Greater Efficacy of Avalglucosidase vs Alglucosidase Alfa in Adult Pompe Disease?

Pompe disease, glycogen storage disease type II, is a rare autosomal recessive disease caused by pathogenic variants in the GAA gene leading to deficient synthesis of acid alfa-glucosidase (GAA). Deficiency of GAA causes lysosomal dysfunction and glycogen accumulation particularly in cardiac and skeletal muscles.1 The phenotype is largely dependent on the specific variant and the residual level of GAA activity. The severe infantile-onset multisystemic form (IOPD), associated with <1% residual GAA activity, is different from a milder phenotype known as late-onset Pompe disease (LOPD). LOPD develops later in life (childhood to adulthood) and is characterized by progressive weakness affecting limb-girdle and respiratory muscles and associated with GAA activity up to 20% of normal levels.