Federal Register Notice: FDA is issuing a priority review voucher to the sponsor of a rare pediatric disease product application, Alexion Pharmaceuticals for Strensiq (asfotase alfa). Asfotase alfa is a long-term enzyme replacement therapy for patients with infantile- and juvenile-onset hypophosphatasia (HPP). HPP is a rare genetic disorder that affects the development of bones and teeth. To view this notice, click here.