Treatment of Fabry Disease: Outcome of a Comparative Trial with Agalsidase Alfa or Beta at a Dose of 0.2 mg/kg

Two different enzyme preparations, agalsidase alfa (Replagal(TM), Shire) and beta (Fabrazyme(TM), Genzyme), are registered for treatment of Fabry disease. We compared the efficacy of and tolerability towards the two agalsidase preparations administered at identical protein dose in a randomized controlled open label trial.Thirty-four Fabry disease patients were treated with either agalsidase alfa or agalsidase beta at equal dose of 0.2 mg/kg biweekly. Primary endpoint was reduction in left ventricular mass after 12 and 24 months of treatment. Other endpoints included occurrence of treatment failure (defined as progression of cardiac, renal or cerebral disease), glomerular filtration rate, pain, anti-agalsidase antibodies, and globotriaosylceramide levels in plasma and urine. After 12 and 24 months of treatment no reduction in left ventricular mass was seen, which was not different between the two treatment groups. Also, no differences in glomerular filtration rate, pain and decline in globotriaosylceramide levels were found. Antibodies developed only in males (4/8 in the agalsidase alfa group and 6/8 in the agalsidase beta group). Treatment failure within 24 months of therapy was seen in 8/34 patients: 6 male patients (3 in each treatment group) and 2 female patients (both agalsidase alfa). The occurrence of treatment failures did not differ between the two treatment groups; chi(2) = 0.38 p = 0.54.Our study revealed no difference in reduction of left ventricular mass or other disease parameters after 12 and 24 months of treatment with either agalsidase alfa or beta at a dose of 0.2 mg/kg biweekly. Treatment failure occurred frequently in both groups and seems related to age and severe pre-treatment disease.International Standard Randomized Clinical Trial ISRCTN45178534 [http://www.controlled-trials.com/ISRCTN45178534]

Screening for Fabry disease using whole blood spots fails to identify one-third of female carriers

Introduction. Recently, a method to analyse dried whole blood spots to diagnose Fabry disease (deficiency of the lysosomal enzyme alphaGal A) was described. However given its X-linked inheritance female Fabry patients can exhibit normal alphaGal A activities. This could lead to underestimation in screening females for Fabry disease using this method. Methods. aGal A activity was measured in dried whole blood spots of 21 females with documented Fabry disease. Results. Only 13/21 (67%) had reduced aGal A activities, concluding that one-third of female carriers would not be identified during screening. Additional determination of alphaGlucosidase activity (alphaGlu) and the construction of an alphaGal/alphaGlu ratio did not increase sensitivity of the assay. Conclusion. Assays using alphaGal activity for determination of Fabry disease in females have a high false-negative value. Screening for a-Gal A deficiency by means of whole blood spots should not be performed in a females. (C) 2004 Elsevier B.V. All rights reserve

Novel therapeutic targets for the treatment of Fabry disease

Fabry disease is an X-linked lysosomal storage disorder resulting from deficient activity of alpha-galactosidase A. The traditional concept that is used to explain the complications of the disease involves progressive accumulation of globotriaosylceramide in endothelial and smooth muscle cells, resulting in vascular damage. Clinically, progressive renal insufficiency, cardiac involvement and brain pathology evolves. Two pharmaceutical companies have developed enzyme replacement therapy in Fabry disease. Although the first clinical trials showed great promise, it is clear that long-term effects are not as robust as was anticipated. Stabilisation of renal function and decreases in cardiac hypertrophy has been observed, but some patients may experience progressive complications. As there are recent indications that serum components contribute to the pathophysiology of Fabry disease, fundamental studies are needed to unravel the precise role and identity of these factors. Combination of these basic studies with clinical follow up may ultimately reveal when the 'point of no return' is reached. Advanced renal insufficiency seems to be a clinical indicator of lack of response, but other signs and symptoms are probably related to adverse outcome. It is anticipated that in the future controlled studies in early symptomatic or presymptomatic patients will be required. In addition, alternative strategies such as substrate reduction or chaperone therapy, either alone or in combination with enzyme replacement therapy, should be explored. Because Fabry disease is rare, collaborative efforts should be undertaken and openness of data should be strived fo

Home treatment for Fabry disease: practice guidelines based on 3 years experience in The Netherlands

INTRODUCTION: Recently, chronic supplementation with alpha-galactosidase A (alphaGal A) has been approved as a treatment modality for Fabry disease. The aim of the current study was to investigate the feasibility of home therapy for Fabry disease during a follow-up of >3 years and to make a proposal for practice guidelines. METHODS: Based on experience in previous clinical trials, an algorithm for home treatment eligibility was developed. The number of successful and uneventful infusions was recorded, as well as adverse and infusion-associated events. The presence and titre of recombinant human (rh)-alphaGal A antibodies were monitored every 3 months. RESULTS: Thirty of the 36 patients eligible for home treatment received a total of 1418 infusions at home (median 44 infusions, range 1-108), between March 2001 and July 2005. Mean age was 44.7 years (17-71). Seventeen patients receiving home treatment (57%) were male. The majority of patients (27 out of 30, 90%) undergoing home treatment received 0.2 mg/kg agalsidase alpha or beta. Six male patients developed an infusion-associated event, of which three developed these at home. All patients with an infusion-associated event were anti-rh-alphaGal A IgG positive at 3 months, but three patients with rh-alphaGal A antibodies did not develop side effects. Antibody titres between these patients did not differ. None of the events was life-threatening or necessitated urgent admission. CONCLUSION: Home treatment with rh-alphaGal A for Fabry disease with 0.2 mg/kg for males and both 1.0 and 2.0 mg/kg for females is feasible and safe, and reduces both the burden related to chronic intravenous therapy and health care costs. Whether this can also be applied for male patients treated with 1.0 mg/kg has not yet been determine

Sustained, long-term renal stabilization after 54 months of agalsidase beta therapy in patients with Fabry disease

Fabry disease, an inherited deficiency of the lysosomal enzyme alpha-galactosidase A, causes progressive intralysosomal accumulation of globotriaosylceramide (GL-3) and premature death from renal, cardiac, and cerebrovascular manifestations. To determine the long-term safety and efficacy of recombinant human alpha-galactosidase A, an open-label, phase III extension study was conducted, involving 58 patients who had classic Fabry disease and completed a 20-wk, double-blind, randomized, placebo-controlled, phase III study of agalsidase beta and were transitioned to an extension trial to receive biweekly 1 mg/kg agalsidase beta for up to an additional 54 mo. GL-3 accumulation was evaluated in the capillary endothelia of the skin, kidney, and heart. Renal function was assessed. By month 54, all patients with optional kidney biopsies (n = 8) maintained complete GL-3 clearance in renal capillary endothelial cells and multiple cell types. Continued, complete clearance of skin (31 of 36) and heart (six of eight) capillary endothelium was demonstrated. Mean plasma GL-3 levels remained decreased in the normal range. Median serum creatinine and estimated GFR remained stable (normal) in patients with renal data at month 54 (n = 41). Six patients had renal disease progression; most (four of six) were older than 40 yr and had significant proteinuria at baseline and evidence of sclerotic glomeruli pretreatment. Adverse events were generally mild and unrelated to treatment. The most common treatment-related adverse events were infusion-associated reactions, which decreased over time. Long-term agalsidase beta therapy stabilizes renal function in patients without renal involvement at baseline, maintains reduction of plasma GL-3, and sustains GL-3 clearance in capillary endothelial cells and multiple renal cell type