Alexion gets FDA approval for Strensiq as first treatment for infant hypophosphatasia

The US Food and Drug Administration has approved Alexion Pharmaceuticals’ (Nasdaq: ALXN) Strensiq (asfotase alfa) as the first treatment for perinatal, infant and juvenile-onset hypophosphatasia (HPP).

Strensiq has been designated a Breakthrough therapy and orphan drug by the FDA. It works by replacing tissue-nonspecific alkaline phosphatase "responsible for formation of an essential mineral in normal bone, which has been shown to improve patient outcomes." The drug’s efficacy and safety were established across four trials and 99 patients receiving treatment for up to 6.5 years. Patients with perinatal- and infantile-onset HPP treated with Strensiq improved overall survival and ventilator-free survival, with 97% of treated patients being alive at one year of age, versus 42% of controls selected from a natural history database. Ventilator-free survival at one year was 85% in Strensiq-treated patients, compared with less than 50% of control patients.

Those with juvenile-onset HPP given Strensiq showed improvements in growth and bone health compared to controls, while around 20% of control patients experienced growth delays over time.