A Study of the Safety and Efficacy of Fabrazyme in Patients With Fabry Disease

A Multicenter, Open-label Study of Low Dose Maintenance Treatment of Fabrazyme (Recombinant Human Alpha-Galactosidase A (R-h Alpha-GAL)) Replacement Therapy in Patients With Fabry Disease

People with Fabry disease have an alteration in their genetic material (DNA) which causes a deficiency of the alpha-galactosidase A enzyme. This enzyme helps to break down and remove certain types of fatty substances called "glycolipids." These glycolipids are normally present within the body in most cells. In people with Fabry disease, glycolipids build up in various tissues such as the liver, kidney, skin, and blood vessels because alpha-galactosidase A is not present, or is present in small quantities. The build up of glycolipid levels (also referred to as "globotriaosylceramide" or "GL-3") in these tissues is thought to cause the clinical symptoms that are common to Fabry disease. Symptoms commonly appear during childhood with pain in the hands and feet. This trial is designed to evaluate the efficacy of a lower dose of Fabrazyme in patients who initially received 1.0 mg/kg every 2 weeks of Fabrazyme by investigating if the achieved clearance of glycosphingolipid deposits in the vascular endothelium of the kidney can be maintained at a lower dose.

Inclusion Criteria:

• Have clinical manifestations of Fabry disease
• All patients have to have a plasma αGAL activity of < 1.5 nmol/hr/mL or a documented leukocyte αGAL activity of < 4 nmol/hr/mg
• Patient or patient's parent/guardian had to provide written informed consent prior to any study-related procedures being performed
• Patients had to be male and ≥ 16 years of age

Exclusion Criteria:

• There is evidence of renal insufficiency, as defined by serum creatinine greater than or equal to 2.2 mg/dL (194.7 μmol/L) AND/OR has an estimated glomerular filtration rate (GFR) of <80 mL/min (using the equation derived from the Modification of Diet in Renal Disease Study (MDRD))
• Has undergone kidney transplantation or is currently on dialysis
• Has a clinically significant organic disease or an unstable condition (with the exception of symptoms relating to Fabry disease) that in the opinion of the Investigator would preclude participation in the trial
• Has participated in a study employing an investigational drug within 30 days of the start of this trial
• Patients who received prior treatment with enzyme replacement therapy for Fabry disease
• Patient was unable to comply with the requirements of the protocol