ESPE Abstracts

Background: XLH is a rare, genetic, life-long disease caused by PHEX pathogenic variants. It is associated with progressive accumulation of musculoskeletal features and symptoms that evolve across the patient’s lifetime if untreated. Although the disease is well characterised in children and adults, there are limited data describing the health outcomes and experiences of adolescents, particularly at end of skeletal growth (EOSG), a crucial phase during t...

Objectives: X-linked hypophosphataemia (XLH) is a rare, hereditary phosphate-wasting disorder characterised by excessive activity of fibroblast growth factor 23. The International XLH Registry (NCT03193476) (initiated in August 2017, target 1,200 children and adults with XLH, running for 10 years) will provide information on the natural history of XLH and impact of treatment on patient outcomes. This report summarises baseline data from the first interim analy...

Background: X-linked hypophosphatemia (XLH) is a rare, progressive, genetic phosphate wasting disorder leading to rickets, lower limb deformities as well as short and disproportionate stature. The condition is inherited in the majority, however spontaneous mutations are reported in ≈30% of cases. Its rarity, coupled with its diverse clinical manifestations, may lead to delayed diagnosis and subsequently delayed treatment initiation. The objective of this an...

In a randomized open-label phase 3 trial in 62 children (1–12 years) with X-linked hypophosphatemia (XLH) (NCT 02915705), switching from conventional therapy (oral phosphate plus active vitamin D) to burosumab, a monoclonal antibody targeting fibroblast growth factor 23, significantly improved serum phosphate concentration, rickets, lower-extremity deformities, growth, mobility, and patient-reported outcomes (PROs) at 64 weeks. Children in Europe, USA, Canada, and Australia wh...