Safety and pharmacodynamic effects of a pharmacological chaperone on α-galactosidase A activity and globotriaosylceramide clearance in Fabry disease: report from two phase 2 clinical studies.

Abstract

BACKGROUND:

Fabry disease (FD) is a genetic disorder resulting from deficiency of the lysosomal enzyme α-galactosidase A (α-Gal A), which leads to globotriaosylceramide (GL-3) accumulation in multiple tissues. We report on the safety and pharmacodynamics of migalastat hydrochloride, an investigational pharmacological chaperone given orally at 150 mg every-other-day.

METHODS:

Two open-label uncontrolled phase 2 studies of 12 and 24 weeks (NCT00283959 and NCT00283933) in 9 males with FD were combined. At multiple time points, α-Gal A activity and GL-3 levels were quantified in blood cells, kidney and skin. GL-3 levels were also evaluated through skin and renal histology.

RESULTS:

Compared to baseline, increased α-Gal A activity of at least 50% was demonstrated in blood, skin and kidney in 6 of 9 patients. Patients' increased α-Gal A activities paralleled the α-Gal A increases observed in vitro in HEK-293 cells transfected with the corresponding mutant form of the enzyme. The same 6 patients who demonstrated increases of α-Gal A activity also had GL-3 reduction in skin, urine and/or kidney, and had α-Gal A mutations that responded in transfected cells incubated with the drug. The 3 patients who did not show a consistent response in vivo had α-Gal A mutations that did not respond to migalastat HCl in transfected cells. Migalastat HCl was well tolerated.

CONCLUSIONS:

Migalastat HCl is a candidate pharmacological chaperone that provides a novel genotype-specific treatment for FD. It enhanced α-Gal A activity and resulted in GL-3 substrate decrease in patients with responsive GLA mutations. Phase 3 studies are ongoing.

• Authors: Dominique P Germain, Roberto Giugliani, Derralynn A Hughes, Atul Mehta, Kathy Nicholls, Laura Barisoni, Charles J Jennette, Alexander Bragat, Jeff Castelli, Sheela Sitaraman, David J Lockhart, Pol F Boudes
• Journal: Orphanet journal of rare diseases (Orphanet J Rare Dis) Vol. 7 Pg. 91 (Nov 24 2012) ISSN: 1750-1172 [Electronic] England
• PMID: 23176611 (Publication Type: Clinical Trial, Phase II, Journal Article)

Chemical References

• Molecular Chaperones
• Trihexosylceramides
• globotriaosylceramide
• alpha-Galactosidase

Topics

• Fabry Disease (drug therapy, enzymology, metabolism, pathology)
• Humans
• Male
• Molecular Chaperones (adverse effects, therapeutic use)
• Trihexosylceramides (metabolism)
• alpha-Galactosidase (metabolism)