The FDA Prescription Drug User Fee Act (PDUFA) action date for burosumab to treat X-Linked Hypophosphatemia is 17 April 2018.-Ultragenyx + Kyowa Hakko Kirin.

Ultragenyx Pharmaceutical Inc.and Kyowa Hakko Kirin Co., Ltd. and Kyowa Kirin International PLC announced that the FDA has indicated in the "Day 74" filing communication that it is not currently planning to hold an advisory committee meeting to discuss the Biologics License Application (BLA) for burosumab to treat pediatric and adult patients with X-Linked Hypophosphatemia (XLH). Additionally, the FDA indicated that the review is proceeding according to its internal review timelines described in their Guidance on Good Review Management Principles and Practices for PDUFA Products.

The FDA previously granted burosumab Priority Review status, which is available to drugs that treat a serious condition and, if approved, would provide a significant improvement in safety or effectiveness. The Prescription Drug User Fee Act (PDUFA) action date for the BLA is 17 April 2018. The FDA has designated burosumab as a drug for a "rare pediatric disease", enabling issuance of a priority review voucher if burosumab is approved. Burosumab previously received Breakthrough Therapy Designation from the FDA for the treatment of XLH in pediatric patients one year of age and older.