A Study to Describe the Lived Experience of XLH for Adolescents at End of Skeletal Growth

NCT05181839 | Completed

• 1 other identifier: 2020-70-EU-CRY
• Study Type: observational
• Target: 25
• Locations: 5 countries
• Sites: 14

Brief Summary

An observational, prospective, mixed-methods study involving the integration of quantitative and qualitative data exploring the lived experience of burosumab-treated adolescents with XLH at the end of skeletal growth.

Conditions

X-Linked Hypophosphatemia

Outcome Measures

Primary Outcomes (4)

• Describe the lived experience of adolescents with XLH who are being treated with burosumab within the 12 weeks prior to reaching the end of skeletal growth.

  12 Weeks

• Describe the lived experience of adolescents with XLH during the 26 weeks immediately after the end of skeletal growth, overall and according to whether they continue or discontinue burosumab treatment.

  26 weeks

• Describe within-person changes in the lived experience of adolescents with XLH after reaching end of skeletal growth, in relation to their own pre-end of skeletal growth period.

  Up to 52 weeks

• Explore the supportive care needs and burden on carers at the time the adolescent with XLH reaches end of skeletal growth.

  will be completed between weeks 21 and 25

Interventions

Burosumab DRUG

To describe the lived experience of XLH for adolescents who are being treated with burosumab at the end of skeletal growth with a focus on adolescent-reported symptoms, activity duration and intensity, and wider burden, describing change over time for those who continue and discontinue burosumab after the end of skeletal growth.

Eligibility Criteria

• Age: 12 Years - 17 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17)
• Sampling Method: Non-Probability Sample

Study Population

The population for this study is adolescents with XLH approaching end of skeletal growth, who are being treated with burosumab for at least 12 months as part of routine clinical care at specialist paediatric centres within the UK, France, Germany, Spain and the Netherlands.

You may qualify if:

• Confirmed diagnosis of XLH (documented diagnosis of XLH in medical records, and evidence of at least one of the following: hypophosphataemia and/or impaired phosphate reabsorption due to elevated FGF23; PHEX mutation).
• Aged 12 to 17 years at start of study.
• Has open growth plates at enrolment and is estimated by their treating clinician to reach end of skeletal growth within the next 26 weeks (based on clinician's judgement in accordance with their normal approach used in routine practice).
• Has been receiving treatment with burosumab for at least study le (52 weeks).
• Provides informed consent to take part in the study (or provides assent, and carer provides consent, where applicable in accordance with specific country regulations).
• A main carer of a study participant (i.e. a parent or guardian who provides day-today support or care for the adolescent with XLH who is taking part in this study).
• Provides informed consent to take part in the study (for self and/or on behalf of eligible adolescent, where applicable in accordance with specific country regulations).

You may not qualify if:

• Unwilling and unable to participate in all aspects of the study (i.e. interviews, app, EQ- 5D-Y, wearable data collection) and /or does not agree to the collection of data from medical records.
• Missed two or more injections of burosumab in the past 6 months.
• Is planned to have any surgery during the study period.

Sponsors & Collaborators

• Kyowa Kirin Pharmaceutical Development Ltd: lead

Study Sites (14)

Centre Hospitalier Universitair de Lille

Lille, France

Location

Hospices Civils De Lyon

Lyon, France

Location

APHP Paris - Assistance Publique Hopitaux de Paris

Paris, France

Location

Charité - Universitätsmedizin Berlin

Berlin, State of Berlin, 10117, Germany

Location

University Medical Center Groningen - Beatrix Children's Hospital

Groningen, Netherlands

Location

Hospital Saint Joan de Deu

Barcelona, Catalona, 08907, Spain

Location

Hospital Universitari Vall d'Hebron

Barcelona, Catalonia, 08035, Spain

Location

Hospital Universitario Virgen a de las Nieves

Granada, Granada, 18014, Spain

Location

Hospital General Universitario Santa Lucía

Cartagena, Murcia, 30202, Spain

Location

Royal Manchester Childrens Hospital

Manchester, Greater Manchester, M13 9WL, United Kingdom

Location

Birmingham Women's and Children's Hospital

Birmingham, United Kingdom

Location

Bristol Royal

Bristol, United Kingdom

Location

Alder Hey Children's Hospital

Liverpool, United Kingdom

Location

Great Ormond Street Hospital

London, United Kingdom

Location

Related Publications (3)

• Saraff V, Boot AM, Linglart A, Semler O, Harvengt P, Williams A, Bailey KMA, Glen F, Davies EH, Wood S, Greentree S, Rylands AJ. A patient-centred and multi-stakeholder co-designed observational prospective study protocol: Example of the adolescent experience of treatment for X-linked hypophosphataemia (XLH). PLoS One. 2024 Jan 19;19(1):e0295080. doi: 10.1371/journal.pone.0295080. eCollection 2024.

  PMID: 38241270 BACKGROUND

• Saraff V, Sancho PA, Bacchetta J, Boot AM, Burren C, Chinoy A, Dharmaraj P, Llorente MAG, Rodriguez JDG, Gueorguieva I, Davies EH, Hayes W, Komarzynski S, Duro HR, Rylands AJ, Sandilands K, Williams A, Hardie E, Ishii H, Schnabel D, Selveindran SM, Linglart A. The lived experience of adolescents with X-linked hypophosphataemia treated with burosumab at end of skeletal growth: a mixed-methods analysis. PLoS One. 2026 Mar 20;21(3):e0344902. doi: 10.1371/journal.pone.0344902. eCollection 2026.

  PMID: 41860923 RESULT

• Saraff V, Arango-Sancho P, Bacchetta J, Boot AM, Burren CP, Chinoy A, Dharmaraj P, Gomez Llorente MA, Gonzalez Rodriguez JD, Gueorguieva I, Hayes W, Schnabel D, Duro HR, Davies EH, Komarzynski S, Rylands AJ, Sandilands K, Ishii H, Williams A, Selveindran S, Barlassina A, Bowden A, Linglart A. Adolescents' experience of living with X-linked hypophosphataemia (XLH): a mixed-methods analysis of those who continued and discontinued burosumab treatment after end of skeletal growth. Orphanet J Rare Dis. 2026 Feb 3;21(1):107. doi: 10.1186/s13023-026-04244-2.

  PMID: 41634723 RESULT

MeSH Terms

Conditions

Familial Hypophosphatemic Rickets

Interventions

burosumab

Condition Hierarchy (Ancestors)

Rickets, Hypophosphatemic; Rickets; Bone Diseases, Metabolic; Bone Diseases; Musculoskeletal Diseases; Hypophosphatemia, Familial; Renal Tubular Transport, Inborn Errors; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Male Urogenital Diseases; Metal Metabolism, Inborn Errors; Metabolism, Inborn Errors; Genetic Diseases, Inborn; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Metabolic Diseases; Nutritional and Metabolic Diseases; Calcium Metabolism Disorders; Hypophosphatemia; Phosphorus Metabolism Disorders; Vitamin D Deficiency; Avitaminosis; Deficiency Diseases; Malnutrition; Nutrition Disorders

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Target Duration: 52 Weeks
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: November 15, 2021
• First Posted: January 6, 2022
• Study Start: November 24, 2021
• Primary Completion: May 22, 2024
• Study Completion: May 22, 2024
• Last Updated: July 13, 2026

Record last verified: 2024-09

Data Sharing

• IPD Sharing: Will not share

Locations

DE (1); ES (4); FR (3); GB (5); NL (1)