Evaluation of the long-term treatment effects of idursulfase using statistical modelling: Data from the Hunter Outcome Survey (HOS)

Treatment for mucopolysaccharidosis type II (MPS II Hunter syndrome) is available in the form of intravenous enzyme replacement therapy (ERT) with idursulfase (Shire, Lexington, MA, USA). This analysis used statistical modelling to evaluate the long-term treatment effects of idursulfase on selected clinical parameters based on data from HOS, a global, observational registry (Shire, Lexington, MA, USA). Mixed modelling was used to analyse data from male patients followed prospectively in HOS who had received idursulfase for 5-8 years and information available for two or more timepoints, of which one was pre-ERT. Data were excluded from patients with only pre-ERT information available, who ha…

Correction: Corrigendum: Long-term, open-labeled extension study of idursulfase in the treatment of Hunter syndrome

CORRIGENDUM: Long-term, open-labeled extension study of idursulfase in the treatment of Hunter syndrome

Cervical spine pathology in Hunter syndrome: Data from the Hunter Outcome Survey

Longitudinal analysis of endurance and respiratory function from a natural history study of Morquio A syndrome

Objectives: Baseline data from the Morquio A Clinical Assessment Program (MorCAP) revealed that individuals with Morquio A syndrome show substantial impairment in multiple domains including endurance and respiratory function (Harmatz et al., Mol Genet Metab, 2013). Here, 1- and 2-year longitudinal endurance and respiratory function data are presented.Methods: Endurance was assessed using the 6-minute walk test (6MWT) and the 3-minute stair climb test (3MSCT). Respiratory function was evaluated by measuring forced vital capacity (PVC) and maximum voluntary ventilation (MW). Data were analyzed using repeated measures ANCOVA models. Annualized estimates of change were determined using model es…

Long-term follow-up of endurance and safety outcomes during enzyme replacement therapy for mucopolysaccharidosis VI: Final results of three clinical studies of recombinant human N-acetylgalactosamine 4-sulfatase

Abstract The objective of this study was to evaluate the long-term clinical benefits and safety of recombinant human arylsulfatase B (rhASB) treatment of mucopolysaccharidosis type VI (MPS VI: Maroteaux-Lamy syndrome), a lysosomal storage disease. Fifty-six patients derived from 3 clinical studies were followed in open-label extension studies for a total period of 97–260 Weeks. All patients received weekly infusions of rhASB at 1mg/kg. Efficacy was evaluated by (1) distance walked in a 12-minute walk test (12MWT) or 6-minute walk test (6MWT), (2) stairs climbed in the 3-minute stair climb (3MSC), and (3) reduction in urinary glycosaminoglycans (GAG). Safety was evaluated by compliance, adve…

Impact of elosulfase alfa in patients with morquio A syndrome who have limited ambulation: An open-label, phase 2 study.

Efficacy and safety of elosulfase alfa enzyme replacement therapy (ERT) were assessed in an open-label, phase 2, multi-national study in Morquio A patients aged ≥5 years unable to walk ≥30 meters in the 6-min walk test. Patients received elosulfase alfa 2.0 mg/kg/week intravenously for 48 weeks. Efficacy measures were functional dexterity, pinch/grip strength, mobility in a modified timed 25-foot walk, pain, quality of life, respiratory function, and urine keratan sulfate (KS). Safety/tolerability was also assessed. Fifteen patients received elosulfase alfa, three patients discontinued ERT due to adverse events (two were grade 3 drug-related adverse events, the other was not drug-related), …

Observational Prospective Natural History of Patients with Sanfilippo Syndrome Type B

To evaluate the natural course of disease progression in patients with Sanfilippo syndrome type B (mucopolysaccharidosis type IIIB), identify potential end points for future therapy trials, and characterize biomarkers related to the disease.A prospective, multicenter study was conducted. Baseline, 6-month, and 12-month assessments included neurodevelopmental status (Bayley Scales of Infant Development, Third edition), adaptive status (Vineland Adaptive Behavior Scales, Second Edition), volumetric brain magnetic resonance imaging, cerebrospinal fluid heparan sulfate, and urine glycosaminoglycan (GAG) measurements.Nineteen patients aged 1.6-31.7 years were enrolled. Over 12 months, cognition,…

Systemic therapies for mucopolysaccharidosis: ocular changes following haematopoietic stem cell transplantation or enzyme replacement therapy - a review

The management of mucopolysaccharidosis (MPS) is focused on the multi-organ, sometimes life-threatening, clinical manifestations that occur over time. In the past, the limited, symptom-based treatment options led physicians to adopt a palliative approach towards individual disease-associated complications. The availability of systemic treatments such as haematopoietic stem cell transplantation (HSCT) and enzyme replacement therapy (ERT) has created a better prognosis for MPS patients, particularly when initiated early in life. As part of an integrated management approach, these therapies could be valuable in managing the ocular features that are present in many children with MPS. HSCT has b…

Multidisciplinary management of Hunter syndrome.

Hunter syndrome is a rare, X-linked disorder caused by a deficiency of the lysosomal enzyme iduronate-2-sulfatase. In the absence of sufficient enzyme activity, glycosaminoglycans accumulate in the lysosomes of many tissues and organs and contribute to the multisystem, progressive pathologies seen in Hunter syndrome. The nervous, cardiovascular, respiratory, and musculoskeletal systems can be involved in individuals with Hunter syndrome. Although the management of some clinical problems associated with the disease may seem routine, the management is typically complex and requires the physician to be aware of the special issues surrounding the patient with Hunter syndrome, and a multidiscipl…

Cardiac disease in patients with mucopolysaccharidosis: presentation, diagnosis and management

The mucopolysaccharidoses (MPSs) are inherited lysosomal storage disorders caused by the absence of functional enzymes that contribute to the degradation of glycosaminoglycans (GAGs). The progressive systemic deposition of GAGs results in multi-organ system dysfunction that varies with the particular GAG deposited and the specific enzyme mutation(s) present. Cardiac involvement has been reported in all MPS syndromes and is a common and early feature, particularly for those with MPS I, II, and VI. Cardiac valve thickening, dysfunction (more severe for left-sided than for right-sided valves), and hypertrophy are commonly present; conduction abnormalities, coronary artery and other vascular in…

Mutational analysis of 105 mucopolysaccharidosis type VI patients

Mucopolysaccharidosis type VI (MPS VI; Maroteaux-Lamy syndrome) is a lysosomal storage disorder caused by mutations in the N-acetylgalactosamine-4-sulfatase (arylsulfatase B, ARSB) gene. ARSB is a lysosomal enzyme involved in the degradation of the glycosaminoglycans (GAG) dermatan and chondroitin sulfate. ARSB mutations reduce enzyme function and GAG degradation, causing lysosomal storage and urinary excretion of these partially degraded substrates. Disease onset and rate of progression is variable, producing a spectrum of clinical presentation. In this study, 105 MPS VI patients—representing about 10% of the world MPS VI population—were studied for molecular genetic and biochemical parame…

Iron Chelation Therapy in thalassaemia major: a sistematic review with meta-analyses of 1520 patients included on randomized clinical trials

The effectiveness of deferoxamine (DFO), deferiprone (DFP), or deferasirox (DFX) in thalassemia major was assessed. Outcomes were reported as means±SD, mean differences with 95% CI, or standardized mean differences. Statistical heterogeneity was tested using χ2 (Q) and I2. Sources of bias and Grading of Recommendations Assessment, Development and Evaluation system (GRADE) were considered. Overall, 1520 patients were included. Only 7.4% of trials were free of bias. Overall measurements suggest low trial quality (GRADE). The meta-analysis suggests lower final liver iron concentrations during associated versus monotherapy treatment (p<0.0001), increases in serum ferritin levels during DFX 5, 1…

Management of chronic viral hepatitis in patients with thalassemia: recommendations from an international panel.

AbstractChelation therapy with new drugs prevents cardiac damage and improves the survival of thalassemia patients. Liver diseases have emerged as a critical clinical issue. Chronic liver diseases play an important role in the prognosis of thalassemia patients because of the high frequency of viral infections and important role of the liver in regulating iron metabolism. Accurate assessment of liver iron overload is required to tailor iron chelation therapy. The diagnosis of hepatitis B virus– or hepatitis C virus–related chronic hepatitis is required to detect patients who have a high risk of developing liver complications and who may benefit by antiviral therapy. Moreover, clinical manage…

Development of a Scoring System to Evaluate the Severity of Craniocervical Spinal Cord Compression in Patients with Mucopolysaccharidosis IVA (Morquio A Syndrome).

BackgroundAs spinal cord compression at the craniocervical junction (CCJ) is a life-threatening manifestation in patients with mucopolysaccharidosis (MPS) IVA, surgical decompression should be performed before damage becomes irreversible. We evaluated the diagnostic value of several examinations for determining the need for decompression surgery.MethodsWe retrospectively analysed results of clinical neurological examination, somatosensory evoked potential (SEP) and magnetic resonance imaging (MRI) in 28 MPS IVA patients. A scoring system - based on the severity of findings - was used to compare results of patients with and without indication for decompression surgery. Individual test scores…

The Morquio A Clinical Assessment Program: Baseline results illustrating progressive, multisystemic clinical impairments in Morquio A subjects

Abstract Objectives The objectives of this study are to quantify endurance and respiratory function and better characterize spectrum of symptoms and biochemical abnormalities in mucopolysaccharidosis IVA subjects. Methods MorCAP was a multicenter, multinational, cross sectional study amended to be longitudinal in 2011. Each study visit required collection of medical history, clinical assessments, and keratan sulfate (KS) levels. Results Data from the first visit of 325 subjects (53% female) were available. Mean age was 14.5 years. Mean ± SD height z-scores were − 5.6 ± 3.1 as determined by the CDC growth charts. Mean ± SD from the 6-minute-walk-test was 212.6 ± 152.2 m, revealing limitation…

Enzyme replacement therapy for mucopolysaccharidosis VI: evaluation of long-term pulmonary function in patients treated with recombinant human N-acetylgalactosamine 4-sulfatase.

Pulmonary function is impaired in untreated mucopolysaccharidosis type VI (MPS VI). Pulmonary function was studied in patients during long-term enzyme replacement therapy (ERT) with recombinant human arylsulfatase B (rhASB; rhN-acetylgalactosamine 4-sulfatase). Pulmonary function tests prior to and for up to 240 weeks of weekly infusions of rhASB at 1 mg/kg were completed in 56 patients during Phase 1/2, Phase 2, Phase 3 and Phase 3 Extension trials of rhASB and the Survey Study. Forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1) and, in a subset of patients, maximum voluntary ventilation (MVV), were analyzed as absolute volume in liters. FEV1 and FVC showed little change f…

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 >= 5 aged years were randomized 1:1:1 to elosulfase alfa 2.0 mg/kg/week (qw; N = 58), elosulfase alfa 2.0 mg/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 r…

A multinational, multidisciplinary consensus for the diagnosis and management of spinal cord compression among patients with mucopolysaccharidosis VI.

Cervical cord compression is a sequela of mucopolysaccharidosis VI, a rare lysosomal storage disorder, and has devastating consequences. An international panel of orthopedic surgeons, neurosurgeons, anesthesiologists, neuroradiologists, metabolic pediatricians, and geneticists pooled their clinical expertise to codify recommendations for diagnosing, monitoring, and managing cervical cord compression; for surgical intervention criteria; and for best airway management practices during imaging or anesthesia. The recommendations offer ideal best practices but also attempt to recognize the worldwide spectrum of resource availability. Functional assessments and clinical neurological examinations …

Brain MRI patterns in MPS IIIB (Sanfilippo syndrome type B): A longitudinal study

A multi-national, randomized, double-blind, placebo-controlled study to evaluate the efficacy and safety of BMN 110 treatment for mucopolysaccharidosis IVA (Morquio syndrome type A)

39 Formation of a Lysosomal Disease Testing Network to enhance the delivery of diagnostic services to patients with lysosomal storage disorders

Long-term, open-labeled extension study of idursulfase in the treatment of Hunter syndrome.

Purpose: This study evaluated the safety and effectiveness of long-term enzyme replacement therapy with idursulfase (recombinant human iduronate-2-sulfatase) in patients with Hunter syndrome. Methods: All 94 patients who completed a 53-week double-blinded study of idursulfase enrolled in this open-labeled extension study and received intravenous idursulfase at a dose of 0.5 mg/kg weekly for 2 years, and clinical outcomes and safety were assessed. Results: No change in percent predicted forced vital capacity was seen, but absolute forced vital capacity demonstrated sustained improvement and was increased 25.1% at the end of the study. Statistically significant increases in 6-minute walking t…

29 Clinical benefit of enzyme replacement therapy (ERT) in mucopolysaccharidosis II (MPS II, Hunter syndrome)

A phase II/III clinical study of enzyme replacement therapy with idursulfase in mucopolysaccharidosis II (Hunter syndrome)

Purpose: To evaluate the safety and efficacy of recombinant human iduronate-2-sulfatase (idursulfase) in the treatment of mucopolysaccharidosis II. Methods: Ninety-six mucopolysaccharidosis II patients between 5 and 31 years of age were enrolled in a double-blind, placebo-controlled trial. Patients were randomized to placebo infusions, weekly idursulfase (0.5 mg/kg) infusions or every-other-week infusions of idursulfase (0.5 mg/kg). Efficacy was evaluated using a composite endpoint consisting of distance walked in 6 minutes and the percentage of predicted forced vital capacity based on the sum of the ranks of change from baseline. Results: Patients in the weekly and every-other-week idursul…