Ultragenyx and Kyowa Kirin Co., Ltd., announced plans to submit a sBLA to the FDA for Crysvita for the treatment of tumor-induced osteomalacia

Ultragenyx Pharmaceutical Inc.and Kyowa Kirin Co., Ltd., announced plans to submit a supplemental Biologics License Application (sBLA) to the FDA for Crysvita (burosumab) for the treatment of FGF23-related hypophosphatemia associated with phosphaturic mesenchymal tumors (tumor-induced osteomalacia; TIO) that cannot be curatively resected or localized.

The decision to submit follows the completion of a pre-sBLA meeting with the FDA and agreement on the filing package. The submission of the Crysvita sBLA is planned for the first half of 2020 and will be based on the current clinical data package.The BLA package will include data from two single-arm Phase II studies, a 144-week Phase II study in 14 adult patients conducted by Ultragenyx in the U.S. and an 88-week Phase II study in 13 adult patients conducted by Kyowa Kirin in Japan and South Korea. In both studies, Crysvita was associated with increases in serum phosphorus and serum 1,25-dihydroxyvitamin D levels. Increased phosphate levels led to improvements in osteomalacia, mobility, and vitality. Bone scans also demonstrated an increase in healed fractures and decrease in new fractures during Crysvita treatment. Adverse events generally reflected the patients’ underlying disease, and there were no serious treatment-related adverse events during the studies.