X-linked Hypophosphatemia Disease Monitoring Program

Study Overview
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Brief Summary
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The objectives of this observational study are to characterize XLH disease presentation and progression and to assess long-term effectiveness and safety of burosumab.

Detailed Description
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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.

Official Title
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X-linked Hypophosphatemia Disease Monitoring Program (XLH-DMP)

Conditions
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X-linked Hypophosphatemia, Hypophosphatemic Rickets

Intervention / Treatment
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* Other: No intervention


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Willing and able to provide informed consent or, in the case of patients under the age of 18 years (or 16 years, depending on the region), provide assent (if required) and informed consent by a legally authorized representative after the nature of the study has been explained, and prior to any research-related procedures. Clinical diagnosis of XLH based on family history, OR confirmed PHEX mutation, OR biochemical profile consistent with XLH. Willing and able to comply with the study visit schedule and study procedures. Exclusion Criteria: Concurrent enrollment in an Ultragenyx-sponsored clinical trial is NOT permitted. Serious medical or psychiatric comorbidity. Less than one year of life expectancy.
Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Prior Burosumab Clinical Trial Participants<br>Patients who participated in burosumab clinical trials and continue to receive burosumab via prescription from their physician. | Other: No intervention<br>* Access to any treatment is through authorized commercial use and not as a part of this DMP<br>|
| Not from Prior Burosumab Clinical Trial<br>Patients may take other treatments for XLH and may start burosumab treatment at any time as prescribed by a physician. | Other: No intervention<br>* Access to any treatment is through authorized commercial use and not as a part of this DMP<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 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. | 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. | 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. | 10 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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X-linked Hypophosphatemia, Fibroblast growth factor 23 (FGF23), KRN23, XLH, Hypophosphatemia, Familial Hypophosphatemic Rickets, FGF23, Crysvita