G.P.8.08 Early results in a cohort of late-onset Pompe patients treated with enzyme replacement

Introduction: Pompe disease, a rare, recessively inherited lysosomal storage disease and glycogenosis (type II) affecting infants severely and in adults causing skeletal muscle and respiratory weakness with a less aggressive course, has become part of the changing face of neuromuscular medicine as specific treatments become available. Acid alpha-glucosidase (GAA) enzyme replacement has a clearly advantageous effect on survival in infantile disease (Kishnani 2007, Neurology 68). Methods: GAA (Myozyme®, Genzyme Corp.) has been used in France since May 2005 in adults and we have collected clinical and evaluation data from 13 French neuromuscular reference centres in a database, the independent French Pompe Registry. Results: Of 79 patient with data recorded in the Register 62 are currently receiving enzyme replacement. Four patients have died and another 3 have discontinued treatment. Results of functional respiratory (forced seated and slow supine vital capacity) and muscular measures (timed transfer tasks, Motor Function Measure) were compared before and after the start of IV GAA at 20 mg/kg/fortnight in 35 patients with a pretreatment measurement period of at least 12 months and a treatment duration of 18 months to 3 years. The rates of change of these parameters before and after the start of treatment are analysed to evaluate whether this therapy has a positive effect in stabilising the course of this disease in adults.