Treatments for Hypophosphatasia

Abstract

Hypophosphatasia due to genetically determined deficient activity of the tissue non-specific alkaline phosphatase (TNAP) is characterized by a wide spectrum of potential clinical manifestations, both, regarding the type of symptoms, as well as the severity of associated deficits. Appropriate treatment strategies should be built on a multimodal approach specifically considering individual disease manifestation. For patients with disease onset before adulthood, enzyme replacement therapy with Asfotase alfa (Strensiq) is approved in Europe to treat the bone manifestation of the disease. Both, available data from clinical trials as well as clinical routine experience confirm basically encouraging results of that treatment in severely affected children with substantial improvement regarding radiographic and functional outcome parameters as well as overall survival. Even in adult patients with severe disease manifestation pursuant to the approval, first results confirm substantial amelioration of disease-specific deficits and functional improvements. Meanwhile, there is also data supporting safety and efficacy of long-term treatment Asfotase alfa over several years. While inflammatory pain, which is typically perceived as being burdensome, can commonly be addressed successfully with NSAIDs on-demand, overall musculoskeletal health requires sustained, multimodal, supportive treatment strategies including exercise interventions as well as age and health state adjusted technical orthopedic support. The use and potential clinical impact of Phosphate and Vitamin B6 on the course of the disease requires further investigation. Current data regarding the use of bone-targeted compounds is critical in terms of antiresorptives while osteoanabolic treatment strategies appear feasible. Ideally, the entirety of therapeutic measures should be coordinated and overlooked at an experienced center while individual tasks can preferably be accomplished at local facilities near the patient's home.