A Study of Two Fabrazyme (Agalsidase Beta) Dosing Regimens in Treatment-naïve, Male Pediatric Patients Without Severe Symptoms

The purpose of this study was to determine whether 2 alternative dosing regimens of Fabrazyme (Agalsidase beta) (1.0 mg/kg every 4 weeks or 0.5 mg/kg every 2 weeks) were effective in treatment-naïve pediatric participants without severe symptoms. Participants were to be treated for 5 years.


Eligibility Criteria:
Inclusion Criteria:

* The participant and/or participant's parent(s)/legal guardian(s) must provide written informed assent/consent prior to any protocol-related procedures being performed.
* The participant must had a confirmed diagnosis of Fabry disease as documented by leukocyte α-Galactosidase A (αGAL) activity of \<4 nmol/hr/mg leukocyte (preferred assay; resulted from a central laboratory). If the leukocyte αGAL activity assay was difficult to obtain, the participant might be enrolled based on documented plasma αGAL \<1.5 nmol/hr/mL, with the agreement of the Medical Monitor (resulted from a central laboratory).
* The participant must had evidence of globotriaosylceramide (GL-3) accumulation as documented by plasma GL-3 (\>7.0 µg/mL) or urinary GL-3 (\>0.3 mg GL-3/mmol creatinine) levels (results from a central laboratory).
* The participant must be male ≥5 and ≤18 years of age.

Exclusion Criteria:

* Participant had albuminuria (first morning void urinary albumin/creatinine ratio \>30 mg/g on at least 2 out of 3 consecutive samples, each at least 1 week apart).
* Participant had a Glomerular Filtration Rate (GFR) by iohexol \<90 L/min/1.73m\^2. In case of properly documented low protein intake, values as low as 80 mL/min/1.73 m\^2 might be acceptable, after consultation with the Medical Monitor.
* Participant had documented evidence of stroke or transient ischemic attack (TIA), or if a brain magnetic resonance imaging (MRI) had been performed, bright lesions \>2 mm on T2- or fluid attenuated inversion recovery (FLAIR)- weighted images within the white matter or the basal ganglia.
* Participant had severe and recurrent acroparesthesia, judged by the physician as frequent (more than once a week) pain episodes for at least 3 months that influenced daily activities, irrespective of medication.
* Participant had an end-diastolic left ventricular posterior wall thickness (LVPWTd) and/or an end-diastolic interventricular septum thickness (IVSTd)≥2 standard deviations (SD) compared to normal (based on body surface area \[BSA\] normal ranges from Kampmann, et al 2000) as read at the study site.
* Participant had received prior treatment specific to Fabry Disease.
* Participant had participated in a study employing an investigational drug within 30 days of the start of their participation in this study.
* Participant had any medical condition or extenuating circumstance, which in the opinion of the Study Investigator, could interfere with study compliance.
* Participant had any medical condition or extenuating circumstance, for example diabetes mellitus, which in the opinion of the Study Investigator, could interfere with the interpretation of study results.
* Participant was on treatment with angiotensin converting enzyme inhibitors/angiotensin receptor blockers (ACEIs/ARBs).
* Participant had any contra-indication mentioned in the labeling of Fabrazyme and/or iohexol (Omnipaque).
* Participant or parent(s)/legal guardian(s) was unwilling to comply with the requirements of the protocol.