Pompe Disease
BMN-103: Acid Alpha-Glucosidase for Pompe
Pompe Disease is a fatal genetic muscle disorder caused by a deficiency of acid α-glucosidase (GAA), a lysosomal enzyme that is responsible for the breakdown of glycogen. Pompe Disease is a glycogen storage disorder affecting almost all tissues of the body, with the heart, diaphragm, and skeletal muscles being the most seriously affected. This disease presents itself mainly in three phenotypes; the infantile form which is the most severe phenotype; the juvenile form, and the adult form, which has the highest incidence of occurrence (1/50,000). The estimated worldwide prevalence of all forms is 5,000-10,000 people.
BioMarin’s proposed treatment for Pompe disease is enzyme replacement of GAA, which is expected to result in clearance of glycogen from the lysosome. Although a product is on the market that works by the same mechanism (Myozyme® by Genzyme), BioMarin has a version of recombinant human acid α-glucosidase (rhGAA) that has increased numbers of mannose-6-phosphates, which are expected to provide better delivery to tissues resulting in improved efficacy with less enzyme.