X Linked HypophosphatemiaIdeFIXNCT04946409
Burden of Disease and Functional Impairment in XLH
An observational study of X Linked Hypophosphatemia, run by Wuerzburg University Hospital at 1 site in Germany.
Trial summary
Observational study comprising prospective follow up as well as retrospective chart review in order to evaluate the longitudinal course of the disease in XLH patients with a specific focus on functional impairment, physical performance and complications associated with the disease or respective treatment. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- X Linked Hypophosphatemia
- How many people
- 60 participants
- Where
- 1 siteGermany
- Study dates
- 1 Oct 2020to Oct 2026
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Adult, Older adult
Study population: Adult patients with X-linked Hypophosphatemia
Who may be able to join
- Male or female, aged ≥ 18 years, inclusive, at the time of enrollment
- Diagnosis of X-linked Hypophosphatemia confirmed by
- documented PHEX mutation in either the patient, or in a directly related family member
- positive family history of XLH and symptoms of the disease or
- Phosphaturia + elevated serum levels of c-term FGF23 or iFGF23 and symptoms of the disease
- Written informed consent
Who cannot join
- Suspected of confirmed diagnosis of another phosphate wasting disorder
Trial locations and contacts
1 site in 1 country.
Germany1 site
Orthopedic Center for Musculoskeletal Research, Orthopedic Department, University of Wuerzburg
Würzburg, 97074
About this study
Official title: Identification of Longitudinal Burden of Disease and Functional Impairment in X-Linked Hypophosphatemia
Observational study comprising prospective follow up as well as retrospective chart review in order to evaluate the longitudinal course of the disease in XLH patients with a specific focus on functional impairment, physical performance and complications associated with the disease or respective treatment.
Read the detailed description
This is an observational / non-interventional study in order to assess the longitudinal course of XLH including disease related burden of disease and functional impairment. This is accomplished by both prospective follow up of affected patients as well as retrospective chart review. Evaluation conducted as per clincal routine and specifically evaluated as part of this study will include
- baseline documententation / demographic (as obtained from medical records)
- general data on XLH-disease specific medical history
- physical examination results
- functional assessments
- technical assessments
- quality of life / questionnaires
- laboratory evaluations
- Conditions
- X Linked Hypophosphatemia
- Being tested
- no intervention
- Medical subject headings
- Familial Hypophosphatemic Rickets
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
no interventionOther
no intervention
What is being measured
The primary outcome is the main question the study is designed to answer.
Course of disease
To document and assess the natural course of disease, associated symptoms and functional impairment in adult patients with XLH.
Measured: retrospective and up to 48 months from enrollment
Secondary outcomes (6)
Comorbidities and medical treatment
Assess and document comorbidities and medical treatment regimens applied in adult patients with XLH
Measured: retrospective and up to 48 months from enrollment
Functional deficits and mobility constraints
Assess and document functional deficits and mobility constraints in adult patients with XLH
Measured: retrospective and up to 48 months from enrollment
Laboratory values
Assess laboratory parameters over time in adults with XLH
Measured: retrospective and up to 48 months from enrollment
Organ / tissue specific health issues
Describe frequency and outcome of organ / tissue specific health issues (affecting e.g. skeleton, dental health, muscles and joints) in adults with XLH
Measured: retrospective and up to 48 months from enrollment
Safety and tolerability of treatment
Evaluate safety and tolerability of various treatment regimens commonly applied in XLH patients
Measured: retrospective and up to 48 months from enrollment
Quality of life
Assess quality of life and respective determining factors in adults patients with XLH
Measured: retrospective and up to 48 months from enrollment
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted30 Jun 2021
- Study start1 Oct 2020
- Primary completion30 Nov 2024
- Study completionOct 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for X Linked HypophosphatemiaStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Other
- Enrolment
- 60 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Wuerzburg University Hospital
- Sponsor type
- University, hospital or other
- Collaborators
- Kyowa Kirin, Inc.
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04946409
- Sponsor's protocol ID
- IdeFIX
- Acronym
- IdeFIX
- Status last verified
- Jul 2025
- First submitted
- 22 Jun 2021
- Last updated
- 20 Jul 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data cannot be shared in order to warrant patients privacy.
Study at a glance
From the registry record, last updated by the sponsor on 20 Jul 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Identification of Longitudinal Burden of Disease and Functional Impairment in X-Linked Hypophosphatemia
- ClinicalTrials.gov ID
- NCT04946409
- Acronym / sponsor ID
- IdeFIX / IdeFIX
- Conditions
- X Linked Hypophosphatemia
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 60 participants (estimated)
- Lead sponsor
- Wuerzburg University HospitalUniversity, hospital or other
- Collaborators
- Kyowa Kirin, Inc.
- Study start
- 1 Oct 2020 (actual)
- Primary completion
- 30 Nov 2024 (actual)
- Study completion
- Oct 2026 (estimated)
- First posted
- 30 Jun 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Observational study comprising prospective follow up as well as retrospective chart review in order to evaluate the longitudinal course of the disease in XLH patients with a specific focus on functional impairment, physical performance and complications associated with the disease or respective treatment.
Detailed description
This is an observational / non-interventional study in order to assess the longitudinal course of XLH including disease related burden of disease and functional impairment. This is accomplished by both prospective follow up of affected patients as well as retrospective chart review. Evaluation conducted as per clincal routine and specifically evaluated as part of this study will include
- baseline documententation / demographic (as obtained from medical records)
- general data on XLH-disease specific medical history
- physical examination results
- functional assessments
- technical assessments
- quality of life / questionnaires
- laboratory evaluations
Study design
- Observational model
- Cohort
- Time perspective
- Other
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Age groups
- Adult, Older adult
- Study population
- Adult patients with X-linked Hypophosphatemia
Key inclusion criteria (6 listed)
- Male or female, aged ≥ 18 years, inclusive, at the time of enrollment
- Diagnosis of X-linked Hypophosphatemia confirmed by
- Written informed consent
Key exclusion criteria (1 listed)
- Suspected of confirmed diagnosis of another phosphate wasting disorder
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| no interventionno intervention | Other | – |
Primary outcome
Course of disease
Time frame: retrospective and up to 48 months from enrollment
To document and assess the natural course of disease, associated symptoms and functional impairment in adult patients with XLH.
6 secondary outcomes
Comorbidities and medical treatment
Time frame: retrospective and up to 48 months from enrollment
Functional deficits and mobility constraints
Time frame: retrospective and up to 48 months from enrollment
Laboratory values
Time frame: retrospective and up to 48 months from enrollment
Organ / tissue specific health issues
Time frame: retrospective and up to 48 months from enrollment
Safety and tolerability of treatment
Time frame: retrospective and up to 48 months from enrollment
Quality of life
Time frame: retrospective and up to 48 months from enrollment
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 20 Jul 2025.
- Individual participant dataSharing planned: No. Individual participant data cannot be shared in order to warrant patients privacy.
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Recruiting
Phosphorus-31 Spectroscopy in Phosphate Diabetes
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Registry for Patients With X-Linked Hypophosphatemia
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of X Linked Hypophosphatemia, run by Wuerzburg University Hospital at 1 site in Germany.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 20 Jul 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Germany. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Course of disease (time frame: retrospective and up to 48 months from enrollment). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 20 Jul 2025.