asfotase

Asfotase, also known as asfotase alfa, is a recombinant human enzyme designed as an enzyme replacement therapy for hypophosphatasia (HPP), a rare inherited disorder caused by loss-of-function mutations in the ALPL gene that encode tissue nonspecific alkaline phosphatase (TNSALP). It provides alkaline phosphatase activity and is modified with a bone-targeting domain to localize to bone, where it catalyzes the hydrolysis of pyrophosphate, an inhibitor of mineralization, thereby promoting proper bone mineralization.

Indications include pediatric-onset hypophosphatasia, particularly perinatal and infantile forms, with use in other pediatric cases as determined by clinicians. The therapy is administered by subcutaneous injection on a regular schedule, and dosing is weight-based and individualized to the patient.

In clinical use, asfotase alfa has been associated with improved survival in the infantile form of HPP and with improvements in skeletal mineralization, growth, respiratory function, and motor development. The safety profile includes injection-site reactions and fever as common events, with rare hypersensitivity and other adverse events requiring monitoring. Long-term effects on mineral metabolism and bone health are overseen by treating physicians.

History and availability: asfotase alfa was developed for hypophosphatasia and is marketed under the brand name Strensiq. It received regulatory approval in 2015 in the United States and has since been approved in multiple regions for the treatment of hypophosphatasia, particularly in pediatric populations, with ongoing evaluation of long-term outcomes.