Hypophosphastasia (HPP): pathogenesis and current treatment options

Hypophosphatasia (HPP) is a rare, inherited, metabolic bone disease characterized by the abnormal development of bones and teeth, due to defective mineralization (1,2). HPP is caused by inactivating mutation(s) within the gene that encodes the tissue-nonspecific isozyme of alkaline phosphatase (TNSALP) (1). These mutations lead to impaired bone mineralization leading to various skeletal abnormalities such as rickets and fractures, as well as other systemic complications including respiratory manifestations, seizures, dental anomalies, pain, and nephrocalcinosis (1–4). Historically, management of HPP focused solely on supportive therapy in an attempt to minimize disease-related symptoms (1,2). However, in 2015, the Food and Drug Administration (FDA) approved Strensiq® (asfotase alfa), an enzyme replacement therapy approved for the treatment of patients with perinatal/infantile- and juvenile-onset HPP (3,5). This paper will provide an overview of HPP and current and past treatment options for HPP, specially analyzing the effectiveness of the newest enzyme-replacement therapy, Strensiq®, which will be more effective than previously used therapies in preventing the adverse clinical outcomes of HPP