Clinical Effectiveness of Newborn Screening for Spinal Muscular Atrophy: A Nonrandomized Controlled Trial.

Importance: There is increasing evidence that early diagnosis and treatment are key for outcomes in infants with spinal muscular atrophy (SMA), and newborn screening programs have been implemented to detect the disease before onset of symptoms. However, data from controlled studies that reliably confirm the benefits of newborn screening are lacking. Objective: To compare data obtained on patients with SMA diagnosed through newborn screening and those diagnosed after clinical symptom onset. Design, Setting, and Participants: This nonrandomized controlled trial used data from the SMARTCARE registry to evaluate all children born between January 2018 and September 2021 with genetically confirmed SMA and up to 3 SMN2 copies. The registry includes data from 70 participating centers in Germany, Austria, and Switzerland. Data analysis was performed in February 2023 so that all patients had a minimal follow-up of 18 months. Exposure: Patients born in 2 federal states in Germany underwent screening in a newborn screening pilot project. All other patients were diagnosed after clinical symptom onset. All patients received standard care within the same health care system. Main Outcomes: The primary end point was the achievement of motor milestones. Results: A total of 234 children (123 [52.6%] female) were identified who met inclusion criteria and were included in the analysis: 44 (18.8%) in the newborn screening cohort and 190 children (81.2%) in the clinical symptom onset cohort. The mean (SD) age at start of treatment with 1 of the approved disease-modifying drugs was 1.3 (2.2) months in the newborn screening cohort and 10.7 (9.1) months in the clinical symptom onset cohort. In the newborn screening cohort, 40 of 44 children (90.9%) gained the ability to sit independently vs 141 of 190 (74.2%) in the clinical symptom onset cohort. For independent ambulation, the ratio was 28 of 40 (63.6%) vs 28 of 190 (14.7%). Conclusions and Relevance: This nonrandomized controlled trial demonstrated effectiveness of newborn screening for infants with SMA in the real-world setting. Functional outcomes and thus the response to treatment were significantly better in the newborn screening cohort compared to the unscreened clinical symptom onset group. Trial Registration: German Clinical Trials Register: DRKS00012699.

Long-term efficacy and safety of nusinersen in adults with 5q spinal muscular atrophy: a prospective European multinational observational study.

Background: Evidence for the efficacy of nusinersen in adults with 5q-associated spinal muscular atrophy (SMA) has been demonstrated up to a period of 16 months in relatively large cohorts but whereas patients reach a plateau over time is still to be demonstrated. We investigated the efficacy and safety of nusinersen in adults with SMA over 38 months, the longest time period to date in a large cohort of patients from multiple clinical sites. Methods: Our prospective, observational study included adult patients with SMA from Germany, Switzerland, and Austria (July 2017 to May 2022). All participants had genetically-confirmed, 5q-associated SMA and were treated with nusinersen according to the label. The total Hammersmith Functional Motor Scale Expanded (HFMSE) and Revised Upper Limb Module (RULM) scores, and 6-min walk test (6 MWT; metres), were recorded at baseline and 14, 26, and 38 months after treatment initiation, and pre and post values were compared. Adverse events were also recorded. Findings: Overall, 389 patients were screened for eligibility and 237 were included. There were significant increases in all outcome measures compared with baseline, including mean HFMSE scores at 14 months (mean difference 1.72 [95% CI 1.19-2.25]), 26 months (1.20 [95% CI 0.48-1.91]), and 38 months (1.52 [95% CI 0.74-2.30]); mean RULM scores at 14 months (mean difference 0.75 [95% CI 0.43-1.07]), 26 months (mean difference 0.65 [95% CI 0.27-1.03]), and 38 months (mean difference 0.72 [95% CI 0.25-1.18]), and 6 MWT at 14 months (mean difference 30.86 m [95% CI 18.34-43.38]), 26 months (mean difference 29.26 m [95% CI 14.87-43.65]), and 38 months (mean difference 32.20 m [95% CI 10.32-54.09]). No new safety signals were identified. Interpretation: Our prospective, observational, long-term (38 months) data provides further real-world evidence for the continuous efficacy and safety of nusinersen in a large proportion of adult patients with SMA. Funding: Financial support for the registry from Biogen, Novartis and Roche.

High-sensitive cardiac troponin I (hs-cTnI) concentrations in newborns diagnosed with spinal muscular atrophy.

Background: Spinal muscular atrophy (SMA) is a genetic neurodegenerative disease leading to muscular weakness and premature death. Three therapeutic options are currently available including gene replacement therapy (GRT), which is potentially cardiotoxic. High-sensitive cardiac troponin I (hs-cTnI) is widely used to monitor potential cardiac contraindications or side effects of GRT, but reference data in healthy newborns are limited and lacking in neonates with SMA. The aim of this study is to determine the range of pre-therapeutic hs-cTnI concentrations in neonates with SMA and to provide guidance for the assessment of these values. Methods: Hs-cTnI levels, genetic and clinical data of 30 newborns (age range 2-26 days) with SMA were retrospectively collected from 6 German neuromuscular centers. In addition, hs-cTnI levels were measured in 16 neonates without SMA. Results: The median hs-cTnI concentration in neonates with SMA was 39.5 ng/L (range: 4-1205). In 16 newborns with SMA, hs-cTnI levels were above the test-specific upper reference limit (URL). Exploratory statistical analysis revealed no relevant correlation between hs-cTnI levels and gender, gestational age, mode of delivery, SMN2 copy number, symptoms of SMA or abnormal cardiac findings. Discussion: Our results suggest higher hs-cTnI plasma levels in newborns with and without SMA compared to assay-specific reference values generated in adults. Given the wide range of hs-cTnI values in neonates with SMA, hs-cTnI levels must be determined before treatment in each patient and post-treatment elevations should be interpreted in the context of the course rather than as individual values.

Evaluating case management for caregivers of children with spinal muscular atrophy type I and II-an exploratory, controlled, mixed-methods trial.

Introduction: Spinal muscular atrophy (SMA) is a rare neuromuscular disease requiring various clinical specialists and therapists to provide care. Due to the disease's dynamic nature and the long distances between specialized centers and local providers, integrating care between disciplines can be challenging. Care that is inadequately integrated can compromise the quality of care and become a burden for patients and families. This trial aimed to improve the care of patients through a case management (CM) intervention. Methods: We conducted an exploratory, controlled, two-arm trial with pre-, post-, and follow-up measures (process and outcome evaluation). Proof of efficacy based on statistical significance was not our primary study objective since we were investigating a rare disease. Primary outcomes were caregivers' HRQoL and caregiver-rated quality of care integration. Our secondary outcome was the children's HRQoL. Results: Questionnaires and semi-structured interviews yielded heterogeneous results depending on caregivers' level of experience and desire (or possibility) to delegate care tasks. Discussion: Despite differing perceptions, all participants supported the establishment of a care coordination model. We recommend CM immediately after diagnosis to provide the greatest benefit to families. We hope that our trial will support the further development of CM interventions that can be customized for specific diseases.

Whole-Genome Sequencing Identified New Structural Variations in the DMD Gene That Cause Duchenne Muscular Dystrophy in Two Girls.

Dystrophinopathies are the most common muscle diseases, especially in men. In women, on the other hand, a manifestation of Duchenne muscular dystrophy is rare due to X-chromosomal inheritance. We present two young girls with severe muscle weakness, muscular dystrophies, and creatine kinase (CK) levels exceeding 10,000 U/L. In the skeletal muscle tissues, dystrophin staining reaction showed mosaicism. The almost entirely skewed X-inactivation in both cases supported the possibility of a dystrophinopathy. Despite standard molecular diagnostics (including multiplex ligation-dependent probe amplification (MLPA) and next generation sequencing (NGS) gene panel sequencing), the genetic cause of the girls' conditions remained unknown. However, whole-genome sequencing revealed two reciprocal translocations between their X chromosomes and chromosome 5 and chromosome 19, respectively. In both cases, the breakpoints on the X chromosomes were located directly within the DMD gene (in introns 54 and 7, respectively) and were responsible for the patients' phenotypes. Additional techniques such as Sanger sequencing, conventional karyotyping and fluorescence in situ hybridization (FISH) confirmed the disruption of DMD gene in both patients through translocations. These findings underscore the importance of accurate clinical data combined with histopathological analysis in pinpointing the suspected underlying genetic disorder. Moreover, our study illustrates the viability of whole-genome sequencing as a time-saving and highly effective method for identifying genetic factors responsible for complex genetic constellations in Duchenne muscular dystrophy (DMD).

Continued benefit of nusinersen initiated in the presymptomatic stage of spinal muscular atrophy: 5-year update of the NURTURE study.

INTRODUCTION/AIMS: NURTURE (NCT02386553) is an open-label study of nusinersen in children (two SMN2 copies, n = 15; three SMN2 copies, n = 10) who initiated treatment in the presymptomatic stage of spinal muscular atrophy (SMA). A prior analysis after ~3 y showed benefits on survival, respiratory outcomes, motor milestone achievement, and a favorable safety profile. An additional 2 y of follow-up (data cut: February 15, 2021) are reported. METHODS: The primary endpoint is time to death or respiratory intervention (≥6 h/day continuously for ≥7 days or tracheostomy). Secondary outcomes include overall survival, motor function, and safety. RESULTS: Median age of children was 4.9 (3.8-5.5) y at last visit. No children have discontinued the study or treatment. All were alive. No additional children utilized respiratory intervention (defined per primary endpoint) since the prior data cut. Children with three SMN2 copies achieved all World Health Organization (WHO) motor milestones, with all but one milestone in one child within normal developmental timeframes. All 15 children with two SMN2 copies achieved sitting without support, 14/15 walking with assistance, and 13/15 walking alone. Mean Hammersmith Functional Motor Scale Expanded total scores showed continued improvement. Subgroups with two SMN2 copies, minimum baseline compound muscle action potential amplitude ≥2 mV, and no baseline areflexia had better motor and nonmotor outcomes versus all children with two SMN2 copies. DISCUSSION: These results demonstrate the value of early treatment, durability of treatment effect, and favorable safety profile after ~5 y of nusinersen treatment. Inclusion/exclusion criteria and baseline characteristics should be considered when interpreting presymptomatic SMA trial data.

Mechanographic analysis of the timed 4 stair climb test - methodology and reference data of healthy children and adolescents.

OBJECTIVES: The timed 4 stair climb test (4SC) is an accepted and widely used tool to assess motor function of patients with neuromuscular diseases. We aimed to establish reference data for the 4SC, and for mechanographic analysis of ascent (4SC-Up) and descent (4SC-Dn) in healthy children and adolescents. METHODS: We used a custom-made staircase measuring device to assess force, power and velocity during the ascent of 4 stairs in healthy subjects. Secondary outcome measures included mechanographic analyses such as the Chair-Rising-test and the myometric Grip Force-test. RESULTS: Data of 288 participants aged 4 to 16 years (144 males, 144 females) were analyzed. A simple algorithm integrating the minimal applied force was used to compensate for different movement strategies. Percentiles for average power, force and horizontal velocity were calculated. While results of the 4SC-Up test showed no age or gender dependency, we found 4SC-Dn results to be age dependent. Mean device measured times were significantly shorter than manually measured times (mean difference -0.19 s; p<0.001). CONCLUSIONS: Mechanographic analysis of the 4SC appears to be a promising tool for evaluation of muscle strength and function of the lower extremities as it enables physically exact measurements of a highly relevant activity of daily living.

Caregiver Burden of Spinal Muscular Atrophy: A Systematic Review.

OBJECTIVE: The objective of our study was to review, synthesize, and grade published evidence of caregiver burden of spinal muscular atrophy (SMA), a rare autosomal-recessive neuromuscular disease. METHODS: We searched Embase and PubMed for full-text articles published from inception up until 28 February, 2022, reporting results from studies of caregiver burden (i.e., negative aspects of providing informal care) in SMA. Two investigators independently screened article titles and abstracts for eligibility, reviewed full-text versions of selected records, extracted the data, and assessed risk of bias using the Newcastle-Ottawa Scale. The evidence was synthesized to answer the following questions: (1) In which geographical settings have the caregiver burden of SMA been studied? (2) What aspects of the caregiver burden of SMA have been investigated? (3) What instruments have been used to measure the caregiver burden of SMA? (4) What is known of the caregiver burden of SMA? (5) How is the caregiver burden of SMA impacted by available disease-modifying drugs? RESULTS: We identified 15 publications, covering samples from a total of ten countries (i.e., Australia, Canada, China, France, Germany, Romania, Spain, Turkey, the UK, and the USA), reporting estimates of caregiver burden derived using data recorded via surveys or interviews. The most common instruments used to measure caregiver burden were the Zarit Caregiver Burden Interview, the EQ-5D-5L, and the PedsQL Family Impact Model. Caregiving in SMA was found to be associated with reduced health-related quality of life, impaired family function, depression and anxiety, strain, and stress, as well as a substantial impact on work life and productivity. Evidence of the impact of disease-modifying drugs on caregiver burden in SMA was scarce. CONCLUSIONS: Caregivers to patients with SMA were found to be subject to a significant burden, including impaired health-related quality of life, reduced work ability and productivity, and financial stress, and many devote a substantial proportion of their time to provide informal care. Yet, the current body of literature is relatively scarce and more research is needed to better understand the clinical implications of informal caregiving in SMA and the relationship between caregiver burden and SMA types, as well as the impact of new disease-modifying treatments. Our synthesis will be helpful in informing clinical and social support programs (e.g., the routine screening of depression among caregivers, as well as financial support schemes to help manage the long-term day-to-day care) directed towards families caring for patients with SMA.

Improvements in Walking Distance during Nusinersen Treatment - A Prospective 3-year SMArtCARE Registry Study.

BACKGROUND AND OBJECTIVES: Disease progression in patients with spinal muscular atrophy (SMA) has changed dramatically within the past years due to the approval of three different disease-modifying treatments. Nusinersen was the first drug to be approved for the treatment of SMA patients. Clinical trials provided data from infants with SMA type 1 and children with SMA type 2, but there is still insufficient evidence and only scarcely reported long-term experience for nusinersen treatment in ambulant patients. Here, we report data from the SMArtCARE registry of ambulant patients under nusinersen treatment with a follow-up period of up to 38 months. METHODS: SMArtCARE is a disease-specific registry in Germany, Austria and Switzerland. Data are collected as real-world data during routine patient visits. Our analysis included all patients under treatment with nusinersen able to walk independently before start of treatment with focus on changes in motor function. RESULTS: Data from 231 ambulant patients were included in the analysis. During the observation period, 31 pediatric walkers (27.2%) and 31 adult walkers (26.5%) experienced a clinically meaningful improvement of≥30 m in the 6-Minute-Walk-Test. In contrast, only five adult walkers (7.7%) showed a decline in walking distance≥30 m, and two pediatric walkers (1.8%) lost the ability to walk unassisted under treatment with nusinersen. HFMSE and RULM scores improved in pediatric and remained stable in adult patients. CONCLUSION: Our data demonstrate a positive effect of nusinersen treatment in most ambulant pediatric and adult SMA patients. We not only observed a stabilization of disease progression or lack of deterioration, but clinically meaningful improvements in walking distance.

Effect of nusinersen on motor, respiratory and bulbar function in early-onset spinal muscular atrophy.

5q-associated spinal muscular atrophy is a rare neuromuscular disorder with the leading symptom of a proximal muscle weakness. Three different drugs have been approved by the European Medicines Agency and Food and Drug Administration for the treatment of spinal muscular atrophy patients, however, long-term experience is still scarce. In contrast to clinical trial data with restricted patient populations and short observation periods, we report here real-world evidence on a broad spectrum of patients with early-onset spinal muscular atrophy treated with nusinersen focusing on effects regarding motor milestones, and respiratory and bulbar insufficiency during the first years of treatment. Within the SMArtCARE registry, all patients under treatment with nusinersen who never had the ability to sit independently before the start of treatment were identified for data analysis. The primary outcome of this analysis was the change in motor function evaluated with the Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders and motor milestones considering World Health Organization criteria. Further, we evaluated data on the need for ventilator support and tube feeding, and mortality. In total, 143 patients with early-onset spinal muscular atrophy were included in the data analysis with a follow-up period of up to 38 months. We observed major improvements in motor function evaluated with the Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders. Improvements were greater in children >2 years of age at start of treatment than in older children. 24.5% of children gained the ability to sit independently. Major improvements were observed during the first 14 months of treatment. The need for intermittent ventilator support and tube feeding increased despite treatment with nusinersen. Our findings confirm the increasing real-world evidence that treatment with nusinersen has a dramatic influence on disease progression and survival in patients with early-onset spinal muscular atrophy. Major improvements in motor function are seen in children younger than 2 years at the start of treatment. Bulbar and respiratory function needs to be closely monitored, as these functions do not improve equivalent to motor function.

Risdiplam in types 2 and 3 spinal muscular atrophy: A randomised, placebo-controlled, dose-finding trial followed by 24 months of treatment.

BACKGROUND AND PURPOSE: Spinal muscular atrophy (SMA) is caused by reduced levels of survival of motor neuron (SMN) protein due to deletions and/or mutations in the SMN1 gene. Risdiplam is an orally administered molecule that modifies SMN2 pre-mRNA splicing to increase functional SMN protein. METHODS: SUNFISH Part 1 was a dose-finding study conducted in 51 individuals with types 2 and 3 SMA aged 2-25 years. A dose-escalation method was used to identify the appropriate dose for the subsequent pivotal Part 2. Individuals were randomized (2:1) to risdiplam or placebo at escalating dose levels for a minimum 12-week, double-blind, placebo-controlled period, followed by treatment for 24 months. The dose selection for Part 2 was based on safety, tolerability, pharmacokinetic, and pharmacodynamic data. Exploratory efficacy was also measured. RESULTS: There was no difference in safety findings for all assessed dose levels. A dose-dependent increase in blood SMN protein was observed; a median twofold increase was obtained within 4 weeks of treatment initiation at the highest dose level. The increase in SMN protein was sustained over 24 months of treatment. Exploratory efficacy showed improvement or stabilization in motor function. The pivotal dose selected for Part 2 was 5 mg for patients with a body weight ≥20 kg or 0.25 mg/kg for patients with a body weight <20 kg. CONCLUSIONS: SUNFISH Part 1 demonstrated a twofold increase in SMN protein after treatment with risdiplam. The observed safety profile supported the initiation of the pivotal Part 2 study. The long-term efficacy and safety of risdiplam are being assessed with ongoing treatment.

Newbornscreening SMA - From Pilot Project to Nationwide Screening in Germany.

Now that targeted therapies for spinal muscular atrophy are available, attempts are being made worldwide to include screening for spinal muscular atrophy in general newborn screening. In Germany, after pilot projects from 2018-2021, it was included in the general newborn screening from October 2021. To ensure a smooth transition, criteria for follow-up were developed together with key stakeholders. At the beginning of the transition to nationwide screening, false positive findings were reported in 3 patients. After optimization of the screening method in the laboratories concerned, all findings have been subsequently confirmed. On average, the first presentation to a neuromuscular center occurred on day 12 of life, and in patients with 2 or 3 SMN2 copies, therapy started on day 26 of life. Compared with the pilot project, there was no significant delay in timing.

Improved upper limb function in non-ambulant children with SMA type 2 and 3 during nusinersen treatment: a prospective 3-years SMArtCARE registry study.

BACKGROUND: The development and approval of disease modifying treatments have dramatically changed disease progression in patients with spinal muscular atrophy (SMA). Nusinersen was approved in Europe in 2017 for the treatment of SMA patients irrespective of age and disease severity. Most data on therapeutic efficacy are available for the infantile-onset SMA. For patients with SMA type 2 and type 3, there is still a lack of sufficient evidence and long-term experience for nusinersen treatment. Here, we report data from the SMArtCARE registry of non-ambulant children with SMA type 2 and typen 3 under nusinersen treatment with a follow-up period of up to 38 months. METHODS: SMArtCARE is a disease-specific registry with data on patients with SMA irrespective of age, treatment regime or disease severity. Data are collected during routine patient visits as real-world outcome data. This analysis included all non-ambulant patients with SMA type 2 or 3 below 18 years of age before initiation of treatment. Primary outcomes were changes in motor function evaluated with the Hammersmith Functional Motor Scale Expanded (HFMSE) and the Revised Upper Limb Module (RULM). RESULTS: Data from 256 non-ambulant, pediatric patients with SMA were included in the data analysis. Improvements in motor function were more prominent in upper limb: 32.4% of patients experienced clinically meaningful improvements in RULM and 24.6% in HFMSE. 8.6% of patients gained a new motor milestone, whereas no motor milestones were lost. Only 4.3% of patients showed a clinically meaningful worsening in HFMSE and 1.2% in RULM score. CONCLUSION: Our results demonstrate clinically meaningful improvements or stabilization of disease progression in non-ambulant, pediatric patients with SMA under nusinersen treatment. Changes were most evident in upper limb function and were observed continuously over the follow-up period. Our data confirm clinical trial data, while providing longer follow-up, an increased number of treated patients, and a wider range of age and disease severity.

Patientenpartizipation in der pädiatrischen Versorgungsforschung am Universitätsklinikum Freiburg: von der Projektbeteiligung zum Patientenbeirat.

Participation of patients and relatives in research means that those affected are involved in the research process in a partnership role. Despite the growing importance of participatory approaches and the large number of available concepts, many researchers and patients are faced with the question of how participatory research can be realized and organized in concrete terms. Here we report on our experiences with two different forms of patient participation in research in the context of pediatric health care research at a university hospital: (1) In a project for the development and evaluation of a case management for patients with spinal muscular atrophy, patient representatives have an consultative role. (2) In the patient advisory board, which is to accompany the research activities of the research group at the site continuously and systematically, i.e. in all phases, the participation currently corresponds to a contributory role (involvement) which, in the future, could be moved onto the collaborative stage. In both forms of participation, the essential questions include the selection of the participating patients, the type and extent of participation, and the evaluation of the effect of participation on the research that is carried out. In our experience, both forms of participation add value to research from the perspective of all participants. At the same time, they bring different opportunities and challenges. While in project-based participation the sphere of influence is already delineated by researchers, the context of the patient advisory board provides more room and openness to develop, for example, a research agenda and thus identify new research topics. In our experience, however, sufficient resources (in terms of time and money) are required from all participants, as well as good, trusting cooperation with jointly developed processes to realize both forms of participation.

Deep dynamic modeling with just two time points: Can we still allow for individual trajectories?

Longitudinal biomedical data are often characterized by a sparse time grid and individual-specific development patterns. Specifically, in epidemiological cohort studies and clinical registries we are facing the question of what can be learned from the data in an early phase of the study, when only a baseline characterization and one follow-up measurement are available. Inspired by recent advances that allow to combine deep learning with dynamic modeling, we investigate whether such approaches can be useful for uncovering complex structure, in particular for an extreme small data setting with only two observations time points for each individual. Irregular spacing in time could then be used to gain more information on individual dynamics by leveraging similarity of individuals. We provide a brief overview of how variational autoencoders (VAEs), as a deep learning approach, can be linked to ordinary differential equations (ODEs) for dynamic modeling, and then specifically investigate the feasibility of such an approach that infers individual-specific latent trajectories by including regularity assumptions and individuals' similarity. We also provide a description of this deep learning approach as a filtering task to give a statistical perspective. Using simulated data, we show to what extent the approach can recover individual trajectories from ODE systems with two and four unknown parameters and infer groups of individuals with similar trajectories, and where it breaks down. The results show that such dynamic deep learning approaches can be useful even in extreme small data settings, but need to be carefully adapted.

Cathepsin D as biomarker in cerebrospinal fluid of nusinersen-treated patients with spinal muscular atrophy.

BACKGROUND AND PURPOSE: The therapeutic landscape of spinal muscular atrophy (SMA) has changed dramatically during the past 4 years, but treatment responses differ remarkably between individuals, and therapeutic decision-making remains challenging, underlining the persistent need for validated biomarkers. METHODS: We applied untargeted proteomic analyses to determine biomarkers in cerebrospinal fluid (CSF) samples of SMA patients under treatment with nusinersen. Identified candidate proteins were validated in CSF samples of SMA patients by Western blot and enzyme-linked immunosorbent assay. Furthermore, levels of peripheral neurofilament heavy and light chain were determined. RESULTS: Untargeted proteomic analysis of CSF samples of three SMA type 1 patients revealed the lysosomal protease cathepsin D as a candidate biomarker. Subsequent validation analysis in a larger cohort of 31 pediatric SMA patients (type 1, n = 12; type 2, n = 9; type 3, n = 6; presymptomatically treated, n = 4; age = 0-16 years) revealed a significant decline of cathepsin D levels in SMA patients aged ≥2 months at the start of treatment. Although evident in all older age categories, this decline was only significant in the group of patients who showed a positive motor response. Moreover, downregulation of cathepsin D was evident in muscle biopsies of SMA patients. CONCLUSIONS: We identified a decline of cathepsin D levels in CSF samples of SMA patients under nusinersen treatment that was more pronounced in the group of "treatment responders" than in "nonresponders." We believe that our results indicate a suitability of cathepsin D levels as a possible biomarker in SMA also in older patients, in combination with analysis of peripheral neurofilament light chain in adolescents or alone in adult patients.

Parents' Perspectives on Diagnosis and Decision-Making regarding Ventilator Support in Children with SMA Type 1.

Spinal muscular atrophy (SMA) is a rare neuromuscular disorder with a broad clinical spectrum. The most severe phenotype-SMA type 1-is characterized by marked muscle weakness also affecting bulbar and respiratory function. Life expectancy of children with SMA type 1 is expected to be less than 2 years without ventilator support or disease-specific drug treatment. The aim of this study was to evaluate parents' perspectives on the process of decision-making regarding ventilator support in children with SMA type 1. Fourteen semi-structured interviews were performed with parents of children with SMA type 1 that decided either for or against ventilator support for their child. All children were diagnosed prior to the approval of SMA-specific drug treatment. Interviews were recorded and transcribed verbatim. Data analysis was performed using a qualitative content analysis approach according to Mayring. Parents experienced that they were not adequately informed about the disease and treatment options in first informed consent discussions. Especially regarding ventilator support, parents perceived that they were not offered ventilator support as an actual option for treatment. Regarding the decision of whether or not to offer ventilator support, parents reported that their attitude toward ventilator support and contact with other affected families or patient advocacy groups were more likely to influence the decision than the content of informed consent discussions with physicians. Our results underline the importance of an interdisciplinary team not only to provide parents with relevant information but also to consider the criteria of a patient-centered medicine.

Gene replacement therapy with onasemnogene abeparvovec in children with spinal muscular atrophy aged 24 months or younger and bodyweight up to 15 kg: an observational cohort study.

BACKGROUND: Given the novelty of gene replacement therapy with onasemnogene abeparvovec in spinal muscular atrophy, efficacy and safety data are limited, especially for children older than 24 months, those weighing more than 8·5 kg, and those who have received nusinersen. We aimed to provide real-world data on motor function and safety after gene replacement therapy in different patient subgroups. METHODS: We did a protocol-based, multicentre prospective observational study between Sept 21, 2019, and April 20, 2021, in 18 paediatric neuromuscular centres in Germany and Austria. All children with spinal muscular atrophy types 1 and 2 receiving onasemnogene abeparvovec were included in our cohort, and there were no specific exclusion criteria. Motor function was assessed at the time of gene replacement therapy and 6 months afterwards, using the Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP INTEND) and Hammersmith Functional Motor Scale-Expanded (HFMSE) scores. Additionally, in children pretreated with nusinersen, motor function was assessed before and after treatment switch. Off-target adverse events were analysed with a focus on liver function, thrombocytopaenia, and potential cardiotoxicity. FINDINGS: 76 children (58 pretreated with nusinersen and 18 who were nusinersen naive) with spinal muscular atrophy were treated with onasemnogene abeparvovec at a mean age of 16·8 months (range 0·8-59·0, IQR 9-23) and a mean weight of 9·1 kg (range 4·0-15·0, IQR 7·4-10·6). In 60 patients with available data, 49 had a significant improvement on the CHOP-INTEND score (≥4 points) and HFMSE score (≥3 points). Mean CHOP INTEND scores increased significantly in the 6 months after therapy in children younger than 8 months (n=16; mean change 13·8 [SD 8·5]; p<0·0001) and children aged between 8 and 24 months (n=34; 7·7 [SD 5·2]; p<0·0001), but not in children older than 24 months (n=6; 2·5 [SD 5·2]; p=1·00). In the 45 children pretreated with nusinersen and had available data, CHOP INTEND score increased by 8·8 points (p=0·0003) at 6 months after gene replacement therapy. No acute complications occurred during infusion of onasemnogene abeparvovec, but 56 (74%) patients had treatment-related side-effects. Serious adverse events occurred in eight (11%) children. Liver enzyme elevation significantly increased with age and weight at treatment. Six (8%) patients developed acute liver dysfunction. Other adverse events included pyrexia (n=47 [62%]), vomiting or loss of appetite (41 [54%]), and thrombocytopenia (n=59 [78%]). Prednisolone treatment was significantly prolonged with a mean duration of 15·7 weeks (IQR 9-19), mainly due to liver enzyme elevation. Cardiac adverse events were rare; only two patients had abnormal echocardiogram and echocardiography findings. INTERPRETATION: This study provides class IV evidence that children with spinal muscular atrophy aged 24 months or younger and patients pretreated with nusinersen significantly benefit from gene replacement therapy, but adverse events can be severe and need to be closely monitored. FUNDING: None. TRANSLATION: For the German translation of the abstract see Supplementary Materials section.

Post-dural puncture headache-a single-centre analysis in paediatric patients with and without SMA.

AIM: To gather epidemiologic data on post-dural puncture headache (PDPH) after diagnostic or therapeutic lumbar puncture (LP) in children and adolescents with SMA as well as in a cohort of paediatric patients without SMA. METHODS: We performed a retrospective, single-centre analysis via chart review and questionnaire. Patients were identified using the German procedure classification. Respective charts and SMArtCARE documentation forms (SMA patients) were reviewed concerning documentation of headaches fulfilling criteria of the IHS-classification for PDPH of 2004. Non-SMA patients received additional questionnaires. RESULTS: We identified a total of 218 LPs in 95 patients. Of those 141 were performed in 22 patients with known SMA (mean age SMA patients 9.2 years; non-SMA patients 11.4 years). Following chart review, IHS criteria for PDPH were fulfilled in 6.9% of all procedures (3.5% in SMA patients; 13.0% in non-SMA patients; p = 0.008). Data from questionnaires of non-SMA patients confirmed this result (position dependent headache within 72 h after intervention in 13.0% of procedures). CONCLUSION: The prevalence of PDPH after therapeutic LPs in our cohort of SMA patients was significantly lower than after LPs in the general paediatric cohort. Data of this retrospective analysis show a similar overall prevalence of PDPH in paediatric patients as reported in bigger adult cohorts.

Costs of Illness of Spinal Muscular Atrophy: A Systematic Review.

OBJECTIVES: The objective of our study was to conduct a systematic literature review of estimates of costs of illness of spinal muscular atrophy (SMA). METHODS: We searched MEDLINE (through PubMed), CINAHL, Embase, Web of Science, National Health Service Economic Evaluation Database, and the National Health Service Health Technology Assessment Database for studies published from inception up until 31 August, 2020, reporting direct medical, direct non-medical, and/or indirect costs of any phenotype of SMA. Two reviewers independently screened records for eligibility, extracted the data, and assessed studies for risk of bias using the Newcastle-Ottawa Scale. Costs were adjusted and converted to 2018 US dollars. RESULTS: The search identified 14 studies from eight countries (Australia, France, Germany, Italy, Spain, Sweden, the UK, and the USA). The mean per-patient annual direct medical cost of illness was estimated at between $3320 (SMA type III, Italy) and $324,410 (SMA type I, USA), mean per-patient annual direct non-medical cost between $25,880 (SMA types I-III, Spain) and $136,800 (SMA type I, Sweden), and mean per-patient annual indirect cost between $9440 (SMA type I, Germany) and $74,910 (SMA type II, Australia). Most studies exhibited a risk of bias. CONCLUSIONS: The current body of evidence of costs of illness of SMA is relatively scarce and characterized by considerable variability across geographical settings and disease phenotypes. Our review provides data pertaining to the economic impact of SMA, which is of particular relevance in light of emerging treatments and ongoing research in this field, and underscores the substantial unmet medical need in this patient population.