Elosulfase Alfa Research Articles

Mucopolysaccharidosis type 4 (Morquio syndrome): A case report

Abstract Introduction Mucopolysaccharidosis (MPS) IVA (Morquio syndrome) is a rare lysosomal storage disease, that is caused by a deficiency in the enzyme N-acetylgalactosamine-6-sulfatase (GALNS) due to an autosomal recessive mutation in the GALNS gene. Herein, we present a MPS IVA case without regular follow-up, whose enzyme replacement was planned to start at age 30 for the first time, so as to attract attention to this rare disease. Clinical Case A 30-year-old female patient diagnosed with MPS IVA, that was evaluated due to corneal clouding referred to the Marmara University endocrinology outpatient clinic for enzyme replacement. On admission, she complains of impaired vision, hearing loss, hypoglycemic symptoms and numbness of hands and feet. While she was normal for about 2 years after birth, she was noticed for delays in crawling and walking from 2–3 year of age. However, she had definitive diagnosis of MPS-IVA at the age of 9 years, with low enzymatic analysis and genetic mutation in the GALNS gene located on chromosome 16q24.3. She operated on for bilateral glaucoma and cerebellar mass when she was 17. Her parents were third degree consanguineous, and she had one healthy younger brother. On physical examination, blood pressure: 99/67 mmHg, pulse: 72/min, temperature: 36°C, SpO2:99. She was in a wheelchair. Her height was 92 cm, weight was 30 kg, BMI: 25.6 kg/m2. Disproportionate short stature, coarse facial features, hypertelorism, genu valgum, pectus carinatum, kyphoscoliosis, were detected. Her neuromotor development was normal. Laboratory findings were unremarkable except for vitamin D hypovitaminosis. Radiographic findings were dysostosis multiplex, include abnormally shaped vertebral bodies with anterior beaking, posterior scalloping, platyspondyly and dens hypoplasia, thoracolumbar kyphosis, short, broad metacarpals, acetabular dysplasia, genu valgum, pectus carinatum, paddle-shaped ribs and short, and thick clavicles (Fig 1). Bone densitometry results were in osteoporotic range BMD at the femoral neck was 0.491 g/cm2, Z score was -2.8 and at the lumbar spine was 0.707 g/cm2, Z score was -3.6. She continued the 6-min walk test with the help of a walker and knee pad for 2.37 minutes and walked 3.4 meters. Echocardiography demonstrated that ejection fraction was 65%, normal left ventricular systolic function, no ventricular segmental wall motion defect, aortic 3 cusps, mild to moderate aortic valvular regurgitation, mild mitral valvular regurgitation. Pectus carinatum was detected on thorax CT imaging, whereas a restrictive disease pattern was not observed in PFT and DLCO. Bilateral severe mixed hearing loss was detected. Recombinant human GALNS (elosulfase alfa), 2.0 mg/kg/week, was planned to administer IV in 4 hr. Conclusion Because of the progressive nature of MPS- IVA, early diagnosis and early initiation of enzyme replacement therapy are critical to prevent cumulative systemic manifestations of the patient, especially the skeletal system.

Efficacy of Intravenous Elosulfase Alfa for Mucopolysaccharidosis Type IVA: A Systematic Review and Meta-Analysis.

Mucopolysaccharidosis type IVA (MPS IVA or Morquio A), a lysosomal storage disease with an autosomal recessive inherited pattern, is induced by GALNS gene mutations causing deficiency in N-acetylgalactosamine-6-sulfatase activity (GALNS; EC 3.1.6.4). Currently, intravenous (IV) enzyme replacement therapy (ERT) with elosulfase alfa is employed for treating MPS IVA patients. A systematic literature review was conducted to evaluate the efficacy and safety of IV elosulfase alfa for MPS IVA by searching the National Center for Biotechnology Information, U.S. National Library of Medicine National Institutes of Health (PubMed), Excerpta Medica dataBASE, and Cochrane Library databases, limited to clinical trials. Four cohort studies and two randomized controlled trials, with a total of 550 participants (327 on ERT treatment versus 223 on placebo treatment), satisfied the inclusion criteria. Pooled analysis of proportions and confidence intervals were also utilized to systematically review clinical cohort studies and trials. Per the pooled proportions analysis, the difference in means of urinary keratan sulfate (uKS), 6-min walk test, 3-min stair climb test, self-care MPS-Health Assessment Questionnaire, caregiver assistance and mobility, forced vital capacity, the first second of forced expiration, and maximal voluntary ventilation between the ERT and placebo treatment groups were −0.260, −0.102, −0.182, −0.360, −0.408, −0.587, −0.293, −0.311, and −0.213, respectively. Based on the currently available data, our meta-analysis showed that there is uKS, physical performance, quality of life, and respiratory function improvements with ERT in MPS IVA patients. It is optimal to start ERT after diagnosis.

Consensus statement on enzyme replacement therapy for mucopolysaccharidosis IVA in Central and South-Eastern European countries

BackgroundMucopolysaccharidosis IVA (MPS IVA), or Morquio A syndrome, is a rare inherited metabolic disorder caused by deficiency of the lysosomal enzyme N-acetylgalactosamine-6-sulfatase. A progressive systemic skeletal chondrodysplasia, leading to significant morbidity and reduced life expectancy is the main clinical feature of this multisystemic disease. Although enzyme replacement therapy with elosulfase alfa is established in Europe, the rarity of disease and other factors still set hurdles in having patients treated in some countries. Aim of this statement is to provide evidence-based guidance for the enzyme replacement treatment of Morquio A patients, harmonizing recommendations from published guidelines with the real-life clinical practice in the Central and South-Eastern European region.ParticipantsThe Consensus Group, convened by 8 Steering Committee (SC) members from 7 Central and South-Eastern European countries, consisted of a multidisciplinary group of 17 experts in the management of MPS in Central and South-Eastern Europe.Consensus processThe SC met in a first virtual meeting with an external scientific coordinator, to discuss on clinical issues to be analyzed in guidance statements. Statements were developed by the scientific coordinator, evaluated by the SC members in a first modified-Delphi voting and adapted accordingly, to be submitted to the widest audience in the Consensus Conference. Following discussion and further modifications, all participants contributed to a second round of modified-Delphi voting.ResultsNine of ten statements, concerning general guidelines for management of MPS IVA patients and specific recommendations for treatment, received final consensus.ConclusionsEuropean guidelines and evidence-based recommendations for Morquio A patients should be considered in the real life of Central and South-Eastern European countries and adapted to unique clinical practice approaches and criteria for patients’ access to treatment and reimbursement in the region.

Clinical characteristics and effects of enzyme replacement therapy with elosulfase alfa in Korean patients with mucopolysaccharidosis type IVA

Mucopolysaccharidosis type IVA (MPS IVA) is a rare autosomal recessive disorder caused by a deficiency in N-acetylgalactosamine-6-sulfatase, which results in skeletal and connective tissue abnormalities, as well as various non-skeletal manifestations. Although enzyme replacement therapy (ERT) is recommended as the first-line treatment, the outcomes of ERT on bone pathology remain controversial. We report clinical characteristics and outcomes of ERT in 9 patients with MPS IVA (6 males and 3 females) from 7 unrelated families. During ERT, results from pulmonary function tests, echocardiography, the 6-min walk test, and the Functional Independence Measure were monitored biannually. Anthropometric data were compared with previously reported growth charts of subjects with MPS IVA.Among the 9 patients (5 severe, and 4 slowly progressive form), 7 patients (5 severe, 2 slowly progressive) commenced ERT at a median age of 3.8 years (range: 0.8–13.7 years) and were treated for a median duration of 1.9 years (range: 1.2–5.7 years). Mean height standard deviation scores using MPS IVA growth charts were + 0.4 (+0.0 in severe phenotypes) at initiation and + 0.7 (+0.2 in severe phenotypes) at the last follow-up. Four patients with severe phenotypes underwent surgery for cervical myelopathy and 1 patient with a slowly progressive phenotype underwent a bilateral pelvic osteotomy for hip pain during ERT. The parameters of pulmonary and heart function, endurance, and Functional Independence Measure scores were maintained or increased after ERT. Overall, ERT was well tolerated without deterioration of cardiorespiratory and functional outcomes during treatment, although skeletal outcomes, including growth, were limited.

Mucopolysaccharidosis type IVA in children: Clinical cases

Background. Mucopolysaccharidosis type IVA (Morquio syndrome) is a rare genetic lysosomal storage disease. Due to rarity, the syndrome is typically diagnosed at a later stage of gross affections of musculoskeletal and central nervous systems, leading to disability and a markedly reduced quality of life. A replacement therapy is nowadays available with recombinant human N-acetylgalactosamine-6-sulfatase (elosulfase alfa) enzyme.Clinical cases description. Two siblings, 10-yo male and 8-yo female, were admitted with complaints of growth retardation, deformity of the spine, thorax and joints, impaired hearing and visual acuity, poor tolerance to exercise. In the boy’s medical history, first manifestations appeared in the first year of life and progressed gradually; the patient was being observed as spondylodysplastic. Mental development was unaffected. The diagnosis was confirmed only by age of 7 at the National Medical Research Center for Children's Health Federal State Autonomous Institution of the Ministry of Health of the Russian Federation. Genotyping revealed two SNP mutations in gene GALNS (g.88909227C>A and g.88884454G>A in heterozygous state), and enzymatic assays — a severely reduced N-acetylgalactosamin-6-sulfatase activity. A routine elosulfase alfa replacement therapy has been received since 8-year age.The younger sister had neonatal cardiomegaly; congenital carditis and cardiomyopathy not excluded. Musculoskeletal affections developed by age of 3–4 years. By age of 5 and simultaneously with brother, the same GALNS mutations and severely impaired N-acetylgalactosamine-6-sulfatase activity were detected. A replacement therapy has been routinely received since 6-year age. The therapy triggered positive dynamics of restoring activity and muscle strength in both children, as well as significantly abating the musculoskeletal affection progress.Conclusion. The clinical cases of Morquio syndrome presented demonstrate its long-term and complex diagnosis. A replacement therapy is nowadays available, which warrants an earliest disease detection to halt progression and improve the patient’s life quality and expectancy.

Clinical Utility of Elosulfase Alfa in the Treatment of Morquio A Syndrome.

Mucopolysaccharidosis type IVA (MPS IVA or Morquio A) is an autosomal recessive disorder and is one of the lysosomal storage diseases. Patients with MPS IVA have a striking skeletal phenotype but normal intellect. The phenotypic continuum of MPS IVA ranges from severe and rapid progress to mild and slow progress. The diagnosis of MPS IVA is usually suspected based on abnormal bone findings and dysplasia on physical examination and radiographic investigation in the preschool years. In the past, only supportive care was available. Due to the early and severe skeletal abnormalities, the orthopedic specialist was usually the main care provider. However, patients need aggressive monitoring and management of their systemic disease. Therefore, they need an interdisciplinary team for their care, comprising medical geneticists, cardiologists, pulmonary specialists, gastroenterologists, otolaryngologists, audiologists, and ophthalmologists. After the US Food and Drug Administration approved elosulfase alfa in 2014, patients older than 5 years could benefit from this treatment. Clinical trials showed clinically meaningful improvements with once-a-week intravenous dosing (2.0 mg/kg per week), significantly improving the 6min walk test, the 3min stair climb test, and respiratory function when compared with placebo. Elosulfase alfa is well-tolerated, and there is a good response indicated by decreasing urine glycosaminoglycans.

Elosulfase Alfa Treatment in Morquio A Patients in Iran: A Before and After Study

Background: Morquio A, an autosomal recessive lysosomal storage disease, is caused by a defect in the enzyme N-acetyl-galactosamine-6-sulfatase. This leads to the accumulation of the glycosaminoglycans chondroitin-6-sulfate (C6S) and keratan sulfate (KS), resulting in various skeletal manifestations, multisystemic impairments, and significant morbidities. Objectives: This study aimed to evaluate the impact of the addition of elosulfase alfa to the hospital protocol on treating Iranian pediatricians with Morquio A syndrome. Methods: A before and after study was conducted on ten patients with Morquio A syndrome diagnosis from 2019 to 2020. Elosulfase alfa was prescribed with the standard dose of 2 mg/kg/weekly IV infusion for 54 weeks. Then, growth indices, quality of life, and cardiopulmonary data were collected by research assistants using a pre-designed check. Data were entered in SPSS version 23. Quantitative variables were compared between the two periods using the Student's t-test, and qualitative variables were compared using the χ2 test or Fisher's exact test. Results: Ten pediatricians with MPS IV were included, seven of whom were female, with the mean age of 5.8 ± 2.3 years. The meantime for walking 6 m (P = 0.005), standing (P = 0.005), the stair climb test (P = 0.007), and quality of life (P = 0.015) had significant statistical difference before and after treatment by elosulfase alfa. Conclusions: The addition of elosulfase alfa in patients with Morquio A syndrome was associated with a significant improvement outcome in the ‘after’ treatment period.

Clinical features and health-related quality of life in adult patients with mucopolysaccharidosis IVA: the Spanish experience

BackgroundMucopolysaccharidosis (MPS) IVA or Morquio A syndrome is a progressive and disabling disease characterized by a deficiency of the enzyme N-acetylgalactosamine-6-sulphate sulphatase. Its clinical presentation is very heterogeneous and poorly understood in adults.The aim of this study was to describe the clinical manifestations of MPS IVA in adult patients in Spain and to assess their health-related quality of life (HRQoL).ResultsThirty-three patients from nine reference centres participated in the study. The median age was 32 (interquartile range [IQR]: 20.5–40.5) years. The phenotype was classical in 54.5% of patients, intermediate in 33.3% of patients, and non-classical in 12.1% of patients. The most common clinical manifestation was bone dysplasia, with a median height of 118 (IQR: 106–136) cm. Other frequent clinical manifestations were hearing loss (75.7%), ligamentous laxity (72.7%), odontoid dysplasia (69.7%), limb deformities that required orthopaedic aids (mainly hip dysplasia and genu valgus) (63.6%), and corneal clouding (60.6%). In addition, 36.0% of patients had obstructive sleep apnoea/hypopnoea syndrome and 33.3% needed non-invasive ventilation. Cervical surgery and varisation osteotomy were the most common surgical interventions (36.4% each). Almost 80% of patients had mobility problems and 36.4% used a wheelchair at all times. Furthermore, 87.9% needed help with self-care, 33.3% were fully dependent, and 78.8% had some degree of pain. HRQoL according to the health assessment questionnaire was 1.43 (IQR: 1.03–2.00) in patients with the non-classical phenotype, but 2.5 (IQR: 1.68–3.00) in those with the classical phenotype. Seven patients were initiated on enzyme replacement therapy (ERT), but two of them were lost to follow-up. Lung function improved in four patients and slightly worsened in one patient. The distance achieved in the six-minute walk test increased in the four patients who could perform it. HRQoL was better in patients treated with elosulfase alfa, with a median (IQR) of 1.75 (1.25–2.34) versus 2.25 (1.62–3.00) in patients not treated with ERT.ConclusionsThe study provides real-world data on patients with MPS IVA. Limited mobility, difficulties with self-care, dependence, and pain were common, together with poor HRQoL. The severity and heterogeneity of clinical manifestations require the combined efforts of multidisciplinary teams.

Treating a teenager with Morquio A syndrome (mucopolysaccharidosis IV A) with Vimizim

The article describes a clinical case of enzyme replacement therapy (ERT) with elosulfase alfa for a teenager with mucopolysaccharidosis type IVA (MPS IVA, Morquio A syndrome). Treatment was started quite late, at the age of 12, against the background of a severe course of Morquio A syndrome. Nevertheless, the child showedan improvement in enduranceand fine motor skills, and an increase in muscle tone. The article discusses lack of information on modern methods of enzymereplacement therapy, as well as the limitations of this type of therapy. The paper emphasizes the need for an interdisciplinary approach to treat such diseases and alleviate the condition of patients.

Elosulfase alfa in the treatment of mucopolysaccharidosis type IVA: insights from the first managed access agreement

Managed access agreements provide a crucial mechanism whereby real-world data can be collected systematically to reduce uncertainty around available clinical and economic data, whilst providing the opportunity to identify patient sub-populations who are most likely to benefit from a new treatment. This manuscript aims to share learnings from the first managed access agreement, which was initiated following positive conditional approval in 2015 from the National Institute for Health and Care Excellence (NICE) for elosulfase alfa, an enzyme replacement therapy for the treatment of mucopolysaccharidosis type IVA (MPS IVA). This managed access agreement enabled the collection of comprehensive real-world data for patients with MPS IVA, with results demonstrating that patients starting elosulfase alfa treatment showed gains similar to those seen in the pivotal trial for outcomes including endurance, respiratory and cardiac function, pain, quality of life measures and urinary keratan sulfate levels. In addition, former trial patients continued to see benefits in both clinical assessments and quality of life/activities of daily living nine years after beginning treatment. Key strengths of the process included recruitment of a high proportion of MPS IVA patients treated in England (72/89 known eligible patients) with a wide range of ages (2–58 years). Participation of a patient organisation (the MPS society) ensured that the patient voice was present throughout the process, whilst a contract research organisation (Rare Disease Research Partners) ensured that patients were represented when interpreting agreement criteria and during patient assessment meetings. Longer-term follow-up will be required for several MPS IVA outcomes (e.g. skeletal measures) to further reduce uncertainty, and continued follow-up of patients who had stopped treatment was found to be challenging. The burden associated with this managed access agreement was found to be high for patients, physicians, patient organisations, NHS England and the manufacturer, therefore costs and benefits of future agreements should be considered carefully before initiation. Through evaluation of the strengths and limitations of this process, it is hoped that learnings from this managed access agreement can be used to inform future agreements.

Shortened desensitization leading to a 2-year enzyme replacement therapy with elosulfase alfa

Morquio syndrome (mucopolysaccharidosis type IV) is an autosomal-recessive lysosomal storage disease causing bone and joint disorders, respiratory and cardiac diseases, spinal cord compression, impaired vision, hearing loss, and dental problems.1 The only treatment is enzyme replacement therapy (ERT) with elosulfase alfa (recombinant human n-acetyl-galactosamine-6-sulfatase-110; Vimizim [5 mg/5 mL]; BioMarin Pharmaceutical Inc, London, United Kingdom), but hypersensitivity reactions (HSRs) may occur during elosulfase alfa infusion, similar to the other ERTs.

Pectus carinatum as the key to early diagnosis of Morquio A syndrome: a case report

BackgroundA 20-month-old Asian boy with normal growth presented with genu valgum, kyphosis, and pectus carinatum, with no neurological symptoms. No other symptoms suggestive of mucopolysaccharidoses, for example joint contracture and peculiar facies, were present.Case presentationAs part of our differential diagnosis we found elevated urine glycosaminoglycans, which triggered further investigation. Detailed examination showed flattening of the ribs, kyphoscoliosis and ovalization of the thoracolumbar vertebral body, strikingly short metacarpals, and very slight cardiac regurgitation. N-Acetylgalactosamine-6-sulfatase levels in the blood and dermal fibroblasts were very low, thus confirming diagnosis of Morquio A within 2 months of presentation. The patient was placed on elosulfase alfa enzyme replacement therapy and followed for 3 years.ConclusionsThis case exemplifies the importance of considering mucopolysaccharidoses as part of the initial differential diagnosis of pediatric patients with skeletal deformities; urine glycosaminoglycan levels and a blood enzyme mucopolysaccharidoses panel are simple screening tests that could lead to early definitive diagnosis.

Impact of long-term elosulfase alfa treatment on clinical and patient-reported outcomes in patients with mucopolysaccharidosis type IVA: results from a Managed Access Agreement in England

BackgroundWe present baseline characteristics and follow-up data of a Managed Access Agreement (MAA), including patients with mucopolysaccharidosis IVA (MPS IVA) receiving elosulfase alfa enzyme replacement therapy (ERT) in England on a conditional basis. Patients enrolled in the MAA programme are reviewed on an annual basis. Therapy can be continued if patients are compliant, able to tolerate infusions, and meet four out of five pre-defined clinical and patient-reported outcomes (PRO) criteria. Baseline and follow-up clinical and PRO data are presented for all participants who completed ≥ 1 year of assessments in the MAA.ResultsThe analysis included data from 55 patients, including 26 patients previously enrolled in clinical trials and 29 who started ERT after enrolling in the MAA. In patients with both baseline and follow-up data, mean 6-min walk test distance increased from 217 m at baseline to 244 m after a mean follow-up of 4.9 years. Improvement or stabilisation was seen regardless of age at treatment initiation or duration of treatment. Mean forced vital capacity and forced expiratory volume in 1 s were 0.87 L and 0.78 L, respectively at baseline and 1.05 L and 0.88 L after a mean follow-up of 5.5 years. PRO data showed overall improvements over time in Mobility, Self-care, and Caregiver assistance scores of the MPS-Health Assessment Questionnaire, relatively stable quality of life, and some improvements in pain scores.ConclusionsThe MAA data confirm the effects of elosulfase alfa on clinical and PRO results observed in the clinical trials and provide real-world evidence for long-term stabilisation in these measures, suggesting a positive impact on the natural history of MPS IVA.

Enzyme replacement therapy interruption in mucopolysaccharidosis type IVA patients and its impact in different clinical outcomes.

Mucopolysaccharidosis type IVA (MPS IVA) is an autosomal recessive lysosomal storage disorder caused by mutations in the GALNS gene, which leads to deficient activity of N‐acetylglucosamine‐6‐sulfate sulfatase. MPS IVA patients usually present skeletal dysplasia, coarse features, short stature, airway obstruction, cervical spinal cord compression, dental abnormalities, and cardiac valvular alterations. Enzyme replacement therapy (ERT) with elosulfase alfa is the only disease‐specific treatment available for MPS IVA patients and has been shown to improve important clinical and biochemical parameters; however, little is known about the effects of ERT interruption on these patients. In this article, we report the impact of different periods of treatment interruption on clinical outcomes of 18 MPS IVA patients. All MPS IVA patients included in this case series were treated and followed up in Latin American centers and had been receiving elosulfase alfa intravenously for at least 8 months before ERT was interrupted. Different clinical parameters and assessments were evaluated at variable timepoints following therapy interruption. Altogether, our report indicates that some beneficial ERT effects in MPS IVA patients may last after different periods of treatment interruption, as cardiac and respiratory function improvements. However, worsening of important disease parameters after ERT interruption, such as the increase in uGAGs, pain, joint and skeletal aspects, and surgery indications suggests that treatment discontinuation should be avoided in order to maintain the disease as stable as possible, aiming to optimize these patients' life expectancy and quality of life.

Diagnostic journey and impact of enzyme replacement therapy for mucopolysaccharidosis IVA: a sibling control study

BackgroundMucopolysaccharidosis (MPS) IVA, also known as Morquio A syndrome, is a rare autosomal recessive lysosomal storage disorder caused by a deficiency in the enzyme N-acetylgalactosamine-6-sulfatase. Early recognition, diagnosis, and treatment of this progressive, multisystem disease by enzyme replacement therapy (ERT) can lead to improved outcomes and reduced mortality.MethodsThis report documents the diagnostic journey and treatment with ERT of three siblings with MPS IVA. Clinical outcome measures included growth, endurance, imaging, cardiac, respiratory, ophthalmology, and laboratory evaluations.ResultsThree siblings, diagnosed at 14.7, 10.1, and 3.2 years of age, demonstrated clinical improvement with weekly infusions of 2.0 mg/kg elosulfase alfa (Vimizim®, BioMarin Pharmaceutical, Novato, CA, USA). Patient 1 (oldest sibling) and Patient 2 (middle sibling) experienced a diagnostic delay of 8 years 7 months and 4 years after symptom onset, respectively. All three patients demonstrated improvements in growth, 6-min walk distance, joint range of motion, and respiratory function after 30 months of ERT. The treatment was well tolerated without any adverse events.ConclusionsThis case series highlights the importance of early recognition of the clinical and imaging findings that are initially subtle in MPS IVA. Early treatment with ERT is necessary to slow irreversible disease progression and improve patient outcomes. The oldest sibling experienced improvements in mobility despite severe symptoms resulting from a late diagnosis. When evaluating patients with skeletal anomalies, imaging multiple body regions is recommended. When findings such as anterior beaking of vertebrae or bilateral femoral head dysplasia are present, MPS IVA should be included in the differential diagnosis. Newborn screening must be considered for early detection, accurate diagnosis, and initiation of treatment to reduce morbidity.

Clinical characteristics of patients from Quebec, Canada, with Morquio A syndrome: a longitudinal observational study

BackgroundMorquio A syndrome is a rare, autosomal recessive, progressively debilitating disorder, with multi-system impairments and high medical burden. Quebec, Canada has a large Morquio A population, which is considered unique due to the presence of founder pathogenic variants. The objectives of this study were to document the genetic and clinical heterogeneity of patients with Morquio A in Quebec, to better characterize the phenotype of those with the French Canadian founder pathogenic variant (NM_000512.5: c.1171A>G, p.Met391Val), and to describe the natural history of the patients treated with elosulfase alfa enzyme replacement therapy. Patients with Morquio A were genotyped for pathogenic variants in the lysosomal enzyme N-acetylgalactosamine-6-sulfatase. Clinical data were retrospectively collected from medical charts of patients and included medical history, height, physical examination, respiratory function tests, electrocardiogram, echocardiogram, endurance in the 6-min walk test (6MWT), and activities of daily living (ADL) as assessed by the Mucopolysaccharidosis Health Assessment Questionnaire (MPS-HAQ). Longitudinal data were collected retrospectively and prospectively for patients treated with elosulfase alfa.ResultsA total of 33 patients, aged 5–63 years, were included in the analysis. Patients with the founder pathogenic variant (n = 17) generally exhibited a non-classical form of Morquio A. As compared with patients with a non-founder pathogenic variant (n = 16), these patients were generally taller, had greater endurance and were better able to perform ADL. However, they still had significant musculoskeletal disease. Most of the 26 patients treated with elosulfase alfa, regardless of pathogenic variant, showed improvements in endurance and ADL. After 5 to 12 months of treatment, the mean improvement from baseline in the 6MWT was 23% and 10 of 14 patients improved in at least one MPS-HAQ domain. Endurance and ADL generally continued to improve or maintained stable in the long term (up to 7 years). Four out of 19 treated patients with echocardiogram data at follow-up showed progression of cardiac disease.ConclusionsIn Quebec, Canada, Morquio A frequently manifests as a non-classical form of the syndrome due to a founder effect. Patients treated with elosulfase alfa generally show long-term improvement or stability in endurance and function, regardless of pathogenic variant.

Enzyme Replacement Therapy may Affect Blood Immunosuppressant Monitoring.

Although LC-MS/MS is preferred as a reliable method, therapeutic enzyme drugs in the blood matrix may lead to false results. The purpose of this article is to experimentally investigate the effect of five different enzymes used in the treatment of metabolic diseases on blood immunosuppressant measurement. Five different enzyme drugs (galsulfase, alglucosidase alfa, imiglucerase, elosulfase alfa, laronidase) were added to control materials containing tacrolimus, everolimus, sirolimus, and cyclosporine A drugs. Measurements were performed using an LC-MS/MS instrument (Shimadzu 8040, Japan). The amount of deviations from the target values was calculated. Blood Immunosuppressant levels significantly changed after the administration of enzyme drugs. Four different enzyme drugs led to false-positive results in the tacrolimus levels at a rate of 10.58% (95% CI, 9.83-11.32) to 37.28% (95% CI, 33.55-41.27). The highest deviations were observed with the administration of galsulfase and alglucosidase alpha in the sirolimus levels at rates of 336.54% (95% CI, 306.25-366.82) and 395.88% (95% CI, 360.25-431.50), respectively. Imiglucerase was the least effective enzyme for the sirolimus level (0.80% (95% CI, 0.71-0.89). Different deviations between the ratios of - 9.37% (95% CI, -10.40 - -8.33) and 8.33% (95% CI, 7.41-9.24) were determined at the cyclosporin A level. Galsulfase, alglucosidase alpha, imigluserase, elosulfase alpha and laronidase can significantly interfere with immunosuppressant measurements with LC-MS/MS. False immunosuppressant results associated with enzyme injection may result in immunosuppression failure, organ rejection. For the measurement of immunosuppressant levels, sampling should be done before the enzyme infusion. Clinicians should question the time of enzyme infusion and sampling when confounding results in immunosuppressant measurement.

Newborn screening for Morquio disease and other lysosomal storage diseases: results from the 8-plex assay for 70,000 newborns

BackgroundThe necessity of early treatment for lysosomal storage diseases (LSDs) has triggered the development of newborn screening for LSDs in recent years. Here we report the first 70,000 newborns screened for Mucopolysaccharidosis (MPS) type 4A (Morquio syndrome) and other LSDs by an 8-plex assay including the original 4-plex LSD screening tandem mass spectrometry (MS/MS) assay for Pompe disease, Fabry disease, Gaucher disease, and MPS I disease.MethodsThe additional reaction for MPS II, MPS 3B, MPS 4A, and MPS 6 enzymes was performed separately from the 4-plex reaction. The two reactions were quenched and extracted, then combined before carrying out a single 2-min UPLC-MS/MS analysis.ResultsFrom Mar. 2018 to Apr. 2019, 73,743 newborns were screened with the 8-plex LSD screening assay. The 8-plex assay revealed a better analytical precision than the previous 4-plex assay possibly because the 8-plex was carried out using UPLC-MS/MS. Six newborns were found to have low MPS-4A enzyme (N-acetylgalactosamine-6-sulfatase) activity and biallelic GALNS pathogenic mutations in trans; these patients are presumably affected with MPS4A, making an incidence of one in 12,291 (95% confident interval (CI): 5633-26,817). One mutation, c.857C > T (p.T286 M) of the GALNS gene, accounted 5 of the 12 mutated alleles. These newborns had immature vertebral bodies at 1 month of age, and one case was treated with elosulfase alfa 2 mg/kg/week starting from 4 months of age. Among other MPSs screened, one case of MPS I, 3 cases of MPS II, and 3 cases of MPS 3B were detected. One case of mucolipidosis type III was also diagnosed. In conjunction with another 9 patients of Pompe disease, Gaucher disease, and classical Fabry disease, making an incidence of LSDs as one in 3206 newborns (95% CI: 2137 - 4811). The one with infantile-onset Pompe disease and the one with Gaucher disease were treated since the age of 8 days and 41 days respectively.ConclusionsRoutine newborn screening of MPS 4A and other LSDs were made possible by the 8-plex LSD screening assay. However, detailed phenotype prediction and the time to start treatment will need further elucidation.

Long-term clinical outcomes of patients treated with elosulfase alfa: Five-year real-world results from the Morquio A Registry Study (MARS)

Long-term clinical outcomes of patients treated with elosulfase alfa: Five-year real-world results from the Morquio A Registry Study (MARS)

Long-term clinical outcomes of patients with Morquio syndrome type A treated with elosulfase alfa: Results from a managed access agreement in England

Long-term clinical outcomes of patients with Morquio syndrome type A treated with elosulfase alfa: Results from a managed access agreement in England