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.

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.

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

Background We 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. Results The 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. Conclusions The 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.

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

Background Morquio 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. Results A 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. Conclusions In 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 Immunosupressant Monitoring

Background: Although LC-MS/MS is preferred as a reliable method, therapeutic enzyme drugs in the blood matrix may lead to false results. Objective: 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. Methods: 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 LCMS/MS instrument (Shimadzu 8040, Japan). The amount of deviations from the target values was calculated. Results: 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. Conclusion: Galsulfase, alglucosidase alpha, imigluserase, elosulfase alpha, 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 immunsupressant measurement.

A Case Report of a Japanese Boy with Morquio A Syndrome: Effects of Enzyme Replacement Therapy Initiated at the Age of 24 Months

Background: Morquio A syndrome, mucopolysaccharidosis type IVA (MPS IVA), is a lysosomal storage disorder caused by the deficient activity of N-acetylgalactosamine-6-sulfatase (GalNac6S), due to alterations in the GALNS gene. This disorder results in marked abnormalities in bones and connective tissues, and affects multiple organs. Here, we describe the clinical course of a Japanese boy with MPS IVA who began enzyme replacement therapy (ERT) at the age of 24 months. Patient: the patient presented for kyphosis treatment at 22 months of age. An X-ray examination revealed dysostosis multiplex. Uronic acids were elevated in the urine and the keratan sulfate (KS) fraction was predominant. The leukocyte GalNac6S enzyme activity was extremely low. The patient exhibited the c.463G > A (p.Gly155Arg) mutation in GALNS. Based on these findings, his disease was diagnosed as classical (severe) Morquio A syndrome. An elosulfase alfa infusion was initiated at the age of 24 months. The patient’s body height improved from −2.5 standard deviation (SD) to −2 SD and his physical activity increased during the first 9 months on ERT. However, he gradually developed paralysis in the lower legs with declining growth velocity, which required cervical decompression surgery in the second year of the ERT. The mild mitral regurgitation, serous otitis media, and mild hearing loss did not progress during treatment. Conclusion: early initiation of the elosulfase alfa to our patient showed good effects on the visceral system and muscle strength, while its effect on bones appeared limited. Careful observation is necessary to ensure timely surgical intervention for skeletal disorders associated with neurological symptoms. Centralized and multidisciplinary management is essential to improve the prognosis of pediatric patients with MPS IVA.