Search

This multicenter/multinational, open-label, ascending-dose study (NCT01898364) evaluated safety, tolerability, pharmacokinetics, pharmacodynamics, and exploratory efficacy of repeat-dose avalglucosidase alfa (neoGAA), a second-generation, recombinant acid α-glucosidase replacement therapy, in late-onset Pompe disease (LOPD). Patients ≥18 years, alglucosidase alfa naïve (Naïve) or previously receiving alglucosidase alfa for ≥9 months (Switch), with baseline FVC ≥50% predicted and independently ambulatory, received every-other-week avalglucosidase alfa 5, 10, or 20 mg/kg over 24 weeks. 9/10 Naïve and 12/14 Switch patients completed the study. Avalglucosidase alfa was well-tolerated; no deaths/life-threatening serious adverse events (SAEs). One Naïve patient withdrew for study drug-related SAEs (respiratory distress/chest discomfort). Infusion-associated reactions (IARs) affected 8 patients. Most treatment-emergent AEs/IARs were non-serious with mild-to-moderate intensity. At screening, 5 Switch patients tested positive for anti-avalglucosidase alfa antibodies; on-treatment, 2 Switch and 9 Naïve patients seroconverted. Post-infusion, avalglucosidase alfa plasma concentrations declined monoexponentially (t 1/2z ∼1.0 h). AUC was 5-6 × higher in the 20 vs 5 mg/kg group. Pharmacokinetics were similar between Switch and Naïve groups and over time. Baseline quadriceps muscle glycogen was low (∼6%) in most patients, generally remaining unchanged thereafter. Exploratory efficacy parameters (pulmonary function/functional capacity) generally remained stable or improved. Avalglucosidase alfa's well-tolerated safety profile and exploratory efficacy results support further avalglucosidase alfa development., (Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.)

Glycogen storage disease type II, also known as Pompe disease, is an autosomal recessive disorder caused by deficiency of enzymatic activity of acid alpha-glucosidase. The wide phenotypical variation of this disease relates to the amount of residual enzymatic activity depending on the combination of mutations on each allele. We confirmed Pompe disease in a patient that presented with progressive weakness, recurrent episodes of respiratory failure associated with pneumonia, a predominantly demyelinating mixed sensorimotor polyneuropathy and paraspinal complex repetitive discharges. Genetic analysis of the GAA gene from this patient revealed two pathogenic compound heterozygous mutations: c.-32-13T>G (rs386834236, intronic), c.2560C>T (rs121907943, p.Arg854Ter); and one variant of unknown significance: c.1551+42G>A (rs115427918, intronic). We found expected mutations in two siblings and two nieces. Genetic variants reported in this family reflect on the European and African ancestry that we carry in our Costa Rican population., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background: Late-onset Pompe disease is a rare genetic neuromuscular disorder caused by lysosomal acid alpha-glucosidase (GAA) deficiency that ultimately results in mobility loss and respiratory failure. Current enzyme replacement therapy with recombinant human (rh)GAA has demonstrated efficacy in subjects with late-onset Pompe disease. However, long-term effects of rhGAA on pulmonary function have not been observed, likely related to inefficient delivery of rhGAA to skeletal muscle lysosomes and associated deficits in the central nervous system. To address this limitation, reveglucosidase alfa, a novel insulin-like growth factor 2 (IGF2)-tagged GAA analogue with improved lysosomal uptake, was developed. This study evaluated the pharmacokinetics, safety, and exploratory efficacy of reveglucosidase alfa in 22 subjects with late-onset Pompe disease who were previously untreated with rhGAA., Results: Reveglucosidase alfa plasma concentrations increased linearly with dose, and the elimination half-life was <1.2 h. Eighteen of 22 subjects completed 72 weeks of treatment. The most common adverse events were hypoglycemia (63%), dizziness, fall, headache, and nausea (55% for each). Serious adverse events included hypersensitivity (n = 1), symptomatic hypoglycemia (n = 2), presyncope (n = 1), and acute cardiac failure (n = 1). In the dose-escalation study, all treated subjects tested positive for anti-reveglucosidase alfa, anti-rhGAA, anti-IGF1, and anti-IGF2 antibodies at least once. Subjects receiving 20 mg/kg of reveglucosidase alfa demonstrated increases in predicted maximum inspiratory pressure (13.9%), predicted maximum expiratory pressure (8.0%), forced vital capacity (-0.4%), maximum voluntary ventilation (7.4 L/min), and mean absolute walking distance (22.3 m on the 6-min walk test) at 72 weeks., Conclusions: Additional studies are needed to further assess the safety and efficacy of this approach. Improvements in respiratory muscle strength, lung function, and walking endurance in subjects with LOPD may make up for the risk of hypersensitivity reactions and hypoglycemia. Reveglucosidase alfa may provide a new treatment option for patients with late-onset Pompe disease., Trial Registration: ISRCTN01435772 and ISRCTN01230801 , registered 27 October 2011.

Introduction: Late-onset Pompe disease (LOPD) is a rare disorder characterized by progressive proximal muscle weakness and early respiratory insufficiency, for which enzyme replacement therapy (ERT) is available., Methods: Having diagnosed a case of LOPD presenting with bent spine syndrome, we conducted a brief survey in the French centers involved in management of Pompe disease, from which we collected data on 3 other cases., Results: The patients (3 women and 1 man) had a mean age of 64 years (range 51-77 years) and a delay in diagnosis of approximately 10 years (range 8-42 years). At diagnosis, 3 patients already had respiratory symptoms. All had normal or very mildly raised creatine kinase levels and magnetic resonance imaging abnormalities in the paraspinal muscles. They exhibited the most frequent mutation in Pompe disease (c.-32-13 T>G)., Conclusion: Clinicians should be aware of this atypical presentation of LOPD to enable earlier diagnosis and treatment. Muscle Nerve 56: 167-170, 2017., (© 2016 Wiley Periodicals, Inc.)

Enzyme replacement therapy consistently improves cardiac function in infantile and juvenile onset patients with Pompe disease and cardiomyopathy, but is apparently not effective in preventing rhythm disorders, an emerging cardiac phenotype in long term survivors. In patients with late onset Pompe disease cardiomyopathy is an exceptional finding while heart rhythm disorders seem to be more frequent. We retrospectively identified, among a cohort of 131 French late onset Pompe disease patients, four patients with severe atrio-ventricular blocks requiring pacemaker implantation. These patients had no other risk factors for cardiovascular diseases or cardiomyopathy. In one patient the atrioventricular block was discovered while still asymptomatic. Cardiac conduction defects are relatively rare in late onset Pompe disease and may occur even in absence of cardiac symptoms or EKG abnormalities. However because of the possible life-threatening complications associated with these conduction defects, cardiac follow-up in patients with late onset Pompe disease should include periodical Holter-EKG monitoring., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Purpose of Review: The first reports published in 2010 on enzyme replacement therapy in late-onset Pompe disease (LOPD) allow us now to stand back and adapt the strategies. In the meantime, substantial progress has been made in basic and applied research on animal models to enhance the efficacy of treatments. This brief review highlights the new concepts in a contemporary approach., Recent Findings: Interest in LOPD rose since its acknowledgement as a treatable myopathy. New insights from extensive analysis of injurious mechanisms resulted, over the past years, in the development of enzyme replacement therapy and a better understanding of its limits., Summary: It seems reasonable to consider Pompe disease as a large spectrum of a single ubiquitous lysosomal disease resulting from an enzyme defect, more severe in newborns because of rapid cardiopulmonary and hepatic failures, with a much better prognosis when symptomatic after 12 months. This late-onset form demands therapy to avoid progressive motor disability and pulmonary insufficiency. Diagnosis is easy to confirm through rapid and reliable biochemical tests with sampling of blood dots on filter paper. When started early, treatment would avoid serious irrevocable damage to cells. Increasing precocity of diagnosis and efficacy of treatments are the core challenges for the next few years.

Cerebral aneurysms and arteropathies causing severe cerebrovascular events have been reported as rare complications in patients with late-onset Pompe disease. We investigated the frequency of cerebrovascular anomalies in six patients with late-onset Pompe disease followed at our institution. Clinical data collection and magnetic resonance angiography were performed as part of routine annual examinations. Four out of six patients had brain vascular anomalies including dolichoectasia of the basilar artery and ectasia of internal carotids. These patients also complained of gastrointestinal symptoms (chronic constipation and gastrointestinal reflux). Two patients had clinical signs related to the arteriopathy, including partial paralysis of the third cranial nerve and transient ischemic attacks. At 1 year follow-up, enzyme replacement therapy did not modify the size of cerebral vessels, but patients reported a marked improvement of intestinal symptoms. In conclusion, neurologists should be aware that intracranial artery abnormalities are not infrequent in patients with late-onset Pompe disease, and they should be specifically investigated in the presence of unexplained CNS symptoms.

Background and purpose Pompe disease is a rare inheritable muscle disorder for which enzyme replacement therapy ( ERT) has been available since 2006. Uniform criteria for starting and stopping ERT in adult patients were developed and reported here. Methods Three consensus meetings were organized through the European Pompe Consortium, a network of experts from 11 European countries in the field of Pompe disease. A systematic review of the literature was undertaken to determine the effectiveness of ERT in adult patients on a range of clinical outcome measures and quality of life. A narrative synthesis is presented. Results Consensus was reached on how the diagnosis of Pompe disease should be confirmed, when treatment should be started, reasons for stopping treatment and the use of ERT during pregnancy. This was based on expert opinion and supported by the literature. One clinical trial and 43 observational studies, covering a total of 586 individual adult patients, provided evidence of a beneficial effect of ERT at group level. At individual patient level, the response to treatment varied, but factors associated with a patient's response to ERT were not described in many studies. Eleven observational studies focused on more severely affected patients, suggesting that ERT can also be beneficial in these patients. There are no studies on the effects of ERT in pre-symptomatic patients. Conclusions This is the first European consensus recommendation for starting and stopping ERT in adult patients with Pompe disease, based on the extensive experience of experts from different countries. [ABSTRACT FROM AUTHOR]