Ultragenyx Advances Gene Therapy Filing Milestone With DTX401's Final FDA Submission

Rare disease biotech Ultragenyx Pharmaceutical (RARE) has successfully completed its regulatory submission pathway for DTX401, an investigational AAV gene therapy designed to treat Glycogen Storage Disease Type Ia (GSDIa). The stock responded positively to the announcement, closing Tuesday's session on NasdaqGS at $22.78, representing a gain of $3.06 or 15.52%, before retreating slightly in after-hours trading to $22.41.

The completion of the Biologics License Application (BLA) filing marks the culmination of Ultragenyx's multi-phase submission strategy. The company had previously delivered non-clinical and clinical data packages to the FDA in August, and has now finalized the comprehensive application package by submitting the chemistry, manufacturing, and controls (CMC) module. This phased submission approach enabled the company to maintain momentum in its regulatory timeline.

DTX401, known by its investigational name pariglasgene brecaparvovec, represents a novel therapeutic approach for GSDIa patients. If approved by the FDA, the therapy would become the first treatment to directly target the underlying genetic basis of this rare inherited disorder, rather than merely managing symptoms. This represents a watershed moment for a patient population that has historically had limited therapeutic options.

The gene therapy works by delivering a functional copy of the deficient gene directly to affected cells, offering the potential for long-term clinical benefit in patients with this serious metabolic condition. The successful completion of the submission process demonstrates Ultragenyx's commitment to advancing treatments for rare genetic diseases and brings the company closer to a potential FDA decision on DTX401's approvability.