Ultragenyx Starts Rolling FDA Filing for GSDIa Gene Therapy

Ultragenyx Pharmaceutical has started a rolling submission of a Biologics License Application to the U.S. Food and Drug Administration for DTX401, its investigational AAV8 gene therapy for Glycogen Storage Disease Type Ia. The company filed the non-clinical and clinical modules on 18 August and expects to add the chemistry, manufacturing and controls section in the fourth quarter, allowing the agency to review the package in stages. The application is supported by 96-week results from a randomized, placebo-controlled Phase 3 trial in which patients showed a 60%–64% median reduction in their daily cornstarch regimen, the current standard of care used to prevent life-threatening hypoglycaemia. DTX401 has received orphan-drug, regenerative-medicine advanced-therapy and Fast Track designations in the United States, as well as PRIME status in Europe. If approved, DTX401 would become the first FDA-cleared therapy that targets the underlying cause of GSDIa, a metabolic disorder estimated to affect about 6,000 people in commercially accessible markets. Ultragenyx said the staggered review should help it address previously noted manufacturing questions and keeps it on course for a potential U.S. launch in 2026.