Open-label Extension Study to Evaluate the Long-term Safety, Tolerability and Pharmacodynamics of AT1001 in Patients With Fabry Disease

This was a long-term open-label study of migalastat in participants with Fabry disease who were previously enrolled in a Phase 2 study of migalastat (FAB-CL-201 [NCT00214500], FAB-CL-202 [NCT00283959], FAB-CL-203 [NCT00283933], or FAB-CL-204 [NCT00304512]). Participants could enter this extension study immediately upon completion of participation in their previous study of migalastat, or at a later time point. Thus, some participants did not necessarily have continuous treatment with migalastat from the end of the original study to the time of enrollment into this extension study. Participants who enrolled before Protocol Amendment 2 received migalastat 150 milligrams (mg) orally once every other day (QOD). After the amendment, these participants entered a dose escalation period (DEP) at their next scheduled visit. During the DEP, participants received migalastat 250 mg (once daily [QD] for 3 days and 4 days off per week) for the first 2 months. If there were no safety concerns, the dose was then increased to 500 mg QD for 3 days and 4 days off per week). Participants received 500 mg (QD for 3 days and 4 days off per week) for up to 10 months, depending on the approval date of the protocol amendments at each site. An interim review of safety and PD data was performed after all enrolled participants had completed at least 4 months of treatment in the DEP. After the review, the dose and regimen of migalastat was returned to 150 mg QOD for all participants, except those who were on another dose as previously agreed by the investigator and medical monitor.

The sponsor (Amicus Therapeutics) discontinued Study FAB-CL-205 for logistical reasons and not due to either safety concerns or lack of efficacy. Participants who were ongoing in Study FAB-CL-205 at the time of discontinuation were offered participation in another open-label, long-term treatment study of migalastat (AT1001-041 [NCT01458119]). Participants who did not enroll in Study AT1001-041 were contacted by telephone or another suitable method approximately 1 month after the End of Study (EOS) visit to inquire about adverse events and concomitant medications.