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Several studies have shown the efficacy of new disease-modifying therapies in slowing down type II SMA progression using the Hammersmith Functional Motor Scale Expanded (HFMSE). This research aims to enhance understanding of activity changes across age groups post-nusinersen treatment using shift analysis, compared with untreated individuals. Retrospective data from the, international SMA consortium (iSMAc) dataset were analyzed, assessing individual item changes over 12 months. Shift analysis was used to determine the gain or loss of abilities, defining "gain" as a positive change between scores from 0 to either 1 or 2 and "loss" as a negative change from either 2 or 1 to 0. The cohort included 130 SMA II patients who underwent 12-month assessments from their first nusinersen dose, with age range between 0.6 and 49.6 years. One-third of the entire cohort experienced at least a loss in one activity, while 60% experienced a gain, particularly notable in children aged 2.5 to 5 years and 5 to 13 years. Overall, the study demonstrates a positive impact of nusinersen treatment on SMA II patients, showing a trend of increased activity gains and decreased probability of ability loss across different age groups., Competing Interests: Declaration of competing interest Authors’ declaration of financial interests/personal relationships statements are provided as supplementary material., (Copyright © 2024. Published by Elsevier B.V.)

Background and Objectives: Currently approved therapies for spinal muscular atrophy (SMA) reverse the degenerative course, leading to better functional outcome, but they do not address the impairment arising from preexisting neurodegeneration. Apitegromab, an investigational, fully human monoclonal antibody, inhibits activation of myostatin (a negative regulator of skeletal muscle growth), thereby preserving muscle mass. The phase 2 TOPAZ trial assessed the safety and efficacy of apitegromab in individuals with later-onset type 2 and type 3 SMA., Methods: In this study, designed to investigate potential meaningful combinations of eligibility and treatment regimen for future studies, participants aged 2-21 years received IV apitegromab infusions every 4 weeks for 12 months in 1 of 3 cohorts. Cohort 1 stratified ambulatory participants aged 5-21 years into 2 arms (apitegromab 20 mg/kg alone or in combination with nusinersen); cohort 2 evaluated apitegromab 20 mg/kg combined with nusinersen in nonambulatory participants aged 5-21 years; and cohort 3 blindly evaluated 2 randomized apitegromab doses (2 and 20 mg/kg) combined with nusinersen in younger participants ≥2 years of age. The primary efficacy measure was mean change from baseline using the Hammersmith Functional Motor Scale version appropriate for each cohort. Data were analyzed using a paired t test with 2-sided 5% type 1 error for the mean change from baseline for predefined cohort-specific primary efficacy end points., Results: Fifty-eight participants (mean age 9.4 years) were enrolled at 16 trial sites in the United States and Europe. Participants had been treated with nusinersen for a mean of 25.9 months before enrollment in any of the 3 trial cohorts. At month 12, the mean change from baseline in Hammersmith scale score was -0.3 points (95% CI -2.1 to 1.4) in cohort 1 (n = 23), 0.6 points (-1.4 to 2.7) in cohort 2 (n = 15), and in cohort 3 (n = 20), the mean scores were 5.3 (-1.5 to 12.2) and 7.1 (1.8 to 12.5) for the 2-mg/kg (n = 8) and 20-mg/kg (n = 9) arms, respectively. The 5 most frequently reported treatment-emergent adverse events were headache (24.1%), pyrexia (22.4%), upper respiratory tract infection (22.4%), cough (22.4%), and nasopharyngitis (20.7%). No deaths or serious adverse reactions were reported., Discussion: Apitegromab led to improved motor function in participants with later-onset types 2 and 3 SMA. These results support a randomized, placebo-controlled phase 3 trial of apitegromab in participants with SMA., Trial Registration Information: This trial is registered with ClinicalTrials.gov (NCT03921528)., Classification of Evidence: This study provides Class III evidence that apitegromab improves motor function in later-onset types 2 and 3 spinal muscular atrophy.

Background: Spinal muscular atrophy (SMA) is a neuromuscular disorder characterised by progressive motor function decline. Motor function is assessed using several functional outcome measures including the Revised Hammersmith Scale (RHS)., Objective: In this study, we present longitudinal trajectories for the RHS in an international cohort of 149 untreated paediatric SMA 2 and 3 patients (across 531 assessments collected between March 2015 and July 2019)., Methods: We contextualise these trajectories using both the Hammersmith Functional Motor Scale Expanded (HFMSE) and Revised Upper Limb Module (RULM). At baseline, this cohort included 50% females and 15% of patients had undergone spinal fusion surgery. Patient trajectories were modelled using a natural cubic spline with age, sex, and random effects for each patient., Results: RHS and HFMSE scores show similar trends over time in this cohort not receiving disease modifying therapies. The results confirm the strong correlation between the RHS and RULM previously observed in SMA types 2 and 3a. Scoliosis surgery is associated with a reduction of 3 points in the RHS, 4.5 points in the HFMSE for the SMA 2 population, and a reduction of 11.8 points in the RHS, and 13.4 points in the HFMSE for the SMA 3a populations. When comparing the RHS and RULM, there is a lower correlation in the type 3a's than the type 2 patients. In the SMA 2 population, there is no significant difference between the sexes in either the RHS or HFMSE trajectories. There is no significant difference in the RULM trajectory in the SMA 2 or 3a participants by sex., Conclusions: This study demonstrates that the RHS could be used in conjunction with other functional measures such as the RULM to holistically detect SMA disease progression. This will assist with fully understanding changes that occur with treatments, further defining trajectories and therapy outcomes.

Bulbar function in spinal muscular atrophy has been defined as the ability to meet nutritional needs by mouth while maintaining airway protection and communicate verbally. The effects of disease-modifying treatment on bulbar function are not clear. A multidisciplinary team conducted post-hoc analyses of phase 3 SPR1NT trial data to evaluate bulbar function of infants at risk for spinal muscular atrophy who received one-time gene replacement therapy (onasemnogene abeparvovec) before symptom onset. Three endpoints represented adequate bulbar function in SPR1NT: (1) absence of physiologic swallowing impairment, (2) full oral nutrition, and (3) absence of adverse events indicating pulmonary instability. Communication was not assessed in SPR1NT. We descriptively assessed numbers/percentages of children who achieved each endpoint and all three collectively. SPR1NT included infants <6 postnatal weeks with two (n = 14) or three (n = 15) copies of the survival motor neuron 2 gene. At study end (18 [two-copy cohort] or 24 [three-copy cohort] months of age), 100% (29/29) of patients swallowed normally, achieved full oral nutrition, maintained pulmonary stability, and achieved the composite endpoint. When administered to infants before clinical symptom onset, onasemnogene abeparvovec allowed children at risk for spinal muscular atrophy to achieve milestones within published normal ranges of development and preserve bulbar function., Competing Interests: Declaration of Competing Interest Richard D. Shell has been a paid speaker for Novartis Gene Therapies. Katlyn E. McGrattan has received research grants from the National Institutes of Health, National Institute of Child Health and Human Development, National Institute of Environmental Health Sciences, 1R41HD104305-01 on “A novel non-invasive method of aspiration detection in preterm infants (Ongoing).” In addition, she is a consultant for Novartis Gene Therapies, Biogen, and Roche. Rebecca Hurst-Davis is a Cure SMA Medical Advisory Council member. Sally Dunaway Young is an advisory board member/consultant for Biogen, Cure SMA, Genentech/Roche, and Scholar Rock, and receives grant support from Novartis Gene Therapies, Inc., Biogen, Cure SMA, Genentech/Roche, Genzyme, Minoryx, PTC Therapeutics, and Scholar Rock. Giovanni Baranello has received speaker and consulting fees from Biogen, Novartis Gene Therapies, Inc. (AveXis), and Roche, and has worked as a principal investigator of SMA studies sponsored by Novartis Gene Therapies, Inc., and Roche. Arseniy Lavrov, Eamonn O'Brien, Shiri Wallach, Nicole LaMarca, and Sandra P. Reyna are employees of Novartis Gene Therapies and hold stock/other equities. Basil T. Darras has served as an ad-hoc scientific advisory board member for Audentes, AveXis/Novartis Gene Therapies, Biogen, Pfizer, Sarepta, Roche/Genentech, and Vertex; as a steering committee chair and member for the Roche FIREFISH and Biogen ASCEND studies, respectively, and data and safety monitoring board member for Amicus Inc.; he has no financial interests in these companies. He has received research support from the National Institutes of Health/National Institute of Neurological Disorders and Stroke, the Slaney Family Fund for SMA, the Spinal Muscular Atrophy Foundation, CureSMA, and Summit and Working on Walking Fund and has received grants from Ionis Pharmaceuticals, Inc., for the ENDEAR, CHERISH, CS2/CS12 studies; from Biogen for CS11; and from Novartis Gene Therapies, Inc., Sarepta Pharmaceuticals, Novartis, PTC Therapeutics, Roche, Scholar Rock, and Fibrogen. He has also received royalties for books and online publications from Elsevier and UpToDate, Inc., (Copyright © 2023. Published by Elsevier B.V.)

Background: Spinal muscular atrophy (SMA) is a neuromuscular disorder arising from biallelic non-functional survival motor neuron 1 (SMN1) genes with variable copies of partially functional SMN2 gene. Intrathecal onasemnogene abeparvovec administration, at fixed, low doses, may enable treatment of heavier patients ineligible for weight-based intravenous dosing., Objective: STRONG (NCT03381729) assessed the safety/tolerability and efficacy of intrathecal onasemnogene abeparvovec for sitting, nonambulatory SMA patients., Methods: Sitting, nonambulatory SMA patients (biallelic SMN1 loss, three SMN2 copies, aged 6-<60 months) received a single dose of intrathecal onasemnogene abeparvovec. Patients were enrolled sequentially into one of three (low, medium, and high) dose cohorts and stratified into two groups by age at dosing: younger (6-<24 months) and older (24-<60 months). Primary endpoints included safety/tolerability, independent standing ≥3 seconds (younger group), and change in Hammersmith Functional Motor Scale Expanded (HFMSE) from baseline (older group) compared with historic controls., Results: Thirty-two patients were enrolled and completed the study (medium dose, n = 25). All patients had one or more treatment-emergent adverse events, with one serious and related to treatment (transaminase elevations). No deaths were reported. One of 13 patients (7.7%) in the younger group treated with the medium dose achieved independent standing. At Month 12 for the older group receiving the medium dose, change from baseline in HFMSE was significantly improved compared with the SMA historic control population (P < 0.01)., Conclusions: Intrathecal onasemnogene abeparvovec was safe and well-tolerated. Older patients treated with the medium dose demonstrated increases in HFMSE score greater than commonly observed in natural history.

Background: Novel Spinal Muscular Atrophy (SMA) treatments have demonstrated improvements on motor measures that are clearly distinct from the natural history of progressive decline. Comparable measures are needed to monitor bulbar function, which is affected in severe SMA., Objective: To assess bulbar function with patient-reported outcome measures (PROs) and determine their relationships with clinical characteristics., Methods: We recruited 47 non-ambulatory participants (mean (SD) age = 29.8 (13.7) years, range = 10.3-73.2) with SMA. PROs including Voice Handicap Index (VHI) and Eating Assessment Tool-10 (EAT-10) were collected alongside clinical characteristics and standardized motor assessments. Associations were assessed using Spearman correlation coefficients and group comparisons were performed using Wilcoxon rank sum tests., Results: A majority of the 47 participants were SMA type 2 (70.2%), non-sitters (78.7%), 3 copies of SMN2 (77.5%), and using respiratory support (66.0%). A majority (94%) reported voice issues primarily in 8/30 VHI questions. Problems included: difficulty understanding me in a noisy room (87.2%); difficult for people to hear me (74.5%); and people ask me to repeat when speaking face-to-face (72.3%). A majority (85.1%) reported swallowing issues primarily in 3/10 EAT-10 questions: swallowing pills (68.1%); food sticks to my throat (66.0%); and swallowing solids (61.7%). The two PROs were moderately associated (rs = 0.66)., Conclusions: Weaker individuals with SMA experience bulbar problems including difficulties with voice and swallowing. Further refinement and assessment of functional bulbar scales will help determine their relevance and responsiveness to changes in SMA. Additional study is needed to quantify bulbar changes caused by SMA and their response to disease-modifying treatments.

Background: Improvement and maintenance of bulbar function are goals of disease-modifying treatments for spinal muscular atrophy (SMA). Lack of standardized measures and a widely accepted definition of bulbar function represents a gap in SMA care., Objective: A multidisciplinary team conducted post-hoc analyses of pooled data from one phase 1 (START) and two phase 3 (STR1VE-US, STR1VE-EU) studies to define and evaluate bulbar function of infants with SMA type 1 after receiving one-time gene replacement therapy, onasemnogene abeparvovec., Methods: We defined bulbar function as the ability to meet nutritional needs while maintaining airway protection and the ability to communicate verbally. Four endpoints represented adequate bulbar function: (1) absence of clinician-identified physiologic swallowing impairment, (2) receiving full oral nutrition, (3) absence of adverse events indicating pulmonary instability, and (4) the ability to vocalize at least two different, distinct vowel sounds. We descriptively assessed numbers/percentages of patients who achieved each endpoint and all four collectively. Patients were followed until 18 months old (STR1VE-US and STR1VE-EU) or 24 months (START) post-infusion., Results: Overall, 65 patients were analyzed for swallowing, nutrition intake, and adverse events, and 20 were analyzed for communication. At study end, 92% (60/65) of patients had a normal swallow, 75% (49/65) achieved full oral nutrition, 92% (60/65) had no evidence of pulmonary instability, 95% (19/20) met the communication endpoint, and 75% (15/20) achieved all four bulbar function components in the composite endpoint., Conclusions: In these three clinical trials, patients with SMA type 1 who received onasemnogene abeparvovec achieved and maintained the bulbar function criteria utilized within this investigation.

Background: Risdiplam is an orally administered therapy that modifies pre-mRNA splicing of the survival of motor neuron 2 (SMN2) gene and is approved for the treatment of spinal muscular atrophy. The FIREFISH study is investigating the safety and efficacy of risdiplam in treated infants with type 1 spinal muscular atrophy versus historical controls. The primary endpoint of part 2 of the FIREFISH study showed that infants with type 1 spinal muscular atrophy attained the ability to sit without support for at least 5 s after 12 months of treatment. Here, we report on the safety and efficacy of risdiplam in FIREFISH part 2 over 24 months of treatment., Methods: FIREFISH is an ongoing, multicentre, open-label, two-part study. In FIREFISH part 2, eligible infants (aged 1-7 months at enrolment, with a genetically confirmed diagnosis of spinal muscular atrophy, and two SMN2 gene copies) were enrolled in 14 hospitals in ten countries across Europe, North America, South America, and Asia. Risdiplam was orally administered once daily at 0·2 mg/kg for infants between 5 months and 2 years of age; once an infant reached 2 years of age, the dose was increased to 0·25 mg/kg. Infants younger than 5 months started at 0·04 mg/kg (infants between 1 month and 3 months old) or 0·08 mg/kg (infants between 3 months and 5 months old), and this starting dose was adjusted to 0·2 mg/kg once pharmacokinetic data were available for each infant. The primary and secondary endpoints included in the statistical hierarchy and assessed at month 12 have been reported previously. Here we present the remainder of the secondary efficacy endpoints that were included in the statistical hierarchy at month 24: the ability to sit without support for at least 30 s, to stand alone, and to walk alone, as assessed by the Bayley Scales of Infant and Toddler Development, third edition gross motor subscale. These three endpoints were compared with a performance criterion of 5% that was defined based on the natural history of type 1 spinal muscular atrophy; the results were considered statistically significant if the lower limit of the two-sided 90% CI was above the 5% threshold. FIREFISH is registered with ClinicalTrials.gov, NCT02913482. Recruitment is closed; the 36-month extension period of the study is ongoing., Findings: Between March 13 and Nov 19, 2018, 41 infants were enrolled in FIREFISH part 2. After 24 months of treatment, 38 infants were ongoing in the study and 18 infants (44% [90% CI 31-58]) were able to sit without support for at least 30 s (p<0·0001 compared with the performance criterion derived from the natural history of untreated infants with type 1 spinal muscular atrophy). No infants could stand alone (0 [90% CI 0-7]) or walk alone (0 [0-7]) after 24 months of treatment. The most frequently reported adverse event was upper respiratory tract infection, in 22 infants (54%); the most common serious adverse events were pneumonia in 16 infants (39%) and respiratory distress in three infants (7%)., Interpretation: Treatment with risdiplam over 24 months resulted in continual improvements in motor function and achievement of developmental motor milestones. The FIREFISH open-label extension phase will provide additional evidence regarding long-term safety and efficacy of risdiplam., Funding: F Hoffmann-La Roche., Competing Interests: Declaration of interests RM has received consulting fees from Biogen, F Hoffmann-La Roche, and Novartis Gene Therapies, and speaker honoraria from F Hoffmann-La Roche and Novartis Gene Therapies. RM reports that he received travel or meeting attendance support and fees for serving on advisory boards from F Hoffmann-La Roche, Novartis Gene Therapies, and Biogen. MMB has received speaker honoraria and payment for serving on advisory boards for F Hoffmann-La Roche, Sanofi, Novartis, Biogen, and UCB. KR reports she has received consulting fees from F Hoffmann-La Roche, Biogen, and Novartis; she has received support from Biogen for attending meetings; she has received speaker honoraria from F Hoffmann-La Roche and Biogen, and has served on advisory boards for F Hoffmann-La Roche and Biogen. LS reports grants from F Hoffmann-La Roche, Biogen, and Novartis, and consultancy fees from F Hoffmann-La Roche, Biogen, Novartis, BioHaven Pharmaceuticals, and Scholar Rock. He has received speaker fees from and served on advisory boards for F Hoffmann-La Roche, Biogen, and Novartis. He reports he holds the position of secretary at the World Muscle Society. HX declared no competing interests. EZ reports grants from Fundação de Amparo à Pesquisa do Estado de São Paulo, The Brazilian National Council for Scientific and Technological development, Sarepta Therapeutics, F Hoffmann-La Roche, Biogen, and Novartis. He has received consulting fees from F Hoffmann-La Roche, Novartis, Biogen, Sanofi, Astellas, and Sarepta Therapeutics. EZ received speaker honoraria from and served on advisory boards for F Hoffmann-La Roche, Novartis, Biogen, Sanofi, and Astellas. He has received travel and meeting attendance support from F Hoffmann-La Roche, Novartis, Biogen, Sanofi, and Sarepta Therapeutics. GB reports that he has received consulting fees and speaker honoraria from Biogen, F Hoffmann-La Roche, and Novartis Gene Therapies. GB has received fees for serving on advisory boards and has received equipment for indirect calorimetry to University College London from F Hoffmann-La Roche. CB reports he has received grants or contracts from Biogen, Novartis, and F Hoffmann-La Roche. He has served on advisory boards for Sarepta Therapeutics, F Hoffmann-La Roche, Novartis, and Biogen; he has received support from Sarepta Therapeutics and Biogen for attending meetings. JWD has received research grants from Biogen, Cytokinetics, Ionis Pharmaceuticals, Novartis Gene Therapies, F Hoffmann-La Roche, and Scholar Rock. He reports that he has received consulting fees from Shift Therapeutics and that he has served on advisory boards for Biogen, Cytokinetics, Epirium Bio, Ionis Pharmaceuticals, Novartis Gene Therapies, F Hoffmann-La Roche–Genentech, and Scholar Rock. ND reports he has received support from F Hoffmann-La Roche for provision of FIREFISH and SUNFISH clinical trials study materials, paid to the institution (Ghent University Hospital [US Gent]). He reports that he has received consulting fees for the SUNFISH trial advisory board, has received support for attending meetings, travel, or both, and for serving on advisory boards from F Hoffmann-La Roche. AK has received consulting fees for serving on advisory boards for AveXis, Novartis Gene Therapies, Biogen, and F Hoffmann-La Roche. She has received speaker honoraria from F Hoffmann-La Roche and Biogen. AK reports that The Swiss-Reg-NMD receives unconditional financial support from PTC Therapeutics, Sarepta Therapeutics, Pfizer, and F Hoffmann-La Roche and research grants from Novartis Gene Therapies and Biogen. She reports that she receives research grants from the Swiss Foundation for Research on Muscle Diseases. EM has received grants or contracts from Biogen. He has received speaker honoraria for lectures from Biogen, F Hoffmann-La Roche, Novartis, and AveXis. EM reports he has served on advisory boards for Biogen, F Hoffmann-La Roche, Scholar Rock, Novartis, AveXis, and Cytokinetics. DV reports grants from PTC Therapeutics, F Hoffmann-La Roche, Novartis, Biogen, NS Pharma, Sarepta Therapeutics, and Pfizer. He has received consulting fees from F Hoffmann-La Roche, Novartis, AveXis, and Biogen; he has received speaker honoraria for lectures from PTC Therapeutics, F Hoffmann-La Roche, Janssen, and Novartis. DV has served on advisory boards for AveXis, Biogen, Novartis, and F Hoffmann-La Roche. YW reports she has received payment from F Hoffmann-La Roche for the FIREFISH part 2 trial to support the study according to agreement and has received grants or contracts from UCB and Biogen for clinical trial support. BD reports grants from F Hoffmann-La Roche during the conduct of the study; and grants from PTC Therapeutics, Fibrogen, AveXis, Genentech, Ionis Pharmaceuticals, Biogen, Sarepta Therapeutics, and Summit. He reports research support from the National Institutes of Health and National Institute of Neurological Disorders and Stroke, Slaney Family Fun for spinal muscular atrophy, Spinal Muscular Atrophy Foundation, CureSMA, and Working on Walking Fund. He served on advisory boards for AveXis, Vertex, Genentech, F Hoffmann-La Roche, Sanofi–Genzyme, Sarepta Therapeutics, and Biogen; he reports his role as a member of the data safety monitoring board for Amicus Inc, outside of the submitted work. AD, MEK, KG, BJ, HK, EG, and PF report that they are current employees and stockholders in F Hoffmann-La Roche., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Background: ANCHOVY was a global, multicenter, chart-review study that aimed to describe the natural history of Type 1 spinal muscular atrophy (SMA) from a broad geographical area and provide further contextualization of results from the FIREFISH (NCT02913482) interventional study of risdiplam treatment in Type 1 SMA., Methods: Data were extracted from medical records of patients with first symptoms attributable to Type 1 SMA between 28 days and 3 months of age, genetic confirmation of SMA, and confirmed survival of motor neuron 2 copy number of two or unknown. The study period started on 1 January 2008 for all sites; study end dates were site-specific due to local treatment availabilities. Primary endpoints were time to death and/or permanent ventilation and proportion of patients achieving motor milestones. Secondary endpoints included time to initiation of respiratory and feeding support., Results: Data for 60 patients from nine countries across Asia, Europe and North and South America were analyzed. The median age (interquartile range [IQR]) for reaching death or permanent ventilation was ~ 7.3 (5.9-10.5) months. The median age (IQR) at permanent ventilation was ~ 12.7 (6.9-16.4) months and at death was ~ 41.2 (7.3-not applicable) months. No patients were able to sit without support or achieved any level of crawling, standing or walking., Interpretation: Findings from ANCHOVY were consistent with published natural history data on Type 1 SMA demonstrating the disease's devastating course, which markedly differed from risdiplam-treated infants (FIREFISH Part 2). The results provide meaningful additions to the literature, including a broader geographical representation., (© 2022. The Author(s).)

Introduction/aims: Data regarding weight, height/length, and growth status of patients with spinal muscular atrophy (SMA) who have received only supportive care are limited. This cross-sectional study describes these measurements in patients with Type 1 and Types 2/3 SMA and compares them with reference values from typically developing children., Methods: Retrospective baseline data from three sites in the Pediatric Neuromuscular Clinical Research Network (Boston, New York, Philadelphia) were used. Descriptive statistics for weight, height/length, body mass index-for-age, as well as weight-for-length and absolute and relative deviations from reference values (ie, 50th percentile from World Health Organization/Centers for Disease Control growth charts) were calculated. Furthermore, growth status was reported., Results: A total of 91 genetically confirmed patients with SMA receiving optimal supportive care and without any disease-modifying treatment were stratified into Types 1 (n = 28) and 2/3 SMA (n = 63). Patients with Type 1 SMA weighed significantly less (median = -7.5%) compared with reference values and patients with Types 2/3 SMA were significantly shorter (mean = -3.0%) compared with reference values. The median weight was considerably below the 50th percentile in both groups of patients, even if they received a high standard of care and proactive feeding support., Discussion: More research is needed to understand which factors influence growth longitudinally, and how to accurately capture growth in patients with SMA. Further research should investigate the best time to provide feeding support to avoid underweight, especially in patients with Type 1, and how to avoid the risk of overfeeding, especially in patients with Types 2/3 SMA., (© 2022 F. Hoffmann-La Roche Ltd. Muscle & Nerve published by Wiley Periodicals LLC.)

Introduction: The Hammersmith Functional Motor Scale Expanded (HFMSE) and the Revised Upper Limb Module (RULM) have been widely used in natural history studies and clinical trials. Our aim was to establish how the scales relate to each other at different age points in spinal muscular atrophy (SMA) type 2 and 3, and to describe their coherence over 12 mo., Methods: The study was performed by cross-sectional and longitudinal reanalysis of previously published natural history data. The longitudinal analysis of the 12-mo changes also included the analysis of concordance between scales with changes grouped as stable (±2 points), improved (>+2) or declined (>-2)., Results: Three hundred sixty-four patients were included in the cross-sectional analysis, showing different trends in score and point of slope change for the two scales. For type 2, the point of slope change was 4.1 y for the HFMSE and 5.8 for the RULM, while for type 3, it was 6 y for the HFMSE and 7.3 for the RULM. One-hundred-twenty-one patients had at least two assessments at 12 mo. Full concordance was found in 57.3% of the assessments, and in 40.4% one scale remained stable and the other changed. Each scale appeared to be more sensitive to specific age or functional subgroups., Discussion: The two scales, when used in combination, may increase the sensitivity to detect clinically meaningful changes in motor function in patients with SMA types 2 and 3., (© 2021 The Authors. Muscle & Nerve published by Wiley Periodicals LLC.)

Objective: We report longitudinal data from 144 type III SMA pediatric and adult patients treated with nusinersen as part of an international effort., Methods: Patients were assessed using Hammersmith Functional Motor Scale Expanded (HFMSE), Revised Upper Limb Module (RULM), and 6-Minute Walk Test (6MWT) with a mean follow-up of 1.83 years after nusinersen treatment., Results: Over 75% of the 144 patients had a 12-month follow-up. There was an increase in the mean scores from baseline to 12 months on both HFMSE (1.18 points, p = 0.004) and RULM scores (0.58 points, p = 0.014) but not on the 6MWT (mean difference = 6.65 m, p = 0.33). When the 12-month HFMSE changes in the treated cohort were compared to an external cohort of untreated patients, in all untreated patients older than 7 years, the mean changes were always negative, while always positive in the treated ones. To reduce a selection bias, we also used a multivariable analysis. On the HFMSE scale, age, gender, baseline value, and functional status contributed significantly to the changes, while the number of SMN2 copies did not contribute. The effect of these variables was less obvious on the RULM and 6MWT., Interpretation: Our results expand the available data on the effect of Nusinersen on type III patients, so far mostly limited to data from adult type III patients., (© 2021 The Authors. Annals of Clinical and Translational Neurology published by Wiley Periodicals LLC on behalf of American Neurological Association.)

Background: Type 1 spinal muscular atrophy (SMA) is a progressive neuromuscular disease characterized by an onset at 6 months of age or younger, an inability to sit without support, and deficient levels of survival of motor neuron (SMN) protein. Risdiplam is an orally administered small molecule that modifies SMN2 pre-messenger RNA splicing and increases levels of functional SMN protein in blood., Methods: We conducted an open-label study of risdiplam in infants with type 1 SMA who were 1 to 7 months of age at enrollment. Part 1 of the study (published previously) determined the dose to be used in part 2 (reported here), which assessed the efficacy and safety of daily risdiplam as compared with no treatment in historical controls. The primary end point was the ability to sit without support for at least 5 seconds after 12 months of treatment. Key secondary end points were a score of 40 or higher on the Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP-INTEND; range, 0 to 64, with higher scores indicating better motor function), an increase of at least 4 points from baseline in the CHOP-INTEND score, a motor-milestone response as measured by Section 2 of the Hammersmith Infant Neurological Examination (HINE-2), and survival without permanent ventilation. For the secondary end points, comparisons were made with the upper boundary of 90% confidence intervals for natural-history data from 40 infants with type 1 SMA., Results: A total of 41 infants were enrolled. After 12 months of treatment, 12 infants (29%) were able to sit without support for at least 5 seconds, a milestone not attained in this disorder. The percentages of infants in whom the key secondary end points were met as compared with the upper boundary of confidence intervals from historical controls were 56% as compared with 17% for a CHOP-INTEND score of 40 or higher, 90% as compared with 17% for an increase of at least 4 points from baseline in the CHOP-INTEND score, 78% as compared with 12% for a HINE-2 motor-milestone response, and 85% as compared with 42% for survival without permanent ventilation (P<0.001 for all comparisons). The most common serious adverse events were pneumonia, bronchiolitis, hypotonia, and respiratory failure., Conclusions: In this study involving infants with type 1 SMA, risdiplam resulted in higher percentages of infants who met motor milestones and who showed improvements in motor function than the percentages observed in historical cohorts. Longer and larger trials are required to determine the long-term safety and efficacy of risdiplam in infants with type 1 SMA. (Funded by F. Hoffmann-La Roche; FIREFISH ClinicalTrials.gov number, NCT02913482.)., (Copyright © 2021 Massachusetts Medical Society.)

Previous natural history studies suggest that type II SMA patients remain stable over one year but show some progression over two years. Since nusinersen approval, there has been increasing attention to identify more specific age-related changes. The aim of the study was to establish 12-month changes in a cohort of pediatric type II SMA treated with nusinersen and to establish possible patterns of treatment effect in relation to different variables such as age, baseline value and SMN2 copy number. The Hammersmith Functional Motor Scale Expanded and the Revised Upper Limb Module were performed at T0 and 12 months after treatment (T12). Data in treated patients were compared to available data in untreated patients collected by the same evaluators.Seventy-seven patients of age between 2.64 and 17.88 years (mean:7.47, SD:3.79) were included. On t-test there was an improvement, with increased mean scores between T0 and T12 on both scales (p < 0.001). Using multivariate linear regression analysis, age and baseline scores were predictive of changes on both scales (p < 0.05) while SMN2 copy number was not. Differences were also found between study cohort and untreated data on both scales (p < 0.001). At 12 months, an increase in scores was observed in all the age subgroups at variance with natural history data. Our real-world data confirm the treatment effect of nusinersen in pediatric type II SMA patients and that the data interpretation should take into account different variables. These data confirm and expand the ones already reported in the Cherish study., Competing Interests: Declaration of Competing Interest GC, RDS, JM, AMG, SDY, MP, SM, ADA, BTD, EB, VAS, JD, FM, DCDV, RF, CB, EM reports personal fees BIOGEN S.R.L. outside the submitted work; GC, MCP, RDS, JM, AMG, SDY, MS, BTD, EB, JD, FM, DCDV, RF, CB, EM reports personal fees ROCHE outside the submitted work; GC reports personal fees GENESIS PHARMA and Biologix outside the submitted work; GC, RDS, AMG, MP, SM, BTD, EB, VAS, JD, FM, DCDV, RF, CB, EM reports personal fees AVEXIS outside the submitted work; AP, SDY, reports personal fees SMA FOUNDATION outside the submitted work; SDY reports personal fees SCHOLAR ROCK outside the submitted work; ADA, JD, RF reports personal fees NOVARTIS outside the submitted work; SL, SC, LA, AF, FS, PT, MC, TD, have nothing to disclose., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Background: Spinal muscular atrophy type 1 is a motor neuron disorder resulting in death or the need for permanent ventilation by age 2 years. We aimed to evaluate the safety and efficacy of onasemnogene abeparvovec (previously known as AVXS-101), a gene therapy delivering the survival motor neuron gene (SMN), in symptomatic patients (identified through clinical examination) with infantile-onset spinal muscular atrophy., Methods: STR1VE was an open-label, single-arm, single-dose, phase 3 trial done at 12 hospitals and universities in the USA. Eligible patients had to be younger than 6 months and have spinal muscular atrophy with biallelic SMN1 mutations (deletion or point mutations) and one or two copies of SMN2. Patients received a one-time intravenous infusion of onasemnogene abeparvovec (1·1 × 10 14 vector genomes per kg) for 30-60 min. During the outpatient follow-up, patients were assessed once per week, beginning at day 7 post-infusion for 4 weeks and then once per month until the end of the study (age 18 months or early termination). Coprimary efficacy outcomes were independent sitting for 30 s or longer (Bayley-III item 26) at the 18 month of age study visit and survival (absence of death or permanent ventilation) at age 14 months. Safety was assessed through evaluation of adverse events, concomitant medication usage, physical examinations, vital sign assessments, cardiac assessments, and laboratory evaluation. Primary efficacy endpoints for the intention-to-treat population were compared with untreated infants aged 6 months or younger (n=23) with spinal muscular atrophy type 1 (biallelic deletion of SMN1 and two copies of SMN2) from the Pediatric Neuromuscular Clinical Research (PNCR) dataset. This trial is registered with ClinicalTrials.gov, NCT03306277 (completed)., Findings: From Oct 24, 2017, to Nov 12, 2019, 22 patients with spinal muscular atrophy type 1 were eligible and received onasemnogene abeparvovec. 13 (59%, 97·5% CI 36-100) of 22 patients achieved functional independent sitting for 30 s or longer at the 18 month of age study visit (vs 0 of 23 patients in the untreated PNCR cohort; p<0·0001). 20 patients (91%, 79-100]) survived free from permanent ventilation at age 14 months (vs 6 [26%], 8-44; p<0·0001 in the untreated PNCR cohort). All patients who received onasemnogene abeparvovec had at least one adverse event (most common was pyrexia). The most frequently reported serious adverse events were bronchiolitis, pneumonia, respiratory distress, and respiratory syncytial virus bronchiolitis. Three serious adverse events were related or possibly related to the treatment (two patients had elevated hepatic aminotransferases, and one had hydrocephalus)., Interpretation: Results from this multicentre trial build on findings from the phase 1 START study by showing safety and efficacy of commercial grade onasemnogene abeparvovec. Onasemnogene abeparvovec showed statistical superiority and clinically meaningful responses when compared with observations from the PNCR natural history cohort. The favourable benefit-risk profile shown in this study supports the use of onasemnogene abeparvovec for treatment of symptomatic patients with genetic or clinical characteristics predictive of infantile-onset spinal muscular atrophy type 1., Funding: Novartis Gene Therapies., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Background: Type 1 spinal muscular atrophy is a rare, progressive neuromuscular disease that is caused by low levels of functional survival of motor neuron (SMN) protein. Risdiplam is an orally administered, small molecule that modifies SMN2 pre-messenger RNA splicing and increases levels of functional SMN protein., Methods: We report the results of part 1 of a two-part, phase 2-3, open-label study of risdiplam in infants 1 to 7 months of age who had type 1 spinal muscular atrophy, which is characterized by the infant not attaining the ability to sit without support. Primary outcomes were safety, pharmacokinetics, pharmacodynamics (including the blood SMN protein concentration), and the selection of the risdiplam dose for part 2 of the study. Exploratory outcomes included the ability to sit without support for at least 5 seconds., Results: A total of 21 infants were enrolled. Four infants were in a low-dose cohort and were treated with a final dose at month 12 of 0.08 mg of risdiplam per kilogram of body weight per day, and 17 were in a high-dose cohort and were treated with a final dose at month 12 of 0.2 mg per kilogram per day. The baseline median SMN protein concentrations in blood were 1.31 ng per milliliter in the low-dose cohort and 2.54 ng per milliliter in the high-dose cohort; at 12 months, the median values increased to 3.05 ng per milliliter and 5.66 ng per milliliter, respectively, which represented a median of 3.0 times and 1.9 times the baseline values in the low-dose and high-dose cohorts, respectively. Serious adverse events included pneumonia, respiratory tract infection, and acute respiratory failure. At the time of this publication, 4 infants had died of respiratory complications. Seven infants in the high-dose cohort and no infants in the low-dose cohort were able to sit without support for at least 5 seconds. The higher dose of risdiplam (0.2 mg per kilogram per day) was selected for part 2 of the study., Conclusions: In infants with type 1 spinal muscular atrophy, treatment with oral risdiplam led to an increased expression of functional SMN protein in the blood. (Funded by F. Hoffmann-La Roche; ClinicalTrials.gov number, NCT02913482.)., (Copyright © 2021 Massachusetts Medical Society.)

Objective: To describe the respiratory trajectories and their correlation with motor function in an international pediatric cohort of patients with type 2 and nonambulant type 3 spinal muscular atrophy (SMA)., Methods: This was an 8-year retrospective observational study of patients in the International SMA Consortium (iSMAc) natural history study. We retrieved anthropometrics, forced vital capacity (FVC) absolute, FVC percent predicted (FVC%P), and noninvasive ventilation (NIV) requirement. Hammersmith Functional Motor Scale (HFMS) and revised Performance of Upper Limb (RULM) scores were correlated with respiratory function. We excluded patients in interventional clinical trials and on nusinersen commercial therapy., Results: There were 437 patients with SMA: 348 with type 2 and 89 with nonambulant type 3. Mean age at first visit was 6.9 (±4.4) and 11.1 (±4) years. In SMA type 2, FVC%P declined by 4.2%/y from 5 to 13 years, followed by a slower decline (1.0%/y). In type 3, FVC%P declined by 6.3%/y between 8 and 13 years, followed by a slower decline (0.9%/y). Thirty-nine percent with SMA type 2% and 9% with type 3 required NIV at a median age 5.0 (1.8-16.6) and 15.1 (13.8-16.3) years. Eighty-four percent with SMA type 2% and 80% with type 3 had scoliosis; 54% and 46% required surgery, which did not significantly affect respiratory decline. FVC%P positively correlated with HFMS and RULM scores in both subtypes., Conclusions: In SMA type 2 and nonambulant type 3, lung function declines differently, with a common leveling after age 13 years. Lung and motor function correlated in both subtypes. Our data further define the milder SMA phenotypes and provide information to benchmark the long-term efficacy of new treatments for SMA., (Copyright © 2020 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.)

Objective: We report natural history data in a large cohort of 199 patients with spinal muscular atrophy (SMA) type III assessed using the Hammersmith Functional Motor Scale Expanded (HFMSE). The aim of the study was to establish the annual rate and possible patterns of progression according to a number of variables, such as age of onset, age at assessment, SMN2 copy number, and functional status., Methods: HFMSE longitudinal changes were assessed using piecewise linear mixed-effects models. The dependency in the data due to repeated measures was accounted for by a random intercept per individual and an unstructured covariance R matrix was used as correlation structure. An additional descriptive analysis was performed for 123 patients, for a total of 375 12-month assessments., Results: A break point at age 7 years was set for the whole cohort and for SMA IIIA and IIIB. Age, SMA type, and ambulatory status were significantly associated with changes in mean HFMSE score, whereas gender and SMN2 copy number were not. The increase in response before the break point of age 7 years is significant only for SMA IIIA (β = 1.79, p < 0.0001). After the break point, the change in the rate of HFMSE score significantly decrease for both SMA IIIA (β = -1.15, p < 0.0001) and IIIB (β = -0.69, p = 0.002)., Interpretation: Our findings contribute to the understanding of the natural history of SMA type III and will be helpful in the interpretation of the real-world data of patients treated with commercially available drugs. ANN NEUROL 2020;88:1109-1117., (© 2020 American Neurological Association.)

The advent of clinical trials in spinal muscular atrophy (SMA) has highlighted the need to define patterns of progression using functional scales. It has recently been suggested that the analysis of abilities gained or lost applied to functional scales better reflects meaningful changes. We defined as "gain" a positive change between scores from 0 to either 1 or 2 and as "loss" a negative change from either 2 or 1 to 0. The aim of this study was to describe, over 12 months, which abilities on the Hammersmith Functional Motor Scale Expanded (HFMSE) were more frequently lost or gained in patients with SMA II. The cohort included 614 12-month assessments from 243 patients (age range: 30 months - 63 years; mean 9.94, SD ±7.91). The peak of abilities gained occurred before the age of 5 years while the highest number of lost abilities was found in the group 5-13 years. A correlation between the HFMSE baseline score and the ordinal number of the items was found for both lost (p<0.001) or gained (p<0.001) activities. No correlation was found with SMN2 copy number. These findings will have implications for clinical trial design and for the interpretation of real-world data using new therapeutic approaches., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Background: The advent of new therapies in spinal muscular atrophy (SMA) has highlighted the need to have natural history data for comparison. Natural history studies using structured assessments in type I however are very limited. We identified and reviewed all the existing longitudinal history data in infants with type I SMA first assessed before the age of 7 months with the Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP INTEND)., Main Text: Three longitudinal natural history studies, two performed in the United States and one in Italy, were identified. The different study design of these three studies made it possible for the cumulative dataset to include the full spectrum of severity; from infants with neonatal onset to those with a milder phenotype that were not always included in the individual natural history studies. The cumulative analysis confirmed that, even in a larger cohort, there was never an improvement on the CHOP INTEND over time. This was true for all the infants, irrespective of their age or baseline CHOP INTEND scores. Infants with neonatal onset had low CHOP INTEND scores and a fast decline. The relatively large number of patients allowed us to calculate the rate of progression in subgroups identified according to SMN2 copy number and baseline CHOP INTEND scores., Conclusion: A detailed understanding of the existing data is important, as it will be difficult to acquire new systematic longitudinal history data because of the availability of disease modifying therapies. The cumulative findings in this review help to better understand the variability of natural history data in untreated patients and will be of use for comparison to the real world patients treated with the recently approved therapies that have shown encouraging results in clinical trials.

Background: Weakness affects motor performance and causes skeletal deformities in spinal muscular atrophy (SMA). Scoliosis surgery decision-making is based on curve progression, pulmonary function, and skeletal maturity. Benefits include quality of life, sitting balance, and endurance. Post-operative functional decline has not been formally assessed., Objective: To assess the impact of scoliosis surgery on motor function in SMA types 2 and 3., Methods: Prospective data were acquired during a multicenter natural history study. Seventeen participants (12 type 2, 5 type 3 with 4 of the 5 having lost the ability to ambulate) had motor function assessed using the Hammersmith Functional Motor Scale Expanded (HFMSE) performed pre-operatively and at least 3 months post-operatively. Independent t-tests determined group differences based on post-operative HFMSE changes, age, and baseline HFMSE scores., Results: Three participants had minimal HFMSE changes (±2 points) representing stability (mean change = -0.7). Fourteen participants lost >3 points, representing a clinically meaningful progressive change (mean change = -12.1, SD = 8.9). No participant improved >2 points. There were no age differences between stable and progressive groups (p = 0.278), but there were significant differences between baseline HFMSE (p = 0.006) and change scores (p = 0.001). Post-operative changes were permanent over time., Conclusions: Scoliosis surgery has an immediate impact on function. Baseline HFMSE scores anticipate post-operative loss as higher motor function scores were associated with worse decline. Instrumentation that includes fixation to the pelvis reduces flexibility, limiting the ability for compensatory maneuvers. These observations provide information to alert clinicians regarding surgical risk and to counsel families.

Objective: To report results of intrathecal nusinersen in children with later-onset spinal muscular atrophy (SMA)., Methods: Analyses included children from a phase 1b/2a study (ISIS-396443-CS2; NCT01703988) who first received nusinersen during that study and were eligible to continue treatment in the extension study (ISIS-396443-CS12; NCT02052791). The phase 1b/2a study was a 253-day, ascending dose (3, 6, 9, 12 mg), multiple-dose, open-label, multicenter study that enrolled children with SMA aged 2-15 years. The extension study was a 715-day, single-dose level (12 mg) study. Time between studies varied by participant (196-413 days). Assessments included the Hammersmith Functional Motor Scale-Expanded (HFMSE), Upper Limb Module (ULM), 6-Minute Walk Test (6MWT), compound muscle action potential (CMAP), and quantitative multipoint incremental motor unit number estimation. Safety also was assessed., Results: Twenty-eight children were included (SMA type II, n = 11; SMA type III, n = 17). Mean HFMSE scores, ULM scores, and 6MWT distances improved by the day 1,150 visit (HFMSE: SMA type II, +10.8 points; SMA type III, +1.8 points; ULM: SMA type II, +4.0 points; 6MWT: SMA type III, +92.0 meters). Mean CMAP values remained relatively stable. No children discontinued treatment due to adverse events., Conclusions: Nusinersen treatment over ∼3 years resulted in motor function improvements and disease activity stabilization not observed in natural history cohorts. These results document the long-term benefit of nusinersen in later-onset SMA, including SMA type III., Clinicaltrialsgov Identifier: NCT01703988 (ISIS-396443-CS2); NCT02052791 (ISIS-396443-CS12)., Classification of Evidence: This study provides Class IV evidence that nusinersen improves motor function in children with later-onset SMA., (Copyright © 2019 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.)

Background: Nusinersen is an antisense oligonucleotide drug that modulates pre-messenger RNA splicing of the survival motor neuron 2 ( SMN2) gene. It has been developed for the treatment of spinal muscular atrophy (SMA)., Methods: We conducted a multicenter, double-blind, sham-controlled, phase 3 trial of nusinersen in 126 children with SMA who had symptom onset after 6 months of age. The children were randomly assigned, in a 2:1 ratio, to undergo intrathecal administration of nusinersen at a dose of 12 mg (nusinersen group) or a sham procedure (control group) on days 1, 29, 85, and 274. The primary end point was the least-squares mean change from baseline in the Hammersmith Functional Motor Scale-Expanded (HFMSE) score at 15 months of treatment; HFMSE scores range from 0 to 66, with higher scores indicating better motor function. Secondary end points included the percentage of children with a clinically meaningful increase from baseline in the HFMSE score (≥3 points), an outcome that indicates improvement in at least two motor skills., Results: In the prespecified interim analysis, there was a least-squares mean increase from baseline to month 15 in the HFMSE score in the nusinersen group (by 4.0 points) and a least-squares mean decrease in the control group (by -1.9 points), with a significant between-group difference favoring nusinersen (least-squares mean difference in change, 5.9 points; 95% confidence interval, 3.7 to 8.1; P<0.001). This result prompted early termination of the trial. Results of the final analysis were consistent with results of the interim analysis. In the final analysis, 57% of the children in the nusinersen group as compared with 26% in the control group had an increase from baseline to month 15 in the HFMSE score of at least 3 points (P<0.001), and the overall incidence of adverse events was similar in the nusinersen group and the control group (93% and 100%, respectively)., Conclusions: Among children with later-onset SMA, those who received nusinersen had significant and clinically meaningful improvement in motor function as compared with those in the control group. (Funded by Biogen and Ionis Pharmaceuticals; CHERISH ClinicalTrials.gov number, NCT02292537 .).

Background: Training methodology was established to optimize reliability of outcome measures in the nusinersen clinical trials. The Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP INTEND), Hammersmith Functional Motor Scale Expanded (HFMSE), and Revised Upper Limb (RULM) were primary or secondary outcomes., Methods: Video review, quarterly conference calls, and item scoring checks supported evaluator competence. Baseline and screening along with video review established intra and inter-rater reliability., Results: Inter and intra-rater reliability were both excellent. Intraclass correlation coefficients (ICC) ranged between 0.906-0.994 across initial training meetings and 0.824-0.996 across annual retraining meetings. This was similar for CHOP INTEND (ICC = 0.824-0.951), HFMSE (ICC = 0.981-0.996), and RULM (ICC = 0.966-0.990). Intra-rater reliability for the CHOP INTEND, HFMSE, and RULM were ICC = 0.895 (95% CI: 0.852-0.926; n = 116), ICC = 0.959 (95% CI: 0.942-0.971; n = 125), and ICC = 0.948 (95% CI: 0.927-0.963; n = 126) respectively., Conclusions: Rigorous evaluator training ensures reliability of assessment of subjects with spinal muscular atrophy (SMA) in multicenter international trials.

Objective: Infantile-onset spinal muscular atrophy (SMA) is the most common genetic cause of infant mortality, typically resulting in death preceding age 2. Clinical trials in this population require an understanding of disease progression and identification of meaningful biomarkers to hasten therapeutic development and predict outcomes., Methods: A longitudinal, multicenter, prospective natural history study enrolled 26 SMA infants and 27 control infants aged <6 months. Recruitment occurred at 14 centers over 21 months within the NINDS-sponsored NeuroNEXT (National Network for Excellence in Neuroscience Clinical Trials) Network. Infant motor function scales (Test of Infant Motor Performance Screening Items [TIMPSI], The Children's Hospital of Philadelphia Infant Test for Neuromuscular Disorders, and Alberta Infant Motor Score) and putative physiological and molecular biomarkers were assessed preceding age 6 months and at 6, 9, 12, 18, and 24 months with progression, correlations between motor function and biomarkers, and hazard ratios analyzed., Results: Motor function scores (MFS) and compound muscle action potential (CMAP) decreased rapidly in SMA infants, whereas MFS in all healthy infants rapidly increased. Correlations were identified between TIMPSI and CMAP in SMA infants. TIMPSI at first study visit was associated with risk of combined endpoint of death or permanent invasive ventilation in SMA infants. Post-hoc analysis of survival to combined endpoint in SMA infants with 2 copies of SMN2 indicated a median age of 8 months at death (95% confidence interval, 6, 17)., Interpretation: These data of SMA and control outcome measures delineates meaningful change in clinical trials in infantile-onset SMA. The power and utility of NeuroNEXT to provide "real-world," prospective natural history data sets to accelerate public and private drug development programs for rare disease is demonstrated. Ann Neurol 2017;82:883-891., (© 2017 American Neurological Association.)

Background: Spinal muscular atrophy is an autosomal recessive neuromuscular disorder that is caused by an insufficient level of survival motor neuron (SMN) protein. Nusinersen is an antisense oligonucleotide drug that modifies pre-messenger RNA splicing of the SMN2 gene and thus promotes increased production of full-length SMN protein., Methods: We conducted a randomized, double-blind, sham-controlled, phase 3 efficacy and safety trial of nusinersen in infants with spinal muscular atrophy. The primary end points were a motor-milestone response (defined according to results on the Hammersmith Infant Neurological Examination) and event-free survival (time to death or the use of permanent assisted ventilation). Secondary end points included overall survival and subgroup analyses of event-free survival according to disease duration at screening. Only the first primary end point was tested in a prespecified interim analysis. To control the overall type I error rate at 0.05, a hierarchical testing strategy was used for the second primary end point and the secondary end points in the final analysis., Results: In the interim analysis, a significantly higher percentage of infants in the nusinersen group than in the control group had a motor-milestone response (21 of 51 infants [41%] vs. 0 of 27 [0%], P<0.001), and this result prompted early termination of the trial. In the final analysis, a significantly higher percentage of infants in the nusinersen group than in the control group had a motor-milestone response (37 of 73 infants [51%] vs. 0 of 37 [0%]), and the likelihood of event-free survival was higher in the nusinersen group than in the control group (hazard ratio for death or the use of permanent assisted ventilation, 0.53; P=0.005). The likelihood of overall survival was higher in the nusinersen group than in the control group (hazard ratio for death, 0.37; P=0.004), and infants with a shorter disease duration at screening were more likely than those with a longer disease duration to benefit from nusinersen. The incidence and severity of adverse events were similar in the two groups., Conclusions: Among infants with spinal muscular atrophy, those who received nusinersen were more likely to be alive and have improvements in motor function than those in the control group. Early treatment may be necessary to maximize the benefit of the drug. (Funded by Biogen and Ionis Pharmaceuticals; ENDEAR ClinicalTrials.gov number, NCT02193074 .).

Background: Reports on the clinical meaningfulness of outcome measures in spinal muscular atrophy (SMA) are rare. In this two-part study, our aim was to explore patients' and caregivers' views on the clinical relevance of the Hammersmith Functional Motor Scale Expanded- (HFMSE)., Methods: First, we used focus groups including SMA patients and caregivers to explore their views on the clinical relevance of the individual activities included in the HFMSE. Then we asked caregivers to comment on the clinical relevance of possible changes of HFMSE scores over time. As functional data of individual patients were available, some of the questions were tailored according to their functional level on the HFMSE., Results: Part 1: Sixty-three individuals participated in the focus groups. This included 30 caregivers, 25 patients and 8 professionals who facilitated the discussion. The caregivers provided a comparison to activities of daily living for each of the HFMSE items. Part 2: One hundred and forty-nine caregivers agreed to complete the questionnaire: in response to a general question, 72% of the caregivers would consider taking part in a clinical trial if the treatment was expected to slow down deterioration, 88% if it would stop deterioration and 97% if the treatment was expected to produce an improvement. Caregivers were informed of the first three items that their child could not achieve on the HFMSE. In response 75% indicated a willingness to take part in a clinical trial if they could achieve at least one of these abilities, 89% if they could achieve two, and 100% if they could achieve more than 2., Conclusions: Our findings support the use of the HFMSE as a key outcome measure in SMA clinical trials because the individual items and the detected changes have clear content validity and clinical meaningfulness for patients and their caregivers.

Recent translational research developments in Spinal Muscular Atrophy (SMA), outcome measure design and demands from regulatory authorities require that clinical outcome assessments are 'fit for purpose'. An international collaboration (SMA REACH UK, Italian SMA Network and PNCRN USA) undertook an iterative process to address discontinuity in the recorded performance of the Hammersmith Functional Motor Scale Expanded and developed a revised functional scale using Rasch analysis, traditional psychometric techniques and the application of clinical sensibility via expert panels. Specifically, we intended to develop a psychometrically and clinically robust functional clinician rated outcome measure to assess physical abilities in weak SMA type 2 through to strong ambulant SMA type 3 patients. The final scale, the Revised Hammersmith Scale (RHS) for SMA, consisting of 36 items and two timed tests, was piloted in 138 patients with type 2 and 3 SMA in an observational cross-sectional multi-centre study across the three national networks. Rasch analysis demonstrated very good fit of all 36 items to the construct of motor performance, good reliability with a high Person Separation Index PSI 0.98, logical and hierarchical scoring in 27/36 items and excellent targeting with minimal ceiling. The RHS differentiated between clinically different groups: SMA type, World Health Organisation (WHO) categories, ambulatory status, and SMA type combined with ambulatory status (all p < 0.001). Construct and concurrent validity was also confirmed with a strong significant positive correlation with the WHO motor milestones rs = 0.860, p < 0.001. We conclude that the RHS is a psychometrically sound and versatile clinical outcome assessment to test the broad range of physical abilities of patients with type 2 and 3 SMA. Further longitudinal testing of the scale with regards change in scores over 6 and 12 months are required prior to its adoption in clinical trials.

The aim of this retrospective multicentric study was to assess developmental milestones longitudinally in type I SMA infants using the Hammersmith Infant Neurological Examination. Thirty-three type I SMA infants, who classically do not achieve the ability to sit unsupported, were included in the study. Our results confirmed that all patients had a score of 0 out of a scale of 4 on items assessing sitting, rolling, crawling, standing or walking. A score of more than 0 was only achieved in three items: head control (n = 13), kicking (n = 15) and hand grasp (n = 18). In these items, the maximal score achieved was 1 out of a scale of 4, indicating only partial achievement of the milestone. Infants with symptom onset after 6 months of age had longer preservation of a score of 1 when compared to those with onset before 6 months of age. Our results suggest that even when current standards of care are applied, developmental milestones are rarely even partially achieved as part of natural history in type I SMA infants. No infants in this study achieved a major milestone such as rolling over, or sitting independently, which would therefore represent robust outcomes in future interventional trials., (Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.)

The aim of the study was to establish 12-month changes in the Hammersmith Functional motor scale in a large cohort of SMA patients, to identify patterns of disease progression and the effect of different variables. 268 patients were included in this multicentric study. Their age ranged between 2.5 and 55.5 years at baseline, 68 were ambulant and 200 non-ambulant. The baseline scores ranged between 0 and 66 (mean 23.91, SD 20.09). The 12-month change was between -14 and +9 (mean -0.56, SD 2.72). Of the 268 patients, 206 (76.86%) had changes between -2 and +2 points. Ambulant and non-ambulant subjects had a different relationship between baseline values and age (p for age X ambulation interaction = 0.007). There was no association with age in ambulant subjects, while there was a significant heterogeneity at different age for non-ambulant patients (p < 0.001). The 12-month change (adjusted for baseline) was not associated with age in ambulant patients (p = 0.34), but it was significantly different among various age groups in non-ambulant patients. Our results suggest that there are different profiles of progression in ambulant and non-ambulant patients, and that age may play an important role in the progression of non-ambulant patients., (Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.)

Introduction: A recent Rasch analysis performed on the Hammersmith Functional Motor Scale-Expanded (HFMSE) in patients with spinal muscular atrophy (SMA) identified issues impacting scale validity, redundant items, and disordered thresholds on some items., Methods: We modified the HMFSE scoring based on the Rasch analysis and on expert consensus to establish whether the traditional scoring overestimated the number of patients with changes within 2 points from baseline. Data were collected retrospectively from multicenter data sets in 255 type 2 and 3 SMA patients., Results: The mean 12-month changes using the new and the traditional scoring system did not differ significantly (P > 0.05). The numbers of patients who improved or decreased by >2 points were also similar., Conclusions: The presence of outliers using the traditional scoring system was not due to overestimation of changes in activities that were tested bilaterally or to discrepancies in the scoring hierarchy of individual items., (© 2015 Wiley Periodicals, Inc.)

Objectives: Prospective cohort study to characterize the clinical features and course of spinal muscular atrophy type I (SMA-I)., Methods: Patients were enrolled at 3 study sites and followed for up to 36 months with serial clinical, motor function, laboratory, and electrophysiologic outcome assessments. Intervention was determined by published standard of care guidelines. Palliative care options were offered., Results: Thirty-four of 54 eligible subjects with SMA-I (63%) enrolled and 50% of these completed at least 12 months of follow-up. The median age at reaching the combined endpoint of death or requiring at least 16 hours/day of ventilation support was 13.5 months (interquartile range 8.1-22.0 months). Requirement for nutritional support preceded that for ventilation support. The distribution of age at reaching the combined endpoint was similar for subjects with SMA-I who had symptom onset before 3 months and after 3 months of age (p=0.58). Having 2 SMN2 copies was associated with greater morbidity and mortality than having 3 copies. Baseline electrophysiologic measures indicated substantial motor neuron loss. By comparison, subjects with SMA-II who lost sitting ability (n=10) had higher motor function, motor unit number estimate and compound motor action potential, longer survival, and later age when feeding or ventilation support was required. The mean rate of decline in The Children's Hospital of Philadelphia Infant Test for Neuromuscular Disorders motor function scale was 1.27 points/year (95% confidence interval 0.21-2.33, p=0.02)., Conclusions: Infants with SMA-I can be effectively enrolled and retained in a 12-month natural history study until a majority reach the combined endpoint. These outcome data can be used for clinical trial design., (© 2014 American Academy of Neurology.)

Introduction: The purpose of this study was to measure and analyze motor unit number estimation (MUNE) values longitudinally in spinal muscular atrophy (SMA)., Methods: Sixty-two children with SMA types 2 and 3 were observed prospectively for up to 42 months. Longitudinal electrophysiological data were collected, including compound motor action potential (CMAP), single motor unit action potential (SMUP), and MUNE., Results: Significant motor neuron loss and compensatory collateral reinnervation were noted at baseline. Over time, there was a significant mean increase in MUNE (4.92 units/year, P = 0.009), a mean decrease in SMUP amplitude (-6.32 μV/year, P = 0.10), and stable CMAP amplitude., Conclusions: The unexpected longitudinal results differ from findings in amyotrophic lateral sclerosis studies, perhaps indicating that compensatory processes in SMA involve new motor unit development. A better understanding of the mechanisms of motor unit decline and compensation in SMA is important for assessing novel therapeutic strategies and for providing key insights into disease pathophysiology., (Copyright © 2013 Wiley Periodicals, Inc.)

Objective: To characterize the natural history of spinal muscular atrophy type 2 and type 3 (SMA 2/3) beyond 1 year and to report data on clinical and biological outcomes for use in trial planning., Methods: We conducted a prospective observational cohort study of 79 children and young adults with SMA 2/3 who participated in evaluations for up to 48 months. Clinically, we evaluated motor and pulmonary function, quality of life, and muscle strength. We also measured SMN2 copy number, hematologic and biochemical profiles, muscle mass by dual x-ray absorptiometry (DXA), and the compound motor action potential (CMAP) in a hand muscle. Data were analyzed for associations between clinical and biological/laboratory characteristics cross-sectionally, and for change over time in outcomes using all available data., Results: In cross-sectional analyses, certain biological measures (specifically, CMAP, DXA fat-free mass index, and SMN2 copy number) and muscle strength measures were associated with motor function. Motor and pulmonary function declined over time, particularly at time points beyond 12 months of follow-up., Conclusion: The intermediate and mild phenotypes of SMA show slow functional declines when observation periods exceed 1 year. Whole body muscle mass, hand muscle compound motor action potentials, and muscle strength are associated with clinical measures of motor function. The data from this study will be useful for clinical trial planning and suggest that CMAP and DXA warrant further evaluation as potential biomarkers.

Purpose: Preliminary validation of the Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP INTEND) for motor skill assessment in spinal muscular atrophy type I., Methods: A total of 27 subjects 3 to 260 months old (mean = 49, SD = 69) with spinal muscular atrophy-I were evaluated with the CHOP INTEND. Subjects were evaluated as part of a multicenter natural history study., Results: CHOP INTEND scores and age were significantly correlated (r = -0.51, P = .007; 2 survival of the motor neuron [SMN] 2 gene copies, n = 16, r = -0.60, 3 SMN2 gene copies, n = 9, r = -0.83). Respiratory support and CHOP INTEND scores were correlated (r = -0.74, P < .0001, n = 26). The CHOP INTEND and age regression in patients with 2 copies versus 3 copies of SMN2 approached significance (P = .0711, n = 25). Subjects who required respiratory support scored significantly lower (mean = 15.5, SD = 10.2 vs mean = 31.2, SD = 4.2, P < .0001, n = 27). Correlation with motor unit number estimation and combined motor unit activation were not significant., Conclusion: The CHOP INTEND reflects measures of disease severity and supports continued exploration of the CHOP INTEND.

The relationships between the Expanded Hammersmith Functional Motor Scale (HFMSE) and genotype and motor and respiratory outcomes were examined in patients with spinal muscular atrophy types II and III (n = 70). The correlation between the HFMSE and Gross Motor Function Measure was r = 0.98. Correlations between HFMSE and forced vital capacity (percentage of predicted normal) (n = 56) and a functional rating (n = 57) were r = 0.87 and r = 0.92, respectively. Correlations with strength were as follows: knee extension, r = 0.74 (n = 60); elbow flexion, r = 0.77 (n = 61); and knee flexion, r = 0.74 (n = 58). The HFMSE differentiated patients by SMN2 copy number (P = .0007); bi-level positive airway pressure use, <8 versus ≥8 hours/day (P < .0001); ambulatory status (P < .0001); and spinal muscular atrophy type (P < .0001). The HFMSE demonstrates significant associations with established measures of function, strength, and genotype, and discriminates patients based on function, diagnostic category, and bi-level positive airway pressure need. Time of administration averaged 12 minutes. The HFMSE is a valid, time-efficient outcome measure for clinical trials in spinal muscular atrophy types II and III.

Objective: To characterize the short-term course of spinal muscular atrophy (SMA) in a genetically and clinically well-defined cohort of patients with SMA., Design: A comprehensive multicenter, longitudinal, observational study., Setting: The Pediatric Neuromuscular Clinical Research Network for SMA, a consortium of clinical investigators at 3 clinical sites., Participants: Sixty-five participants with SMA types 2 and 3, aged 20 months to 45 years, were prospectively evaluated., Intervention: We collected demographic and medical history information and determined the SMN 2 copy number., Main Outcome Measures: Clinical outcomes included measures of motor function (Gross Motor Function Measure and expanded Hammersmith Functional Motor Scale), pulmonary function (forced vital capacity), and muscle strength (myometry). Participants were evaluated every 2 months for the initial 6 months and every 3 months for the subsequent 6 months. We evaluated change over 12 months for all clinical outcomes and examined potential correlates of change over time including age, sex, SMA type, ambulatory status, SMN2 copy number, medication use, and baseline function., Results: There were no significant changes over 12 months in motor function, pulmonary function, and muscle strength measures. There was evidence of motor function gain in ambulatory patients, especially in those children younger than 5 years. Scoliosis surgery during the observation period led to a subsequent decline in motor function., Conclusions: Our results confirm previous clinical reports suggesting that SMA types 2 and 3 represent chronic phenotypes that have relatively stable clinical courses. We did not detect any measurable clinical disease progression in SMA types 2 and 3 over 12 months, suggesting that clinical trials will have to be designed to measure improvement rather than stabilization of disease progression.

Objective: To assess the value of quantitative ultrasound in patients with type 2 and 3 spinal muscular atrophy (SMA)., Methods: Twenty-five patients with SMA (15 type 2 and 10 type 3) and 21 normal subjects were enrolled for this observational study. Strength of biceps brachii, wrist extensors, quadriceps, and tibialis anterior were measured with hand-held dynamometry. In addition, these 4 muscles were studied with a standard ultrasound system using a 5-MHz probe, and luminosity values for each muscle and the overlying subcutaneous fat were obtained by subsequent image analysis. A luminosity ratio (LR) for each muscle was calculated by dividing the muscle by the subcutaneous fat luminosity. The LR and strength scores for all 4 muscles were averaged to provide a single summary value for each patient., Results: The LRs increased with disease severity: 1.27 +/- 0.26 for normal subjects, 2.43 +/- 0.78 for type 3 SMA, and 3.85 +/- 1.3 for type 2 SMA (p < 0.001). Taking all the normal subject and patient data together, there was a good correlation between strength and LR (r = -0.711, p < 0.001). There was also a moderate relationship between LR and strength in the patients with SMA alone (r = -0.588, p = 0.008), and, as expected, a nonsignificant relationship between LR and strength in normal subjects (r = -0.011)., Conclusions: Quantitative ultrasound has the potential of serving as a marker of SMA severity and may be useful in future clinical trials.

Purpose of Review: Spinal muscular atrophy is a neuromuscular disorder manifesting as weakness and hypotonia across a broad spectrum of severity. Mutations in the telomeric copy of the survival motor neuron gene (SMN1) cause the autosomal recessive form. Disease severity is modified by the number of centromeric copies of the gene (SMN2) and the quantity of survival motor neuron protein. This has given rise to a number of treatment strategies., Recent Findings: Histone deacetylase inhibitors appear to increase the expression of SMN2, with an increase in survival motor neuron protein in various cell types. Clinical trials have been performed with three histone deacetylase inhibitors which are already licensed in the USA. Phenylbutyrate showed promise in a mouse model and an open-label pilot study, but was not effective in a phase 2 trial. Valproate may enhance transcription and reverse SMN2 splicing pattern, and has induced promising motor-function improvement in patients. Hydroxyurea may enhance splice function and increase the number of nuclear 'gems', small nuclear organelles in which survival motor neuron protein concentrates., Summary: Discoveries regarding the genetics and pathogenesis of spinal muscular atrophy have identified potential targets for pharmacotherapy, raising hope that better treatments will eventually be developed.

Purpose: To develop and evaluate an expanded version of the Hammersmith Functional Motor Scale allowing for evaluation of ambulatory SMA patients., Procedures: Thirty-eight patients with SMA type II or III were evaluated using the Gross Motor Function Measure and the Hammersmith Functional Motor Scale. Based on statistical and clinical criteria, we selected 13 Gross Motor Function Measure items to develop an expanded HFMS. The expanded Hammersmith Functional Motor Scale was validated by comparison with the Gross Motor Function Measure minus the 13 items (GMFM-75) and an assessment of clinical function. The reliability of the expanded Hammersmith Functional Motor Scale in 36 patients was established., Findings: The expanded Hammersmith Functional Motor Scale was highly correlated with the GMFM-75 and the clinical function assessment (p=0.97, and p=0.90). The expanded Hammersmith Functional Motor Scale showed excellent test-retest reliability (International Coordinating Committee = 0.99)., Conclusions: The expanded Hammersmith Functional Motor Scale allows assessment of high functioning SMA type II and III patients. Ease of administration and correlation with established motor function measures justify use in future SMA clinical trials.

Spinal muscular atrophy type III (SMA III, Kugelberg-Welander disease) typically presents with symmetric proximal weakness, areflexia, and hypotonia. We present four children with spinal muscular atrophy type III who had atypical phenotypes. Three patients clearly had asymmetric weakness at presentation and two had upper motor neuron signs in the lower extremities (one patient had both features). Two of the patients had prolonged evaluations before the diagnosis was made. All patients had Gowers signs and two had pes planus. In patients with proximal muscle weakness the presence of asymmetrical weakness, upper motor neuron signs, or both, may be compatible with spinal muscular atrophy type III. The diagnosis of spinal muscular atrophy should be considered when other possibilities have been excluded.