preschool , Chromatography, Liquid , Disease Progression , Humans , Male , Mass Spectrometry , Muscular Dystrophy, Duchenne/blood , Young AdultABSTRACT
OBJECTIVE: We aimed to perform an observational study of age at loss of independent ambulation (LoA) and side-effect profiles associated with different glucocorticoid corticosteroid (GC) regimens in Duchenne muscular dystrophy (DMD). METHODS: We studied 340 participants in the Cooperative International Neuromuscular Research Group Duchenne Natural History Study (CINRG-DNHS). LoA was defined as continuous wheelchair use. Effects of prednisone or prednisolone (PRED)/deflazacort (DFZ), administration frequency, and dose were analyzed by time-varying Cox regression. Side-effect frequencies were compared using χ(2) test. RESULTS: Participants treated ≥1 year while ambulatory (n = 252/340) showed a 3-year median delay in LoA (p < 0.001). Fourteen different regimens were observed. Nondaily treatment was common for PRED (37%) and rare for DFZ (3%). DFZ was associated with later LoA than PRED (hazard ratio 0.294 ± 0.053 vs 0.490 ± 0.08, p = 0.003; 2-year difference in median LoA with daily administration, p < 0.001). Average dose was lower for daily PRED (0.56 mg/kg/d, 75% of recommended) than daily DFZ (0.75 mg/kg/d, 83% of recommended, p < 0.001). DFZ showed higher frequencies of growth delay (p < 0.001), cushingoid appearance (p = 0.002), and cataracts (p < 0.001), but not weight gain. CONCLUSIONS: Use of DFZ was associated with later LoA and increased frequency of side effects. Differences in standards of care and dosing complicate interpretation of this finding, but stratification by PRED/DFZ might be considered in clinical trials. This study emphasizes the necessity of a randomized, blinded trial of GC regimens in DMD. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that GCs are effective in delaying LoA in patients with DMD.