An observational study in X-linked Hypophosphatemia and Hypophosphatemic Rickets, sponsored by Ultragenyx Pharmaceutical Inc. Active, not recruiting at 38 sites in 6 countries. Per ClinicalTrials.gov, last updated 2026-08-28.
Sponsored by Ultragenyx Pharmaceutical Inc · Observational
The objectives of this observational study are to characterize XLH disease presentation and progression and to assess long-term effectiveness and safety of burosumab.
The XLH-DMP is a global, prospective, multicenter, longitudinal, long-term outcomes program for subjects on or off any treatment designed to characterize XLH disease presentation and progression, assess long-term safety and effectiveness of burosumab, as well as prospectively investigate longitudinal change over time across biomarker(s), clinical assessments, and patient/caregiver-reported outcome measures in a representative population. The XLH-DMP will collect demographic, biochemical, physiologic, disease severity, and progression data in patients taking burosumab and those not taking burosumab. In this DMP, patients will only have access to burosumab through authorized prescribed use. The Sponsor will not provide any treatments as part of the DMP.
49 studies on the registry are indexed under Familial Hypophosphatemic Rickets; 8 are open to participants now.
This study's enrollment of 782 is above the median of 50 across 16 observational studies indexed under Familial Hypophosphatemic Rickets.
Browse Familial Hypophosphatemic Rickets studies →Ultragenyx Pharmaceutical Inc is the lead sponsor of 63 studies on the registry; 8 are open to participants now.
Of its 16 completed or terminated interventional studies of FDA-regulated products, 12 (75%) have results posted.
Counted across the registry records on this site, refreshed daily.
Approximately 800 eligible adult and pediatric patients with XLH will be enrolled globally, with a minimum of 200 pediatric patients. Patients can enter the XLH-DMP regardless of how their XLH is being treated. Patients on Crysvita (burosumab) via prescription may begin taking Crysvita, per standard of care before or after enrolling in the XLH DMP.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Life expectancy
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Patients who participated in burosumab clinical trials and continue to receive burosumab via prescription from their physician.
Other: No intervention
Patients may take other treatments for XLH and may start burosumab treatment at any time as prescribed by a physician.
Other: No intervention
Access to any treatment is through authorized commercial use and not as a part of this DMP
Long-Term Safety of Burosumab
To assess the long-term safety of burosumab treatment in adult and pediatric patients with XLH, including overall renal health, the presence and/or progression of nephrocalcinosis and spinal stenosis, and pregnancy outcomes.
Time frame: 10 years
Long-Term Effectiveness of Burosumab
To evaluate the long-term effectiveness of burosumab treatment on key manifestations of XLH, including skeletal health, stiffness, mobility and physical functioning.
Time frame: 10 years
Clinical Course of XLH Disease
To illustrate the clinical, radiological, biochemical manifestations and progression of XLH over time in both untreated and treated patients with XLH.
Time frame: 10 years
This study is active, not recruiting, as verified in Aug 2026. You cannot join it, but the record below documents what was studied.
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Familial Hypophosphatemic Rickets →
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