The data show no significant decline in renal function as measured by estimated glomerular filtration rate (eGFR) in treatment-naive patients (n=29); the mean change from baseline, 83.85 +/- 7.12 mL/min/1.73m(2), to 12 months was -1.29 +/- 4.34 mL/min/1.73 m(2), p=0.175. Results were similar in switch patients (n=62), the mean change from baseline, 81.96 +/- 4.57 mL/min/1.73m(2), to 12 months was -3.17 +/- 1.69 mL/min/1.73m(2), p=0.009.Biologic activity by reduction of pathological substrate globotriaosylceramide (Gb(3)) was also demonstrated by decline in both plasma Gb(3) (-2.60 +/- 0.52 nmol/mL; p<0.001 and -6.70 +/- 1.18 nmol/mL; p<0.001 for switch [n=56] and treatment naive patients [n=25] respectively) and creatinine normalized urine Gb(3) (-0.87 +/- 0.37 nmol/mg; p=0.009 and -2.11 nmol/mg; p=0.021) for switch and treatment naive patients respectively. The data suggest that REPLAGAL was generally well tolerated. Safety and tolerability was consistent with the known safety profile of REPLAGAL and no new safety concerns emerged in naive or switch patients over one year of treatment. The safety of REPLAGAL has been well established in over 15 years of clinical and commercial experience. This study was established to provide US Fabry patients with access to REPLAGAL during the Fabrazyme supply shortage. More than 2,800 Fabry patients are being treated with REPLAGAL globally. About REPLAGAL (agalsidase alfa) REPLAGAL is a human form of enzyme alpha-galactosidase A (alpha-Gal A) manufactured in a human cell line by gene activation. 2012 marks over 15 years of clinical experience with REPLAGAL, which is now approved in 46 countries worldwide. REPLAGAL is not approved for commercial sale in the US. REPLAGAL is the only human-cell-line-derived form of enzyme replacement therapy that is indicated for the long-term treatment of patients with a confirmed diagnosis of Fabry disease (alpha-Gal A deficiency). REPLAGAL Important Safety Information The most serious adverse reactions seen with REPLAGAL were hypersensitivity reactions. Infusion-related reactions were the most commonly observed adverse reactions in patients treated with REPLAGAL in clinical studies. Most side effects are mild to moderate and include headache, tingling, numbness, tremors, fatigue, change in temperature sensation, increased blood pressure, upset stomach, diarrhea, coughing, sore throat, difficulty sleeping, change in the taste of food, change in smell, difficulty speaking, acne, dry skin and eye problems. About 1 out of 10 patients may have a reaction during or shortly after infusion of REPLAGAL. These effects include chills and facial flushing (warmth and redness). As with all therapeutic proteins, there is a potential for immunogenicity. IgG antibodies appeared to develop following approximately 3 to 12 months of treatment. After 12 to 54 months of therapy, 17% of REPLAGAL treated patients were antibody positive whereas 7% showed evidence for the development of immunologic tolerance, based on the disappearance of IgG antibodies over time. No IgE antibodies have been detected in any patient receiving REPLAGAL.