Migalastat (GR181413A free base) hydrochloride is an orally active α-galactosidase A molecular chaperone, with an IC 50 value of 0.04 μM for human α-Gal A. Migalastat binds to the active site of certain unstable mutant forms of α-galactosidase A, facilitating their transport to the lysosome. After dissociation in the acidic environment, Migalastat enables the mutant α-galactosidase A to exhibit biological activity.