Assessment of plasma lyso-Gb(3) for clinical monitoring of treatment response in migalastat-treated patients with Fabry disease

PURPOSE: To assess the utility of globotriaosylsphingosine (lyso-Gb(3)) for clinical monitoring of treatment response in patients with Fabry disease receiving migalastat. METHODS: A post hoc analysis evaluated data from 97 treatment-naive and enzyme replacement therapy (ERT)–experienced patients with migalastat-amenable GLA variants from FACETS (NCT00925301) and ATTRACT (NCT01218659) and subsequent open-label extension studies. The relationship between plasma lyso-Gb(3) and measures of Fabry disease progression (left ventricular mass index [LVMi], estimated glomerular filtration rate [eGFR], and pain) and the relationship between lyso-Gb(3) and incidence of Fabry-associated clinical events (FACEs) were assessed in both groups. The relationship between changes in lyso-Gb(3) and kidney interstitial capillary (KIC) globotriaosylceramide (Gb(3)) inclusions was assessed in treatment-naive patients. RESULTS: No significant correlations were identified between changes in lyso-Gb(3) and changes in LVMi, eGFR, or pain. Neither baseline lyso-Gb(3) levels nor the rate of change in lyso-Gb(3) levels during treatment predicted FACE occurrences in all patients or those receiving migalastat for ≥24 months. Changes in lyso-Gb(3) correlated with changes in KIC Gb(3) inclusions in treatment-naive patients. CONCLUSIONS: Although used as a pharmacodynamic biomarker in research and clinical studies, plasma lyso-Gb(3) may not be a suitable biomarker for monitoring treatment response in migalastat-treated patients.