Study of the Safety, Pharmacodynamics (PD) and Efficacy of KRN23 in Children From 1 to 4 Years Old With X-linked Hypophosphatemia (XLH)

UX023-CL205 is a multicenter, open-label, Phase 2 study in children from 1 to 4 years old with XLH to assess the safety, PD, and efficacy of KRN23 administered via subcutaneous (SC) injections every 2 weeks (Q2W) for a total of 160 weeks.

The study will enroll approximately 10 pediatric subjects between 1 and 4 years old, inclusive, with a confirmed diagnosis of XLH and radiographic evidence of rickets. Subjects will discontinue oral phosphate and active vitamin D therapy after initial Screening and for the duration of the study.

All subjects will receive treatment with KRN23. Safety, PD, pre-dose KRN23 concentrations, and efficacy measures (rickets, growth, functional outcomes) will be evaluated throughout the study. Radiographs will be taken to assess rickets periodically throughout the study duration.


Study Type: Interventional  (Clinical Trial)
Actual Enrollment: 13 participants
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: An Open-Label, Phase 2 Study to Assess the Safety, Pharmacodynamics, and Efficacy of KRN23 in Children From 1 to 4 Years Old With X-linked Hypophosphatemia (XLH)
Actual Study Start Date: May 2016
Estimated Primary Completion Date: October 2019
Estimated Study Completion Date: October 2019

Arms and Interventions
- Experimental: KRN23