A Study of AT1001 (Migalastat Hydrochloride) in Participants With Fabry Disease

This was a Phase 2, open-label study in male participants with Fabry disease. All
participants who met initial eligibility criteria underwent a 28-day screening period,
including a 14-day run-in with migalastat (150 milligrams [mg] migalastat once a day [QD]
from Days -28 to -15) to assess eligibility for entering the treatment period of the study.
Participants who entered the treatment period were required to have α-galactosidase A (α-Gal
A) activity responsive to migalastat.

Fifteen participants received at least 1 dose of study drug, however, 6 of these participants
did not demonstrate α-Gal A activity responsive to migalastat and were thus screen failures
(these participants are hereafter referred to as "dosed screen failures") due to not meeting
all inclusion criteria for treatment. Therefore, 9 participants were enrolled into the
treatment period (these participants are hereafter referred to as "eligible-enrolled").

Eligible-enrolled participants (those who satisfied the criteria for inclusion in the study)
received escalating doses of migalastat twice a day (BID) for 6 weeks (Days 1 to 42),
followed by 6 weeks at 1 dose level BID (Days 43 to 84) during the treatment period.
Participants could then opt to participate in the extension period. The study consisted of 2
optional extension periods, the first through Week 48 and the second through Week 96. For
participants who did not continue into the optional treatment extension, the study included a
2-week follow-up period.

Inclusion Criteria:

- Males between 18 and 55 years of age (inclusive)

- Hemizygous for Fabry disease

- Had a confirmed diagnosis of Fabry disease with a documented missense gene mutation
(individual or familial)

- Had enhanceable enzyme activity

- In the judgment of the investigator, were either able to safely suspend ERT throughout
the study, or be ERT naive

- Agreed to be sexually abstinent or use a condom with spermicide when engaging in
sexual activity during the course of the study and for a period of 30 days following
completion of the study

- Were willing and able to sign an informed consent form

Exclusion Criteria:

- History of significant disease other than Fabry disease (for example, end-stage renal
disease; Class III or IV heart disease [per the New York Heart Association
classification]; current diagnosis of cancer, except for basal cell carcinoma of the
skin; diabetes [unless hemoglobin A1c ≤8]; or neurological disease that would have
impaired the participant's ability to participate in the study)

- History of organ transplant

- Serum creatinine >2 mg per deciliter on Day -2

- Screening 12-lead electrocardiogram demonstrating corrected QT interval >450
milliseconds prior to dosing

- Taking a medication prohibited by the protocol: Fabrazyme® (agalsidase beta),
Replagal™ (agalsidase alfa), Glyset® (miglitol), Zavesca® (miglustat), or any
experimental therapy for any indication

- Participated in a previous clinical trial in the last 30 days

- Any other condition, which, in the opinion of the investigator, would jeopardize the
safety of the participant or impact the validity of the study results