Patient Monitoring

Treating physicians will determine the actual frequency of necessary assessments according to a patient’s individualized need for medical care and routine follow-up. As a minimum, however, a Recommended Schedule of Assessments has been developed based on the input of physicians from the international medical community with expertise in the care of patients with Fabry disease and from regulatory agencies. The recommended schedule represents the core assessments that are currently thought to monitor Fabry-related clinical manifestations and to stage disease progression across the life-long course of the disease. The assessments include cerebrovascular, cardiac, renal, ophthalmologic, gastroenterologic, dermatologic, and neurologic (pain) manifestations, as well as quality of life (QOL).

Initial assessments such as enzyme activity levels and genotyping as well as periodic monitoring of laboratory values, in particular serum creatinine, urine protein excretion (24 hour or first morning void urine for protein, microalbumin and urine creatinine), IgG antibodies (to Fabrazyme) and plasma GL-3 are also recommended. Glomerular filtration rate (GFR) can be measured using methods such as inulin clearance, creatinine clearance, EDTA clearance and iothalamate at the physician’s discretion. GFR will be estimated using an equation derived from the Modification of Diet in Renal Disease Study^[1] for adults and from the Schwartz formula ^[2] for children when analyzing the data.

Plasma GL-3 level and IgG antibody testing are provided by Genzyme. Plasma GL-3 level measurements are recommended prior to the start of treatment with Fabrazyme, every 3 months for the first 18 months of treatment, and then every 6 months. Samples will be obtained on the same schedule as recommended for antibody collection. Additional GL-3 or IgG samples collected by the treating physician outside of this monitoring schedule may be tested with consultation with a Genzyme Safety Officer. Plasma GL-3 may be a useful pharmacodynamic marker for long-term patient follow-up. If significant elevations of plasma GL-3 are observed over time in patients receiving Fabrazyme, serum specimens may be tested for inhibitory antibodies to Fabrazyme after consultation with a Genzyme Safety Officer.

Adherence to these recommendations is encouraged since they facilitate the Fabry Registry’s intent for consistent and thorough clinical evaluations, which may reveal changes in a patient’s status and provide information for a database to fulfill the scientific objectives of the Fabry Registry.

Download Recommended Schedule of Assessments (PDF)

References
1. Levey, A.S., T. Greene, J.W. Kusek, G.L. Beck, MDRD Study Group. A simplified equation to predict glomerular filtration rate from serum creatinine (abstract). J Am Soc Nephrol, 2000, Sep; 11:155A.

2. Schwartz GJ, Brion LP, Spitzer A. The use of plasma creatinine concentration for estimating glomerular filtration rate in infants, children and adolescents. Pediatr Clin North Am 34 (1987) 571-590.