Ultragenyx's Crysvita meets in Phase III for pediatric XLH

Ultragenyx Pharmaceutical Inc. (NASDAQ:RARE) and Kyowa Hakko Kirin Co. Ltd. (Tokyo:4151) said Crysvita burosumab-twza (KRN23, UX023) met the primary endpoint of improving rickets compared with conventional therapy in the Phase III PIXLES trial to treat X-linked hypophosphatemia (XLH) in patients ages 1-12.

The open-label, international trial enrolled 61 patients to receive individualized daily doses of vitamin D plus oral phosphate or subcutaneous Crysvita every two weeks. On the primary endpoint, Crysvita significantly improved mean Radiographic Global Impression of Change (RGI-C) score from baseline to week 40 by 1.92 points vs. 0.77 points for vitamin D plus oral phosphate (p<0.0001). Additionally, a significantly greater proportion of patients who received Crysvita achieved an increase in RGI-C score of ≥2 points at week 40 vs. conventional therapy (72% vs. 6%, p<0.0001)...