ALPL and hypophosphatasia: Asfotase alfa (Strensiq®; Alexion, AstraZeneca Rare Disease, Boston, MA, USA) is a human recombinant TNSALP enzyme replacement therapy (ERT) approved for the treatment of perinatal/infantile- and juvenile-onset HPP; in Japan, asfotase alfa is approved for all patients with HPP, regardless of age at onset.