Ultragenyx initiates rolling submission of BLA to U.S. FDA for DTX401

Ultragenyx (RARE) Pharmaceutical announced the initiation of a rolling submission of a Biologics License Application, BLA, to the U.S. Food and Drug Administration, FDA, seeking approval for DTX401 AAV gene therapy as a treatment for Glycogen Storage Disease Type Ia, GSDIa. The company has submitted the non-clinical and clinical modules to the FDA and plans to complete the full BLA including submission of the chemistry, manufacturing and controls, CMC, module in the fourth quarter of 2025. “Initiating the BLA for DTX401, for the potential treatment of GSDIa, is an important milestone for this much needed treatment option for individuals and families affected by this disorder. Currently, patients are required to take large and frequent doses of cornstarch to protect themselves from the risk of potentially life-threatening hypoglycemia,” said Eric Crombez, M.D., chief medical officer at Ultragenyx. “By granting a rolling review, the FDA can begin reviewing the non-clinical and clinical sections of the BLA, where we demonstrate the clinically significant reduction in cornstarch burden and improved clinical outcomes, while we proactively resolve any relevant CMC and facility questions that were learned in our UX111 program. Over the next few months, we expect to resolve the FDA’s observations and then complete our DTX401 BLA submission in the fourth quarter of this year.”