A 24-Week Safety and Pharmacodynamic Study of AT1001 (Migalastat Hydrochloride) in Participants With Fabry Disease

Inclusion Criteria: * Males between 18 and 65 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 based on in vitro tests * Had documented evidence of cardiac and/or renal dysfunction (for example, abnormal electrocardiogram (ECG), left ventricular hypertrophy, renal insufficiency) * Were previously untreated by enzyme replacement therapy (ERT) or substrate depletion for Fabry disease, or if ERT or other specific treatment for Fabry disease was administered, were able to stop ERT for at least 30 weeks. * Were willing to undergo 2 kidney and 3 skin biopsies * 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 \>176 millimole per deciliter on Day -2 * Screening 12-lead ECG 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