Low-dose agalsidase beta treatment in male pediatric patients with Fabry disease: A 5-year randomized controlled trial

Mol Genet Metab. 2019 May;127(1):86-94. doi: 10.1016/j.ymgme.2019.03.010. Epub 2019 Apr 3.


Background: Fabry disease is a rare, X-linked, lifelong progressive lysosomal storage disorder. Severely deficient α-galactosidase A activity in males is associated with the classic phenotype with early-onset, multisystem manifestations evolving to vital organ complications during adulthood. We assessed the ability of 2 low-dose agalsidase beta regimens to lower skin, plasma, and urine globotriaosylceramide (GL-3) levels, and influence clinical manifestations in male pediatric Fabry patients.

Methods: In this multicenter, open-label, parallel-group, phase 3b study, male patients aged 5-18 years were randomized to receive agalsidase beta at 0.5 mg/kg 2-weekly (n = 16) or 1.0 mg/kg 4-weekly (n = 15) for 5 years. All had plasma/urine GL-3 accumulation but no clinically evident organ involvement. The primary outcome was GL-3 accumulation in superficial skin capillary endothelium (SSCE).

Results: The mean age was 11.6 (range: 5-18) years and all but one of the 31 patients had classic GLA mutations. In the overall cohort, shifts from non-0 to 0-scores for SSCE GL-3 were significant at years 1, 3, and 5, but results were variable. Plasma GL-3 normalized and urine GL-3 reduced substantially. Higher anti-agalsidase beta antibody titers were associated with less robust SSCE GL-3 clearance and higher urine GL-3 levels. Renal function remained stable and normal. Most Fabry signs and symptoms tended to stabilize; abdominal pain was significantly reduced (-26.3%; P = .0215). No new clinical major organ complications were observed. GL-3 accumulation and cellular and vascular injury were present in baseline kidney biopsies (n = 7). Treatment effects on podocyte GL-3 content and foot process width were highly variable. Fabry arteriopathy overall increased in severity. Two patients withdrew and 2 had their agalsidase beta dose increased.

Conclusions: Our findings increase the limited amount of available data on long-term effects of enzyme replacement therapy in pediatric, classic Fabry patients. The low-dose regimens studied here over a period of 5 years did not demonstrate a consistent benefit among the patients in terms of controlling symptomatology, urine GL-3 levels, and pathological histology. The current available evidence supports treatment of pediatric, classic male Fabry patients at the approved agalsidase beta dose of 1.0 mg/kg 2-weekly if these patients are considered for enzyme replacement therapy with agalsidase beta.

Keywords: Agalsidase beta; Biopsy; Classic phenotype; Clinical outcomes; Enzyme replacement therapy; Fabry disease; Globotriaosylceramide; Pediatric; Podocytes; Superficial skin capillary endothelium; Symptoms.

Publication types

  • Clinical Trial, Phase III
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Child
  • Child, Preschool
  • Dose-Response Relationship, Drug
  • Enzyme Replacement Therapy / statistics & numerical data*
  • Fabry Disease / drug therapy*
  • Humans
  • Isoenzymes / therapeutic use*
  • Male
  • Skin / chemistry
  • Skin / pathology
  • Treatment Outcome
  • Trihexosylceramides / analysis
  • alpha-Galactosidase / therapeutic use*


  • Isoenzymes
  • Trihexosylceramides
  • globotriaosylceramide
  • alpha-Galactosidase
  • agalsidase beta