Safety and Efficacy of Topiramate in Individuals With Cryptogenic Sensory Peripheral Neuropathy With Metabolic Syndrome: The TopCSPN Randomized Clinical Trial.

Importance: Cryptogenic sensory peripheral neuropathy (CSPN) is highly prevalent and often disabling due to neuropathic pain. Metabolic syndrome and its components increase neuropathy risk. Diet and exercise have shown promise but are limited by poor adherence. Objective: To determine whether topiramate can slow decline in intraepidermal nerve fiber density (IENFD) and/or neuropathy-specific quality of life measured using the Norfolk Quality of Life-Diabetic Neuropathy (NQOL-DN) scale. Design, Setting, and Participants: Topiramate as a Disease-Modifying Therapy for CSPN (TopCSPN) was a double-blind, placebo-controlled, randomized clinical trial conducted between February 2018 and October 2021. TopCSPN was performed at 20 sites in the National Institutes of Health-funded Network for Excellence in Neurosciences Clinical Trials (NeuroNEXT). Individuals with CSPN and metabolic syndrome aged 18 to 80 years were screened and randomly assigned by body mass index (<30 vs ≥30), which is calculated as weight in kilograms divided by height in meters squared. Patients were excluded if they had poorly controlled diabetes, prior topiramate treatment, recurrent nephrolithiasis, type 1 diabetes, use of insulin within 3 months before screening, history of foot ulceration, planned bariatric surgery, history of alcohol or drug overuse in the 2 years before screening, family history of a hereditary neuropathy, or an alternative neuropathy cause. Interventions: Participants received topiramate or matched placebo titrated to a maximum-tolerated dose of 100 mg per day. Main Outcomes and Measures: IENFD and NQOL-DN score were co-primary outcome measures. A positive study was defined as efficacy in both or efficacy in one and noninferiority in the other. Results: A total of 211 individuals were screened, and 132 were randomly assigned to treatment groups: 66 in the topiramate group and 66 in the placebo group. Age and sex were similar between groups (topiramate: mean [SD] age, 61 (10) years; 38 male [58%]; placebo: mean [SD] age, 62 (11) years; 44 male [67%]). The difference in change in IENFD and NQOL-DN score was noninferior but not superior in the intention-to-treat (ITT) analysis (IENFD, 0.21 fibers/mm per year; 95% CI, -0.43 to ∞ fibers/mm per year and NQOL-DN score, -1.52 points per year; 95% CI, -∞ to 1.19 points per year). A per-protocol analysis excluding noncompliant participants based on serum topiramate levels and those with major protocol deviations demonstrated superiority in NQOL-DN score (-3.69 points per year; 95% CI, -∞ to -0.73 points per year). Patients treated with topiramate had a mean (SD) annual change in IENFD of 0.56 fibers/mm per year relative to placebo (95% CI, -0.21 to ∞ fibers/mm per year). Although IENFD was stable in the topiramate group compared with a decline consistent with expected natural history, this difference did not demonstrate superiority. Conclusion and Relevance: Topiramate did not slow IENFD decline or affect NQOL-DN score in the primary ITT analysis. Some participants were intolerant of topiramate. NQOL-DN score was superior among those compliant based on serum levels and without major protocol deviations. Trial Registration: ClinicalTrials.gov Identifier: NCT02878798.

Evaluating Neutral PFAS for Potential Dermal Absorption from the Gas Phase.

Exposures to per- and polyfluoroalkyl substances (PFAS) are of increasing concern. Assessments typically focus only on ingestion and inhalation exposure due to a lack of generally accepted approaches for estimating dermal absorption. Prior work indicates limited dermal absorption of ionic PFAS, but absorption of neutral PFAS has not been examined from the liquid vehicle or from vapor. Partitioning of semivolatile organic compounds from the gas phase to the skin surface (i.e., stratum corneum) is well known, but the potential for partitioning of neutral PFAS from the gas phase to the stratum corneum has yet to be estimated. The SPARC-estimated physicochemical properties were used to calculate transdermal permeability coefficients (kp_g) and dermal-to-inhalation (D/I) exposure ratios for two groups of neutral PFAS, including those on a U.S. Environmental Protection Agency PFAS list. 11 neutral PFAS gave calculated D/I ratios >5, indicating that direct transdermal absorption may be an important exposure pathway compared to inhalation. Data on consumer products or indoor air is needed for the 11 neutral PFAS, followed by possible biomonitoring to experimentally verify dermal absorption from air. Additional PFAS should be estimated by the protocol used here as they are identified in commercial products.

Epidemiological evidence for a hereditary contribution to myasthenia gravis: a retrospective cohort study of patients from North America.

OBJECTIVES: To approximate the rate of familial myasthenia gravis and the coexistence of other autoimmune disorders in the patients and their families. DESIGN: Retrospective cohort study. SETTING: Clinics across North America. PARTICIPANTS: The study included 1032 patients diagnosed with acetylcholine receptor antibody (AChR)-positive myasthenia gravis. METHODS: Phenotype information of 1032 patients diagnosed with AChR-positive myasthenia gravis was obtained from clinics at 14 centres across North America between January 2010 and January 2011. A critical review of the epidemiological literature on the familial rate of myasthenia gravis was also performed. RESULTS: Among 1032 patients, 58 (5.6%) reported a family history of myasthenia gravis. A history of autoimmune diseases was present in 26.6% of patients and in 28.4% of their family members. DISCUSSION: The familial rate of myasthenia gravis was higher than would be expected for a sporadic disease. Furthermore, a high proportion of patients had a personal or family history of autoimmune disease. Taken together, these findings suggest a genetic contribution to the pathogenesis of myasthenia gravis.

Minimal manifestation status and prednisone withdrawal in the MGTX trial.

OBJECTIVE: To examine whether sustained minimal manifestation status (MMS) with complete withdrawal of prednisone is better achieved in thymectomized patients with myasthenia gravis (MG). METHODS: This study is a post hoc analysis of data from a randomized trial of thymectomy in MG (Thymectomy Trial in Non-Thymomatous Myasthenia Gravis Patients Receiving Prednisone Therapy [MGTX]). MGTX was a multicenter, randomized, rater-blinded 3-year trial that was followed by a voluntary 2-year extension for patients with acetylcholine receptor (AChR) antibody-positive MG without thymoma. Patients were randomized 1:1 to thymectomy plus prednisone vs prednisone alone. Participants were age 18-65 years at enrollment with disease duration less than 5 years. All patients received oral prednisone titrated up to 100 mg on alternate days until they achieved MMS, which prompted a standardized prednisone taper as long as MMS was maintained. The achievement rate of sustained MMS (no symptoms of MG for 6 months) with complete withdrawal of prednisone was compared between the thymectomy plus prednisone and prednisone alone groups. RESULTS: Patients with MG in the thymectomy plus prednisone group achieved sustained MMS with complete withdrawal of prednisone more frequently (64% vs 38%) and quickly compared to the prednisone alone group (median time 30 months vs no median time achieved, p < 0.001) over the 5-year study period. Prednisone-associated adverse symptoms were more frequent in the prednisone alone group and distress level increased with higher doses of prednisone. CONCLUSIONS: Thymectomy benefits patients with MG by increasing the likelihood of achieving sustained MMS with complete withdrawal of prednisone. CLINICALTRIALSGOV IDENTIFIER: NCT00294658. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that for patients with generalized MG with AChR antibody, those receiving thymectomy plus prednisone are more likely to attain sustained MMS and complete prednisone withdrawal than those on prednisone alone.

Use of benchmark dose models in risk assessment for occupational handlers of eight pesticides used in pome fruit production.

The benchmark dose has been frequently recommended for the creation of points of departure for regulatory dose limits, but many regulations, including pesticide risk assessment and registration in the United States, continues to rely on NOAEL methods as the OECD toxicological standard methods recommend. This study used data from studies in support of pesticide registration for eight different compounds to build dose-response models and calculate benchmark doses and confidence limits. The results were compared to the NOAEL of the same study. A probabilistic estimate of dose was compared with all points of departure to demonstrate differences in the protective ability of each different selected limit. While neither the BMD/BMDL nor the NOAEL was consistently more protective, the advantage of using the BMD in quantifying the uncertainty of the point of departure is highlighted, and the feasibility of using current OECD-guideline studies for derivation of a BMD is demonstrated in these cases.

Stabilization of Early Duchenne Cardiomyopathy With Aldosterone Inhibition: Results of the Multicenter AIDMD Trial.

Background Duchenne muscular dystrophy incurs nearly universal dilated cardiomyopathy by the third decade of life, preceded by myocardial damage and impaired left ventricular strain by cardiac magnetic resonance. It has been shown that (1) mineralocorticoid receptor antagonist therapy with spironolactone attenuated damage while maintaining function when given early in a mouse model and (2) low-dose eplerenone stabilized left ventricular strain in boys with Duchenne muscular dystrophy and evident myocardial damage but preserved ejection fraction. We hypothesized that moderate-dose spironolactone versus eplerenone would provide similar cardioprotection in this first head-to-head randomized trial of available mineralocorticoid receptor antagonists, the AIDMD (Aldosterone Inhibition in Duchenne Muscular Dystrophy) trial. Methods and Results This was a multicenter, double-blind, randomized, noninferiority trial. Subjects were randomized to eplerenone, 50 mg, or spironolactone, 50 mg, orally once daily for 12 months. The primary outcome was change in left ventricular systolic strain at 12 months. Among 52 enrolled male subjects, aged 14 (interquartile range, 12-18) years, spironolactone was noninferior to eplerenone (∆strain, 0.4 [interquartile range, -0.4 to 0.6] versus 0.2 [interquartile range, -0.2 to 0.7]; P=0.542). Renal and pulmonary function remained stable in both groups, and no subjects experienced serious hyperkalemia. Infrequent adverse events included gynecomastia in one subject in the spironolactone arm and facial rash in one subject in the eplerenone arm. Conclusions In boys with Duchenne muscular dystrophy and preserved left ventricular ejection fraction, spironolactone added to background therapy is noninferior to eplerenone in preserving contractile function. These findings support early mineralocorticoid receptor antagonist therapy as effective and safe in a genetic disease with high cardiomyopathy risk. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT02354352.

Safety and efficacy of intravenous bimagrumab in inclusion body myositis (RESILIENT): a randomised, double-blind, placebo-controlled phase 2b trial.

BACKGROUND: Inclusion body myositis is an idiopathic inflammatory myopathy and the most common myopathy affecting people older than 50 years. To date, there are no effective drug treatments. We aimed to assess the safety, efficacy, and tolerability of bimagrumab-a fully human monoclonal antibody-in individuals with inclusion body myositis. METHODS: We did a multicentre, double-blind, placebo-controlled study (RESILIENT) at 38 academic clinical sites in Australia, Europe, Japan, and the USA. Individuals (aged 36-85 years) were eligible for the study if they met modified 2010 Medical Research Council criteria for inclusion body myositis. We randomly assigned participants (1:1:1:1) using a blocked randomisation schedule (block size of four) to either bimagrumab (10 mg/kg, 3 mg/kg, or 1 mg/kg) or placebo matched in appearance to bimagrumab, administered as intravenous infusions every 4 weeks for at least 48 weeks. All study participants, the funder, investigators, site personnel, and people doing assessments were masked to treatment assignment. The primary outcome measure was 6-min walking distance (6MWD), which was assessed at week 52 in the primary analysis population and analysed by intention-to-treat principles. We used a multivariate normal repeated measures model to analyse data for 6MWD. Safety was assessed by recording adverse events and by electrocardiography, echocardiography, haematological testing, urinalysis, and blood chemistry. This trial is registered with ClinicalTrials.gov, number NCT01925209; this report represents the final analysis. FINDINGS: Between Sept 26, 2013, and Jan 6, 2016, 251 participants were enrolled to the study, of whom 63 were assigned to each bimagrumab group and 62 were allocated to the placebo group. At week 52, 6MWD change from baseline did not differ between any bimagrumab dose and placebo (least squares mean treatment difference for bimagrumab 10 mg/kg group, 17·6 m, SE 14·3, 99% CI -19·6 to 54·8; p=0·22; for 3 mg/kg group, 18·6 m, 14·2, -18·2 to 55·4; p=0·19; and for 1 mg/kg group, -1·3 m, 14·1, -38·0 to 35·4; p=0·93). 63 (100%) participants in each bimagrumab group and 61 (98%) of 62 in the placebo group had at least one adverse event. Falls were the most frequent adverse event (48 [76%] in the bimagrumab 10 mg/kg group, 55 [87%] in the 3 mg/kg group, 54 [86%] in the 1 mg/kg group, and 52 [84%] in the placebo group). The most frequently reported adverse events with bimagrumab were muscle spasms (32 [51%] in the bimagrumab 10 mg/kg group, 43 [68%] in the 3 mg/kg group, 25 [40%] in the 1 mg/kg group, and 13 [21%] in the placebo group) and diarrhoea (33 [52%], 28 [44%], 20 [32%], and 11 [18%], respectively). Adverse events leading to discontinuation were reported in four (6%) participants in each bimagrumab group compared with one (2%) participant in the placebo group. At least one serious adverse event was reported by 21 (33%) participants in the 10 mg/kg group, 11 (17%) in the 3 mg/kg group, 20 (32%) in the 1 mg/kg group, and 20 (32%) in the placebo group. No significant adverse cardiac effects were recorded on electrocardiography or echocardiography. Two deaths were reported during the study, one attributable to subendocardial myocardial infarction (secondary to gastrointestinal bleeding after an intentional overdose of concomitant sedatives and antidepressants) and one attributable to lung adenocarcinoma. Neither death was considered by the investigator to be related to bimagrumab. INTERPRETATION: Bimagrumab showed a good safety profile, relative to placebo, in individuals with inclusion body myositis but did not improve 6MWD. The strengths of our study are that, to the best of our knowledge, it is the largest randomised controlled trial done in people with inclusion body myositis, and it provides important natural history data over 12 months. FUNDING: Novartis Pharma.

Impact of Age and Motor Function in a Phase 1/2A Study of Infants With SMA Type 1 Receiving Single-Dose Gene Replacement Therapy.

BACKGROUND: This study characterizes motor function responses after early dosing of AVXS-101 (onasemnogene abeparvovec) in gene replacement therapy in infants with severe spinal muscular atrophy type 1 (SMA1). METHODS: This study is a follow-up analysis of 12 infants with SMA1 who received the proposed therapeutic dose of AVXS-101 in a Phase 1 open-label study (NCT02122952). Infants were grouped according to age at dosing and baseline Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders scores: (1) early dosing/low motor, dosed age less than three months with scores <20 (n = 3), (2) late dosing, dosed at age three months or greater (n = 6), and (3) early dosing/high motor, dosed age less than three months with scores ≥20 (n = 3). RESULTS: Early dosing/low motor group demonstrated a mean gain of 35.0 points from a mean baseline of 15.7, whereas the late dosing group had a mean gain of 23.3 from a mean baseline of 26.5. The early dosing/high motor group quickly reached a mean score of 60.3, near the scale maximum (64), from a mean baseline of 44.0. Despite a lower baseline motor score, the early dosing/low motor group achieved sitting unassisted earlier than the late dosing group (mean age: 17.0 vs 22.0 months). The early dosing/high motor group reached this milestone earliest (mean age: 9.4 months). CONCLUSIONS: The rapid, significant motor improvements among infants with severe SMA1 treated with AVXS-101 at an early age highlight the importance of newborn screening and early treatment and demonstrate the therapeutic potential of AVXS-101 regardless of baseline motor function.

Long-term safety and efficacy of eculizumab in generalized myasthenia gravis.

INTRODUCTION: Eculizumab is effective and well tolerated in patients with antiacetylcholine receptor antibody-positive refractory generalized myasthenia gravis (gMG; REGAIN; NCT01997229). We report an interim analysis of an open-label extension of REGAIN, evaluating eculizumab's long-term safety and efficacy. METHODS: Eculizumab (1,200 mg every 2 weeks for 22.7 months [median]) was administered to 117 patients. RESULTS: The safety profile of eculizumab was consistent with REGAIN; no cases of meningococcal infection were reported during the interim analysis period. Myasthenia gravis exacerbation rate was reduced by 75% from the year before REGAIN (P < 0.0001). Improvements with eculizumab in activities of daily living, muscle strength, functional ability, and quality of life in REGAIN were maintained through 3 years; 56% of patients achieved minimal manifestations or pharmacological remission. Patients who had received placebo during REGAIN experienced rapid and sustained improvements during open-label eculizumab (P < 0.0001). DISCUSSION: These findings provide evidence for the long-term safety and sustained efficacy of eculizumab for refractory gMG. Muscle Nerve 2019.

Long-term effect of thymectomy plus prednisone versus prednisone alone in patients with non-thymomatous myasthenia gravis: 2-year extension of the MGTX randomised trial.

BACKGROUND: The Thymectomy Trial in Non-Thymomatous Myasthenia Gravis Patients Receiving Prednisone (MGTX) showed that thymectomy combined with prednisone was superior to prednisone alone in improving clinical status as measured by the Quantitative Myasthenia Gravis (QMG) score in patients with generalised non-thymomatous myasthenia gravis at 3 years. We investigated the long-term effects of thymectomy up to 5 years on clinical status, medication requirements, and adverse events. METHODS: We did a rater-blinded 2-year extension study at 36 centres in 15 countries for all patients who completed the randomised controlled MGTX and were willing to participate. MGTX patients were aged 18 to 65 years at enrolment, had generalised non-thymomatous myasthenia gravis of less than 5 years' duration, had acetylcholine receptor antibody titres of 1·00 nmol/L or higher (or concentrations of 0·50-0·99 nmol/L if diagnosis was confirmed by positive edrophonium or abnormal repetitive nerve stimulation, or abnormal single fibre electromyography), had Myasthenia Gravis Foundation of America Clinical Classification Class II-IV disease, and were on optimal anticholinesterase therapy with or without oral corticosteroids. In MGTX, patients were randomly assigned (1:1) to either thymectomy plus prednisone or prednisone alone. All patients in both groups received oral prednisone at doses titrated up to 100 mg on alternate days until they achieved minimal manifestation status. The primary endpoints of the extension phase were the time-weighted means of the QMG score and alternate-day prednisone dose from month 0 to month 60. Analyses were by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT00294658. It is closed to new participants, with follow-up completed. FINDINGS: Of the 111 patients who completed the 3-year MGTX, 68 (61%) entered the extension study between Sept 1, 2009, and Aug 26, 2015 (33 in the prednisone alone group and 35 in the prednisone plus thymectomy group). 50 (74%) patients completed the 60-month assessment, 24 in the prednisone alone group and 26 in the prednisone plus thymectomy group. At 5 years, patients in the thymectomy plus prednisone group had significantly lower time-weighted mean QMG scores (5·47 [SD 3·87] vs 9·34 [5·08]; p=0·0007) and mean alternate-day prednisone doses (24 mg [SD 21] vs 48 mg [29]; p=0·0002) than did those in the prednisone alone group. 14 (42%) of 33 patients in the prednisone group, and 12 (34%) of 35 in the thymectomy plus prednisone group, had at least one adverse event by month 60. No treatment-related deaths were reported during the extension phase. INTERPRETATION: At 5 years, thymectomy plus prednisone continues to confer benefits in patients with generalised non-thymomatous myasthenia gravis compared with prednisone alone. Although caution is appropriate when generalising our findings because of the small sample size of our study, they nevertheless provide further support for the benefits of thymectomy in patients with generalised non-thymomatous myasthenia gravis. FUNDING: National Institutes of Health, National Institute of Neurological Disorders and Stroke.

Single-Dose Gene-Replacement Therapy for Spinal Muscular Atrophy.

BACKGROUND: Spinal muscular atrophy type 1 (SMA1) is a progressive, monogenic motor neuron disease with an onset during infancy that results in failure to achieve motor milestones and in death or the need for mechanical ventilation by 2 years of age. We studied functional replacement of the mutated gene encoding survival motor neuron 1 (SMN1) in this disease. METHODS: Fifteen patients with SMA1 received a single dose of intravenous adeno-associated virus serotype 9 carrying SMN complementary DNA encoding the missing SMN protein. Three of the patients received a low dose (6.7×1013 vg per kilogram of body weight), and 12 received a high dose (2.0×1014 vg per kilogram). The primary outcome was safety. The secondary outcome was the time until death or the need for permanent ventilatory assistance. In exploratory analyses, we compared scores on the CHOP INTEND (Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders) scale of motor function (ranging from 0 to 64, with higher scores indicating better function) in the two cohorts and motor milestones in the high-dose cohort with scores in studies of the natural history of the disease (historical cohorts). RESULTS: As of the data cutoff on August 7, 2017, all 15 patients were alive and event-free at 20 months of age, as compared with a rate of survival of 8% in a historical cohort. In the high-dose cohort, a rapid increase from baseline in the score on the CHOP INTEND scale followed gene delivery, with an increase of 9.8 points at 1 month and 15.4 points at 3 months, as compared with a decline in this score in a historical cohort. Of the 12 patients who had received the high dose, 11 sat unassisted, 9 rolled over, 11 fed orally and could speak, and 2 walked independently. Elevated serum aminotransferase levels occurred in 4 patients and were attenuated by prednisolone. CONCLUSIONS: In patients with SMA1, a single intravenous infusion of adeno-associated viral vector containing DNA coding for SMN resulted in longer survival, superior achievement of motor milestones, and better motor function than in historical cohorts. Further studies are necessary to confirm the safety and efficacy of this gene therapy. (Funded by AveXis and others; ClinicalTrials.gov number, NCT02122952 .).

Safety and efficacy of eculizumab in anti-acetylcholine receptor antibody-positive refractory generalised myasthenia gravis (REGAIN): a phase 3, randomised, double-blind, placebo-controlled, multicentre study.

BACKGROUND: Complement is likely to have a role in refractory generalised myasthenia gravis, but no approved therapies specifically target this system. Results from a phase 2 study suggested that eculizumab, a terminal complement inhibitor, produced clinically meaningful improvements in patients with anti-acetylcholine receptor antibody-positive refractory generalised myasthenia gravis. We further assessed the efficacy and safety of eculizumab in this patient population in a phase 3 trial. METHODS: We did a phase 3, randomised, double-blind, placebo-controlled, multicentre study (REGAIN) in 76 hospitals and specialised clinics in 17 countries across North America, Latin America, Europe, and Asia. Eligible patients were aged at least 18 years, with a Myasthenia Gravis-Activities of Daily Living (MG-ADL) score of 6 or more, Myasthenia Gravis Foundation of America (MGFA) class II-IV disease, vaccination against Neisseria meningitides, and previous treatment with at least two immunosuppressive therapies or one immunosuppressive therapy and chronic intravenous immunoglobulin or plasma exchange for 12 months without symptom control. Patients with a history of thymoma or thymic neoplasms, thymectomy within 12 months before screening, or use of intravenous immunoglobulin or plasma exchange within 4 weeks before randomisation, or rituximab within 6 months before screening, were excluded. We randomly assigned participants (1:1) to either intravenous eculizumab or intravenous matched placebo for 26 weeks. Dosing for eculizumab was 900 mg on day 1 and at weeks 1, 2, and 3; 1200 mg at week 4; and 1200 mg given every second week thereafter as maintenance dosing. Randomisation was done centrally with an interactive voice or web-response system with patients stratified to one of four groups based on MGFA disease classification. Where possible, patients were maintained on existing myasthenia gravis therapies and rescue medication was allowed at the study physician's discretion. Patients, investigators, staff, and outcome assessors were masked to treatment assignment. The primary efficacy endpoint was the change from baseline to week 26 in MG-ADL total score measured by worst-rank ANCOVA. The efficacy population set was defined as all patients randomly assigned to treatment groups who received at least one dose of study drug, had a valid baseline MG-ADL assessment, and at least one post-baseline MG-ADL assessment. The safety analyses included all randomly assigned patients who received eculizumab or placebo. This trial is registered with ClinicalTrials.gov, number NCT01997229. FINDINGS: Between April 30, 2014, and Feb 19, 2016, we randomly assigned and treated 125 patients, 62 with eculizumab and 63 with placebo. The primary analysis showed no significant difference between eculizumab and placebo (least-squares mean rank 56·6 [SEM 4·5] vs 68·3 [4·5]; rank-based treatment difference -11·7, 95% CI -24·3 to 0·96; p=0·0698). No deaths or cases of meningococcal infection occurred during the study. The most common adverse events in both groups were headache and upper respiratory tract infection (ten [16%] for both events in the eculizumab group and 12 [19%] for both in the placebo group). Myasthenia gravis exacerbations were reported by six (10%) patients in the eculizumab group and 15 (24%) in the placebo group. Six (10%) patients in the eculizumab group and 12 (19%) in the placebo group required rescue therapy. INTERPRETATION: The change in the MG-ADL score was not statistically significant between eculizumab and placebo, as measured by the worst-rank analysis. Eculizumab was well tolerated. The use of a worst-rank analytical approach proved to be an important limitation of this study since the secondary and sensitivity analyses results were inconsistent with the primary endpoint result; further research into the role of complement is needed. FUNDING: Alexion Pharmaceuticals.

QMG and MG-ADL correlations: Study of eculizumab treatment of myasthenia gravis.

INTRODUCTION: A phase 2 study of eculizumab for treating myasthenia gravis (MG) used the quantitative myasthenia gravis score (QMG) and myasthenia gravis activities of daily living profile (MG-ADL) to evaluate baseline disease severity and treatment response. Correlations were then analyzed between these assessments. METHODS: Patients were given eculizumab or placebo during the first 16-week treatment period of the crossover study, with treatment assignments reversed for the second treatment period following a 5-week washout. QMG and MG-ADL scores at baseline and endpoint of each treatment period generated correlation coefficients for baseline status and treatment response during eculizumab therapy. RESULTS: Correlation strength between QMG and MG-ADL scores was higher for treatment response (R = 0.726; 95% confidence interval, 0.264-0.907; P = 0.0036) than for assessing baseline disease status (R = 0.552; 95% confidence interval, -0.022-0.839; P = 0.0495). CONCLUSIONS: MG-ADL may be more sensitive for assessing treatment response than point-in-time disease status. Muscle Nerve 56: 328-330, 2017.

The Limb-Girdle Muscular Dystrophies and the Dystrophinopathies.

PURPOSE OF REVIEW: The classic approach to identifying and accurately diagnosing limb-girdle muscular dystrophies (LGMDs) relied heavily on phenotypic characterization and ancillary studies including muscle biopsy. Because of rapid advances in genetic sequencing methodologies, several additional LGMDs have been molecularly characterized, and the diagnostic approach to these disorders has been simplified. This article summarizes the epidemiology, clinical features, and genetic defects underlying the LGMDs. RECENT FINDINGS: In recent years, the advent of next-generation sequencing has heralded an era of molecular diagnosis in conjunction with physical characterization. Inadvertently, this process has also led to the "next-generation aftermath," whereby variants of unknown significance are identified in most patients. Similar to the published diagnostic and treatment guidelines for Duchenne muscular dystrophy, diagnostic and treatment guidelines have recently been published for LGMDs. In addition, the first medication (based on the exon-skipping strategy) for treatment of patients with a subset of Duchenne muscular dystrophy has been recently approved by the US Food and Drug Administration (FDA). SUMMARY: The LGMDs are a heterogeneous group of hereditary, progressive, and degenerative neuromuscular disorders that present with primary symptoms of shoulder girdle and pelvic girdle weakness. Although a combination of clinical and molecular genetic evaluations may be sufficient for accurate diagnosis of LGMDs in many cases, the contribution of imaging and histopathologic correlations still remains a critical, if not a necessary, component of evaluation in some cases.

Randomized Trial of Thymectomy in Myasthenia Gravis.

BACKGROUND: Thymectomy has been a mainstay in the treatment of myasthenia gravis, but there is no conclusive evidence of its benefit. We conducted a multicenter, randomized trial comparing thymectomy plus prednisone with prednisone alone. METHODS: We compared extended transsternal thymectomy plus alternate-day prednisone with alternate-day prednisone alone. Patients 18 to 65 years of age who had generalized nonthymomatous myasthenia gravis with a disease duration of less than 5 years were included if they had Myasthenia Gravis Foundation of America clinical class II to IV disease (on a scale from I to V, with higher classes indicating more severe disease) and elevated circulating concentrations of acetylcholine-receptor antibody. The primary outcomes were the time-weighted average Quantitative Myasthenia Gravis score (on a scale from 0 to 39, with higher scores indicating more severe disease) over a 3-year period, as assessed by means of blinded rating, and the time-weighted average required dose of prednisone over a 3-year period. RESULTS: A total of 126 patients underwent randomization between 2006 and 2012 at 36 sites. Patients who underwent thymectomy had a lower time-weighted average Quantitative Myasthenia Gravis score over a 3-year period than those who received prednisone alone (6.15 vs. 8.99, P<0.001); patients in the thymectomy group also had a lower average requirement for alternate-day prednisone (44 mg vs. 60 mg, P<0.001). Fewer patients in the thymectomy group than in the prednisone-only group required immunosuppression with azathioprine (17% vs. 48%, P<0.001) or were hospitalized for exacerbations (9% vs. 37%, P<0.001). The number of patients with treatment-associated complications did not differ significantly between groups (P=0.73), but patients in the thymectomy group had fewer treatment-associated symptoms related to immunosuppressive medications (P<0.001) and lower distress levels related to symptoms (P=0.003). CONCLUSIONS: Thymectomy improved clinical outcomes over a 3-year period in patients with nonthymomatous myasthenia gravis. (Funded by the National Institute of Neurological Disorders and Stroke and others; MGTX ClinicalTrials.gov number, NCT00294658.).

Prospective exploratory muscle biopsy, imaging, and functional assessment in patients with late-onset Pompe disease treated with alglucosidase alfa: The EMBASSY Study.

BACKGROUND: Late-onset Pompe disease is characterized by progressive skeletal myopathy followed by respiratory muscle weakness, typically leading to loss of ambulation and respiratory failure. In this population, enzyme replacement therapy (ERT) with alglucosidase alfa has been shown to stabilize respiratory function and improve mobility and muscle strength. Muscle pathology and glycogen clearance from skeletal muscle in treatment-naïve adults after ERT have not been extensively examined. METHODS: This exploratory, open-label, multicenter study evaluated glycogen clearance in muscle tissue samples collected pre- and post- alglucosidase alfa treatment in treatment-naïve adults with late-onset Pompe disease. The primary endpoint was the quantitative reduction in percent tissue area occupied by glycogen in muscle biopsies from baseline to 6months. Secondary endpoints included qualitative histologic assessment of tissue glycogen distribution, secondary pathology changes, assessment of magnetic resonance images (MRIs) for intact muscle and fatty replacement, and functional assessments. RESULTS: Sixteen patients completed the study. After 6months of ERT, the percent tissue area occupied by glycogen in quadriceps and deltoid muscles decreased in 10 and 8 patients, respectively. No changes were detected on MRI from baseline to 6months. A majority of patients showed improvements on functional assessments after 6months of treatment. All treatment-related adverse events were mild or moderate. CONCLUSIONS: This exploratory study provides novel insights into the histopathologic effects of ERT in late-onset Pompe disease patients. Ultrastructural examination of muscle biopsies demonstrated reduced lysosomal glycogen after ERT. Findings are consistent with stabilization of disease by ERT in treatment-naïve patients with late-onset Pompe disease.

A randomized controlled trial of methotrexate for patients with generalized myasthenia gravis.

OBJECTIVE: To determine the steroid-sparing effect of methotrexate (MTX) in patients with symptomatic generalized myasthenia gravis (MG). METHODS: We performed a 12-month multicenter, randomized, double-blind, placebo-controlled trial of MTX 20 mg orally every week vs placebo in 50 acetylcholine receptor antibody-positive patients with MG between April 2009 and August 2014. The primary outcome measure was the prednisone area under the dose-time curve (AUDTC) from months 4 to 12. Secondary outcome measures included 12-month changes of the Quantitative Myasthenia Gravis Score, the Myasthenia Gravis Composite Score, Manual Muscle Testing, the Myasthenia Gravis Quality of Life, and the Myasthenia Gravis Activities of Daily Living. RESULTS: Fifty-eight patients were screened and 50 enrolled. MTX did not reduce the month 4-12 prednisone AUDTC when compared to placebo (difference MTX - placebo: -488.0 mg, 95% confidence interval -2,443.4 to 1,467.3, p = 0.26); however, the average daily prednisone dose decreased in both groups. MTX did not improve secondary measures of MG compared to placebo over 12 months. Eight participants withdrew during the course of the study (1 MTX, 7 placebo). There were no serious MTX-related adverse events. The most common adverse event was nonspecific pain (19%). CONCLUSIONS: We found no steroid-sparing benefit of MTX in MG over 12 months of treatment, despite being well-tolerated. This study demonstrates the challenges of conducting clinical trials in MG, including difficulties with recruitment, participants improving on prednisone alone, and the need for a better understanding of outcome measure variability for future clinical trials. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that for patients with generalized MG MTX does not significantly reduce the prednisone AUDTC over 12 months of therapy.

Oral Bioavailability, Bioaccessibility, and Dermal Absorption of PAHs from Soil-State of the Science.

This article reviews the state of the science regarding oral bioavailability, bioaccessibility, and dermal absorption of carcinogenic polycyclic aromatic hydrocarbons (cPAHs) in soil by humans, and discusses how chemical interactions may control the extent of absorption. Derived from natural and anthropomorphic origins, PAHs occur in a limited number of solid and fluid matrices (i.e., PAH sources) with defined physical characteristics and PAH compositions. Existing studies provide a strong basis for establishing that oral bioavailability of cPAHs from soil is less than from diet, and an assumption of 100% relative bioavailability likely overestimates exposure to cPAHs upon ingestion of PAH-contaminated soil. For both the oral bioavailability and dermal absorption studies, the aggregate data do not provide a broad understanding of how different PAH source materials, PAH concentrations, or soil chemistries influence the absorption of cPAHs from soil. This article summarizes the existing studies, identifies data gaps, and provides recommendations for the direction of future research to support new default or site-specific bioavailability adjustments for use in human health risk assessment.

Correlation of single-breath count test and neck flexor muscle strength with spirometry in myasthenia gravis.

INTRODUCTION: Although formal spirometry is the gold standard for monitoring respiratory function in patients with myasthenia gravis (MG), such testing is often delayed or unavailable. There is a need for a simple bedside test that can accurately measure respiratory function. METHODS: We conducted a prospective, cross-sectional, single-blind study in adults with acetylcholine receptor antibody positive MG. Participants performed the single breath count test (SBCT) and underwent manual muscle strength testing, and a respiratory therapist performed spirometry blinded to SBCT and strength results. RESULTS: Thirty-one patients, aged 57 ± 19 years participated. SBCT showed significant correlations with forced vital capacity (FVC), negative inspiratory force, and neck flexor strength (P < 0.01). FVC showed significant correlation with neck flexor strength (P = 0.02) but no correlation with shoulder abductor strength. CONCLUSIONS: These data suggest that the SBCT and neck flexor strength testing are valuable tools for bedside assessment of respiratory function in MG patients.