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ARTICLE | Clinical News

UX023: Extension study data

October 27, 2014 7:00 AM UTC

Data from 22 patients with XLH who received once-monthly 0.1-1 mg/kg subcutaneous KRN23 in the 12-month, open-label INT-002 extension of the 4-month, open-label, dose-escalation, U.S. and Canadian Phase I/II INT-001 trial showed that increases in serum phosphorus levels, urinary phosphorus reabsorption and 1,25 dihydroxy vitamin D levels that were observed in INT-001 were generally sustained during the extension study, with all patients continuing to demonstrate increases in serum phosphorous levels. Specifically, 52.6-85.7% of patients in the extension had serum phosphorus levels that reached the normal range (2.5-4.5 mg/dL) at peak time on day 7 or 14 after each dose throughout the extension. KRN23 was generally well tolerated. Data were presented at the American Society for Bone and Mineral Research meeting in Houston.

Previously reported data from the Phase I/II INT-001 trial in 28 adults with XLH showed that once-monthly 0.05-0.6 mg/kg subcutaneous KRN23 increased urinary phosphorus reabsorption, serum phosphorus levels and 1,25 dihydroxy vitamin D levels. Specifically, KRN23 over 4 months increased serum phosphorus levels in all patients, with about 89% of patients reaching the low end of the normal range. Peak mean serum phosphorus levels increased to 3.03 mg/dL after the fourth dose from a mean of 1.89 mg/dL at baseline. KRN23 also increased biomarkers of bone formation and bone resorption, including procollagen type I N-propeptide (PINP), osteocalcin, bone alkaline phosphatase and c-terminal telopeptide of type I collage ( CTX-I), compared to baseline. ...