Clinical outcomes in elderly patients receiving agalsidase alfa treatment in the Fabry Outcome Survey

Background and objectives: Treatment with agalsidase alfa in patients with Fabry disease is most effective when initiated early in the disease course; however, the clinical benefits in elderly patients are less well established. This analysis assesses outcomes in patients aged 65 years or older from the Fabry Outcome Survey (FOS) who were treated with agalsidase alfa. Methods: FOS data were extracted for adult patients aged 65 years or older who received agalsidase alfa, had baseline data and at least 3 years of post-baseline data, and had undergone no renal transplantation and/or dialysis before treatment. The data of patients who had undergone renal transplantation and/or dialysis during follow-up were excluded from estimated glomerular filtration rate (eGFR) analysis after the date of the renal transplantation and/or dialysis. Adult patients were stratified into two groups: those who started treatment before 65 years of age and who were still being treated when aged 65 years or older (group A), and those who started treatment when aged 65 years or older (group B). Mean annual changes in left ventricular mass index (LVMI), eGFR and proteinuria were assessed in group A (before and after the age of 65 years to understand if there was an age-related effect once patients turned 65 years of age) and in group B. Results: Estimated mean (standard error [SE]) annual changes in LVMI were 0.46 (0.26) g/m2.7 and 0.21 (0.42) g/m2.7 in patients in group A when they were younger than 65 years and when they were aged 65 years or older, respectively, and 0.12 (0.65) g/m2.7 in patients in group B. For eGFR, mean (SE) annual changes were 0.83 (2.12) mL/min/1.73 m2 and 2.64 (2.18) mL/min/1.73 m2 in patients in group A when they were younger than 65 years and when they were aged 65 years or older, respectively, and 2.31 (1.44) mL/min/1.73 m2 in patients in group B. Proteinuria remained relatively stable in both subgroups of group A (before and after the age of 65 years) and group B. Conclusions: Continuation and initiation of agalsidase alfa treatment in patients aged 65 years or older with Fabry disease were associated with stabilization of proteinuria and minimal increases in cardiac (LVMI) and renal (eGFR) outcomes.