The primary analysis compared the number of responders in the migalastat HCl versus placebo groups, based on a 50% or greater reduction in interstitial capillary globotriaosylceramide (GL-3) during the 6-month, double-blind treatment period. GL-3 – also referred to as peritubular capillary (PTC) inclusions – is measured in kidney biopsies. Pathologists blinded to biopsy sequence used the published, quantitative Barisoni Lipid Inclusion Scoring System with virtual microscopy (BLISS-VM) for the histological evaluation of interstitial capillary GL-3 in Study 011. BLISS is a more sensitive scoring system to measure GL-3 inclusions in PTCs compared to the semi-quantitative methodology used in previous pivotal studies of enzyme replacement therapy (ERT) for Fabry disease. Secondary endpoints for Study 011 include safety and tolerability, urine GL-3 and kidney function.
About Migalastat HCl
Amicus in collaboration with GlaxoSmithKline (GSK) is developing the investigational pharmacological chaperone migalastat HCl for the treatment of Fabry disease. Amicus has commercial rights to all Fabry products in the United States and GSK has commercial rights to all of these products in the rest of world. As a monotherapy, migalastat HCl is designed to bind to and stabilize, or "chaperone" a patient's own alpha-galactosidase A (alpha-Gal A) enzyme in those patients with genetic mutations that are amenable to this chaperone in a cell-based assay. Oral migalastat HCl monotherapy is in Phase 3 development ( Study 011 and Study 012) for Fabry patients with amenable mutations. Study 011 is a placebo-controlled study intended primarily to support U.S. registration, and Study 012 is comparing open-label migalastat HCl to ERT to primarily support global registration.
For patients currently receiving ERT for Fabry disease, migalastat HCl in combination with ERT may improve ERT outcomes by keeping the infused alpha-Gal A enzyme in its properly folded and active form. Migalastat HCl co-administered with ERT is in Phase 2 ( Study 013) and migalastat HCl co-formulated with JCR Pharmaceutical Co. Ltd's proprietary investigational ERT (JR-051, recombinant human alpha-Gal A enzyme) is in preclinical development. Migalastat HCl is subject to evaluation by regulatory authorities before being made available as a treatment for patients.About Fabry Disease Fabry disease is an inherited lysosomal storage disorder caused by deficiency of an enzyme called alpha-galactosidase A (alpha-Gal A). The role of alpha-Gal A within the body is to break down specific lipids in lysosomes, including globotriaosylceramide (GL-3, also known as Gb3). Lipids that can be degraded by the action of α-Gal are called "substrates" of the enzyme. Reduced or absent levels of alpha-Gal A activity leads to the accumulation of GL-3 in the affected tissues, including the kidneys, heart, central nervous system, and skin. This accumulation of GL-3 is believed to cause the various manifestations of Fabry disease, including pain, kidney failure, and increased risk of heart attack and stroke.