Effectiveness of enzyme replacement therapy in adults with late-onset Pompe disease: results from the NCS-LSD cohort study.

OBJECTIVES: To determine the effectiveness of enzyme replacement therapy (ERT) for adults with late-onset Pompe disease. DESIGN: A longitudinal cohort study including prospective and retrospective clinical outcome data. Age- and gender-adjusted treatment effects were estimated using generalised linear mixed models. Treated patients contributed data before and during treatment. Untreated patients contributed natural history data. PARTICIPANTS: Consenting adults (N = 62) with a diagnosis of late-onset Pompe disease who attended a specialist treatment centre in England. This cohort represented 83 % of all patients in the UK with a confirmed diagnosis of this rare condition. At study entry, all but three patients were receiving ERT (range of treatment duration, 0 to 3.1 years). OUTCOME MEASURES: Percent predicted forced vital capacity (%FVC); ventilation dependency; mobility; 6 min walk test (6MWT); muscle strength and body mass index (BMI). RESULTS: An association was found between time on ERT and significant increases in the distance walked in the 6MWT (p < 0.001) and muscle strength scores (p < 0.001). Improvements in both these measures were seen over the first 2 years of treatment with ERT. No statistically significant relationship was found between time on ERT and respiratory function or in BMI. CONCLUSIONS: These data provide some further evidence of the effectiveness of ERT in adults with late-onset Pompe disease. SYNOPSIS: The results of this longitudinal cohort study of 62 adults with late-onset Pompe disease, provide further evidence on the effectiveness of ERT in this rare condition.