DTX401 AAV gene therapy (pariglasgene brecaparvovec)

Feb. 23, 2026: Ultragenyx Pharmaceutical Inc. (NASDAQ: RARE) said the FDA accepted for review its Biologics License Application (BLA) for DTX401 (pariglasgene brecaparvovec), an investigational AAV gene therapy for Glycogen Storage Disease Type Ia (GSDIa). The BLA received Priority Review, and the FDA set a PDUFA action date of Aug. 23, 2026.

The filing is supported by a clinical program including 52 treated patients with up to six years of follow-up. Previously announced results from the randomized, double-blind, placebo-controlled Phase 3 GlucoGene study showed DTX401-treated patients had significant, clinically meaningful reductions in the quantity and frequency of daily cornstarch intake while maintaining low hypoglycemia levels, with improved euglycemia and fasting tolerance. Patient-reported quality of life improved on the Patient Global Impression of Change (PGIC) scale. The company reported DTX401 was well tolerated with an acceptable safety profile.

Ultragenyx noted that, if approved, DTX401 would be manufactured in the U.S. at its Bedford, Massachusetts gene therapy facility.