Long-Term Extension Study of KRN23 in Adult Subjects With X-Linked Hypophosphatemia (XLH)

Summary

The primary objectives of this study are to: * Assess the long-term safety of KRN23 subcutaneous (SC) administration in adult subjects with XLH * Assess the proportion of subjects achieving serum phosphorus levels in the normal range (2.5-4.5 mg/dL) with long-term administration of KRN23 * Assess long-term pharmacodynamics (PD) of KRN23 as measured by changes in the following: serum intact parathyroid hormone (iPTH); serum and urinary phosphorus; ratio of renal tubular maximum phosphate reabsorption rate to glomerular filtration rate (TmP/GFR) and tubular reabsorption of phosphate (TRP); serum 1,25-dihydroxy vitamin D (1,25\[OH\]2D); serum fibroblast growth factor 23 (FGF23); bone biomarkers: serum alkaline phosphatase (ALP), bone-specific ALP (BALP), carboxy terminal crosslinked telopeptide of type I collagen (CTx), and procollagen type 1 N-terminal propeptide (P1NP) * Assess long-term immunogenicity of KRN23 as measured by presence of anti-KRN23 antibody (ADA)

Timeline

Start

2015-01-30

Primary completion

2018-11-30

Completion

2018-11-30

Publications

• Weber TJ, Imel EA, Carpenter TO, Peacock M, Portale AA, Hetzer J, Merritt JL, Insogna K. Long-term Burosumab Administration Is Safe and Effective in Adults With X-linked Hypophosphatemia. J Clin Endocrinol Metab. 2022 Dec 17;108(1):155-165. doi: 10.1210/clinem/dgac518.

Drugs

Indications