Findings from the Morquio A Registry Study (MARS) after 6 years: Long-term outcomes of MPS IVA patients treated with elosulfase alfa.

BACKGROUND: The Morquio A Registry Study (MARS) is an ongoing, multinational, observational study of patients with MPS IVA. Key objectives of MARS are to characterize the heterogeneity and natural history of disease and to evaluate long-term effectiveness and safety of elosulfase alfa enzyme replacement therapy (ERT). Enrollment began in September 2014; data on medical history, clinical outcomes, and safety assessments are collected as part of routine care. RESULTS: As of February 2021, 381 subjects from 17 countries had enrolled in MARS: 58 ERT-naïve subjects and 323 ERT-treated subjects (≥1 infusion), with a mean ERT exposure of 5.5 years (SD 2.8) and median age at first ERT treatment of 9.8 years. ERT-treated subjects were younger at diagnosis (median 3.4 vs 6.5 years) relative to ERT-naïve subjects. Among ERT-treated subjects, urinary keratan sulfate (uKS) levels declined from pre-ERT baseline to last follow-up on treatment (mean % change [95% confidence interval]: -52.5% [-57.5%, -47.4%]; n = 115) and 6-min walk test distance remained stable (mean change: -6.1 [-27.6, 15.5] m; n = 131) over a mean follow-up of 5.5 years. Forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) increased in subjects who were < 18 years of age at ERT initiation (mean change: +0.3 [0.1, 0.4] L and + 0.4 [0.3, 0.5] L; mean follow-up: ∼6 years; n = 82) and were stable in subjects ≥18 years (mean change: 0.0 [-0.0, 0.1] L and 0.0 [-0.1, 0.1] L; mean follow-up: 4.6 years; n = 38). Overall, 148 (47.1%) ERT-treated subjects experienced ≥1 adverse event (AE) and 110 subjects (35%) reported ≥1 serious AE. Drug-related AEs were reported in 39 (12.4%) subjects; the most common were hypersensitivity (9 subjects [2.9%]), urticaria (8 subjects [2.5%]), and pyrexia (7 subjects [2.2%]). CONCLUSIONS: MARS is the longest and largest observational study of MPS IVA patients to date, with a heterogenous population that is representative of the MPS IVA population overall. Data collected over the first 6 years of MARS provide real-world evidence for long-term stabilization of endurance and respiratory function among ERT-treated patients, with no new safety concerns identified.

The youngest pair of siblings with Mucopolysaccharidosis type IVA to receive enzyme replacement therapy to date: A case report.

Mucopolysaccharidosis type IVA (OMIM 253000) is an autosomal recessive disorder caused by defective activity of the N-acetylgalactosamine 6-sulfatase (GALNS) enzyme. In 2014, enzyme replacement therapy (ERT) using recombinant human GALNS became available for affected patients. There is a limited number of studies to date that have explored the effect of ERT in infancy and there is also a lack of data assessing the effect of ERT in systems other than the skeletal. Here, we report on the effect of ERT in the youngest pair of siblings treated to date: Patient A, currently 4 years old, who started treatment at the age of 5 months; and Patient B, currently 3 years old, who started treatment at 58 days of life. Moreover, we investigate the effect of early ERT on the cardiovascular system. Our results show that, even when ERT is started before 2 months of age, it cannot fully prevent disease progression. As for the effect of ERT on the cardiovascular system, our preliminary results suggest that early treatment might play a role in preserving a normal left ventricular mass index in affected patients at least up to 1 year, but further observation over time will be required. Overall, this report shows that early diagnosis remains crucial and that prompt initiation of ERT has limited effect in slowing progression of the skeletal phenotype, thus confirming the need for new therapeutic approaches that target the skeletal system in affected patients.

Intravenous Enzyme Replacement Therapy in Mucopolysaccharidoses: Clinical Effectiveness and Limitations.

The aim of this review is to summarize the evidence on efficacy, effectiveness and safety of intravenous enzyme replacement therapy (ERT) available for mucopolysaccharidoses (MPSs) I, II, IVA, VI and VII, gained in phase III clinical trials and in observational post-approval studies. Post-marketing data are sometimes conflicting or controversial, possibly depending on disease severity, differently involved organs, age at starting treatment, and development of anti-drug antibodies (ADAs). There is general agreement that ERT is effective in reducing urinary glycosaminoglycans and liver and spleen volume, while heart and joints outcomes are variable in different studies. Effectiveness on cardiac valves, trachea and bronchi, hearing and eyes is definitely poor, probably due to limited penetration in the specific tissues. ERT does not cross the blood-brain barrier, with the consequence that the central nervous system is not cured by intravenously injected ERT. All patients develop ADAs but their role in ERT tolerance and effectiveness has not been well defined yet. Lack of reliable biomarkers contributes to the uncertainties about effectiveness. The data obtained from affected siblings strongly indicates the need of neonatal screening for treatable MPSs. Currently, other treatments are under evaluation and will surely help improve the prognosis of MPS patients.

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.

Safety, immunogenicity, and clinical outcomes in patients with Morquio A syndrome participating in 2 sequential open-label studies of elosulfase alfa enzyme replacement therapy (MOR-002/MOR-100), representing 5 years of treatment.

Elosulfase alfa is an enzyme replacement therapy for Morquio A syndrome (mucopolysaccharidosis IVA), a multisystemic progressive lysosomal storage disorder. This report includes the primary treatment outcomes and immunogenicity profile of elosulfase alfa in patients with Morquio A syndrome from 2 sequential studies, MOR-002 (ClinicalTrials.govNCT00884949) and MOR-100 (NCT01242111), representing >5 years of clinical study data. MOR-002 was an open-label, single-arm phase 1/2 study that evaluated the pharmacokinetics, safety, immunogenicity, and preliminary efficacy of 3 sequential doses of elosulfase alfa (0.1, 1.0, and 2.0 mg/kg/week) in patients with Morquio A syndrome (n = 20) over 36 weeks, followed by an optional 36- to 48-week treatment period using elosulfase alfa 1.0 mg/kg once weekly (qw). During the 0.1 mg/kg dosing phase, 1 patient discontinued due to a type I hypersensitivity adverse event (AE), and that patient's sibling voluntarily discontinued in the absence of AEs. An additional patient discontinued due to recurrent infusion reactions during the 1.0 mg/kg continuation phase. The remaining 17 patients completed MOR-002 and enrolled in MOR-100, an open-label, long-term extension study that further evaluated safety and clinical outcomes with elosulfase alfa administered at 2.0 mg/kg qw. During the course of MOR-100, patients were given the option of receiving elosulfase alfa infusions at home with nursing assistance. Over the course of both studies, all patients experienced ≥1 AE and most patients experienced a drug-related AE, generally of mild or moderate severity. Hypersensitivity reactions reported as related to study drug occurred in 25% of patients. Thirteen patients who chose to receive infusions at home had the same tolerability and safety profile, as well as comparable compliance rates, as patients who chose to receive on-site infusions. All patients developed antibodies to elosulfase alfa. Positivity for neutralizing antibodies was associated with increased drug half-life and decreased drug clearance. Despite formation of antidrug-binding (total antidrug antibodies, TAb) and in vitro neutralizing antibodies (NAb) in all patients, these types of immunogenicity to elosulfase alfa were not correlated with safety or clinical outcomes. In contrast with the reported natural history of Morquio A, no trends toward decreasing endurance, respiratory function, or ability to perform activities of daily living were observed in this cohort over the 5-year period.

Impact of long-term elosulfase alfa on activities of daily living in patients with Morquio A syndrome in an open-label, multi-center, phase 3 extension study.

BACKGROUND: Long-term safety and efficacy of elosulfase alfa enzyme replacement therapy (ERT) were assessed in 173 patients with Morquio A syndrome (mucopolysaccharidosis IVA) in a 96-week, open-label, multi-center, phase 3 extension study (MOR-005) of the pivotal 24-week, placebo-controlled study (MOR-004). Changes in efficacy endpoints were evaluated over 120weeks, from MOR-004 baseline to MOR-005 week 96. We report the impact of ERT on activities of daily living (ADL) across three domains (mobility, self-care, and caregiver-assistance), as assessed by the Mucopolysaccharidosis Health Assessment Questionnaire (MPS-HAQ) after 72 and 120weeks or approximately 1 and 2years. RESULTS: Mean baseline MPS-HAQ domain scores showed impairments in mobility, self-care, and independence. The MOR-005 intent-to-treat population (ITT; N=169, including 158 with 2years follow-up) showed sustained significant reductions (representing improvements) in mobility and self-care domain least square (LS) mean scores vs. baseline at 1 and 2years and a non-significant decrease in the caregiver-assistance domain at 2years. At week 120, LS mean (SE) changes from baseline were -0.5 (0.1) for mobility (P=0.002), -0.4 (0.1) for self-care (P=0.001), and -1.0 (0.5) for caregiver-assistance (P=0.06) (ITT population). Improvements in MPS-HAQ domain scores vs. baseline at 1 and 2years were greater in patients continuously treated with the weekly dosing regimen than in the total MOR-005 population and statistically significant across domains. A comparable untreated cohort of patients from the Morquio A Clinical Assessment Program (MorCAP) natural history study (ITT population, N=94, including 37 with 2years follow-up) showed no improvement over 2years, with two of the three domains worsening (LS mean (SE) changes from baseline: 0.3 (0.3) for mobility, 0.4 (0.2) for self-care, -0.5 (0.8) for caregiver-assistance). Changes in LS mean scores vs. baseline were statistically significantly different between MOR-005 and MorCAP for the mobility domain (-0.7 (SE 0.4), P=0.0490) and the self-care domain (-0.7 (SE 0.3), P=0.0146) at 2years. CONCLUSIONS: Together, these findings suggest that long-term elosulfase alfa ERT is associated with partial recovery of functional abilities, improving Morquio A patients' abilities to perform ADL. TRIAL REGISTRATION: ClinicalTrials.govNCT01415427. Registered 8 August 2011, retrospectively registered.

Long-term endurance and safety of elosulfase alfa enzyme replacement therapy in patients with Morquio A syndrome.

Long-term efficacy and safety of elosulfase alfa enzyme replacement therapy were evaluated in Morquio A patients over 96weeks (reaching 120weeks in total from pre-treatment baseline) in an open-label, multi-center, phase III extension study. During this extension of a 24-week placebo-controlled phase III study, all patients initially received 2.0mg/kg elosulfase alfa either weekly or every other week, prior to establishment of 2.0mg/kg/week as the recommended dose, at which point all patients received weekly treatment. Efficacy measures were compared to baseline of the initial 24-week study, enabling analyses of changes over 120weeks. In addition to performing analyses for the entire intent-to-treat (ITT) population (N=173), analyses were also performed for a modified per-protocol (MPP) population (N=124), which excluded patients who had orthopedic surgery during the extension study or were non-compliant with the study protocol (as determined by ≥20% missed infusions). Six-minute walk test (6MWT) was the primary efficacy measure; three-minute stair climb test (3MSCT) and normalized urine keratan sulfate (uKS) were secondary efficacy measures. Mean (SE) change from baseline to Week 120 in 6MWT distance was 32.0 (11.3)m and 39.9 (10.1)m for patients receiving elosulfase alfa at 2.0mg/kg/week throughout the study (N=56) and 15.1 (7.1)m and 31.7 (6.8)m in all patients combined, regardless of dosing regimen, for the ITT and MPP populations, respectively. Further analyses revealed that durability of 6MWT improvements was not impacted by baseline 6MWT distance, use of a walking aid, or age. Mean (SE) change at Week 120 in the 3MSCT was 5.5 (1.9) and 6.7 (2.0)stairs/min for patients receiving elosulfase alfa at 2.0mg/kg/week throughout the study and 4.3 (1.2) and 6.8 (1.3)stairs/min in all patients combined, regardless of dosing regimen, for the ITT and MPP populations, respectively Across all patients, mean (SE) change at Week 120 in normalized uKS was -59.4 (1.8)% and -62.3 (1.8)% in the ITT and MPP populations, respectively. In the absence of a placebo group, significance of the sustained improvements could not be evaluated directly. However, to provide context for interpretation of results, comparisons were performed with untreated patients from a Morquio A natural history study. In contrast to the results of the extension study, the untreated patients experienced constant uKS levels and a gradual decline in endurance test results over a similar period of time. Differences from the untreated natural history study patients were significant for 6MWT, 3MSCT, and uKS outcomes for the cohort of patients receiving optimal dosing throughout the study and for all cohorts pooled together, for both ITT and MPP populations (P<0.05). Safety findings were consistent with those of the initial 24-week study, with no new safety signals identified.

Multi-domain impact of elosufase alfa in Morquio A syndrome in the pivotal phase III trial.

OBJECTIVE: To report and discuss the multi-domain impact of elosulfase alfa, with focus on tertiary and composite endpoints, in the 24-week, randomized, double-blind, placebo-controlled phase 3 trial in patients with Morquio A syndrome (mucopolysaccharidosis IVA). METHODS: Patients with Morquio A syndrome aged ≥5 years were randomized 1:1:1 to elosulfase alfa 2.0mg/kg/week (qw; N=58), elosulfase alfa 2.0mg/kg/every other week (qow; N=59), or placebo (N=59) for 24 weeks. Primary and secondary efficacy measures were 6-minute walk test (6MWT; primary), 3-minute stair climb test (3-MSCT) and urinary keratan sulfate (KS). Safety was also evaluated. Tertiary efficacy measures included respiratory function measures, activities of daily living (MPS Health Assessment Questionnaire [MPS-HAQ]), anthropometric, echocardiographic and radiographic measures, hearing and corneal clouding assessment. In order to fully characterize treatment impact in this heterogeneous disorder, the effect of elosulfase alfa on composite efficacy measures was evaluated as well. RESULTS: The study was not designed to have sufficient power for any of the tertiary outcomes. For most tertiary endpoints, subjects treated with the weekly dose of elosulfase alfa improved more than those receiving placebo. The largest treatment effects were seen in maximal voluntary ventilation (MVV), MPS-HAQ, height, and growth rate. The qow group appeared similar to placebo. The analysis of a pre-specified composite endpoint (combining changes from baseline in 6MWT, 3MSCT and MVV z-scores equally weighted) showed a modest positive impact of elosulfase alfa qw versus placebo group (P=0.053). As a pre-specified supportive analysis, the O'Brien Rank Sum composite endpoint (changes from baseline in 6MWT, 3MSC, and MVV), analysis also showed that the qw group performed better than the placebo group (P=0.011). In post-hoc analyses, combinations of other endpoints were also explored using the O'Brien Rank Sum test and showed statistically significant differences between elosulfase alfa qw and placebo favoring elosulfase alfa qw. Differences between elosulfase alfa qow and placebo were not statistically significant. Positive changes were observed in most tertiary variables, demonstrating the efficacy of weekly treatment with elosulfase alfa. CONCLUSIONS: Treatment with weekly elosulfase alfa led to improvements across most efficacy measures, resulting in clinically meaningful benefits in a heterogeneous study population.

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

BACKGROUND: Mucopolysaccharidosis 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. PARTICIPANTS: The 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 PROCESS: The 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. RESULTS: Nine of ten statements, concerning general guidelines for management of MPS IVA patients and specific recommendations for treatment, received final consensus. CONCLUSIONS: European 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.

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.

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.

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.

Morquio A syndrome and effect of enzyme replacement therapy in different age groups of Turkish patients: a case series.

BACKGROUND: This case series includes longitudinal clinical data of ten patients with Morquio A syndrome from south and southeastern parts of Turkey, which were retrospectively collected from medical records. All patients received enzyme replacement therapy (ERT). Clinical data collected included physical appearance, anthropometric data, neurological and psychological examinations, cardiovascular evaluation, pulmonary function tests, eye and ear-nose-throat examinations, endurance in the 6-min walk test and/or 3-min stair climb test, joint range of motion, and skeletal investigations (X-rays, bone mineral density). RESULTS: At the time of ERT initiation, two patients were infants (1.8 and 2.1 years), five were children (3.4-7.1 years), and three were adults (16.5-39.5 years). Patients had up to 4 years follow-up. Most patients had classical Morquio A, based on genotypic and phenotypic data. Endurance was considerably reduced in all patients, but remained relatively stable or increased over time in most cases after treatment initiation. Length/height fell below normal growth curves, except in the two infants who started ERT at ≤ 2.1 years of age. All patients had skeletal and/or joint abnormalities when ERT was started. Follow-up data did not suggest improvements in skeletal abnormalities, except in one of the younger infants. Nine patients had corneal clouding, which resolved after treatment initiation in the two infants, but not in the other patients. Hepatomegaly was reported in seven patients and resolved with treatment in five of them. Other frequent findings at treatment initiation were coarse facial features (N = 9), hearing loss (N = 6), and cardiac abnormalities (N = 6). Cardiac disease deteriorated over time in three patients, but did not progress in the others. CONCLUSIONS: Overall, this case series with Morquio A patients confirms clinical trial data showing long-term stabilization of endurance after treatment initiation across ages and suggest that very early initiation of ERT optimizes growth outcomes.

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

BACKGROUND: Mucopolysaccharidosis (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). RESULTS: Thirty-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. CONCLUSIONS: The 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.

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.

Enzyme-Loaded Gel Core Nanostructured Lipid Carriers to Improve Treatment of Lysosomal Storage Diseases: Formulation and In Vitro Cellular Studies of Elosulfase Alfa-Loaded Systems.

Mucopolysaccharidosis IVA (Morquio A) is a rare inherited metabolic disease caused by deficiency of the lysosomal enzyme N-acetylgalatosamine-6-sulfate-sulfatase (GALNS). Until now, treatments employed included hematopoietic stem cell transplantation and enzyme replacement therapy (ERT); the latter being the most commonly used to treat mucopolysaccharidoses, but with serious disadvantages due to rapid degradation and clearance. The purpose of this study was to develop and evaluate the potential of nanostructured lipid carriers (NLCs) by encapsulating elosulfase alfa and preserving its enzyme activity, leading to enhancement of its biological effect in chondrocyte cells. A pegylated elosulfase alfa-loaded NLC was characterized in terms of size, ζ potential, structural lipid composition (DSC and XRD), morphology (TEM microscopy), and stability in human plasma. The final formulation was freeze-dried by selecting the appropriate cryoprotective agent. Viability assays confirmed that NLCs were non-cytotoxic to human fibroblasts. Imaging techniques (confocal and TEM) were used to assess the cellular uptake of NLCs loaded with elosulfase alfa. This study provides evidence that the encapsulated drug exhibits enzyme activity inside the cells. Overall, this study provides a new approach regarding NLCs as a promising delivery system for the encapsulation of elosulfase alfa or other enzymes and the preservation of its activity and stability to be used in enzymatic replacement therapy (ERT).

Recommendations for the management of MPS IVA: systematic evidence- and consensus-based guidance.

INTRODUCTION: Mucopolysaccharidosis (MPS) IVA or Morquio A syndrome is an autosomal recessive lysosomal storage disorder (LSD) caused by deficiency of the N-acetylgalactosamine-6-sulfatase (GALNS) enzyme, which impairs lysosomal degradation of keratan sulphate and chondroitin-6-sulphate. The multiple clinical manifestations of MPS IVA present numerous challenges for management and necessitate the need for individualised treatment. Although treatment guidelines are available, the methodology used to develop this guidance has come under increased scrutiny. This programme was conducted to provide evidence-based, expert-agreed recommendations to optimise management of MPS IVA. METHODS: Twenty six international healthcare professionals across multiple disciplines, with expertise in managing MPS IVA, and three patient advocates formed the Steering Committee (SC) and contributed to the development of this guidance. Representatives from six Patient Advocacy Groups (PAGs) were interviewed to gain insights on patient perspectives. A modified-Delphi methodology was used to demonstrate consensus among a wider group of healthcare professionals with experience managing patients with MPS IVA and the manuscript was evaluated against the validated Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument by three independent reviewers. RESULTS: A total of 87 guidance statements were developed covering five domains: (1) general management principles; (2) recommended routine monitoring and assessments; (3) disease-modifying interventions (enzyme replacement therapy [ERT] and haematopoietic stem cell transplantation [HSCT]); (4) interventions to support respiratory and sleep disorders; (5) anaesthetics and surgical interventions (including spinal, limb, ophthalmic, cardio-thoracic and ear-nose-throat [ENT] surgeries). Consensus was reached on all statements after two rounds of voting. The overall guideline AGREE II assessment score obtained for the development of the guidance was 5.3/7 (where 1 represents the lowest quality and 7 represents the highest quality of guidance). CONCLUSION: This manuscript provides evidence- and consensus-based recommendations for the management of patients with MPS IVA and is for use by healthcare professionals that manage the holistic care of patients with the intention to improve clinical- and patient-reported outcomes and enhance patient quality of life. It is recognised that the guidance provided represents a point in time and further research is required to address current knowledge and evidence gaps.

Cardiopulmonary Exercise Testing Reflects Improved Exercise Capacity in Response to Treatment in Morquio A Patients: Results of a 52-Week Pilot Study of Two Different Doses of Elosulfase Alfa.

OBJECTIVE: To assess impact of a 52-week elosulfase alfa enzyme replacement therapy (ERT) on exercise capacity in Morquio A patients and analyze cardiorespiratory and metabolic function during exercise to uncover exercise limitations beyond skeletal abnormalities. METHODS: Morquio A patients aged ≥7 years, able to walk >200 m in the 6-minute walk test (6MWT), received elosulfase alfa 2.0 mg/kg/week (N = 15) or 4.0 mg/kg/week (N = 10) for 52 weeks in the randomized, double-blind MOR-008 study ( ClinicalTrials.gov NCT01609062) and its extension. Exercise capacity was assessed by 6MWT, 3-minute stair climb test (3MSCT), and cardiopulmonary exercise test (CPET; N = 15 dosage groups combined). RESULTS: Changes over 52 weeks in 6MWT and 3MSCT were minimal. Baseline CPET results showed impaired weight-adjusted peak oxygen uptake (VO2), partly attributable to inability to increase tidal volume during exercise. CPET measures of exercise function showed significant improvement at 25 and/or 52 weeks in exercise duration, peak workload, O2 pulse, and peak tidal volume (% increases in duration, 16.9 (P = 0.0045) and 9.4 (P = 0.0807); peak workload, 26.5 (P = 0.0026) and 21.2 (P = 0.0132); O2 pulse, 10.7 (P = 0.0187) and 2.3 (P = 0.643); peak tidal volume, 11.7 (P = 0.1117) and 29.1 (P = 0.0142)). In addition, decreased VO2/work ratio was noted (% decrease -7.6 [-11.9, 1.3] and -9.2 [-25.7, 5.1]), indicating performance of work at reduced oxygen cost. CONCLUSIONS: CPET uncovers limitation in exercise capacity in Morquio A related to reduced lung function. ERT improves exercise capacity and efficiency of oxygen utilization, not attributable to changes in cardiac or pulmonary function. Further study of the long-term impact of ERT on exercise capacity and the clinical relevance of the observed changes is warranted.

Elosulfase alfa for mucopolysaccharidosis type IVA: Real-world experience in 7 patients from the Spanish Morquio-A early access program.

There is a growing interest in evaluating the effectiveness of enzyme replacement therapy (ERT) with elosulfase alfa in patients with mucopolysaccharidosis type IVA (MPS-IVA) under real-world conditions. We present the experience of seven pediatric MPS-IVA patients from the Spanish Morquio-A Early Access Program. Efficacy was evaluated based on the distance walked in the 6-min walking test (6-MWT) and the 3-min-stair-climb-test (3-MSCT) at baseline and after 8 months of ERT treatment. Additionally, urinary glycosaminoglycans were measured, and a molecular analysis of a GALNS mutation was performed. The health-related quality of life was evaluated using the EuroQoL (EQ)-5D-5 L. The distance walked according to the 6-MWT ranged from 0 to 325 m at baseline and increased to 12-300 m after 8 months with elosulfase alfa (the walked distance improved in all patients except one). An increase was observed for the two patients who had to use a wheelchair. Improvements were also observed for the 3-MSCT in four patients, whereas two patients showed no changes. Three patients showed an improvement in the EQ-VAS score, whereas the scores of three patients remained stable. Regarding urinary glycosaminoglycans measurements, an irregular response was observed. Our results showed overall improvement in endurance and functionality after 8 months of elosulfase alfa treatment in a heterogeneous subset of MPS IVA patients with severe clinical manifestations managed in a real-world setting.