Cardiomyopathy and kidney function in agalsidase beta‐treated female Fabry patients: a pre‐treatment vs. post‐treatment analysis

Aims Long‐term treatment effect studies in large female Fabry patient groups are challenging to design because of phenotype heterogeneity and lack of appropriate comparison groups, and have not been reported. We compared long‐term cardiomyopathy and kidney function outcomes after agalsidase beta treatment with preceding treatment‐naive outcomes. Methods and results Self‐controlled pretreatment and post‐treatment comparison (piecewise mixed linear modelling) included Fabry female patients ≥18 years at treatment initiation who received agalsidase beta (0.9–1.1 mg/kg every other week) for ≥2 years, with ≥2 pretreatment and ≥2 post‐treatment outcome measurements during 10‐year follow‐up. Left ventricular posterior wall thickness (LVPWT)/interventricular septal thickness (IVST) and estimated glomerular filtration rate (eGFR, Chronic Kidney Disease Epidemiology Collaboration creatinine equation) analyses included 42 and 86 patients, respectively, aged 50.0 and 46.3 years at treatment initiation, respectively. LVPWT and IVST increased pretreatment (follow‐up 3.5 years) but stabilized during 3.6 years of treatment (LVPWT: n = 38, slope difference [95% confidence interval (CI)] = −0.41 [−0.68, −0.15] mm/year, Ppre–post difference