Ultragenyx Reports Positive Results From Phase 1/2 Trial Of KRN23

(RTTNews) - Ultragenyx Pharmaceutical Inc. (RARE) Monday reported positive results from its long-term Phase 1/2 extension trial of the investigational KRN23 in patients with X-linked hypophosphatemia or XLH. It was observed that KRN23 was generally safe and well tolerated over the cumulative treatment period.

"By binding and inhibiting FGF23, patients treated with KRN23 demonstrated increases in phosphate levels over the cumulative 16-month treatment period," said Sunil Agarwal, chief medical officer of Ultragenyx. He added that the company plans to continue development in adult XLH patients and are enrolling pediatric XLH patients in the ongoing Phase 2 study. The Phase 1/2 extension trial aimed to evaluate long-term safety and efficacy following an initial four-month dose escalation study that was conducted in the US and Canada. During the extension study, 22 adult patients with XLH were evaluated over an additional 12 months.