The U.S. FDA cleared Ultragenyx’s one-time gene therapy Genglycos (pariglasgene brecaparvovec; DTX-401) for glycogen storage disease type Ia (GSDIa) in patients aged 8 and older, marking both an accelerated milestone for the company and the first approved treatment to address the underlying enzyme deficiency. The approval was granted under accelerated pathways, and Ultragenyx positions the therapy as a functional gene delivery approach intended to restore normal blood-sugar stabilization between meals. Commercial plans include treatment availability within specialized centers soon after launch. From a market and platform perspective, the clearance adds a key revenue driver for a company that has faced earlier regulatory setbacks, and it reinforces investor focus on rare-disease gene delivery as a repeatable regulatory track.