CraniosynostosesHYPO-BLASTESNCT04159675
Burosumab and 1-25 (OH) Vitamin D on Human Osteoblasts
An observational study of Craniosynostoses, run by Hospices Civils de Lyon at 1 site in France.
Trial summary
FGF23 is the cornerstone of phosphate / calcium / vitamin D metabolism: it is synthesized mainly by osteocytes and acts as a phosphaturizing agent, inhibitor of dihydroxyvitamin D, and inhibitor of synthesis and secretion of PTH in most tissues. The specific role of FGF23 on bone has yet to be demonstrated. Read more about this study
- Who is it for?
- Ages 4 months to 18 years
- Conditions the study is for
- Craniosynostoses
- What is being tested?
- osteoblast biology study
- How many people
- 20 participants
- Where
- 1 siteFrance
- Study dates
- 4 Sep 2020to 4 Apr 2029
- 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 4 months to 18 years
- All sexes
- No healthy volunteers
- Child, Adult
Study population: patients with craniosynostosis, idiopathic (control patients) or due to HR
Who may be able to join
- Children from 4 months-old to 18 years-old
- Patients requiring craniosynostosis surgery followed by reference centers for rare diseases of calcium and phosphate metabolism / craniofacial malformations
- Patients and parent / holder of parental authority who have been informed of the study and do not object to participate
Who cannot join
- Patient being treated with oral corticosteroid or having received more than 3 months of corticosteroid treatment before surgery.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
France1 site, 1 recruiting
- Recruiting
Centre de référence des craniosténoses et malformations cranio-faciales Service de neurochirurgie Pédiatrique
Bron, 69500
Federico DI ROCCO, MD, federico.dirocco@chu-lyon.fr
Justine BACCHETTA, MD, justine.bacchetta@chu-lyon.fr
About this study
Official title: Effect of Burosumab and 1-25 (OH) Vitamin D on Human Osteoblasts From Patients Requiring Craniosynostosis Surgery for Idiopathic Reason or Due to Hypophosphatemic Rickets (HR)
FGF23 is the cornerstone of phosphate / calcium / vitamin D metabolism: it is synthesized mainly by osteocytes and acts as a phosphaturizing agent, inhibitor of dihydroxyvitamin D, and inhibitor of synthesis and secretion of PTH in most tissues.
The specific role of FGF23 on bone has yet to be demonstrated. In osteoblasts, overexpression of FGF23 in vitro suppresses not only osteoblastic differentiation but also the synthesis of the mineralized matrix independently of its systemic action on phosphate metabolism. In osteoblasts, FGF23 also regulates the secretion of osteopontin by directly suppressing transcription of alkaline phosphatase.
Read more
In some diseases such as hypophosphatemic rickets (HR), the direct role of FGF23 on bone has not yet been studied to our knowledge, whereas these genetic hypophosphatemias are secondary to overexpression of FGF23, whether an activating mutation of FGF23 or inhibitory mutations of its inhibitors (DMP1 and PHEX). However, patients with X-linked hypophosphatemic rickets (XLH) have higher circulating FGF23 levels than healthy controls and these levels are higher in treated patients.
Management of XLH consists primarily of correcting the native vitamin D defect by prescribing active vitamin D analogs as well as phosphate supplementation to improve bone mineralization and decrease dental complications, growth, and bone deformities. Recently, a new therapeutic option has been developed for XLH, burosumab, a human monoclonal antibody that binds and inhibits FGF23 activity. The use of burosumab is currently authorized in France in some pediatric patients with severe forms of XLH.
Independently of the indirect bone effects of phosphate correction and vitamin D levels, the direct role of burosumab on bone cells has never been studied. The objective of this project is to study the osteoblastic biology of patients with RH compared to control patients, and to evaluate the direct impact of the treatments used in this pathology on human osteoblasts.
- Conditions
- Craniosynostoses
- Being tested
- osteoblast biology study
- Medical subject headings
- Craniosynostoses
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
osteoblast biology studyBiological
Describe the in-vitro action of burosumab and vitamin D on human osteoblastogenesis from osteoblasts from patients with craniosynostosis due to HR
| Study group | Role | What they receive |
|---|---|---|
| control patients | Patients with idiopathic craniosynostosis Receives: Biological: osteoblast biology study | |
| HR patients | Patients with craniosynostosis due to HR Receives: Biological: osteoblast biology study |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of osteoblastic cells obtained at the end of differentiation
The analysis of osteoblastic differentiation obtained from the bone cells from patients with burosumab and/or 1-25 (OH) vitamin D (HR patients vs idiopathic craniosynostosis)
Measured: Day 0
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Nov 2019
- Study start4 Sep 2020
- Primary completion4 Apr 2029 (estimated)
- Study completion4 Apr 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for CraniosynostosesStudies of the same condition, open and under way.
- More trials run by Hospices Civils de LyonThe sponsor's other registered studies.
- 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
- Case-control
- Time perspective
- Prospective
- Enrolment
- 20 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Hospices Civils de Lyon
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Federico DI ROCCO, MD, Principal investigator, Hospices Civils de Lyon Centre de référence des craniosténoses et malformations cranio-faciales Service de neurochirurgie Pédiatrique
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04159675
- Sponsor's protocol ID
- 69HCL19_0773
- Other IDs
- 2019-A02762-55
- Acronym
- HYPO-BLASTES
- Status last verified
- Apr 2026
- First submitted
- 7 Nov 2019
- Last updated
- 16 Apr 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 16 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Burosumab and 1-25 (OH) Vitamin D on Human Osteoblasts From Patients Requiring Craniosynostosis Surgery for Idiopathic Reason or Due to Hypophosphatemic Rickets (HR)
- ClinicalTrials.gov ID
- NCT04159675
- Acronym / sponsor ID
- HYPO-BLASTES / 69HCL19_0773
- Conditions
- Craniosynostoses
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 20 participants (estimated)
- Lead sponsor
- Hospices Civils de LyonUniversity, hospital or other
- Study start
- 4 Sep 2020 (actual)
- Primary completion
- 4 Apr 2029 (estimated)
- Study completion
- 4 Apr 2029 (estimated)
- First posted
- 12 Nov 2019 (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.
FGF23 is the cornerstone of phosphate / calcium / vitamin D metabolism: it is synthesized mainly by osteocytes and acts as a phosphaturizing agent, inhibitor of dihydroxyvitamin D, and inhibitor of synthesis and secretion of PTH in most tissues.
The specific role of FGF23 on bone has yet to be demonstrated. In osteoblasts, overexpression of FGF23 in vitro suppresses not only osteoblastic differentiation but also the synthesis of the mineralized matrix independently of its systemic action on phosphate metabolism. In osteoblasts, FGF23 also regulates the secretion of osteopontin by directly suppressing transcription of alkaline phosphatase.
In some diseases such as hypophosphatemic rickets (HR), the direct role of FGF23 on bone has not yet been studied to our knowledge, whereas these genetic hypophosphatemias are secondary to overexpression of FGF23, whether an activating mutation of FGF23 or inhibitory mutations of its inhibitors (DMP1 and PHEX). However, patients with X-linked hypophosphatemic rickets (XLH) have higher circulating FGF23 levels than healthy controls and these levels are higher in treated patients.
Management of XLH consists primarily of correcting the native vitamin D defect by prescribing active vitamin D analogs as well as phosphate supplementation to improve bone mineralization and decrease dental complications, growth, and bone deformities. Recently, a new therapeutic option has been developed for XLH, burosumab, a human monoclonal antibody that binds and inhibits FGF23 activity. The use of burosumab is currently authorized in France in some pediatric patients with severe forms of XLH.
Independently of the indirect bone effects of phosphate correction and vitamin D levels, the direct role of burosumab on bone cells has never been studied. The objective of this project is to study the osteoblastic biology of patients with RH compared to control patients, and to evaluate the direct impact of the treatments used in this pathology on human osteoblasts.
Study design
- Observational model
- Case-control
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| control patients | – | Biological: osteoblast biology studyPatients with idiopathic craniosynostosis |
| HR patients | – | Biological: osteoblast biology studyPatients with craniosynostosis due to HR |
Who may qualify
- Ages
- 4 months to 18 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult
- Study population
- patients with craniosynostosis, idiopathic (control patients) or due to HR
Key inclusion criteria (3 listed)
- Children from 4 months-old to 18 years-old
- Patients requiring craniosynostosis surgery followed by reference centers for rare diseases of calcium and phosphate metabolism / craniofacial malformations
- Patients and parent / holder of parental authority who have been informed of the study and do not object to participate
Key exclusion criteria (1 listed)
- Patient being treated with oral corticosteroid or having received more than 3 months of corticosteroid treatment before surgery.
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 |
|---|---|---|
| osteoblast biology studyDescribe the in-vitro action of burosumab and vitamin D on human osteoblastogenesis from osteoblasts from patients with craniosynostosis due to HR | Biological | HR patients, control patients |
Primary outcome
Number of osteoblastic cells obtained at the end of differentiation
Time frame: Day 0
The analysis of osteoblastic differentiation obtained from the bone cells from patients with burosumab and/or 1-25 (OH) vitamin D (HR patients vs idiopathic craniosynostosis)
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 16 Apr 2026.
Related trials for Craniosynostoses
Not yet recruitingObservational study
Multimodal Mechanical, Tissue, Architectural, and Histological Evaluation of the Bone and Sutures of the Parietal Bone in an Infant With Craniosynostosis.
Craniostenosis
Active, not recruitingPhase 1
Safety and Anti-Tumor Activity of TYRA-200 in Advanced Cholangiocarcinoma With Activating FGFR2 Gene Alterations
Locally Advanced Cholangiocarcinoma, Intrahepatic Cholangiocarcinoma
Not yet recruiting
Frontal Reconstruction Without Orbital Advancement for Moderate Metopic Craniosynostosis
Metopic Craniosynostosis, Craniosynostosis
Not yet recruiting
Effects of Tummy Time Associated With Therapeutic Positioning in Premature Newborns With Cranial Asymmetry
Premature Newborns, Cranial Asymmetry
RecruitingObservational study
Comparing Conservative to Surgical Treatment of Trigonocephaly Craniofacial Surgery in Children With Trigonocephaly: an Observational Cohort Study on Clinical Outcomes, Psychosocial Wellbeing, and Costs
Metopic Synostosis
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.
Federico DI ROCCO, MD principal investigator
Hospices Civils de Lyon Centre de référence des craniosténoses et malformations cranio-faciales Service de neurochirurgie Pédiatrique
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 Craniosynostoses, run by Hospices Civils de Lyon at 1 site in France.
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 3 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: looking for participants now, as of the sponsor's last update on 16 Apr 2026. 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 France. 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?
Contact Federico DI ROCCO, MD (04 72 35 75 72 ext. +33, federico.dirocco@chu-lyon.fr), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of osteoblastic cells obtained at the end of differentiation (time frame: Day 0). 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 16 Apr 2026.