Ibiglustat (GZ402671) is a potent and selective Glucosylceramide synthase inhibitor and ceramide glucosyltransferase inhibitor. Ibiglustat blocks the formation of glucosylceramide (GL-1), a key intermediate in the synthesis of GL-3. Ibiglustat is potentially useful for treating Fabry disease. Fabry disease is a rare lysosomal storage disorder, which results in abnormal tissue deposits of a particular fatty substance called globotriaosylceramide (GL-3 or Gb3) throughout the body.