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

Study to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of migalastat hydrochloride (HCl) (migalastat) 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.

Eligibility Criteria:
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