MedTrace Logo

Effective Dosing of Burosumab in XLH

NCT07183579 · Status: RECRUITING · Type: OBSERVATIONAL · Enrollment: 120

Last updated 2026-05-11

No results posted yet for this study

Summary

X-linked hypophosphataemia (XLH) is a rare, hereditary condition. The genetic defect leads to low blood phosphate levels and vitamin D suppression. Phosphate is required for strong bones and teeth and to store energy in cells. Low phosphate leads to soft bones (rickets). Patients experience bowed legs, short stature, bone pain and dental pain.

Prior to Burosumab, conventional treatment of XLH previously consisted of two medications. On this regimen, patients take oral phosphate supplements 4-6 times a day and an active form of vitamin D daily. This treatment can leave patients with residual symptoms. They report significant disabilities and reduced quality of life.

Burosumab (Crysvita, Kyowa Kirin) is now the standard paediatric treatment for XLH. It is given once a fortnight by injection under the skin. Early studies used a starting dose of 0.4mg/kg per dose. NICE recommends a starting dose of 0.4mg/kg, a normal maintenance dose of 0.8mg/kg and a maximum of 2mg/kg (up to 90mg). The British National Formulary for Children (BNFC) gives the same advice.

However, the European Medicines Agency recommends a starting dose of 0.8mg/kg per dose which is, therefore, the standard starting dose now. Some patients achieve symptom and biochemical control on less than 0.8 mg/kg per dose. They may be exposed to higher doses than necessary.

To date, approximately 200 patients have started on Burosumab in England. They are all managed by specialist centres. The rare status of XLH means there are relatively few patients in each centre. Treatment effects and trends can only be described by collating data from multiple centres.

The investigators will undertake a review across multiple English centres of the doses of Burosumab. The review will only collect data already in the patients' health records. It will look at factors affecting the starting dose. The investigators will assess the association between dose, blood markers and growth.

Conditions

  • X-linked Hypophosphatemia (XLH)

Sponsors & Collaborators

  • Nottingham University Hospitals NHS Trust

    collaborator OTHER

  • Birmingham Women's and Children's NHS Foundation Trust

    collaborator OTHER

  • University Hospitals Bristol and Weston NHS Foundation Trust

    collaborator OTHER

  • University Hospital Southampton NHS Foundation Trust

    collaborator OTHER

  • Sheffield Children's NHS Foundation Trust

    collaborator OTHER

  • Manchester University NHS Foundation Trust

    collaborator OTHER_GOV

  • Newcastle-upon-Tyne Hospitals NHS Trust

    collaborator OTHER

  • Alder Hey Children's NHS Foundation Trust

    collaborator OTHER

  • University of Nottingham

    lead OTHER

Principal Investigators

  • James Law, BMBS, PhD, MRCPCH · University of Nottingham

Eligibility

Min Age
2 Years
Max Age
18 Years
Sex
ALL
Healthy Volunteers
No

Timeline & Regulatory

Start
2025-11-03
Primary Completion
2026-07-01
Completion
2026-07-01

Countries

  • United Kingdom

Study Locations

More Related Trials

Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT07183579 on ClinicalTrials.gov