Nusinersen versus Sham Control in Infantile-Onset Spinal Muscular Atrophy

RNA-binding proteins as therapeutic targets in cancer

RNA-binding proteins (RBPs) have emerged as critical regulators of cancer progression, influencing virtually all hallmarks of cancer. Their ability to modulate gene expression patterns that promote or inhibit tumorigenesis has positioned RBPs as promising targets for novel anti-cancer therapies. This mini-review summarizes the current state of RBP-targeted cancer treatments, focusing on five examples, eIF4F, FTO, SF3B1, RBM39 and nucleolin. We highlight the diversity of current targeting approaches and discuss ongoing challenges including the complexity of RBP regulatory networks, potential off-target effects and the need for more specific targeting methods. By assessing the future potential of novel therapeutic avenues, we provide insights into the evolving landscape of cancer treatment and the critical role RBPs may play in next-generation therapeutics.

Echocardiographic evaluation of left ventricular function in children with spinal muscular atrophy before and after nusinersen treatment

BACKGROUND

Spinal muscular atrophy (SMA) is a genetic neuromuscular disease associated with cardiovascular abnormalities. The impact of nusinersen treatment on myocardial function in children with SMA remains unclear. This study aimed to evaluate changes in left ventricular (LV) function in children with SMA before and after nusinersen treatment using echocardiography.

METHODS

A prospective observational study was conducted on 35 children with SMA who received six doses of nusinersen within 10 months at a tertiary hospital in China. 35 healthy controls were included for comparison. LV function was assessed using echocardiography at baseline and after 10 months of treatment. LV dyssynchrony and myocardial strain were measured using two-dimensional speckle tracking echocardiography.

RESULTS

The mean age of the SMA children was 6.58 ± 3.11 years. Before treatment, the global longitudinal strain (GLS) in the SMA group was significantly lower than in the control group (p < 0.001), and LV systolic synchronization was poorer (p < 0.001). Following nusinersen treatment, GLS increased (p < 0.001) and synchrony improved (p = 0.004) in the SMA group. However, even after 10 months of treatment, GLS in the SMA group remained lower than in the control group (p = 0.011), and LV synchronization was still inferior (p = 0.028).

CONCLUSIONS

Short-term nusinersen treatment improved LV function in children with SMA, as evidenced by changes in LV myocardial strain indicators. Further research is warranted to explore the treatment of myocardial injury in SMA patients.

Personalized allele-specific antisense oligonucleotides for GNAO1-neurodevelopmental disorder

GNAO1-associated disorders are ultra-rare autosomal dominant conditions, which can manifest, depending on the exact pathogenic variant in GNAO1, as a spectrum of neurological phenotypes, including epileptic encephalopathy, developmental delay with movement disorders, or late-onset dystonia. There are currently no effective treatments available, apart from symptomatic options. In this work, we suggest harnessing personalized RNA therapy to treat GNAO1 patients and focus specifically on a recurrent pathogenic variant (E246K). We systemically screened allele-specific antisense oligonucleotides (ASOs) targeting the mutated allele to identify a potent and specific sequence using both reporter-based platforms and a patient-derived cellular model. We show that reduction of mutated GNAO1 in vitro by knockout or by ASO has a beneficial functional outcome, which can be measured by cAMP accumulation and gene expression changes. We established a Gnao1-E246K mouse model that shows a neurological phenotype, which partially recapitulates the human condition. Due to sequence similarity, the mouse can be treated with the selected ASO to test treatment efficacy in animal models, as shown in vitro using murine neural progenitor cells. Our results demonstrate a beneficial effect for the reduction of mutated GNAO1 by ASO in patient-derived models, demonstrating its feasibility as a therapeutic approach.

Unveiling sequence-agnostic mixed-chemical modification patterns for splice-switching oligonucleotides using the NATURA platform

Chemical optimization of ribose has significantly advanced nucleic acid therapeutics (NATs) by improving the stability, specificity, and safety of therapies like small interfering RNAs, CRISPR-Cas9 guide RNAs, and GAPmers. Recent research has extended this approach to splice-switching oligonucleotides (SSOs), which target splicing events. Our study identifies a set of mixed-modification patterns-combining 2'-O-Methyl, 2'-MethOxyEthyl, 2'-Locked Nucleic Acid, and 2'-Constrained Ethyl ribose moieties (2'OMe, 2'MOE, LNA, and cET)-that enhance SSO potency. We term this strategy lateral mixed positional configuration, which improves SSO efficacy across various sequences and could reduce the trial-and-error process in SSO development. This advancement is supported by NAT Unlabeled Reporter Assay (NATURA), a novel platform for high-throughput quantification of NATs' functional delivery and potency. NATURA uses a reporter gene system and a comprehensive sequence library to test modifications and delivery methods, validated in a transgenic mouse model. This approach aims to accelerate NAT development and address challenges in delivering these therapies to patients.

Long-Term Dynamics of CSF and Serum Neurofilament Light Chain in Adult Patients With 5q Spinal Muscular Atrophy Treated With Nusinersen

BACKGROUND AND OBJECTIVES

The availability of disease-modifying therapies for 5q-associated spinal muscular atrophy (SMA) has heightened the need to identify suitable biomarkers. This study investigates neurofilament light chain (NfL) concentrations during long-term nusinersen treatment in adult SMA.

METHODS

In a retrospective study of prospectively collected data, NfL concentrations in the CSF (cNfL) and serum (sNfL) were measured in patients with SMA from 8 German centers and in neurologic controls using a single-molecule array (Simoa) assay. NfL concentrations and clinical characteristics, including the clinical scores Hammersmith Functional Motor Scale Expanded (HFMSE), Revised Upper Limb Module (RULM), and Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R), were analyzed for defined treatment intervals (T1-T4 [loading phase until 4 months], T5-T8 [until 23 months], T9-T12 [until 37 months], and T13-T19 [until 60 months]). Linear mixed models with a random intercept were used to assess the changes in NfL levels during treatment, considering time and covariates as fixed effects.

RESULTS

One hundred thirteen adult patients with SMA (median age 35, 46% female), with a treatment duration of maximum 60 months, and 52 controls were included. At baseline, NfL concentrations were significantly higher in SMA {cNfL median, 585 (interquartile range [IQR] 428-787) pg/mL; sNfL, 11 (IQR 8-14) pg/mL} than in controls (cNfL, 420 [IQR 323-662] pg/mL; sNfL, 8 [IQR 6-12] pg/mL) (cNfL, p = 0.021; sNfL, p = 0.030). Median differences for all clinical scores were the highest for T5-T8 compared with the loading phase (Δ HFMSE, 0.6 [IQR 0.1-1.4], p = 0.017; Δ RULM, 0.9 [IQR 0.4-1.3], p < 0.001; Δ ALSFRS-R, 0.7 [IQR 0.4-1.0], p < 0.001), but not for subsequent intervals. Longitudinal analysis revealed a significant decrease of NfL concentrations during each treatment interval compared with the loading phase (p < 0.05, respectively) except for sNfL in T13-T19. Even among patients with no measurable clinical improvement (Δ HFMSE ≤ 0), more than 50% showed declining cNfL and sNfL levels up to T13-T19.

DISCUSSION

NfL decreased during nusinersen treatment, suggesting its potential as a pharmacodynamic response marker in adult SMA. However, in patients without detectable clinical improvement, our study cannot determine whether they represent a more sensitive outcome measure or are not clinically meaningful.

A historical perspective on the development of antisense oligonucleotide treatments for Duchenne muscular dystrophy and spinal muscular atrophy

Splice modulating antisense oligonucleotides (ASOs) have been approved for the treatment of spinal muscular atrophy (nusinersen) and Duchenne muscular dystrophy (eteplirsen) since 2016. Nusinersen obtained full approval based on convincing functional evidence in treated patients. The treatment is currently approved in over 40 countries. By contrast, eteplirsen received accelerated approval and functional evidence from clinical trials that treatment slows down disease progression is still lacking. Approval and access is restricted to the USA and several countries in the Middle-East. In this historical perspective we look back to the development paths of these two ASOs focusing on the differences between the approaches, the target tissues and the diseases. Based on this we propose learnings for future development of ASOs for progressive neuromuscular diseases.

The nature and pathological impact of the c.1748A > G variant of the neurofibromin 1 gene

Neurofibromatosis type 1 (NF1) is an autosomal dominant genetic disorder, and mutations in the NF1 gene lead to RAS overactivation, which stimulates abnormal cell proliferation and can cause various tumors. The c.1748A > G mutation in the NF1 gene was initially classified as a missense mutation, but has also been suggested to be a splice mutation. It is thought that the substitution of A for G generates a cryptic splice site, resulting in a 27 bp deletion in the mRNA transcript, but this conclusion has not been documented in currently available databases. The present study was conducted to establish whether the NF1 c.1748A > G mutation induces a splicing error, and to determine whether it is pathogenic i.e. activates RAS and increases the expression of NF1-related downstream signaling molecules. We have confirmed by RT-PCR analysis of NF1 transcripts produced in the patient's peripheral blood lymphocytes as well as in a minigene construct and in iPSCs harboring the c.1748A > G mutation that this mutation creates a cryptic splice site which has the effect of deleting the first 27 bases of exon 16, and leading to transcriptional haploinsufficiency. Additionally, NPCs expressing the splicing mutant exhibited increased phosphorylation of NF1-related AKT/mTOR and Raf/MEK/Erk, as well as more effective wound healing and chemotaxis. We conclude that the NF1 c.1748A > G mutation acts as a splice mutation forming a novel cryptic site, causing a 27 bp deletion in the mRNA. This leads to increased expression of NF1-related downstream signaling molecules through RAS activation, inducing cell proliferation and potential tumor formation.

2024 VCP International Conference: Exploring multi-disciplinary approaches from basic science of valosin containing protein, an AAA+ ATPase protein, to the therapeutic advancement for VCP-associated multisystem proteinopathy

Valosin-containing protein (VCP/p97) is a ubiquitously expressed AAA+ ATPase associated with numerous protein-protein interactions and critical cellular functions including protein degradation and clearance, mitochondrial homeostasis, DNA repair and replication, cell cycle regulation, endoplasmic reticulum-associated degradation, and lysosomal functions including autophagy and apoptosis. Autosomal-dominant missense mutations in the VCP gene may result in VCP-associated multisystem proteinopathy (VCP-MSP), a rare degenerative disorder linked to heterogeneous phenotypes including inclusion body myopathy (IBM) with Paget's disease of bone (PDB) and frontotemporal dementia (FTD) or IBMPFD, amyotrophic lateral sclerosis (ALS), Alzheimer's disease (AD), parkinsonism, Charcot-Marie Tooth disease (CMT), and spastic paraplegia. The complexity of VCP-MSP makes collaboration among stakeholders essential and necessitates a multi-disciplinary approach. The 2024 VCP International Conference was hosted at Caltech between February 22 and 25. Co-organized by Cure VCP Disease and Dr. Tsui-Fen Chou, the meeting aimed to center the patient as a research partner, harmonize diverse stakeholder engagement, and bridge the gap between basic and clinical neuroscience as it relates to VCP-MSP. Over 100 multi-disciplinary experts attended, ranging from basic scientists to clinicians to patient advocates. Attendees discussed genetics and clinical presentation, cellular and molecular mechanisms underlying disease, therapeutic approaches, and strategies for future VCP research. The conference included three roundtable discussions, 29 scientific presentations, 32 scientific posters, nine patient and caregiver posters, and a closing discussion forum. The following conference proceedings summarize these sessions, highlighting both the identified gaps in knowledge and the significant strides made towards understanding and treating VCP diseases.

Onasemnogene Abeparvovec Gene Therapy and Risdiplam for the Treatment of Spinal Muscular Atrophy in Thailand: A Cost-Utility Analysis

OBJECTIVES

Caring for individuals with spinal muscular atrophy (SMA), a rare genetic disorder, poses tremendous challenges for the economy and healthcare system. This study evaluated the cost-utility of onasemnogene abeparvovec-xioi gene therapy and risdiplam for SMA in Thailand.

METHODS

A Markov model was used to analyze the lifetime costs and outcomes of these treatments compared with standard of care for symptomatic SMA types 1 and 2-3. SMA type 1 patients were treated with one of either onasemnogene or risdiplam, while SMA types 2-3 patients received risdiplam. Data on disease progression and medical costs were sourced from hospital databases, while treatment efficacy was based on clinical trials. Interviews with patients and caregivers provided data on non-medical costs and utilities. Base case cost-effectiveness and sensitivity analyses were conducted, with the incremental cost-effectiveness ratio (ICER) calculated in US dollars (USD) per quality-adjusted life year (QALY) gained, against a willingness-to-pay threshold of 4444 USD/QALY gained.

RESULTS

For SMA type 1, the ICERs for onasemnogene and risdiplam were 163,102 and 158,357 USD/QALY gained, respectively. For SMA types 2-3, the ICER for risdiplam was 496,704 USD/QALY gained.

CONCLUSIONS

While onasemnogene and risdiplam exceeded the value-for-money threshold of the Thai healthcare system, they yielded the highest QALY gains among all approved medications. Policy-makers should incorporate various pieces of evidence alongside the cost-effectiveness results for rare diseases with costly drugs. Additionally, cost-effectiveness findings are useful for price negotiations and alternative financial funding, which allows policy-makers to seek solutions to ensure patient access, aligning with universal health coverage principles in Thailand.

Swallowing function in patients with spinal muscular atrophy before and after the introduction of new gene-based therapies: what has changed?

OBJECTIVE

Individuals diagnosed with Spinal Muscular Atrophy (SMA), particularly those presenting with the most severe phenotypes, have long contended with significant swallowing dysfunction. The recent emergence of efficacious advanced therapy has fundamentally altered the landscape of SMA management. By encompassing both the pre and post gene-based therapy eras within our analysis, we endeavour to elucidate the potential impact of these novel therapeutic interventions on this function.

METHODS

Following the established methodology outlined by the Joanna Briggs Institute, a scoping review was conducted. This review encompassed relevant literature published up to March 2024. Two electronic databases were searched, with additional studies identified by reviewing reference lists of pertinent articles. The search strategy employed a combination of keywords including "spinal muscular atrophy", "SMA", "swallowing", "feeding", and "nutrition". Articles were initially screened based on title and abstract, followed by a full-text review of eligible studies published in peer-reviewed English language journals.

RESULTS

The initial database search resulted in 462 articles, from which 23 studies were ultimately selected for analysis. Pre gene-based therapy studies revealed swallowing dysfunction as a prominent feature. Patients frequently reported challenges with chewing, choking on solids and liquids, and abnormal tongue movements during eating. Early dysphagia research relied on subjective measures (questionnaires, scales). objective measures like video fluoroscopic (VFSS) were rare. After gene-based therapies (GBTs), VFSS became the dominant, more objective method. Studies investigating the post-gene therapy era suggest potential clinical benefits, with trends towards improvement or stabilization of swallowing function.

CONCLUSION

Pre gene-based therapy studies revealed widespread swallowing dysfunction in SMA. Conversely, the post-treatment era suggests potential improvement. Future research should prioritize identifying optimal therapies for individual swallowing function and develop validated assessments to optimize SMA management.

Delayed Diagnosis of Spinal Muscular Atrophy in Two Chinese Families due to Novel SMN1 Deletions

Autosomal recessive spinal muscular atrophy (SMA) is a leading cause of infant and child mortality, with homozygous deletion in exon 7 of the SMN1 gene being a major genetic cause. However, routine genetic testing methods may overlook structural variants outside of exon 7, potentially leading to misdiagnosis of SMA patients. Here, we reported two Chinese SMA patients who primarily exhibited developmental delays. Physical examinations revealed markedly reduced muscle strength and tone in their extremities, and electromyography suggested extensive neurogenic damage in the anterior horn of the spinal cord. The MLPA results indicated a single copy number of SMN1 in both patients, which is inconsistent with the typical genetic pattern of SMA. Through RNA sequencing and ultra-long read sequencing, we ultimately identified a rare structural variant involving the deletion of exons 2a-5 in both unrelated patients. This confirmed the presence of compound heterozygous variants in the SMN1 gene as the actual genetic cause. To our knowledge, this is the first case where a combination of RNA sequencing and ultra-long read sequencing has been used to diagnose SMA. We demonstrated the significant value of RNA sequencing in cases where children are highly suspected of having SMA but present negative results in routine genetic testing. This underscores the crucial role of accurate genetic testing methods in achieving early diagnosis of SMA.

Transitioning From Nusinersen to Risdiplam for Spinal Muscular Atrophy in Clinical Practice: A Single-Center Experience

BACKGROUND

Nusinersen and risdiplam are U.S. Food and Drug Administration (FDA)-approved treatments for spinal muscular atrophy (SMA). No head-to-head clinical trials to assess efficacy exist. Observational studies are needed to determine if transitioning to risdiplam is safe and efficacious.

METHODS

This retrospective study at Nationwide Children's Hospital included individuals with SMA treated with nusinersen who switched to risdiplam. Motor, pulmonary and bulbar function were assessed before and 2 years after nusinersen and risdiplam initiation.

RESULTS

Forty-four individuals were included: 11 with SMA type 1, 25 with SMA type 2 and 8 with SMA type 3. Motor function improved after initiation of nusinersen treatment with the most significant improvements seen in the first year. After transition to risdiplam, motor function remained largely stable. Need for noninvasive ventilation (NIV) overnight occurred in both groups. Cough peak flow significantly improved in the risdiplam group. Hospitalizations were the same in both groups. One individual in the nusinersen group gained the ability to take some food by mouth; two individuals in the risdiplam group achieved some oral feeding and two became exclusively orally fed.

CONCLUSIONS

As expected, motor function was most improved in treatment naïve individuals in the first year after nusinersen initiation. Over half of our study population had posterior spinal fusion surgery (57%) which significantly impacted motor and respiratory outcomes, though slightly less so in the risdiplam group. Overall, our data demonstrates that transitioning from nusinersen to risdiplam is associated with a favorable safety profile and stable motor outcomes.

Real-world analysis of the efficacy and safety of nusinersen in pediatric patients with spinal muscular atrophy

BACKGROUND

Spinal muscular atrophy (SMA) is a rare neurodegenerative disease that significantly affects multiple systems in children. Nusinersen, the first approved treatment for SMA, enhances SMN protein production by targeting the RNA splicing site of the SMN2 gene, thus improving motor function. However, the high cost of nusinersen treatment raises concerns about its economic feasibility.

METHODS

This study retrospectively analyzed clinical data of 42 pediatric SMA patients treated with nusinersen from January 2022 to October 2024 at our hospital. We assessed the efficacy, safety, and economic impact of nusinersen in different SMA types. Motor function was evaluated using the CHOP-INTEND, HINE-2, HFMSE, and RULM scales. Safety was assessed based on adverse reactions and events, and economic evaluation considered total treatment costs and average cost per injection.

RESULTS

Nusinersen significantly improved motor function in SMA patients, especially in type I patients, who showed notable increases in CHOP-INTEND and HINE-2 scores. The RULM score had the highest increase among type II patients, while improvements were relatively lower in type III patients. Regarding safety, the incidence of adverse events was 40.48%, with fever being the most common adverse reaction, occurring in 36.36% of cases. Economic analysis indicated that the total treatment cost was highest for type III patients, though the cost differences among types were not statistically significant (P > 0.05).

CONCLUSION

Nusinersen demonstrated significant clinical efficacy and favorable safety in pediatric SMA patients, with improved economic feasibility after insurance coverage. Our findings support early SMA screening and presymptomatic nusinersen administration to maximize therapeutic benefits. Further multicenter, large-sample, long-term follow-up studies are warranted to validate and expand upon these findings.

Treating neuromuscular diseases: unveiling gene therapy breakthroughs and pioneering future applications

In this review, we highlight recent advancements in adeno-associated virus (AAV)-based gene therapy for genetic neuromuscular diseases (NMDs), focusing on spinal muscular atrophy (SMA) and Duchenne muscular dystrophy (DMD). We discuss the current FDA-approved gene therapies for NMDs and provide updates on preclinical studies that demonstrate the potential of various AAV-based gene therapies to reduce SMA severity and serve as effective treatments for DMD. Additionally, we explore the transformative impact of CRISPR/Cas9 technology on the future of gene therapy for NMDs. Despite these encouraging developments, further research is required to identify robust biomarkers that can guide treatment decisions and predict outcomes. Overall, these pioneering advancements in AAV-based gene therapy lay the groundwork for future efforts aimed at curing genetic NMDs and offer a roadmap for developing gene therapies for other neurodegenerative diseases.

Elucidating the Pathogenic Mechanism of Spinal Muscular Atrophy Through the Investigation of UTS2

BACKGROUND

Spinal muscular atrophy (SMA) is a severe neuromuscular disorder caused by mutations in the survival motor neuron 1 (SMN1) gene, resulting in progressive motor neuron loss and muscle atrophy. The urotensin 2 (UTS2) gene, located on chromosome 9q34.2, plays a significant role in cellular activities such as proliferation, apoptosis, and inflammatory responses. Notably, elevated expression levels of UTS2 have been observed in SMA patients. However, its precise contribution to disease pathogenesis remains unclear. This study aimed to investigate the effects of UTS2, which is overexpressed in SMA patients, in SMA cell models using a UTS2 inhibitor.

METHODS

We conducted genomic sequencing and bioinformatics analysis on clinical samples to identify proteins highly expressed in association with SMA. Using RNA interference technology, we suppressed SMN1 gene expression in bone marrow mesenchymal stem cells (MSCs) to establish an in vitro cellular model of SMA. To assess the biological consequences of SMN1 gene knockdown, we employed molecular biological techniques such as immunofluorescence, reverse transcription quantitative polymerase chain reaction (RT-qPCR), and western blotting. Furthermore, we treated the SMA cellular model with the urantide UTS2 receptor inhibitor and examined its effects on cell proliferation, apoptosis, and the expression of relevant proteins.

RESULTS

UTS2 was successfully identified as a highly expressed protein associated with SMA. A stable MSC model with SMN1 gene knockdown was established. RNA interference (RNAi) technology effectively suppressed SMN1 gene expression, leading to changes in cellular morphology and neuron-specific marker expression. Urantide intervention significantly affected both proliferation and apoptosis in the SMA cell model in a dose-dependent manner. Techniques such as the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, TUNEL fluorescence staining, and flow cytometry analysis revealed that uride decreased cell viability while increasing the proportion of apoptotic cells. Following urantide intervention, there was a notable increase in caspase-3 messenger ribonucleic acid (mRNA) levels, as well as an increase in caspase-3 protein expression, as demonstrated by immunofluorescence analysis.

CONCLUSION

We elucidated the role of the UTS2 gene in an SMA cell model, emphasizing its dysregulation and identifying potential therapeutic targets. Urantide, a UTS2 inhibitor, had significant biological effects on the SMA cell model, indicating that it is a promising therapeutic strategy for SMA. These findings provide valuable insights for advancing drug development and clinical treatment of SMA.

Nucleic Acid Conjugates: Unlocking Therapeutic Potential

Nucleic acids have emerged as a powerful class of therapeutics. Through simple base pair complementarity, nucleic acids allow the targeting of a variety of pathologically relevant proteins and RNA molecules. However, despite the preliminary successes of nucleic acids as drugs in the clinic, limited biodistribution, inadequate delivery mechanisms, and target engagement remain key challenges in the field. A key area of research has been the chemical optimization of nucleic acid backbones to significantly enhance their "drug-like" properties. Alternatively, this review focuses on the next generation of nucleic acid chemical modifications: covalent biochemical conjugates. These conjugates are being applied to improve the delivery, functionality, and targeting. Exploiting research on heterobifunctionals, such as PROTACs, RIBOTACs, molecular glues, etc., has the potential to dramatically expand nucleic acid drug functionality and target engagement capabilities. Such next-generation chemistry-based enhancements have the potential to unlock nucleic acids as effective and versatile therapeutic agents.

Healthcare Resource Utilization, Economic Burden, and Multi-Level Medical Security System for Individuals with Spinal Muscular Atrophy in Shaanxi Province, China

Objectives: The objective of this study is to quantify healthcare resource utilization, economic burden, and the multi-level medical security system for Spinal Muscular Atrophy (SMA) patients in Shaanxi Province, China, from a societal perspective using a survey. Methods: This observational study employed an online survey with a retrospective cross-sectional design in Shaanxi Province, China. The survey examined various aspects of SMA, including resource utilization, direct and indirect economic burdens, and co-payment mechanisms within a multi-level medical security system. Results: Following the inclusion of nusinersen in the National Reimbursement Drug List (NRDL) in 2022, the treatment rate for SMA patients increased significantly. After risdiplam was added to the NRDL in 2023, its use also saw a marked increase. Treatment costs varied by SMA type: Type 1 incurred the highest costs (RMB 300,000 or USD 41,000), followed by Type 2 (RMB 270,000 or USD 37,000), Type 3 (RMB 200,000 or USD 27,000), and Type 4 (RMB 80,000 or USD 11,000). The primary sources of costs were productivity losses due to primary caregivers (32.94%), nusinersen usage (29.29%), and risdiplam usage (17.33%). Out-of-pocket costs for SMA patients accounted for 29.29% of the total costs. In 2023, basic medical insurance covered 49% of direct costs and 32% of total costs. Patients still had to pay 25.73% of the total cost for the direct costs. Conclusions: Basic medical insurance is a critical foundation for patient security and plays a pivotal role in reimbursement. In contrast, commercial insurance has a relatively limited impact on covering the costs for SMA patients. These findings highlight the substantial healthcare burden faced by SMA patients under the current healthcare system in China.

Extracellular vesicles efficiently deliver survival motor neuron protein to cells in culture

Spinal Muscular Atrophy (SMA) is a genetic neuromuscular disorder caused by homozygous mutation or deletion of the survival motor neuron 1 (SMN1) gene, leading to a low quantity of SMN protein in cells. This depletion of SMN protein preferentially leads to death of motor neurons and, consequently, muscle atrophy, in addition to defects in many other peripheral tissues. SMN protein is naturally loaded into extracellular vesicles (EVs), which are sub-micron-sized, membrane-bound particles released from all cell types. The innate ability of EVs to deliver cargo to recipient cells has caused these vesicles to gain interest as therapeutic delivery vehicles. In this study, we show that adenovirus-mediated overexpression of SMN protein in HepG2 cells leads to the release of EVs loaded with high levels of SMN protein into conditioned medium. Application of this medium to recipient cells in tissue culture led to uptake of the SMN protein, which subsequently transited to the nucleus and co-localized with Gemin2 protein, forming nuclear gem-like structures similar to the native SMN protein. Overall, this work demonstrates that SMN protein can be delivered to cells through EVs, which holds promise as a potential therapy for patients with SMA.

Performance of cellulose-based card for direct genetic testing of spinal muscular atrophy

BACKGROUND

Spinal muscular atrophy (SMA) is a devastating neuromuscular condition resulting from the loss of the survival motor neuron 1 (SMN1) gene. Precise genetic testing has become essential after the authorization of several potent medications. To achieve this objective, the use of dried blood spot (DBS) has assured convenient and extensive testing from a distance. Nevertheless, developing countries such as Indonesia sometimes lack access to standard filter papers like FTA or Guthrie cards for DBS processing. Here, we aim to develop a cellulose-based card as an alternative filter paper for DBS preparation suitable for the genetic testing of SMA including but not limited to a direct polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and multiplex allele-specific amplification (multi-ASA).

RESULTS

An in-house paper was developed from a 180 gsm cellulose-based paper and was used for DBS preparation. The performance of dried blood spotted on the cellulose-based card (DBSc) was compared to pure genomic DNA (gDNA) isolate and dried blood spotted on FTA cards (DBSf) for genetic testing. The results of the genetic testing of our cellulose-based card were completely matched with those of gDNA and DBSf in both direct PCR-RFLP and Multi-ASA to separate SMN1 from SMN2. In addition, after three months of storing, the DBSc continued to exhibit a clear result, suggesting its high stability for DNA storage.

CONCLUSION

Our cellulose-based card has the potential to be used for DBS carrier and for further genetic testing using PCR. Our findings can assist physicians in sending DBS samples from SMA suspicion cases to genetic testing centers, thereby preventing diagnosis delay or misdiagnosis.

Experience of nusinersen treatment in advanced spinal muscular atrophy type 1: Characteristics of late responders with delayed treatment efficacy

OBJECTIVE

Little clinical data is available for advanced cases of spinal muscular atrophy (SMA) type 1, particularly those requiring ventilation support. Therefore, this study aimed to evaluate the effectiveness of nusinersen treatment on motor and respiratory function in advanced cases of SMA type 1.

METHODS

This observational cohort study included seven patients with advanced SMA type 1, requiring permanent ventilator support and tracheostomy, at Hyogo Medical University School of Medicine Hospital between July 2017 and July 2019. The primary outcome was change in motor function, assessed using the Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP-INTEND) score. Subjective changes, which could not be measured with CHOP-INTEND, were also evaluated. The secondary outcomes included changes in respiratory function, measured by tidal volume (TV) and transcutaneous carbon dioxide (TcCO2) levels.

RESULTS

Two patients showed a meaningful improvement in CHOP-INTEND scores (an increase of 4 points) after 2-3 years of nusinersen treatment. The remaining five showed changes ranging from 0 to 2 points. Subjective changes were observed in all patients. Patient respiratory function outcomes varied; TV increased in two patients and decreased in five, and TcCO2 levels decreased in three patients and increased in four.

CONCLUSIONS

Nusinersen may provide meaningful improvement in motor function in some patients with advanced SMA type 1; however, treatment response may take a while and varies between individuals. Further research is needed to substantiate these findings and identify potential prognostic factors for nusinersen treatment.

Motor pool selectivity of neuromuscular degeneration in type I spinal muscular atrophy is conserved between human and mouse

Spinal muscular atrophy (SMA) is caused by low levels of the survival motor neuron (SMN) protein. Even though SMN is ubiquitously expressed, the disease selectively affects motor neurons, leading to progressive muscle weakness. Even among motor neurons, certain motor units appear more clinically resistant to SMA. To quantitatively survey selective resistance, we studied extensive neuromuscular autopsies of Type I SMA patients and age-matched controls. We found highly divergent degrees of degeneration of neighboring motor units, even within individual cranial nerves or a single anatomical area such as the neck. Examination of a Type I SMA patient maintained on life support for 17 years found that most muscles were atrophied, but the diaphragm was strikingly preserved. Nevertheless, some resistant human muscles with preserved morphology displayed nearly complete conversion to slow Type I myofibers. Remarkably, a similar pattern of selective resistance was observed in the SMNΔ7 mouse model. Overall, differential motor unit vulnerability in human Type I SMA suggests the existence of potent, motor unit-specific disease modifiers. Mechanisms that confer selective resistance to SMA may represent therapeutic targets independent of the SMN protein, particularly in patients with neuromuscular weakness refractory to current treatments.

IL-1ra and CCL5, but not IL-10, are promising targets for treating SMA astrocyte-driven pathology

Spinal muscular atrophy (SMA) is a pediatric genetic disorder characterized by the loss of spinal cord motor neurons (MNs). Although the mechanisms underlying MN loss are not clear, current data suggest that glial cells contribute to disease pathology. We have previously found that SMA astrocytes drive microglial activation and MN loss potentially through the upregulation of NF-κB-mediated pro-inflammatory cytokines. In this study, we tested the ability of neutralizing C-C motif chemokine ligand 5 (CCL5) while increasing either interleukin-10 (IL-10) or IL-1 receptor antagonist (IL-1ra) to reduce the pro-inflammatory phenotype of SMA astrocytes. While IL-10 was ineffective, IL-1ra ameliorated SMA astrocyte-driven glial activation and MN loss in induced pluripotent stem cell-derived cultures in vitro. In vivo AAV5 delivered IL-1ra overexpression, and miR-30 small hairpin RNA knockdown of CCL5 made modest but significant improvements in lifespan, weight gain, MN number, and motor function of SMNΔ7 mice. These data identify IL-1ra and CCL5 as possible therapeutic targets for SMA and highlight the importance of glial-targeted therapeutics for neurodegenerative disease.

Spinal Muscular Atrophy Update in Best Practices: Recommendations for Treatment Considerations

Background and Objectives

Spinal muscular atrophy (SMA) is an autosomal recessive disorder caused by biallelic variants of the Survival Motor Neuron 1 gene (SMN1) that affects approximately 1 in 15,000 live births. Availability of 3 SMN-enhancing treatments for SMA has led to urgency to review how clinicians and patients use these treatments for SMA, while additional research and real-world data and experience are being collected. This work describes important factors to assist with decision-making for SMN-enhancing treatments.

Methods

A systematic literature review was conducted on SMN-enhancing treatments for SMA and related studies. A working group of American and European health care providers with expertise in SMA care identified barriers and developed recommendations through a modified Delphi technique with serial surveys and feedback through virtual meetings to fill gaps for information where evidence is limited. A community working group of an individual living with SMA and caregivers provided insight and perspective on SMA treatments and support through a virtual meeting to guide recommendations.

Results

The health care provider working group and the community working group agreed that when determining whether to start, change, add, or discontinue a treatment, essential considerations include patient and family/caregiver perspective, and treatment safety and side effects. When initiating treatment for patients newly diagnosed with SMA, important patient characteristics are age and Survival Motor Neuron 2 gene (SMN2) copy number. Furthermore, when initiating, changing, or adding treatment, current clinical status and comorbidities drive decision-making. When considering a medication or treatment plan change, unless there is an urgent indication, a treatment and associated patient outcomes should be monitored for a minimum of 6-12 months. When determining a treatment plan with an adolescent or adult with SMA, consider factors such as quality of life, burden vs benefit of treatment, and reproductive issues. Access to care coordination and interdisciplinary/multidisciplinary care are essential to treatment success.

Discussion

Sharing information about current knowledge of treatments and shared decision-making between health care providers and patients living with SMA and caregivers are essential to overcoming barriers to providing SMN-enhancing treatments.

RNA dysregulation in neurodegenerative diseases

Dysregulation of RNA processing has in recent years emerged as a significant contributor to neurodegeneration. The diverse mechanisms and molecular functions underlying RNA processing underscore the essential role of RNA regulation in maintaining neuronal health and function. RNA molecules are bound by RNA-binding proteins (RBPs), and interactions between RNAs and RBPs are commonly affected in neurodegeneration. In this review, we highlight recent progress in understanding dysregulated RNA-processing pathways and the causes of RBP dysfunction across various neurodegenerative diseases. We discuss both established and emerging mechanisms of RNA-mediated neuropathogenesis in this rapidly evolving field. Furthermore, we explore the development of potential RNA-targeting therapeutic approaches for the treatment of neurodegenerative diseases.

Effect of Nusinersen on Respiratory and Bulbar Function in Children with Spinal Muscular Atrophy: Real-World Experience from a Single Center

BACKGROUND

Due to the limited data from clinical trials and real-world settings in the realm of nusinersen, there is a need for further evidence. This study seeks to assess the impact of nusinersen, when combined with standard care, on bulbar function, respiratory function, and the necessity for respiratory support among pediatric patients with spinal muscular atrophy (SMA).

METHODS

Prospective observational study, involving pediatric SMA patients (Types 1-3) undergoing nusinersen treatment at the Hospital Universitario Virgen del Rocío in Spain over at least 24 months. The cohort included 11 SMA type 1 patients, comprising 6 type 1b and 5 type 1c, 12 SMA type 2 patients, and 5 SMA type 3 patients.

RESULTS

Twenty-eight pediatric patients were enrolled with the majority being male (n = 20). Patients with type 1 were diagnosed and received treatment significantly earlier than those with types 2 and 3 (p < 0.001). Additionally, there was a longer period between diagnosis and the start of treatment in types 2 and 3 (p = 0.002). Follow-up revealed statistically improved functional and respiratory outcomes associated with earlier initiation of nusinersen treatment at 6, 12, and 24 months in all phenotypes. The ability to swallow and feed correctly remained unchanged throughout the study, with SMA type 1c patients maintaining oral feeding in contrast to patients with SMA type 1b. Notably, no deaths were recorded.

CONCLUSIONS

This study provides important insights into the real-world clinical progress of pediatric SMA patients and their response to nusinersen treatment, highlighting the significance of early intervention for better functional and respiratory outcomes.

Comprehensive assessment reveals numerous clinical and neurophysiological differences between MECP2-allelic disorders

OBJECTIVE

Rett syndrome (RTT) and MECP2 duplication syndrome (MDS) result from under- and overexpression of MECP2, respectively. Preclinical studies using genetic-based treatment showed robust phenotype recovery for both MDS and RTT. However, there is a risk of converting MDS to RTT, or vice versa, if accurate MeCP2 levels are not achieved. The aim of this study was to identify biomarkers distinguishing RTT from MDS.

MATERIALS AND METHODS

We prospectively enrolled 11 MDS and 6 male RTT like (MRL) individuals for a panel of clinical and neurophysiological assessments over two visits, 8-10 months apart.

RESULTS

We identified numerous clinical and physiological features as promising biomarkers. MRL individuals exhibited large amplitude whole body tremor, midline stereotypies (vs. hand flapping at sides in MDS), earlier neuromotor regression, and earlier onset but less commonly refractory epilepsy. In the neurophysiological domain, we observed several marked differences in sleep physiology between MDS/MRL and typically developing (TD) individuals including reduced sleeping time, increased delta power during rapid eye movement (REM) sleep, decreased occipital alpha and increased brain-wide delta power during wakefulness, and reduced spindle density and duration. MRL individuals also had much lower delta power during NREM 2 and 3 stages than the TD group. We found differences in spindle duration in the temporal lobes and spindle amplitude in the frontal lobes between MDS and MRL.

DISCUSSION

Our study revealed distinct clinical features of MDS and MRL that can be monitored during a clinical trial and may serve as target engagement, disease progression, or safety biomarkers for interventional studies.

Motor function and compound muscle action potential amplitude in children with spinal muscular atrophy treated with nusinersen

BACKGROUND

Disease-modifying therapies can improve motor function in patients with spinal muscular atrophy (SMA), but efficacy varies between individuals. The aim was to evaluate the efficacy and safety of nusinersen treatment in children with SMA and to investigate prognostic factors.

METHODS

Motor function, compound muscle action potential (CMAP), and other indicators were prospectively collected before and 14 months after nusinersen treatment.

RESULTS

A total of 55 children were included in our study to assess safety. 41 patients (with at least 6 months of nusinersen treatment) were included in the final efficacy analyses, with a median age at first treatment of 4.2 years. After 14 months of treatment with nusinersen, motor function improved, with increases in CHOP INTEND (Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders), HINE-2 (Hammersmith Infant Neurological Exam-Part 2), HFMSE (Hammersmith Functional Motor Scale-Expanded) and RULM (Revised Upper Limb Module) of 5.5 (95 % CI -2.4-13.4), 0.8 (95 % CI -0.2-1.9), 5.0 (95 % CI 2.5-7.4) and 2.4 (95 % CI 0.7-4.1) points, respectively. The CMAP amplitudes of the bilateral tibial, median and ulnar nerves increased, with greatest improvements of 0.87 ± 1.41 mV, 1.08 ± 1.71 mV and 0.59 ± 1.01 mV, respectively. Spearman correlation analysis showed that age at first treatment, disease duration, joint contractures and scoliosis were associated with treatment efficacy (r = -0.4-0.7, P < 0.05). Subgroup analyses showed that the mean HFMSE and RULM scores improved in the Physical therapy group (P < 0.05).

CONCLUSION

Early treatment, mild bone and joint complications, and regular rehabilitation training were associated with better outcomes. The other motor-related functions, such as respiratory and bullar function, and prognostic factors should be studied in the future.

Neonatal Screening for Spinal Muscular Atrophy and Severe T- and B-Cell Lymphopenias in Andalusia: A Prospective Study

Spinal muscular atrophy (SMA) and severe T- and/or B-cell lymphopenias (STBCL) in the form of severe combined immunodeficiencies (SCID) or X-linked agammaglobulinemia (XLA) are rare but potentially fatal pathologies. In January 2021, we initiated the first pilot study in Spain to evaluate the efficacy of a very early detection technique for SMA and SCID. RT-PCR was performed on prospectively collected dried blood spots (DBSs) from newborns in Western Andalusia (Spain). Internal and external controls (SCID, XLA and SMA) were included. The determination of SMA was relative (positive/negative) and that of TRECs and KRECs was quantitative (copies/punch). A total of 14.035 prospective samples were analysed. All controls were correctly identified while no cases of SMA or SCID/XLA were prospectively identified. DBS analysis of infants with suspected SMA or STBCL that presented to our centre showed pathological values in two cases each for SMA and SCID and one for XLA, all of them being subsequently confirmed genetically. In this prospective pilot study, no infants with SMA or STBCL were detected; however, the technique applied here was shown to be reliable and fast, further supporting the benefits and need to include SMA and SCID in national newborn screening (NBS) programs, as it will allow early supportive and curative therapy.

Italian survey on evolving SMA care with disease-modifying therapies: a consensus workshop on nutrition, swallowing, respiratory and rehabilitation care

The landscape of spinal muscular atrophy care is evolving with the emergence of disease-modifying therapies and newborn screening programs, leading to new phenotypes and changing patient needs. This necessitates a reevaluation of existing care recommendations to address new challenges and opportunities in spinal muscular atrophy management. To better evaluate how different areas of care have evolved since the advent of disease-modifying therapies, we focused on highlighting areas where existing practices remain valid, those in which changes are needed and supported by evidence, and those in which further research or experience is required. The initiative brought together experts from the Italian spinal muscular atrophy community, initially involving a survey of care practices and a two-day event with workshops on specific topics. The results of the survey and focus groups provide the experts' opinions of the changing aspects of care for key domains: nutrition and bone health, swallowing, respiratory function, and rehabilitation and management of spine deformities. Suggestions were provided, identifying immediate actionable changes and areas requiring further investigation. This framework represents an initial step towards updating care recommendations in the era of novel therapies. It offers a critical view of the evolving care landscape, balancing established practices with emerging evidence and identifying key areas for future research.

Identification of candidate genes involved in Zika virus-induced reversible paralysis of mice

Zika virus (ZIKV) causes a variety of peripheral and central nervous system complications leading to neurological symptoms such as limb weakness. We used a mouse model to identify candidate genes potentially involved in causation or recovery from ZIKV-induced acute flaccid paralysis. Using Zikv and Chat chromogenic and fluorescence in situ RNA hybridization, electron microscopy, immunohistochemistry, and ZIKV RT-qPCR, we determined that some paralyzed mice had infected motor neurons, but motor neurons are not reduced in number and the infection was not present in all paralyzed mice; hence infection of motor neurons were not strongly correlated with paralysis. Consequently, paralysis was probably caused by by-stander effects. To address this, we performed bioinformatics analysis on spinal cord RNA to identify 2058 differentially expressed genes (DEGs) that were altered during paralysis and then normalized after paralysis. Of these "biphasic" DEGs, 951 were up-regulated and 1107 were down-regulated during paralysis, followed by recovery. To refine the search for candidate DEGs we used gene ontology analysis and RT-qPCR to select 3 DEGs that could be involved with the node of Ranvier function and 5 DEGs that could be involved with synaptic function. Among these, SparcL1:Sparc DEG ratios were identified to be inversely correlated with ZIKV-induced paralysis, which is consistent with the known function of SPARC protein to antagonize the synaptogenesis of SPARCL1. Ank3, Sptbn1, and Epb41l3 affecting the structures at and near the nodes of Ranvier were significantly downregulated during ZIKV-induced paralysis. The primary contribution is the identification of 8 candidate genes that may be involved in the causation or recovery of ZIKV-induced paralysis.

Spinal presentations in children with type 1 spinal muscular atrophy on nusinersen treatment across the SMA-REACH UK network: a retrospective national observational study

BACKGROUND

Prior to the introduction of disease-modifying treatments (DMTs), children with type 1 spinal muscular atrophy (SMA) typically did not survive beyond the age of 2 years; management was mainly palliative. Novel therapies have made this a treatable condition, resulting in increased life expectancy and more time spent upright. Survival and improved function mean spinal asymmetry is a new complication with limited data on its prevalence and severity and no current guidelines on management and treatment. This study aimed to evaluate the spinal presentation and management of type 1 SMA children on nusinersen across the SMA-REACH UK network.

METHODS

Spinal presentation and management of 80 children (age range 4 months-14 years, median 4 years 2 months) with type 1 SMA on nusinersen across the SMA-REACH UK network were reviewed through retrospective data analysis.

RESULTS

There were 60 type 1 children who developed a spinal asymmetry, of which 40 had kyphosis and 50 used a supportive thoraco-lumbar-sacral orthosis (TLSO). TLSOs were predominantly a one-piece jacket with abdominal hole, advised to be worn when upright during the day. Reduced neck range of movement was found in 33, 1 of these had plagiocephaly and 5 had torticollis. Of those with reduced neck range of movement, 26 (79%) had spinal asymmetry. Spinal surgery was performed in 7.

CONCLUSIONS

Our study confirms high prevalence of spinal asymmetry in this cohort, requiring long-term management planning. It provides information on presentation and treatment options, facilitating development of guidelines for these new complications observed in children surviving longer with DMTs.

Application of antisense oligonucleotide drugs in amyotrophic lateral sclerosis and Huntington's disease

Amyotrophic lateral sclerosis (ALS) and Huntington's disease (HD) are diverse in clinical presentation and are caused by complex and multiple factors, including genetic mutations and environmental factors. Numerous therapeutic approaches have been developed based on the genetic causes and potential mechanisms of ALS and HD. Currently, available treatments for various neurodegenerative diseases can alleviate symptoms but do not provide a definitive cure. Gene therapy, which aims to modify or express specific proteins for neuroprotection or correction, is considered a powerful tool in managing neurodegenerative conditions. To date, antisense oligonucleotide (ASO) drugs targeting the pathological genes associated with ALS and HD have shown promising results in numerous animal studies and several clinical trials. This review provides a comprehensive overview of the development, mechanisms of action, limitations, and clinical applications of ASO drugs in neurodegenerative diseases, with a specific focus on ALS and HD therapeutic strategies.

FORCE platform overcomes barriers of oligonucleotide delivery to muscle and corrects myotonic dystrophy features in preclinical models

BACKGROUND

We developed the FORCETM platform to overcome limitations of oligonucleotide delivery to muscle and enable their applicability to neuromuscular disorders. The platform consists of an antigen-binding fragment, highly specific for the human transferrin receptor 1 (TfR1), conjugated to an oligonucleotide via a cleavable valine-citrulline linker. Myotonic dystrophy type 1 (DM1) is a neuromuscular disorder caused by expanded CUG triplets in the DMPK RNA, which sequester splicing proteins in the nucleus, lead to spliceopathy, and drive disease progression.

METHODS

Multiple surrogate conjugates were generated to characterize the FORCE platform. DYNE-101 is the conjugate designed to target DMPK and correct spliceopathy for the treatment of DM1. HSALR and TfR1hu/mu;DMSXLTg/Tg mice were used as models of myotonic dystrophy, the latter expresses human TfR1 and a human DMPK RNA with >1,000 CUG repeats. Cynomolgus monkeys were used to determine translatability of DYNE-101 pharmacology to higher species.

RESULTS

In HSALR mice, a surrogate FORCE conjugate achieves durable correction of spliceopathy and improves myotonia to a greater extent than unconjugated ASO. In patient-derived myoblasts, DYNE-101 reduces DMPK RNA and nuclear foci, consequently improving spliceopathy. In TfR1hu/mu;DMSXLTg/Tg mice, DYNE-101 reduces mutant DMPK RNA in muscle, thereby correcting splicing. Reduction of DMPK foci in cardiomyocyte nuclei accompanies these effects. Low monthly dosing of DYNE-101 in TfR1hu/mu;DMSXLWT/Tg mice or cynomolgus monkeys leads to a profound reduction of DMPK expression in muscle.

CONCLUSIONS

These data validate FORCE as a drug delivery platform and support the notion that DM1 may be treatable with low and infrequent dosing of DYNE-101.

Quality of life in patients with spinal muscular atrophy in Brazil: patient self-assessment and carer perception

OBJECTIVES

The aim of this study was to assess the perception of quality of life of patients with spinal muscular atrophy (SMA) and investigate whether there is a correlation between patients' perception and that of their carers.

METHODS

Cross-sectional analytical observational study. In the first part, socioeconomic, demographic, clinical, and treatment information were collected from patients diagnosed with SMA, regardless of type, sex, or age. SMA type 1 does not sit; SMA type 2 sits; SMA type 3 walks; and SMA type 4 begins in adulthood. In the second part of the study, patients aged between 2 and 25 years and their caregivers responded to the Pediatric Quality of Life Inventory 4.0 questionnaire.

RESULTS

Of the 235 families recruited, 167 were eligible to respond to the questionnaire, 115 caregivers and 49 patients were included. The results point to a different perception of quality of life between patients and caregivers. Patients with SMA type 2 perceive more impaired physical and emotional capacity compared to SMA type 3 and 1, respectively. As for caregivers, the perception of quality of life in relation to physical and social capacity and the total score are worse for patients with SMA type 1 compared to other types. Perceptions correlate with emotional capacity in SMA type 2 and the total aspect in SMA type 3.

CONCLUSIONS

Patients with SMA type 2 had a worse perception of their quality of life than other patients. Perception differed between patients and their caregivers, with the former having a better perception than the latter.

Effect of nusinersen on pulmonary function in children with spinal muscular atrophy in the plateau region: A pilot study

Background

The drug nusinersen is applied to improve motor function in patients with spinal muscle atrophy (SMA). However, research on the effects of this treatment on lung function is lacking.

Aim

To investigate the effect of nusinersen on lung function in children with SMA in the Plateau.

Methods

A total of 20 patients with SMA (types 1, 2, or 3) who started nusinersen treatment at the Department of Pediatrics at Yunnan First People's Hospital from March 2022 and February 2024 were studied. A retrospective study was conducted to investigate changes in lung function parameters (including forced vital capacity, forced expiratory volume at 1 s, forced expiratory volume at 1 s/forced vital capacity, and peak expiratory flow) in patients with SMA treated with nusinersen.

Results

20 patients (13 male, 7 female; aged 5-16 years) were enrolled, including 2, 9, and 9 with SMA types 1, 2, and 3, respectively. The mean value of FVC % and FEV1/FVC % did not decrease further following nusinersen treatment in any patients. The mean value of FEV1% was 4.4 % and 5.0 % higher than before treatment in all patients (P = 0.03), and those with type 2 SMA (P = 0.04), respectively. The overall mean PEF % did not decrease any further after treatment. However, the average level in the type 2 group increased by 2.9 % (P = 0.03).

Conclusion

Patients with SMA, particularly those classified as type 2, showed a trend of improvement in lung function following nusinersen treatment.

Identifying novel response markers for spinal muscular atrophy revealed by targeted proteomics following gene therapy

Spinal muscular atrophy (SMA) is a progressive disease that affects motor neurons, with symptoms usually starting in infancy or early childhood. Recent breakthroughs in treatments targeting SMA have improved both lifespan and quality of life for infants and children with the disease. Given the impact of these treatments, it is essential to develop methods for managing treatment-induced changes in disease characteristics. Zolgensma® is the first effective and approved gene therapy for SMA caused by biallelic mutation in the SMN1 gene. In three children with SMA treated with Zolgensma®, neuronal, glial, inflammation, and vascular markers in the plasma exhibited a quicker response, emphasizing their potential as valuable biomarkers of treatment efficacy in clinical trials. We chose the novel Nucleic acid Linked Immuno-Sandwich Assay, to investigate a predefined panel of neuroinflammatory markers in plasma samples collected from SMA patients at baseline and six months after Zolgensma® treatment. We identified a set of novel targets whose levels differed between pre and post Zolgensma® treatment group and that were responsive to treatment. Even though our results warrant validation in larger SMA cohorts and longer follow-up time, they may pave the way for a panel of responsive proteins solidifying biomarker endpoints in SMA clinical trials.

Pushing the boundaries: future directions in the management of spinal muscular atrophy

Spinal muscular atrophy (SMA) is a devastating, degenerative, paediatric neuromuscular disease which until recently was untreatable. Discovery of the responsible gene 30 years ago heralded a new age of pioneering therapeutic developments. Three disease-modifying therapies (DMTs) have received regulatory approval and have transformed the disease, reducing disability and prolonging patient survival. These therapies - with distinct mechanisms, routes of administration, dosing schedules, side effect profiles, and financial costs - have dramatically altered the clinical phenotypes of this condition and have presented fresh challenges for patient care. In this review article we discuss potential strategies to maximise clinical outcomes through early diagnosis and treatment, optimised dosing, use of therapeutic combinations and state-of-the-art physiotherapy techniques, and the development of innovative therapies targeting alternative mechanisms.

Calculation of the Minimal Clinically Important Difference in Upper and Lower Limb Motor Assessment in Spinal Muscular Atrophy

Objectives

Physical function assessments in patients with spinal muscular atrophy (SMA) are important indicators for assessing the effectiveness of treatment and changes over time in rehabilitation therapy. However, few reports exist on this indicator. This study calculated the minimal clinically important difference (MCID) for assessing motor function in the upper and lower limbs of individuals with SMA to estimate the degree of change within a functional score that is considered clinically meaningful.

Methods

This cohort study relied on individual participant measurements. A distribution-based approach was used to calculate the MCID values, incorporating data from 26 patients with SMA for the 6-Minute Walk Test (6MWT), Hammersmith Functional Motor Scale Expanded (HFMSE), Revised Upper Limb Module (RULM), and grip and pinch strength.

Results

The standard errors of measurement for all patients were: 58.38 m for 6MWT; 4.71 points for HFMSE; 3.25 points for RULM; 10.93 N and 9.86 N for right and left grip strength, respectively; 5.42 N and 4.73 N for right and left Palmar pinch; and 11.96 N and 8.66 N for right and left Key pinch. Significant correlations were observed between the physical function assessments.

Conclusions

We calculated MCID values for physical function evaluations of SMA and, as a sub-analysis, determined the SMA type and ambulatory status. These findings are expected to contribute to future SMA treatment and rehabilitation and promote the selection of appropriate physical function assessments.

Spinal cord gray matter atrophy is associated with disability in spinal muscular atrophy

BACKGROUND

With the approval of disease-modifying treatments for 5q-spinal muscular atrophy (SMA), there is an increasing need for biomarkers for disease course and therapeutic response monitoring. Radially sampled Averaged Magnetization Inversion Recovery Acquisitions (rAMIRA) MR-imaging enables spinal cord (SC) gray matter (GM) delineation and quantification in vivo. This study aims to assess SC GM atrophy in patients with 5q-SMA and its associations with clinical disability.

METHODS

Twenty-one patients with 5q-SMA and twenty-one age- and sex-matched healthy controls (HCs) prospectively underwent 3 T axial 2D-rAMIRA MR-imaging at the intervertebral disc levels C2/C3-C5/C6 and Tmax (lumbar enlargement level). Associations between SC GM areas with muscle strength tested by dynamometry, Motor Function Measure (MFM), revised upper limb module (RULM), Revised Hammersmith Scale (RHS), and SMA-Functional Rating Scale (SMA-FRS) were assessed by Spearman Rank correlations and linear regression analysis.

RESULTS

Compared to HCs, patients had significantly reduced SC GM areas at levels C3/C4 (relative reduction (RR) = 13.6%, p < 0.0001); C4/C5 (RR = 16.7%, p < 0.0001), C5/C6 (RR = 17.1%, p < 0.0001), and Tmax (RR = 17.4%, p < 0.0001). Significant correlations were found between cervical SC GM areas and muscle strength, RULM, MFM, RHS, and SMA-FRS. In linear regression analysis, GM area C3/C4 explained 33% of RHS variance.

CONCLUSION

SC GM atrophy is detectable in patients with 5q-SMA and is consistently associated with clinical measures of upper limb function, physiotherapeutic assessments, and SMA-FRS indicating the clinical relevance of the observed atrophy. Further longitudinal investigations are necessary next steps to evaluate this novel and easily applicable imaging marker as a potential disease course and therapeutic response marker.

Alternative splicing of modulatory immune receptors in T lymphocytes: a newly identified and targetable mechanism for anticancer immunotherapy

Alternative splicing (AS) is a mechanism that generates translational diversity within a genome. Equally important is the dynamic adaptability of the splicing machinery, which can give preference to one isoform over others encoded by a single gene. These isoform preferences change in response to the cell's state and function. Particularly significant is the impact of physiological alternative splicing in T lymphocytes, where specific isoforms can enhance or reduce the cells' reactivity to stimuli. This process makes splicing isoforms defining features of cell states, exemplified by CD45 splice isoforms, which characterize the transition from naïve to memory states. Two developments have accelerated the use of AS dynamics for therapeutic interventions: advancements in long-read RNA sequencing and progress in nucleic acid chemical modifications. Improved oligonucleotide stability has enabled their use in directing splicing to specific sites or modifying sequences to enhance or silence particular splicing events. This review highlights immune regulatory splicing patterns with potential significance for enhancing anticancer immunotherapy.

Discovery platforms for RNA therapeutics

RNA therapeutics are emerging as a unique opportunity to drug currently "undruggable" molecules and diseases. While their advantages over conventional, small molecule drugs, their therapeutic implications and the tools for their effective in vivo delivery have been extensively reviewed, little attention has been so far paid to the technological platforms exploited for the discovery of RNA therapeutics. Here, we provide an overview of the existing platforms and ex vivo assays for RNA discovery, their advantages and disadvantages, as well as their main fields of application, with specific focus on RNA therapies that have reached either phase 3 or market approval. LINKED ARTICLES: This article is part of a themed issue Non-coding RNA Therapeutics. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v182.2/issuetoc.

Rehabilitation is [still] necessary to optimize function in neuromuscular disorders

The landscape of care for children and adults with neuromuscular disorders (NMDs) is rapidly changing as more disease-modifying treatments (DMTs) become available. These DMTs provide hope and opportunity for evolving phenotypes, though none (yet) are curative. Rehabilitation has been the standard of care for patients with NMDs and should remain so, even with the advent of novel DMTs. An interdisciplinary rehabilitation approach is holistic and comprehensive, addressing functional needs, musculoskeletal complications, pain, durable medical equipment, and bracing needs. This care will continue to be essential for patients who experience impairments and disability, despite receiving DMTs. Additionally, we must consider how to care for a new rapidly expanding cohort of patients aging with NMDs. Children with NMDs are expected to live longer into adulthood; a population that we may not have the workforce to support at this time. At this point, we have the perfect opportunity to reemphasize the importance of rehabilitation in the care of persons with NMDs, while we reexamine historical rehabilitation practices and innovatively deliver services to optimize the effects of these high-cost DMTs.

Advances in Therapy for Refractory Epilepsy

Drug-resistant epilepsy (DRE) is defined as failure to achieve sustained seizure control with adequate trials of two appropriate antiseizure medications (ASMs). DRE affects one-third of patients with epilepsy and is associated with significant morbidity and mortality. Newer ASMs provide pharmacological therapy that is better tolerated but not necessarily more effective than older ASMs. Resective brain surgery is the gold standard to treat DRE and achieve seizure freedom, with laser ablation offering an alternative with less morbidity but lower effectiveness. For patients who are not candidates for resection or ablation, multiple neuromodulation options can reduce seizure burden. These neuromodulation devices have shown comparable effectiveness in randomized clinical trials, but the results vary in open-label follow-up cohorts, as do the risks of complications and associated costs. Dietary therapies can help, particularly in pediatric genetic epilepsies. Innovative genetic therapy approaches are being pursued, offering the promise of precision medicine.

A Real-World Study of Nusinersen Effects in Adults with Spinal Muscular Atrophy Type 2 and 3

BACKGROUND

Spinal muscular atrophy (SMA) is a progressive genetic disorder characterized by muscle weakness ultimately leading to pulmonary impairments that can be fatal. The recent approval of nusinersen, a disease-modifying therapy, substantially changed the prognosis for patients, particularly in children. However, real-world evidence about its long-term effectiveness in adults remains limited. This study aimed to document longitudinal data on motor function, pulmonary function and patient-reported outcome measures of Canadian adults with SMA type 2 and 3 treated with nusinersen.

METHODS

Outcomes from 17 patients were collected at the Institut de réadaptation en déficience physique de Québec during routine clinical visits over 36 months post nusinersen treatment, using the Hammersmith Functional Motor Scale Expanded for SMA (HFMSE), Revised Upper Limb Module (RULM), 6-Minute Walk Test (6MWT), Children's Hospital of Philadelphia Adult Test of Neuromuscular Disorders (CHOP-ATEND), SMA functional rating scale (SMAFRS), pulmonary function testing and subjective changes reported by patients.

RESULTS

After 36 months, 9 patients showed motor function improvement. Changes beyond the minimal clinically important difference were seen for four patients on the HFMSE, four patients on the RULM and five patients on the 6MWT. Pulmonary function remained stable for most subjects. Subjective positive changes were reported in 88% of patients and five patients showed improvement in the SMAFRS.

CONCLUSION

This real-world study demonstrates the positive effects of nusinersen in adults with SMA types 2 and 3. Although stabilizing the patient's condition is considered therapeutic success, this study shows an improvement in motor function and subjective gains in several patients.

Antisense Oligonucleotides in Dyslipidemia Management: A Review of Clinical Trials

INTRODUCTION

Elevated serum total cholesterol levels, very low-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, or a decreased serum high-density lipoprotein cholesterol concentration characterize dyslipidemia. Antisense Oligonucleotide therapy in dyslipidemia targets apolipoprotein B (ApoB), an essential component of low-density lipoprotein (LDL) associated with atherosclerosis development.

AIM

This review aims to critically evaluate the efficacy and safety of this group of medications in mitigating dyslipidemia in at-risk individuals and its potential role in advancing personalized medicine in the management of dyslipidemias.

METHODS

A detailed search was conducted from multiple databases adhering to the PRISMA guidelines. Clinical trials and randomized controlled trials on antisense oligonucleotides for management of dyslipidemias were included, excluding non-English studies, case reports and all forms of reviews. Data was screened, with duplicates removed, and key findings were synthesized using a narrative approach.

RESULTS AND CONCLUSION

The potential of antisense oligonucleotides (ASOs) to treat dyslipidemia and other disorders has attracted much interest. Several studies and clinical trials have been conducted on the safety and tolerability of ASOs for dyslipidemia. Although statins are the mainstay management of hypercholesterolemia, there is evidence from clinical trials that ASOs can even be more effective with little to no side effects. Novel therapeutic approaches such as antisense oligonucleotides (ASOs) offer tailored therapeutic alternatives. ASOs such as Mipomersen and Volanesorsen provide additional treatment options for patients with inherited lipid abnormalities by lowering certain atherogenic lipoproteins such as apo B and ApoC-III, respectively.

Development of the SMA EFFORT: A new approach to characterize perceived physical fatigability in spinal muscular atrophy

BACKGROUND

Fatigue and fatigability are commonly reported in spinal muscular atrophy (SMA). Physical fatigability, proposed to be the most relevant to SMA pathophysiology, encompasses performance-based and perceived physical fatigability (PPF) assessments. While performance-based measures have highlighted physical fatigability as an SMA hallmark, PPF is not well characterized due to the lack of disease- and construct-specific scales.

OBJECTIVE

Our aim was to create a patient-reported outcome measure tailored for SMA, named the SMA EFFORT, to improve PPF assessment. Here, we describe the scale development process, assess scale properties, and discuss future research and application.

METHODS

SMA and scale development experts organized a comprehensive physical activity item bank, relevant across the SMA phenotypic spectrum. Activities were systematically categorized by varying intensities and durations. The SMA EFFORT was completed by an international cohort of individuals with all types of SMA. To compare PPF across demographic and clinical variables, SMA EFFORT PPF percent (PPF%) composite scoring was established.

RESULTS

One hundred eighteen participants completed the SMA EFFORT. Total PPF% scores were broadly distributed within functional groups, with differences between non-sitters (35.1 ± 21.0) and sitters (24.9 ± 15.1) (p = 0.006), and those with (34.4 ± 18.1) and without respiratory support (26.4 ± 17.8) (p = 0.02). Participants treated with disease modifying therapy (DMT) showed similar scores to those without treatment (p = 0.70). Further, no differences in scores were observed in participants with scoliosis surgery and those without (p = 0.71). Subscale analyses revealed differences in mean PPF% subscale scores by functional group.

CONCLUSIONS

The novel SMA EFFORT standardizes PPF ratings by anchoring activity to intensity and duration. Item and scale data insights will inform the next iteration, which will undergo additional investigation. The SMA EFFORT aims to improve upon current measures to better assess treatment impact on physical well-being across the SMA spectrum.

Paving the way toward treatment solutions for CTNNB1 syndrome: a patient organization perspective

The CTNNB1 Connect & Cure and CTNNB1 Foundation, alongside Asociación CTNNB1, CTNNB1 Italia, Association CTNNB1 France, and researchers and clinicians globally are dedicated to finding effective treatments and cures for CTNNB1 syndrome. The syndrome is also characterized by progressive spasticity, which can in some cases cause loss of already achieved motor milestones. Since 2019, they have brought together researchers from different fields and invested in various research efforts to advance the search for treatment solutions for patients with CTNNB1 syndrome. Simons Searchlight serves as an important platform by remotely collecting high-quality, standardized data on the natural history of the disease and making it available to researchers around the world. Conducting genotype-phenotype correlation study and biochemically characterizing the mutations were critical to understand the effects of the patients' mutations and related molecular function to symptoms. Several induced pluripotent stem cells were generated from patient cells, and preclinical mouse models have provided new insights into the molecular downstream effects of CTNNB1 haploinsufficiency. Multiple therapeutic approaches are in the developing, including small molecule treatments, RNA- and DNA-based therapies, AAV9 gene replacement therapy, which entered the manufacturing phase in November 2023. In this article, we summarize the journey of the CTNNB1 community and its organizations, highlight ongoing and future research projects, and outline the available research resources. The vision for the CTNNB1 community is that in the future several therapeutic options will be available that can be customized to every CTNNB1 patient's needs.

Safety and Efficacy of Nusinersen Focusing on Renal and Hematological Parameters in Spinal Muscular Atrophy

BACKGROUND

Spinal muscular atrophy (SMA) is a motor neuron disease caused by mutations in the SMN1 gene. Nusinersen, an antisense oligonucleotide, has been shown to improve motor function in SMA patients. However, concerns regarding its renal safety remain as previous studies have linked similar treatments to renal toxicity.

OBJECTIVE

The aim of this study was to evaluate the effects of the nusinersen treatment on platelet counts and renal functions, specifically urine protein excretion, in SMA patients and to estimate safe urinary protein levels before administration of each intrathecal injection.

METHODS

This retrospective study examined data from 33 patients with SMA to assess the effects of nusinersen on motor functions and laboratory parameters including platelet count, serum creatinine, urine protein, and urine creatinine. Measurements were taken at baseline andprior to each maintenance dose, after the completion of four initial loading doses. The baseline values were compared between SMA Type 1 and Type 2 patients, while the changes in these values over time were analyzed within each group.

RESULTS

No significant adverse effects on platelet counts or renal functions were observed. Urine creatinine and protein levels were significantly higher in SMA Type 2 patients compared to SMA Type 1 at baseline; these parameters remained stable in SMA Type 2 but increased significantly after the loading doses in SMA Type 1. Motor function improvements were observed in both groups, with the most significant gains in SMA Type 1 after the loading doses. Thus, improvement in motor functions was associated with increase in urine creatinine.

CONCLUSION

Nusinersen treatment did not cause significant renal toxicity or affect platelet counts. Urine creatinine levels may serve as a potential biomarker for assessing treatment response in SMA Type 1.

Clinicogenetic characterization and response to disease-modifying therapies in spinal muscular atrophy: real-world experience from a reference center in Southern Brazil

OBJECTIVE

Spinal Muscular Atrophy linked to chromosome 5q (SMA) is an autosomal recessive neurodegenerative disease characterized by progressive proximal muscle atrophy and weakness. This study addresses the scarcity of research on novel disease-modifying therapies for SMA in Latin America by reporting a real-world experience in Southern Brazil.

METHODOLOGY

This is a single-center historical cohort that included all patients diagnosed with spinal muscular atrophy at a Regional Reference Service for rare diseases.

RESULTS

Eighty-one patients were included, of whom 7 died during follow-up. Of the remaining 74 patients, 5.4 % were classified as pre-symptomatic, 24.3 % with SMA type 1, 28.4 % with type 2, 36.5 % with type 3, and 5.4 % with type 4. The mean follow-up time ranged from 1.8 years for pre-symptomatic cases to 8.7 years for SMA types 2 and 3. Approximately 42 % of these patients received specific disease-modifying therapy, of these, 96.8 % received Nusinersen, with 19.4 % transitioning to gene therapy using Onasemnogene Abeparvovec, and 6.4 % starting Risdiplam. Most patients with SMA type 1 were on disease-modifying treatment, whereas only slightly over a third of patients with type 2 and about 10 % of type 3 were receiving such treatments. Among treated patients, 80 % demonstrated improvement in motor performance during the follow-up, with a lesser therapeutic response being associated with late initiation of treatment and low motor function scores at baseline.

CONCLUSION

This real-world study reinforces the effectiveness of disease-modifying therapies for SMA in Brazil within the context of low- and middle-income countries, which is greater the earlier and the better the patient's functional status.