36-Months follow-up assessment after cessation and resuming of enzyme replacement therapy in late onset Pompe disease: data from the Swiss Pompe Registry

IntroductionAlthough not curative, enzyme replacement therapy (ERT) with recombinant human acid alpha-glucosidase enzyme has shown to be effective in the treatment of late-onset Pompe disease (LOPD). For this potentially life-long treatment, little is known on the clinical effect of cessation and resuming ERT. Due to a Swiss supreme court decision on ERT reimbursement, a temporary stop of ERT occurred in our study population. The aim of this study was to report the 36-months follow-up assessments after resuming ERT.MethodsAfter resuming ERT, seven patients suffering from genetically and enzymatically confirmed LOPD had periodic, mandatory, prospective assessments of pulmonary function tests, muscle strength summary scores, distances walked in timed walking tests, and patient-reported questionnaires. Data were statistically analyzed for significant differences between time points at ERT cessation, at ERT resuming, and 36 months thereafter.ResultsAfter resuming ERT forced vital capacity (p=0.007) and distance walked in the 6min walk test (6-MWT, p=0.011) significantly increased at 36 months. Compared to before ERT cessation, distance walked in 6-MWT at 36 months still remained significantly lower (p=0.005). Self-reported scores in the fatigue severity scale significantly declined at 36 months after resuming ERT (p=0.019). No other functional or reported parameter significantly changed at 36 months after resuming ERT.ConclusionsOur data suggests that long-term interruption of ERT in LOPD may lead to deterioration of clinical meaningful parameters and quality of life. In addition, a clinical restoration after ERT cessation is possible for most of the LOPD patients within a 36 months follow-up.