Enzyme replacement therapy with alglucosidase alfa in 44 patients with late-onset glycogen storage disease type 2: 12-month results of an observational clinical trial
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Late-onset glycogen storage disease type 2 (GSD2)/Pompe disease is a progressive multi-system disease evoked by a deficiency of lysosomal acid α-glucosidase (GAA) activity. GSD2 is characterized by respiratory and skeletal muscle weakness and atrophy, resulting in functional disability and reduced life span. Since 2006 alglucosidase alfa has been licensed as a treatment in all types of GSD2/Pompe disease. We here present an open-label, investigator-initiated observational study of alglucosidase alfa enzyme replacement therapy (ERT) in 44 late-onset GSD2 patients with various stages of disease severity. Alglucosidase alfa was given i.v. at the standard dose of 20 mg/kg every other week. Assessments included serial arm function tests (AFT), Walton Gardner Medwin scale (WGMS), timed 10-m walk tests, four-stair climb tests, modified Gowers’ maneuvers, 6-min walk tests, MRC sum score, forced vital capacities (FVC), creatine kinase (CK) levels and SF-36 self-reporting questionnaires. All tests were performed at baseline and every 3 months for 12 months of ERT. We found significant changes from baseline in the modified Gowers’ test, the CK levels and the 6-min walk test (341 ± 149.49 m, median 342.25 m at baseline; 393 ± 156.98 m; median 411.50 m at endpoint; p = 0.026), while all other tests were unchanged. ERT over 12 months revealed minor allergic reactions in 10% of the patients. No serious adverse events occurred. None of the patients died or required de novo ventilation. Our clinical outcome data imply stabilization of neuromuscular deficits over 1 year with mild functional improvement.
KeywordsEnzyme replacement therapy Glycogen storage disease type 2 Pompe disease Alglucosidase alfa
We thank the patients and their families for their patience and long-term cooperation. We also thank the technical team at the involved treatment centers. We thank Dr. Dieter Gläser for performing genetic analyses in some of our patients and Prof. Klaus V. Toyka for helpful comments.
- 4.Joshi PR, Glaeser D, Schmidt S, Vorgerd M, Winterholler M, Eger K, Zierz S, Deschauer M Molecular genetic characterization of German patients with late-onset glycogen storage disease type II. J Inherit Metab Dis, PMID: 18607768 (in press)Google Scholar
- 9.Müller-Felber W, Horvath R, Gempel K, Podskarbi T, Shin YS, Pongratz D, Walter MC, Baethmann M, Schlotter-Weigel B, Lochmüller H, Schoser BGH (2007) Late-onset Pompe disease: clinical and neurophysiological spectrum of 38 patients with a long-term follow-up in 18 patients. Neuromuscul Disord 17:698–706CrossRefPubMedGoogle Scholar
- 10.Pompe JC (1932) Over idiopathische hypertrofie van het hart. Ned Tijdsch Geneesk 76:304–311Google Scholar
- 12.Schoser BGH, Müller-Höcker J, Gempel K, Horvath R, Pongratz D, Lochmüller H, Muller-Felber W (2007) Glycogen storage disease type 2: clinic-pathological phenotype revisited. Neuropathol Appl Neurol 33:544–559Google Scholar