ESPE Abstracts

In children with XLH, excess FGF23 causes hypophosphatemia with consequent rickets, skeletal deformities, and impaired growth and mobility. We previously reported that burosumab improved phosphate homeostasis and rickets in children with XLH. Here, we report final data from this Phase 2 Study CL201 (NCT02163577).Fifty-two children with XLH (5-12 years old, Tanner ≤ 2) were randomized 1:1 to receive subcutaneous burosumab every 2 (Q2W) or 4 (Q4W) we...

In children with XLH, excess FGF23 causes hypophosphatemia with consequent rickets, skeletal deformities, and impaired growth and mobility. We reported that burosumab improved phosphate homeostasis and rickets in children with XLH. Here, we present data on 11/52 subjects (all girls) who developed fused growth plates during the phase 2 study CL201 (NCT02163577).In CL201, 52 subjects (Baseline: 5-12 years-old, Tanner ≤ 2) were randomized 1:1 to recei...

Background/Aim: X-linked hypophosphatemia (XLH) is a rare disease caused by mutations in PHEX, leading to elevated FGF23 levels, hypophosphatemia and chronic renal phosphate wasting. Burosumab is a monoclonal antibody against anti-FGF23, which has been recently approved for treatment of XLH. Beyond clinical trials, little is known about its efficacy/safety in clinical practice which is the aim of study.Patients/Methods: ...

Background/Aim: X-linked hypophosphatemia (XLH) is a rare disease caused by inactivating mutations in the phosphate-regulating endopeptidase homolog X-linked (PHEX) gene, characterized by chronic hypophosphatemia. XLH children present with progressive skeletal deformities (leg bowing, waddling gait, poor growth and disproportional short stature), dental abscesses, and craniosynostosis. Most affected children have been treated so far with multiple dail...

Background: In XLH, high circulating FGF23 causes hypophosphatemia, rickets, and short stature.Objective and hypotheses: To evaluate KRN23 effects on serum phosphate (Pi) level and rickets severity in XLH children in a Phase 2 study.Method: 52 XLH children (ages 5–12 years, ≤Tanner 2) received KRN23 subcutaneously biweekly (Q2W) or monthly (Q4W). Serum Pi was measured at 2-week intervals. KRN23 dose was titrated (maximum...

Background: Hereditary Hypophosphatemic Rickets (HHR) is caused by persistently elevated FGF23 resulting in renal phosphate wasting and decreased 25 vitamin D hydroxylation. Treatment with vitamin D analogues (VDA) has been added to phosphate supplements in the late seventies.Objective and hypotheses: Our objective was to evaluate the outcomes of VDA and phosphate supplements in adult patients with HHR in comparison with patients who did not receive VDA ...

Adeno-associated virus (AAV) gene therapy reached the maturity and a liver-targeting approach is currently used as a replacement treatment for rare hepatic and muscular diseases. X-linked hypophosphatemia (XLH) is a rare disease associated with hyperfunction of fibroblast growth factor 23 (FGF23) in bone and characterized by severe skeletal deformities and short stature. The current medical therapies for XLH requires life-long repeated treatment presenting major limitatio...

Objective: KIGS (Pfizer International Growth Survey) was a large, international database of pediatric patients who received recombinant human growth hormone (rhGH) as prescribed in real-world clinical settings. This analysis evaluated the long-term safety and efficacy data from all participants until KIGS close in 2012.Methods: Children with growth disorders and treated with rhGH (Genotropin® [somatropin]...

Background: X-linked hypophosphatemia (XLH) is caused by mutations in PHEX which increases serum Fibroblast Growth Factor 23 (FGF23) concentrations leading to phosphate wasting and osteomalacia. Burosumab is a recombinant fully human IgG1 monoclonal antibody which selectively inhibits the activity of FGF23. In clinical trials burosumab demonstrated significant clinical improvements in radiological rickets severity, growth, and biochemistry among XLH c...

Background: A new classification of pseudohypoparathyroidism is available (Thiele et al. 2016, J Endocrinol). The phenotype variability of inactivating PTH/PTHrP Signaling Disorders (iPPSD, former pseudohypoparathyroidism) cases is still very challenging, even for experts. Thus, it is crucial to collect data in a centralized manner for future investigation.Methods: The EuRRECa/EuRR-Bone registries are the first ...