Safety and efficacy of once-daily risdiplam in type 2 and non-ambulant type 3 spinal muscular atrophy (SUNFISH part 2): a phase 3, double-blind, randomised, placebo-controlled trial

BACKGROUND

Risdiplam is an oral small molecule approved for the treatment of patients with spinal muscular atrophy, with approval for use in patients with type 2 and type 3 spinal muscular atrophy granted on the basis of unpublished data. The drug modifies pre-mRNA splicing of the SMN2 gene to increase production of functional SMN. We aimed to investigate the safety and efficacy of risdiplam in patients with type 2 or non-ambulant type 3 spinal muscular atrophy.

METHODS

In this phase 3, randomised, double-blind, placebo-controlled study, patients aged 2-25 years with confirmed 5q autosomal recessive type 2 or type 3 spinal muscular atrophy were recruited from 42 hospitals in 14 countries across Europe, North America, South America, and Asia. Participants were eligible if they were non-ambulant, could sit independently, and had a score of at least 2 in entry item A of the Revised Upper Limb Module. Patients were stratified by age and randomly assigned (2:1) to receive either daily oral risdiplam, at a dose of 5·00 mg (for individuals weighing ≥20 kg) or 0·25 mg/kg (for individuals weighing <20 kg), or daily oral placebo (matched to risdiplam in colour and taste). Randomisation was conducted by permutated block randomisation with a computerised system run by an external party. Patients, investigators, and all individuals in direct contact with patients were masked to treatment assignment. The primary endpoint was the change from baseline in the 32-item Motor Function Measure total score at month 12. All individuals who were randomly assigned to risdiplam or placebo, and who did not meet the prespecified missing item criteria for exclusion, were included in the primary efficacy analysis. Individuals who received at least one dose of risdiplam or placebo were included in the safety analysis. SUNFISH is registered with ClinicalTrials.gov, NCT02908685. Recruitment is closed; the study is ongoing.

FINDINGS

Between Oct 9, 2017, and Sept 4, 2018, 180 patients were randomly assigned to receive risdiplam (n=120) or placebo (n=60). For analysis of the primary endpoint, 115 patients from the risdiplam group and 59 patients from the placebo group were included. At month 12, the least squares mean change from baseline in 32-item Motor Function Measure was 1·36 (95% CI 0·61 to 2·11) in the risdiplam group and -0·19 (-1·22 to 0·84) in the placebo group, with a treatment difference of 1·55 (0·30 to 2·81, p=0·016) in favour of risdiplam. 120 patients who received risdiplam and 60 who received placebo were included in safety analyses. Adverse events that were reported in at least 5% more patients who received risdiplam than those who received placebo were pyrexia (25 [21%] of 120 patients who received risdiplam vs ten [17%] of 60 patients who received placebo), diarrhoea (20 [17%] vs five [8%]), rash (20 [17%] vs one [2%]), mouth and aphthous ulcers (eight [7%] vs 0), urinary tract infection (eight [7%] vs 0), and arthralgias (six [5%] vs 0). The incidence of serious adverse events was similar between treatment groups (24 [20%] of 120 patients in the risdiplam group; 11 [18%] of 60 patients in the placebo group), with the exception of pneumonia (nine [8%] in the risdiplam group; one [2%] in the placebo group).

INTERPRETATION

Risdiplam resulted in a significant improvement in motor function compared with placebo in patients aged 2-25 years with type 2 or non-ambulant type 3 spinal muscular atrophy. Our exploratory subgroup analyses showed that motor function was generally improved in younger individuals and stabilised in older individuals, which requires confirmation in further studies. SUNFISH part 2 is ongoing and will provide additional evidence regarding the long-term safety and efficacy of risdiplam.

FUNDING

F Hoffmann-La Roche.

Generation of DMBi002-A human induced pluripotent stem cell line from patient with Spinal muscular atrophy type 3

Spinal Muscular Atrophy (SMA) is a genetic neuromuscular disease caused by mutations inSMN1 gene encoding survival motor neuron (SMN) protein. Lack of this protein leads to progressive loss of motor neurons and therefore to gradual loss of signal transmission between motor neurons and skeletal muscle cells. As a consequence, patients develop muscle atrophy and lose the ability to move independently, what is also related to problems with breathing and swallowing. Here, we describe the generation of human induced pluripotent stem cells (hiPSC) from peripheral blood mononuclear cells (PBMC) of adult SMA type 3 patient with a use of Sendai virus vectors.

Safety and efficacy of avalglucosidase alfa versus alglucosidase alfa in patients with late-onset Pompe disease (COMET): a phase 3, randomised, multicentre trial

BACKGROUND

Pompe disease is a rare, progressive neuromuscular disorder caused by deficiency of acid α-glucosidase (GAA) and accumulation of lysosomal glycogen. We assessed the safety and efficacy of avalglucosidase alfa, a recombinant human GAA enzyme replacement therapy specifically designed for enhanced mannose-6-phosphate-receptor targeting and enzyme uptake aimed at increased glycogen clearance, compared with the current approved standard of care, alglucosidase alfa, in patients with late-onset Pompe disease.

METHODS

We did a randomised, double-blind, phase 3 trial at 55 sites in 20 countries. We enrolled individuals (aged ≥3 years) with enzymatically confirmed late-onset Pompe disease who had never received treatment. We used a centralised treatment allocation system to randomly allocate participants to either avalglucosidase alfa or alglucosidase alfa. Participants and investigators were unaware of their treatment allocation. The primary outcome measure was change from baseline to week 49 in upright forced vital capacity percent (FVC%) predicted. We used a hierarchical fixed sequential testing strategy, whereby non-inferiority of avalglucosidase alfa compared with alglucosidase alfa was assessed first, with a non-inferiority margin of 1·1. If non-inferiority was seen, then superiority was tested with a 5% significance level. The key secondary objective was effect on functional endurance, measured by the 6-minute walk test (6MWT). Safety was assessed, including treatment-emergent adverse events and infusion-associated reactions. The modified intent-to-treat population was the primary analysis population for all efficacy analyses. The safety population was the analysis population for safety analyses. This trial is registered with ClinicalTrials.gov, NCT02782741. We report results of the 49-week primary analysis period.

FINDINGS

Between Nov 2, 2016, and March 29, 2019, 100 participants were randomly allocated avalglucosidase alfa (n=51) or alglucosidase alfa (n=49). Treatment with avalglucosidase alfa resulted in a least-squares mean improvement in upright FVC% predicted of 2·89% (SE 0·88) compared with 0·46% (0·93) with alglucosidase alfa at week 49 (difference 2·43% [95% CI -0·13 to 4·99]). Non-inferiority was shown because the lower bound of the 95% CI for the difference far exceeded the predefined non-inferiority margin but did not exclude 0 (p=0·0074). Superiority was not reached (p=0·063), so formal testing was stopped, as per the testing hierarchy. Improvements were also seen in the 6MWT with avalglucosidase alfa compared with alglucosidase alfa, with greater increases in distance covered (difference 30·01 m [95% CI 1·33 to 58·69]) and percent predicted (4·71% [0·25 to 9·17]). Treatment-emergent adverse events potentially related to treatment were reported in 23 (45%) of 51 participants in the avalglucosidase alfa group and in 24 (49%) of 49 in the alglucosidase alfa group, and infusion-associated reactions were reported in 13 (26%) participants in the avalglucosidase alfa group and 16 (33%) in the alglucosidase alfa group. Of the five trial withdrawals, all in the alglucosidase alfa group, four were due to adverse events, including two infusion-associated reactions. Serious treatment-emergent adverse events were reported in eight (16%) participants who received avalglucosidase alfa and in 12 (25%) who received alglucosidase alfa. One participant treated with alglucosidase alfa died because of acute myocardial infarction determined to be unrelated to treatment. Antidrug antibody responses were similar in both groups. High and persistent titres (≥12 800) and neutralising antibodies were more common with alglucosidase alfa (in 16 [33%] participants) than with avalglucosidase alfa (ten [20%]).

INTERPRETATION

We consider that this study provides evidence of clinically meaningful improvement with avalglucosidase alfa therapy over alglucosidase alfa in respiratory function, ambulation, and functional endurance, with no new safety signals reported. An open-label extended-treatment period is ongoing to confirm the long-term safety and efficacy of avalglucosidase alfa, with the aim for this therapy to become the new standard treatment in late-onset Pompe disease.

FUNDING

Sanofi Genzyme.

Targeted Next-Generation Sequencing Reveals Mutations in Non-coding Regions and Potential Regulatory Sequences of Calpain-3 Gene in Polish Limb-Girdle Muscular Dystrophy Patients

Limb–girdle muscular dystrophy type R1 (LGMDR1) is caused by mutations in CAPN3 and is the most common type of recessive LGMD. Even with the use of whole-exome sequencing (WES), only one mutant allele of CAPN3 is found in a significant number of LGMDR patients. This points to a role of non-coding, intronic or regulatory, sequence variants in the disease pathogenesis. Targeted sequencing of the whole CAPN3 gene including not only intronic, 3′ and 5′ UTRs but also potential regulatory regions was performed in 27 patients suspected with LGMDR1. This group included 13 patients with only one mutated CAPN3 allele detected previously with exome sequencing. A second rare variant in the non-coding part of CAPN3 was found in 11 of 13 patients with previously identified single mutation. Intronic mutations were found in 10 cases, with c.1746-20C>G variant present in seven patients. In addition, a large deletion of exons 2–8 was found in one patient. In the patients with no causative mutation previously found, we detected rare CAPN3 variants in 5 out of 10 patients and in two of them in a compound heterozygous state. Rare variants within putative regulatory sequences distant from the CAPN3 gene were found in 15 patients, although in 11 of these cases, other variants are deemed causative. The results indicate that intronic mutations are common in Polish LGMDR patients, and testing for non-coding mutations in CAPN3 should be performed in apparently single heterozygous patients.

Spinal muscular atrophy: epidemiology and health burden in children - a Polish national healthcare database perspective before introduction of SMA-specific treatment

INTRODUCTION

Spinal muscular atrophy (SMA) is one of the most frequent autosomal recessive neuromuscular disorders. It leads to progressive muscle weakness, premature death or permanent ventilation. Significant disability, scoliosis, severe pulmonary infections and other problems require in- and outpatient medical care. Various approaches have been used to evaluate SMA epidemiology, healthcare burden and adherence to standard of care. The recent introduction of pharmacological treatment in a large SMA population will change the course of the disease and the healthcare requirements of patients.

MATERIAL AND METHODS

We have used the National Health Fund database to identify children with SMA and the healthcare service they received in the pre-pharmacological treatment era. Pivotal phase II and III medical trials for nusinersen were conducted between 2013 and 2015. The National Treatment Programme of SMA patients with nusinersen in our country was started in January 2019. The year 2014 was used to evaluate incident cases.

RESULTS

51 new SMA cases (incidence 1:7,356) and 518 SMA patients younger than 18 were identified in 2014. 32 (6.2%) deaths were recorded, half in the first two years of life. 35 (6.8%) patients received palliative and 115 (22.2%) long-term care (including assisted ventilation). A total number of 3,057 days of hospital stay were reported. Only 65/518 (12.6%) patients did not receive publicly-funded healthcare service other than specialist or general practitioner's consultation.

CONCLUSIONS

SMA caused significant mortality and morbidity in children. The National Health Fund database can be used to reliably record incident cases and track the care provided to paediatric SMA patients.

Pediatric CIDP: Diagnosis and Management. A Single-Center Experience

Background: Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare acquired polyneuropathy that especially among youngest children should be differentiated with hereditary neuropathies. Even though upon diagnosis treatment options are similar in children and adults, diagnostic challenges are faced in the pediatric population. Methods: We conducted a retrospective analysis of clinical symptoms, nerve conduction study results, modes of treatment, and final outcome in 37 children aged 3.5-17 years with a final diagnosis of CIDP (18 girls, 19 boys). We established three groups of patients based on age at onset of CIDP: 0-4, 4-13, and 13-18 years. Follow-up ranged from 10 to 222 months. Results: In our analysis, 19/37 patients (51.4%) had an atypical presentation: distal variant of CIDP in 12/37 patients (32.4%) and pure motor variant of CIDP in 5/37 patients (13.5%), and one patient had a pure sensory variant (1/37, 2.7%). Furthermore, 3/37 patients (8.1%) had additional concurring symptoms, including involuntary movements of face muscles (1/37, 2.7%) or hand tremor (2/37, 5.4%). During the follow-up, 23/37 patients (62.2%) received intravenous immunoglobulin (IVIg); 22/37 patients (59.5%) received steroids, 6/37 patients (16.2%) received IVIg and steroids, and 12/37 patients (32.4%) received immunosuppressive drugs, mostly azathioprine, but also methotrexate and rituximab. One patient was treated with plasmapheresis. Complete remission was achieved in 19/37 patients (51.4%) with CIDP in its typical form. Remission with residual symptoms or minimal deficit was observed in 4/37 patients (10.8%), whereas 14/37 patients (37.8%) remain on treatment with gradual improvement. Conclusion: Childhood CIDP may occur in its typical form, but even ~50% of children can present as an atypical variant including distal, pure motor, or pure sensory. Most children have a good prognosis; however, many of them may require long-term treatment. This highlights the importance of an early diagnosis and treatment for childhood CIDP.

Acute Autonomic Neuropathy as a Rare Cause of Severe Arterial Hypertension in a Child

A 7-year-old boy was admitted to the Pediatric Cardiology Department with blood pressure of 160/120 mmHg accompanied by burning pain in his hands and feet and tachycardia, followed by a seizure attack for the first time in his life, which presented shortly after admission. The child underwent a widespread diagnostic process - including laboratory tests and imaging - showing inconclusive results. Acute autonomic neuropathy was eventually diagnosed and successfully treated with intravenous immunoglobulin. The described case illustrates the need for a careful and open-minded approach to patients with hypertension.

A form of muscular dystrophy associated with pathogenic variants in JAG2

JAG2 encodes the Notch ligand Jagged2. The conserved Notch signaling pathway contributes to the development and homeostasis of multiple tissues, including skeletal muscle. We studied an international cohort of 23 individuals with genetically unsolved muscular dystrophy from 13 unrelated families. Whole-exome sequencing identified rare homozygous or compound heterozygous JAG2 variants in all 13 families. The identified bi-allelic variants include 10 missense variants that disrupt highly conserved amino acids, a nonsense variant, two frameshift variants, an in-frame deletion, and a microdeletion encompassing JAG2. Onset of muscle weakness occurred from infancy to young adulthood. Serum creatine kinase (CK) levels were normal or mildly elevated. Muscle histology was primarily dystrophic. MRI of the lower extremities revealed a distinct, slightly asymmetric pattern of muscle involvement with cores of preserved and affected muscles in quadriceps and tibialis anterior, in some cases resembling patterns seen in POGLUT1-associated muscular dystrophy. Transcriptome analysis of muscle tissue from two participants suggested misregulation of genes involved in myogenesis, including PAX7. In complementary studies, Jag2 downregulation in murine myoblasts led to downregulation of multiple components of the Notch pathway, including Megf10. Investigations in Drosophila suggested an interaction between Serrate and Drpr, the fly orthologs of JAG1/JAG2 and MEGF10, respectively. In silico analysis predicted that many Jagged2 missense variants are associated with structural changes and protein misfolding. In summary, we describe a muscular dystrophy associated with pathogenic variants in JAG2 and evidence suggests a disease mechanism related to Notch pathway dysfunction.

Floppy infant syndrome as a first manifestation of LMNA-related congenital muscular dystrophy

LMNA-related congenital muscular dystrophy (L-CMD) is the most severe phenotypic form of skeletal muscle laminopathies. This paper reports clinical presentation of the disease in 15 Polish patients from 13 families with genetically confirmed skeletal muscle laminopathy. In all these patients floppy infant syndrome was the first manifestation of the disease. The genetic diagnosis was established by next generation sequencing (targeted panel or exome; 11 patients) or classic Sanger sequencing (4 patients). In addition to known pathogenic LMNA variants: c.116A > G (p.Asn39Ser), c.745C > T (p.Arg249Trp), c.746G > A (p.Arg249Gln), c.1072G > A (p.Glu358Lys), c.1147G > A (p.Glu383Lys), c.1163G > C (p.Arg388Pro), c.1357C > T (p.Arg453Trp), c.1583C > G (p.Thr528Arg), we have identified three novel ones: c.121C > G (p.Arg41Gly), c.1127A > G (p.Tyr376Cys) and c.1160T > C (p.Leu387Pro). Eleven patients had de novo mutations, 4 - familial. In one family we observed intrafamilial variability of clinical course: severe L-CMD in the male proband, intermediate form in his sister and asymptomatic in their mother. One asymptomatic father had somatic mosaicism. L-CMD should be suspected in children with hypotonia in infancy and delayed motor development, who have poor head control, severe hyperlordosis and unstable and awkward gait. Serum creatine kinase may be high (~1000IU/l). Progression of muscle weakness is fast, leading to early immobilization. In some patients with L-CMD joint contractures can develop with time. MRI shows that the most frequently affected muscles are the serratus anterior, lumbar paraspinal, gluteus, vastus, adductor magnus, hamstrings, medial head of gastrocnemius and soleus. Ultra-rare laminopathies can be a relatively common cause of generalized hypotonia in children. Introduction of wide genome sequencing methods was a breakthrough in diagnostics of diseases with great clinical and genetic variability and allowed approach "from genotype do phenotype". However target sequencing of LMNA gene could be considered in selected patients with clinical picture suggestive for laminopathy.

Observation of the natural course of type 3 spinal muscular atrophy: data from the polish registry of spinal muscular atrophy

BACKGROUND

Spinal muscular atrophy (SMA) is one of the most frequent and severe genetic diseases leading to premature death or severe motor disability. New therapies have been developed in recent years that change the natural history of the disease. The aim of this study is to describe patients included in the Polish Registry of SMA, with a focus on the course of type 3 SMA (SMA3) before the availability of disease-modifying treatments.

RESULTS

790 patients with SMA were included in the registry (173 with type 1 [SMA1], 218 with type 2 [SMA2], 393 with SMA3, and six with type 4 SMA [SMA4]), most (52%) of whom were adults. Data on SMN2 gene copy number were available for 672 (85%) patients. The mean age of onset was 5 months for SMA1, 11.5 months for SMA2, and 4.5 years for SMA3. In patients with SMA3, the first symptoms occurred earlier in those with three copies of SMN2 than in those with four copies of SMN2 (3.2 years vs. 6.7 years). The age of onset of SMA3 was younger in girls than in boys (3.1 years vs. 5.7 years), with no new cases observed in women older than 16 years. Male patients outnumbered female patients, especially among patients with SMA3b (49 female vs. 85 male patients) and among patients with SMA3 with four copies of SMN2 (30 female vs. 69 male patients). 44% of patients with SMA3 were still able to walk; in those who were not still able to walk, the mean age of immobilization was 14.0 years. Patients with SMA3a (age of onset < 3 years) and three copies of SMN2 had significantly worse prognosis for remaining ambulant than patients with SMA3b (age of onset ≥ 3 years) and four copies of SMN2.

CONCLUSIONS

The Registry of SMA is an effective tool for assessing the disease course in the real world setting. SMN2 copy number is an important prognostic factor for the age of onset and ambulation in SMA3. Sex and age of disease onset also strongly affect the course of SMA. Data supplied by this study can aid treatment decisions.

Myasthenia Gravis in Poland: National Healthcare Database Epidemiological Study

INTRODUCTION

Myasthenia gravis (MG) is a rare autoimmune disorder of the neuromuscular junction. MG epidemiology has not been studied in Poland in a nationwide study before.

METHODS

Our epidemiological data were drawn from the National Health Fund (Narodowy Fundusz Zdrowia, NFZ) database; an MG patient was defined as a person who received at least once medical service coded in ICD-10 as MG (G70) and at least 2 reimbursed prescriptions for pyridostigmine bromide (Mestinon®) or ambenonium chloride (Mytelase®) in 2 consecutive years.

RESULTS

On 1st of January 2019, 8,702 patients with MG were receiving symptomatic treatment (female:male ratio: 1.65:1). MG incidence was 2.36/100,000. The mean age of incident cases in 2018 was 61.37 years, 59.17 years for women and 64.12 years for men. Incidence of early-onset MG (<50 years) was 0.80/100,000 and 4.98/100,000 for late-onset MG (LOMG), with male predominance in LOMG. Prevalence was 22.65/100,000. In women, there was a constant increase in prevalence of symptomatic MG from the first decade of life up to 80-89 years. In men, an increase in prevalence appeared in the 6th decade. The highest prevalence was observed in the age group of 80-89 years: 59.65/100,000 in women and 96.25/100,000 in men.

CONCLUSIONS

Our findings provide information on epidemiology of MG in Poland and can serve as a tool to evaluate healthcare resources needed for MG patients.

Ultra-low radiation dose protocol for CT-guided intrathecal nusinersen injections for patients with spinal muscular atrophy and severe scoliosis

Purpose

Intrathecal injection of nusinersen is an approved treatment of spinal muscular atrophy (SMA). CT-guided injection is a method of nusinersen administration in patients with severe scoliosis, in whom standard lumbar puncture is not feasible. The injections are repeated every 4 months for life, and accumulated radiation doses absorbed by the patient can increase the risk of cancer. In this study, we present the results of CT-guided intrathecal nusinersen injections with an ultra-low radiation dose protocol.

Methods

Eighteen patients (15 adults and three children) in whom standard lumbar puncture was not feasible due to severe scoliosis or spinal stabilization were included in this retrospective study. The first 23 injections were performed with a standard radiation dose protocol and the next 42 injections with an ultra-low-dose protocol. The radiation doses, measured as total dose length product (DLP), were acquired and compared between the protocols.

Results

Injections were successful in 100% of patients with both ultra-low-dose and standard protocols. The radiation dose, measured as DLP, was 111.2–1100.7 (Me = 248.1) mGy*cm for the standard protocol. For the ultra-low-dose protocol, the dose range was 5.0–54.4 (Me = 26.7) mGy*cm, which was significantly lower than with the standard protocol (p < 0.001, η² = 0.67).

Conclusion

Radiation doses can be significantly decreased in the CT-guided injection of nusinersen. The proposed protocol allows for effective CT-guided intrathecal nusinersen administration in patients with SMA and severe scoliosis.

Progressive External Ophthalmoplegia in Polish Patients-From Clinical Evaluation to Genetic Confirmation

Mitochondrial encephalomyopathies comprise a group of heterogeneous disorders resulting from impaired oxidative phosphorylation (OxPhos). Among a variety of symptoms progressive external ophthalmoplegia (PEO) seems to be the most common. The aim of this study is to present clinical and genetic characteristics of Polish patients with PEO. Clinical, electrophysiological, neuroradiological, and morphological data of 84 patients were analyzed. Genetic studies of mitochondrial DNA (mtDNA) were performed in all patients. Among nuclear DNA (nDNA) genes POLG was sequenced in 41 patients, TWNK (C10orf2) in 13 patients, and RNASEH1 in 2 patients. Total of 27 patients were included in the chronic progressive external ophthalmoplegia (CPEO) group, 24 in the CPEO+ group. Twenty-six patients had mitochondrial encephalomyopathy (ME), six patients Kearns-Sayre syndrome (KSS), and one patient sensory ataxic neuropathy, dysarthria, ophthalmoparesis (SANDO) syndrome. Genetic analysis of nDNA genes revealed the presence of pathogenic or possibly pathogenic variants in the POLG gene in nine patients, the TWNK gene in five patients and the RNASEH1 gene in two patients. Detailed patients' history and careful assessment of family history are essential in the diagnostic work-up. Genetic studies of both mtDNA and nDNA are necessary for the final diagnosis of progressive external ophthalmoplegia and for genetic counseling.

Transthyretin-related familial amyloid polyneuropathy (ATTR-FAP) in Poland - genetic and clinical presentation

BACKGROUND

Transthyretin-related familial amyloid polyneuropathy (ATTR-FAP) is a rare, progressive, hereditary, highly disabling multisystem disorder. ATTR-FAP phenotypes differ according to the type of TTR mutation, geographic region and other as yet unidentified factors. The aim of this study was to establish the clinical and genetic characteristics of Polish patients.

METHODS AND PATIENTS

Clinical data and necessary examinations were collected from patients diagnosed with ATTR-FAP at the Department of Neurology of Medical University of Warsaw between 1970 and 2019.

RESULTS

16 patients from eight unrelated families with five different TTR mutations were identified. The family with Val71Ala TTR mutation presented with early onset severe progressive polyneuropathy, with marked visual symptoms in a few patients. The next family with Ile73Val TTR mutation developed symptoms in middle age, and presented with mixed neuropathic and cardiologic phenotype. Four unrelated families were found to have the Phe33Leu TTR mutation with mixed neuropathic and cardiologic phenotype and late onset of symptoms. Other TTR mutations identified were: Val30Met and Asp38Val, both with late onset sensory, motor and autonomic neuropathy.

CONCLUSION

Polish ATTR-FAP cases presented with heterogeneity typical for non-endemic areas. Phe33Leu TTR mutation was the most common, found in four unrelated families.

Ethnicity-related DMD Genotype Landscapes in European and Non-European Countries

Objective

Genetic diagnosis and mutation identification are now compulsory for Duchenne (DMD) and Becker muscular dystrophies (BMD), which are due to dystrophin (DMD) gene mutations, either for disease prevention or personalized therapies. To evaluate the ethnic-related genetic assortments of DMD mutations, which may impact on DMD genetic diagnosis pipelines, we studied 328 patients with DMD and BMD from non-European countries.

Methods

We performed a full DMD mutation detection in 328 patients from 10 Eastern European countries (Poland, Hungary, Lithuania, Romania, Serbia, Croatia, Bosnia, Bulgaria, Ukraine, and Russia) and 2 non-European countries (Cyprus and Algeria). We used both conventional methods (multiplex ligation-dependent probe amplification [MLPA] followed by gene-specific sequencing) and whole-exome sequencing (WES) as a pivotal study ran in 28 patients where DMD mutations were already identified by standard techniques. WES output was also interrogated for DMD gene modifiers.

Results

We identified DMD gene mutations in 222 male patients. We identified a remarkable allele heterogeneity among different populations with a mutation landscape often country specific. We also showed that WES is effective for picking up all DMD deletions and small mutations and its adoption could allow a detection rate close to 90% of all occurring mutations. Gene modifiers haplotypes were identified with some ethnic-specific configurations.

Conclusions

Our data provide unreported mutation landscapes in different countries, suggesting that ethnicity may orient genetic diagnosis flowchart, which can be adjusted depending on the mutation type frequency, with impact in drug eligibility.

Determinants of Quality of Life in Myasthenia Gravis Patients

Background: Although approximately half of myasthenia gravis (MG) patents achieve remission, for the remaining group MG is often a life-long disease. Better understanding of the determinants of Quality of Life (QoL) in MG is needed to optimize treatment goals in chronic cases.

Materials and Methods: We performed a single center cross-sectional study in 339 MG adult patients (64.9% women), with ocular or generalized disease. SF-36 and a structured questionnaire was administered, including information on previous and current MG severity, medications, comorbidities, education, occupation and BMI of the patient. Mean disease duration was 7.5 + 9.3 years. Current age was 51.6 + 18.3 years, 55% had Early-Onset (<50 years) MG.

Results: There were no statistically significant differences in mean SF-36 subscores between women and men. Worse MGFA class was related to lower QoL in physical (PCS) and mental (MCS) subscore (p = 0.000 for both). Patients with MGFA I-II class had significantly better QoL in physical and mental subscores than patients with more severe MG (p < 0.005). Late-onset MG patients had worse QoL than EOMG in physical score domain PCS (p = 0.049). Overweight and obese patients had lower PCS (p = 0.002) and MCS (p = 0.038) than patients with normal BMI. University education was related to statistically higher PCS (p = 0.015) and MCS (p = 0.006). QoL in currently employed was better in PCS and MCS (p = 0.000), with white collar workers reporting higher PCS (p = 0.049) than the remaining group. Patients living with family evaluated their MCS (p = 0.015) better than living alone. Moderate physical activity (twice a week) improved PCS (p = 0.045).

Conclusion: Our study confirmed that greater severity of symptoms, age, age of onset but also BMI, type of work, education status and physical activity affect QoL in MG.

European ad-hoc consensus statement on gene replacement therapy for spinal muscular atrophy

Spinal muscular atrophy (SMA) used to be one of the most common genetic causes of infant mortality. New disease modifying treatments have changed the disease trajectories and most impressive results are seen if treatment is initiated in the presymptomatic phase of the disease. Very recently, the European Medicine Agency approved Onasemnogene abeparvovec (Zolgensma®) for the treatment of patients with SMA with up to three copies of the SMN2 gene or the clinical presentation of SMA type 1. While this broad indication provides new opportunities, it also triggers discussions on the appropriate selection of patients in the context of limited available evidence. To aid the rational use of Onasemnogene abeparvovec for the treatment of SMA, a group of European neuromuscular experts presents in this paper eleven consensus statements covering qualification, patient selection, safety considerations and long-term monitoring.

Gross Motor Function Disorders in Patients with Alternating Hemiplegia of Childhood

Background

Alternating hemiplegia of Childhood (AHC) is a rare disease manifested by transient episodes of hemiplegia and other neurological disorders. Delayed motor development has been reported in patients with AHC, but detailed features of the motor impairment have not been described so far.

Aim

The aim of the study was to evaluate gross motor function between attacks in a group of Polish patients with AHC.

Materials and methods

The interictal gross motor function was assessed using the Gross Motor Function AHC scale, which consisted of 41 motor tasks. The study group consisted of 10 patients with AHC older than 2 years of age. The control group consisted of 30 age- and gender-matched subjects. The results achieved in each of the 41 tasks by the study subjects were compared to the results obtained with controls using the non-parametric Mann-Whitney U-test. In tasks 38-41, mean times were compared between the study subjects and controls.

Results

The study revealed gross motor function impairment in patients with AHC. The greatest differences compared to controls concerned such skills as standing on toes, walking on toes, walking on heels, as well as running and hopping on one leg and on alternate legs. Significant impairment of the motor function of the upper limbs was also found.

Conclusions

The study confirmed motor function impairment between attacks in patients with AHC. The study findings may indicate the need to introduce individualised physiotherapy management of patients with AHC.

Minimal manifestation status and prednisone withdrawal in the MGTX trial

OBJECTIVE

To examine whether sustained minimal manifestation status (MMS) with complete withdrawal of prednisone is better achieved in thymectomized patients with myasthenia gravis (MG).

METHODS

This study is a post hoc analysis of data from a randomized trial of thymectomy in MG (Thymectomy Trial in Non-Thymomatous Myasthenia Gravis Patients Receiving Prednisone Therapy [MGTX]). MGTX was a multicenter, randomized, rater-blinded 3-year trial that was followed by a voluntary 2-year extension for patients with acetylcholine receptor (AChR) antibody-positive MG without thymoma. Patients were randomized 1:1 to thymectomy plus prednisone vs prednisone alone. Participants were age 18-65 years at enrollment with disease duration less than 5 years. All patients received oral prednisone titrated up to 100 mg on alternate days until they achieved MMS, which prompted a standardized prednisone taper as long as MMS was maintained. The achievement rate of sustained MMS (no symptoms of MG for 6 months) with complete withdrawal of prednisone was compared between the thymectomy plus prednisone and prednisone alone groups.

RESULTS

Patients with MG in the thymectomy plus prednisone group achieved sustained MMS with complete withdrawal of prednisone more frequently (64% vs 38%) and quickly compared to the prednisone alone group (median time 30 months vs no median time achieved, p < 0.001) over the 5-year study period. Prednisone-associated adverse symptoms were more frequent in the prednisone alone group and distress level increased with higher doses of prednisone.

CONCLUSIONS

Thymectomy benefits patients with MG by increasing the likelihood of achieving sustained MMS with complete withdrawal of prednisone.

CLINICALTRIALSGOV IDENTIFIER

NCT00294658.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that for patients with generalized MG with AChR antibody, those receiving thymectomy plus prednisone are more likely to attain sustained MMS and complete prednisone withdrawal than those on prednisone alone.

Lack of miR-378 attenuates muscular dystrophy in mdx mice

The severity of Duchenne muscular dystrophy (DMD), an incurable disease caused by the lack of dystrophin, might be modulated by different factors, including miRNAs. Among them, miR-378 is considered of high importance for muscle biology, but intriguingly, its role in DMD and its murine model (mdx mice) has not been thoroughly addressed so far. Here, we demonstrate that dystrophic mice additionally globally lacking miR-378 (double-KO [dKO] animals) exhibited better physical performance and improved absolute muscle force compared with mdx mice. Accordingly, markers of muscle damage in serum were significantly decreased in dKO mice, accompanied by diminished inflammation, fibrosis, and reduced abundance of regenerating fibers within muscles. The lack of miR-378 also normalized the aggravated fusion of dystrophin-deficient muscle satellite cells (mSCs). RNA sequencing of gastrocnemius muscle transcriptome revealed fibroblast growth factor 1 (Fgf1) as one of the most significantly downregulated genes in mice devoid of miR-378, indicating FGF1 as one of the mediators of changes driven by the lack of miR-378. In conclusion, we suggest that targeting miR-378 has the potential to ameliorate DMD pathology.

Spinal muscular atrophy - new therapies, new challenges

Spinal muscular atrophy (SMA) is a progressive neurodegenerative disease with an autosomal recessive trait of inheritance and great variability of its clinical course - from the lethal congenital type (SMA0) to the adult-onset form (SMA4). The disease is associated with a deficiency of SMN protein, which is encoded by two genes SMN1 and SMN2. Clinical symptoms depend on mutations in the SMN1 gene. The number of copies of twin similar SMN2 gene, which produces small amounts of SMN protein, is the main phenotype modifier, which determines the clinical severity of the disease. Until recently, it was considered that spinal cord motoneurons undergo selective loss. Recent studies have shown the role of SMN protein in various cellular processes and the multisystemic character of SMA. The aim of the therapeutic strategies developed so far has been to increase the expression of SMN protein by modifying the splicing of SMN2 gene (intrathecally administered antisense oligonucleotide - nusinersen; orally available small molecules: RG7916 and LMI070 or SMN1 gene replacement therapy (AAV9-SMN). The first SMN2-directed antisense oligonucleotide (nusinersen) has demonstrated in clinical trials high efficiency, and it has now been registered. The best effects were obtained in patients who were introduced to the drug in the pre symptomatic period. Studies on other substances are ongoing. The great advances in SMA therapy and increased understanding of the pathogenesis of the disease raise hopes for changes to the natural history of the disease. Simultaneously, it increases awareness of the need to improve the standard of patient care and early diagnosis (newborn screening). Many questions (e.g. emerging phenotypes, combined therapies, systemic vs. intrathecal administration, long-term consequences, and complications of the therapy) will require further studies and observations.