Mary K. Schroth

Phase II open label study of valproic acid in spinal muscular atrophy

Preliminary in vitro and in vivo studies with valproic acid (VPA) in cell lines and patients with spinal muscular atrophy (SMA) demonstrate increased expression of SMN, supporting the possibility of therapeutic benefit. We performed an open label trial of VPA in 42 subjects with SMA to assess safety and explore potential outcome measures to help guide design of future controlled clinical trials. Subjects included 2 SMA type I ages 2–3 years, 29 SMA type II ages 2–14 years and 11 type III ages 2–31 years, recruited from a natural history study. VPA was well-tolerated and without evident hepatotoxicity. Carnitine depletion was frequent and temporally associated with increased weakness in two subjects. Exploratory outcome measures included assessment of gross motor function via the modified Hammersmith Functional Motor Scale (MHFMS), electrophysiologic measures of innervation including maximum ulnar compound muscle action potential (CMAP) amplitudes and motor unit number estimation (MUNE), body composition and bone density via dual-energy X-ray absorptiometry (DEXA), and quantitative blood SMN mRNA levels. Clear decline in motor function occurred in several subjects in association with weight gain; mean fat mass increased without a corresponding increase in lean mass. We observed an increased mean score on the MHFMS scale in 27 subjects with SMA type II (p≤0.001); however, significant improvement was almost entirely restricted to participants <5 years of age. Full length SMN levels were unchanged and Δ7SMN levels were significantly reduced for 2 of 3 treatment visits. In contrast, bone mineral density (p≤0.0036) and maximum ulnar CMAP scores (p≤0.0001) increased significantly. Conclusions While VPA appears safe and well-tolerated in this initial pilot trial, these data suggest that weight gain and carnitine depletion are likely to be significant confounding factors in clinical trials. This study highlights potential strengths and limitations of various candidate outcome measures and underscores the need for additional controlled clinical trials with VPA targeting more restricted cohorts of subjects. Trial Registration ClinicalTrials.gov

SMA CARNI-VAL Trial Part I: Double-Blind, Randomized, Placebo-Controlled Trial of L-Carnitine and Valproic Acid in Spinal Muscular Atrophy

Background Valproic acid (VPA) has demonstrated potential as a therapeutic candidate for spinal muscular atrophy (SMA) in vitro and in vivo. Methods Two cohorts of subjects were enrolled in the SMA CARNIVAL TRIAL, a non-ambulatory group of “sitters” (cohort 1) and an ambulatory group of “walkers” (cohort 2). Here, we present results for cohort 1: a multicenter phase II randomized double-blind intention-to-treat protocol in non-ambulatory SMA subjects 2–8 years of age. Sixty-one subjects were randomized 1∶1 to placebo or treatment for the first six months; all received active treatment the subsequent six months. The primary outcome was change in the modified Hammersmith Functional Motor Scale (MHFMS) score following six months of treatment. Secondary outcomes included safety and adverse event data, and change in MHFMS score for twelve versus six months of active treatment, body composition, quantitative SMN mRNA levels, maximum ulnar CMAP amplitudes, myometry and PFT measures. Results At 6 months, there was no difference in change from the baseline MHFMS score between treatment and placebo groups (difference = 0.643, 95% CI = −1.22–2.51). Adverse events occurred in >80% of subjects and were more common in the treatment group. Excessive weight gain was the most frequent drug-related adverse event, and increased fat mass was negatively related to change in MHFMS values (p = 0.0409). Post-hoc analysis found that children ages two to three years that received 12 months treatment, when adjusted for baseline weight, had significantly improved MHFMS scores (p = 0.03) compared to those who received placebo the first six months. A linear regression analysis limited to the influence of age demonstrates young age as a significant factor in improved MHFMS scores (p = 0.007). Conclusions This study demonstrated no benefit from six months treatment with VPA and L-carnitine in a young non-ambulatory cohort of subjects with SMA. Weight gain, age and treatment duration were significant confounding variables that should be considered in the design of future trials. Trial Registry Clinicaltrials.gov NCT00227266

SMA CARNI-VAL TRIAL PART II: A Prospective, Single-Armed Trial of L-Carnitine and Valproic Acid in Ambulatory Children with Spinal Muscular Atrophy

Background Multiple lines of evidence have suggested that valproic acid (VPA) might benefit patients with spinal muscular atrophy (SMA). The SMA CARNIVAL TRIAL was a two part prospective trial to evaluate oral VPA and l-carnitine in SMA children. Part 1 targeted non-ambulatory children ages 2–8 in a 12 month cross over design. We report here Part 2, a twelve month prospective, open-label trial of VPA and L-carnitine in ambulatory SMA children. Methods This study involved 33 genetically proven type 3 SMA subjects ages 3–17 years. Subjects underwent two baseline assessments over 4–6 weeks and then were placed on VPA and L-carnitine for 12 months. Assessments were performed at baseline, 3, 6 and 12 months. Primary outcomes included safety, adverse events and the change at 6 and 12 months in motor function assessed using the Modified Hammersmith Functional Motor Scale Extend (MHFMS-Extend), timed motor tests and fine motor modules. Secondary outcomes included changes in ulnar compound muscle action potential amplitudes (CMAP), handheld dynamometry, pulmonary function, and Pediatric Quality of Life Inventory scores. Results Twenty-eight subjects completed the study. VPA and carnitine were generally well tolerated. Although adverse events occurred in 85% of subjects, they were usually mild and transient. Weight gain of 20% above body weight occurred in 17% of subjects. There was no significant change in any primary outcome at six or 12 months. Some pulmonary function measures showed improvement at one year as expected with normal growth. CMAP significantly improved suggesting a modest biologic effect not clinically meaningful. Conclusions This study, coupled with the CARNIVAL Part 1 study, indicate that VPA is not effective in improving strength or function in SMA children. The outcomes used in this study are feasible and reliable, and can be employed in future trials in SMA. Trial Regsitration Clinicaltrials.gov NCT00227266

Consensus statement on standard of care for congenital myopathies.

Recent progress in scientific research has facilitated accurate genetic and neuropathological diagnosis of congenital myopathies. However, given their relatively low incidence, congenital myopathies remain unfamiliar to the majority of care providers, and the levels of patient care are extremely variable. This consensus statement aims to provide care guidelines for congenital myopathies. The International Standard of Care Committee for Congenital Myopathies worked through frequent e-mail correspondences, periodic conference calls, 2 rounds of online surveys, and a 3-day workshop to achieve a consensus for diagnostic and clinical care recommendations. The committee includes 59 members from 10 medical disciplines. They are organized into 5 working groups: genetics/diagnosis, neurology, pulmonology, gastroenterology/nutrition/speech/oral care, and orthopedics/rehabilitation. In each care area the authors summarize the committee’s recommendations for symptom assessments and therapeutic interventions. It is the committee’s goal that through these recommendations, patients with congenital myopathies will receive optimal care and improve their disease outcome.

Compound muscle action potential and motor function in children with spinal muscular atrophy.

Reliable outcome measures that reflect the underlying disease process and correlate with motor function in children with SMA are needed for clinical trials. Maximum ulnar compound muscle action potential (CMAP) data were collected at two visits over a 4–6‐week period in children with SMA types II and III, 2–17 years of age, at four academic centers. Primary functional outcome measures included the Modified Hammersmith Functional Motor Scale (MHFMS) and MHFMS‐Extend. CMAP negative peak amplitude and area showed excellent discrimination between the ambulatory and non‐ambulatory SMA cohorts (ROC = 0.88). CMAP had excellent test–retest reliability (ICC = 0.96–0.97, n = 64) and moderate to strong correlation with the MHFMS and MHFMS‐Extend (r = 0.61–0.73, n = 68, P < 0.001). Maximum ulnar CMAP amplitude and area is a feasible, valid, and reliable outcome measure for use in pediatric multicenter clinical trials in SMA. CMAP correlates well with motor function and has potential value as a relevant surrogate for disease status. Muscle Nerve, 2010

Perspectives on clinical trials in spinal muscular atrophy

Spinal muscular atrophy is one of the most heterogeneous of the single-gene neuromuscular disorders. The broad spectrum of severity, with onset from the prenatal period to adulthood, presents unique challenges in the design and implementation of clinical trials. The clinical classification of subjects into severe (type 1), intermediate (type 2), and mild (type 3) subtypes has proved useful both in enhancing communication among clinicians internationally and in forging the collaborative development of outcome measures for clinical trials. Ideally, clinical trial design in spinal muscular atrophy must take into account the spinal muscular atrophy type, patient age, severity-of-affection status, nature of the therapeutic approach, timing of the proposed intervention relative to disease progression, and relative homogeneity of the cohort to be studied. Following is an overview of the challenges and opportunities, current and future therapeutic strategies, and progress to date in clinical trials in spinal muscular atrophy.

SMA valiant trial: A prospective, double-blind, placebo-controlled trial of valproic acid in ambulatory adults with spinal muscular atrophy

Introduction: An open‐label trial suggested that valproic acid (VPA) improved strength in adults with spinal muscular atrophy (SMA). We report a 12‐month, double‐blind, cross‐over study of VPA in ambulatory SMA adults. Methods: There were 33 subjects, aged 20–55 years, included in this investigation. After baseline assessment, subjects were randomized to receive VPA (10–20 mg/kg/day) or placebo. At 6 months, patients were switched to the other group. Assessments were performed at 3, 6, and 12 months. The primary outcome was the 6‐month change in maximum voluntary isometric contraction testing with pulmonary, electrophysiological, and functional secondary outcomes. Results: Thirty subjects completed the study. VPA was well tolerated, and compliance was good. There was no change in primary or secondary outcomes at 6 or 12 months. Conclusions: VPA did not improve strength or function in SMA adults. The outcomes used are feasible and reliable and can be employed in future trials in SMA adults. Muscle Nerve 49: 187–192, 2014

Early laparoscopic fundoplication and gastrostomy in infants with spinal muscular atrophy type I

BACKGROUND/PURPOSE Spinal muscular atrophy (SMA) in children leads to progressive muscle weakness, dysphagia, aspiration, and death. We hypothesized that early laparoscopic fundoplication and gastrostomy in infants with SMA type I could be performed safely perhaps leading to fewer aspiration events and improved nutritional status. METHODS Children diagnosed with SMA type I from 2002 through 2005 were included (n = 12). All children underwent laparoscopic Nissen fundoplication with gastrostomy shortly after diagnosis. Postoperative respiratory management and discharge criteria were standardized. RESULTS All patients were extubated immediately postoperatively. There were no significant complications. Average time to full feeding and inpatient length of stay were 42 +/- 4.9 hours (range, 30-48 hours) and 78 +/- 22.5 hours (range, 44-120 hours), respectively. Mean weight-for-length percentile was doubled at 1 year postoperatively (P = .03). The number of respiratory-related hospitalizations in the cohort decreased by almost 50% in the ensuing 12 months after surgery, although this did not reach statistical significance in this small cohort (P = .34). CONCLUSIONS Early laparoscopic fundoplication and gastrostomy is safe and is associated with improved nutritional status. A trend toward fewer significant long-term aspiration-related events was seen after fundoplication. To better assess the long-term benefits of performing an antireflux procedure in these high-risk patients, a larger prospective trial comparing current nutritional support practices is needed.

Diagnosis and management of spinal muscular atrophy: Part 1: Recommendations for diagnosis, rehabilitation, orthopedic and nutritional care

Spinal muscular atrophy (SMA) is a severe neuromuscular disorder due to a defect in the survival motor neuron 1 (SMN1) gene. Its incidence is approximately 1 in 11,000 live births. In 2007, an International Conference on the Standard of Care for SMA published a consensus statement on SMA standard of care that has been widely used throughout the world. Here we report a two-part update of the topics covered in the previous recommendations. In part 1 we present the methods used to achieve these recommendations, and an update on diagnosis, rehabilitation, orthopedic and spinal management; and nutritional, swallowing and gastrointestinal management. Pulmonary management, acute care, other organ involvement, ethical issues, medications, and the impact of new treatments for SMA are discussed in part 2.

Analysis of tracheal secretions for rhinovirus during natural colds

Rhinoviruses (RV) cause 50% of common colds and are frequently isolated from children and adults hospitalized for asthma exacerbations. Although colds may trigger severe coughing and wheezing, it is not known whether these symptoms are a result of lower airway infection with RV. Previous efforts to address this question by sampling lower airway secretions during experimental RV infections have been complicated by the possibility of contamination of the bronchoscope with nasopharyngeal cells and secretions. To further test the hypothesis that RV infections involve the lower airways, tracheal and nasal secretions were obtained from 23 pediatric tracheostomy patients, including seven with cold symptoms and 16 asymptomatic controls. RV was detected by reverse‐transcription polymerase chain reaction from the nasal and tracheal secretions of three of the seven children with cold symptoms. In the 16 well children, RV was not detected in any samples of nasal secretions, but was isolated from four samples of tracheal secretions. These results demonstrate the presence of RV in the lower airways of children with tracheostomies during community‐acquired colds, without the possibility of nasal contamination. In addition, these findings suggest that children with tracheostomies carry subclinical viral infections in their tracheas, rather than their noses.