Migalastat

Migalastat (or 1-deoxygalactonojirimycin; trade names Galafold and formerly Amigal) is a drug for the treatment of Fabry disease, a rare genetic disorder. It was developed by Amicus Therapeutics. The US Food and Drug Administration (FDA) assigned it orphan drug status in 2004, and the European Committee for Medicinal Products for Human Use (CHMP) followed in 2006. The European Commission approved the drug in May 2016.The enzyme alpha-galactosidase A (α-GalA)Globotriaosylceramide (Gb3), a substrate of α-GalA, has a terminal D-galactose structurally similar to migalastat.Migalastat ('top' view) Migalastat (or 1-deoxygalactonojirimycin; trade names Galafold and formerly Amigal) is a drug for the treatment of Fabry disease, a rare genetic disorder. It was developed by Amicus Therapeutics. The US Food and Drug Administration (FDA) assigned it orphan drug status in 2004, and the European Committee for Medicinal Products for Human Use (CHMP) followed in 2006. The European Commission approved the drug in May 2016. Migalastat is used for the long-term treatment of Fabry disease in adults and adolescents aged 16 or older with an amenable mutation of the enzyme alpha-galactosidase A (α-GalA). An 'amenable' mutation is one that leads to misfolding of the enzyme, but otherwise would not significantly impair its function. Based on an in vitro test, Amicus Therapeutics has published a list of 269 amenable and nearly 600 non-amenable mutations. About 35 to 50% of people with Fabry have an amenable mutation. The most common side effect in clinical trials was headache (in about 10% of people who take it). Less common side effects (between 1 and 10% of people) included unspecific symptoms such as dizziness, fatigue, and nausea, but also depression. Possible rare side effects could not be assessed because of the low number of subjects in the clinical trials in which adverse effects were measured. When combined with intravenous agalsidase alfa or beta, which are recombinant versions of the enzyme α-GalA, migalastat increases tissue concentrations of functional α-GalA compared to agalsidase given alone. This is an expected and desired effect. Migalastat does not inhibit or induce cytochrome P450 liver enzymes or transporter proteins and is therefore expected to have a low potential for interactions with other drugs. Fabry disease is a genetic disorder caused by various mutations of the enzyme α-GalA, which is responsible for breaking down the sphingolipid globotriaosylceramide (Gb3), among other glycolipids and glycoproteins. Some of these mutations result in misfolding of α-GalA, which subsequently fails protein quality control in the endoplasmic reticulum and is decomposed. Lack of functional α-GalA leads to accumulation of Gb3 in blood vessels and other tissues, with a wide range of symptoms including kidney, heart, and skin problems. Migalastat is a potent, orally available inhibitor of α-GalA (IC50: 4 μM). When binding to faulty α-GalA, it shifts the folding behaviour towards the proper conformation, resulting in a functional enzyme provided the mutation is amenable. Molecules with this type of mechanism are called pharmacological chaperones. When the enzyme reaches its destination, the lysosome, migalastat dissociates because of the low pH and the relative abundance of Gb3 and other substrates, leaving α-GalA free to fulfill its function. Depending on the mutation, the EC50 is between 0.8 µM and over 1 mM in cellular models.