A 12-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) and/or cerebral tissue dysfunction documented by evidence of stroke and/or peripheral nervous tissue dysfunction (for example, intolerance to heat/cold, decrease of perspiration) * Must have been previously untreated by enzyme replacement therapy (ERT) or substrate depletion for Fabry disease or were able to stop ERT for at least 18 weeks or up to three months, and be willing to undergo two kidney and three 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 their completion of the study * Were willing and able to sign an informed consent form Exclusion Criteria: * History of significant disease other than Fabry disease * History of organ transplant * Serum creatinine \>2 mg per deciliter on Day -2 * Screening 12-lead ECG demonstrating corrected QT interval \>450 milliseconds prior to dosing * Pacemaker or other contraindication for magnetic resonance imaging (MRI) scanning * Took any of the following prohibited medications: 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