Response of women with Fabry disease to enzyme replacement therapy: Comparison with men, using data from FOS—the Fabry Outcome Survey

Fabry disease (α-galactosidase A deficiency) is an X-linked disorder. Women who are heterozygous for disease-causing mutations often manifest signs and symptoms of Fabry disease, but most studies of the effects of enzyme replacement therapy (ERT) have included only men. To date, no direct comparison has been made of the relative effectiveness of long-term ERT between men and women. The aim of this analysis was to report the effectiveness of agalsidase alfa in a cohort of 78 women treated for 4 years and to compare outcomes with those of 172 men. All data were obtained from the Fabry Outcome Survey—an international database of patients with Fabry disease sponsored by Shire Human Genetic Therapies. Quantifiable clinical parameters were assessed at baseline and the 4-year time point. Measures of pain, health-related quality of life, cardiac structure and function, and renal function changed to a similar extent in women and men during treatment, with the exception of left ventricular mass, which only reduced significantly in women. Changes in the presence of each of 27 clinical features after 4 years of ERT were evaluated in two subpopulations: patients with and patients without clinical features at baseline. It was clear for most types of clinical features that a number of women with a feature at baseline were no longer reported to have it at the 4-year time point, and that clinical features were observed in only a small percentage of women in whom they had been absent at baseline. The percentage of patients who were symptomatic at the 4-year time point was calculated for each type of clinical feature. The results showed no significant differences between men and women for most clinical features evaluated. Overall, both sexes responded to agalsidase alfa in a similar way, suggesting there should be no difference in the criteria for assessment of treatment in women and men.