KRN23 in Adults with X-linked Hypophosphatemia (XLH) -(Final Version)
Research type
Research Study
Full title
A Randomized, Double-Blind, Placebo-Controlled, Phase 3 Study to Assess the Efficacy and Safety of KRN23 in Adults with X-linked Hypophosphatemia (XLH)
IRAS ID
183775
Contact name
Robin Lachmann
Contact email
Sponsor organisation
Ultragenyx Pharmaceutical Inc.
Eudract number
2014-005529-11
Clinicaltrials.gov Identifier
Other identifier , EMA/902676
Duration of Study in the UK
2 years, 0 months, 1 days
Research summary
UX023-CL303 is a well-controlled study, sponsored by Ultragenyx Pharmaceutical, to determine whether KRN23 is a safe and effective treatment for X-linked Hypophosphatemia (XLH). XLH is a rare genetic disorder of phosphate metabolism, caused by excess levels of Fibroblast Growth Factor 23 (FGF23), in which the kidneys do not retain enough phosphorus for healthy bones. In adults this leads to pain, osteomalacia (insufficient bone mineralisation), and pseudofractures detected on X-rays. KRN23 is an investigational drug targeting excess FGF23; previous clinical studies suggest KRN23 regulates phosphorus with no major safety concerns.
Approximately 120 adults with XLH will be enrolled worldwide; 60 individuals will be randomly assigned to each treatment group (KRN23 and placebo). The study is double-blind and placebo (dummy drug)-controlled for scientific integrity. Participants will receive an injection of KRN23 or placebo under the skin monthly for the first 6 months. Patients in the placebo group will then begin KRN23 treatment. The study will continue another 6 months with all patients receiving active treatment (total study duration approximately 1 year).
Safety will be assessed by routine evaluations and reports of adverse effects. Biochemical tests will be routinely completed on blood and urine samples collected after an overnight fast to obtain an accurate measurement of phosphorus levels in the blood, the key indicator of efficacy. Radiographic imaging will identify bone deformities and/or fractures; follow up x-rays will follow changes and/or healing in targeted locations. Questionnaires will evaluate patient-reported pain, fatigue, and health-related quality of life. Participants will complete a diary for 7 consecutive days prior to certain visits to capture pain severity and medication use. To assess walking ability, which is often compromised in this population, participants will walk for six minutes at select visits. After study completion, participants may continue treatment in an extension study.REC name
South Central - Berkshire Research Ethics Committee
REC reference
15/SC/0694
Date of REC Opinion
1 Feb 2016
REC opinion
Further Information Favourable Opinion