Open-label Long-term Safety Study of AT1001 (Migalastat Hydrochloride) in Participants With Fabry Disease Who Have Completed a Previous AT1001 Study

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.

Inclusion Criteria:

- Must have completed another Phase 2 study of migalastat in Fabry Disease

- Women of childbearing potential must have had a negative result on their pregnancy
test

- Male and female participants agreed to use a reliable method of contraception during
study treatment and for 4 weeks after study treatment termination

- Were willing and able to provide written informed consent

Exclusion Criteria:

- Had not completed a Phase 2 study of migalastat in Fabry Disease

- Had a major protocol violation in the preceding migalastat trial and was discontinued

- Had undergone or was scheduled to undergo kidney transplantation or was currently on
dialysis

- Had been treated with another investigational drug (except migalastat) within 30 days
of study start

- Had been treated with Fabrazyme® (agalsidase beta), Replagal™ (agalsidase alfa),
Glyset® (miglitol), or Zavesca® (miglustat) within 2 weeks prior to enrollment