Ultragenyx Initiates Rolling Submission of Biologics License Application (BLA) to U.S. FDA for DTX401 AAV Gene Therapy for the Treatment of Glycogen Storage Disease Type Ia (GSDIa)

Core Viewpoint - Ultragenyx Pharmaceutical Inc. has initiated a rolling submission of a Biologics License Application (BLA) for DTX401 AAV gene therapy to the FDA, aiming for approval as a treatment for Glycogen Storage Disease Type Ia (GSDIa) with full submission expected in Q4 2025 [1][2] Company Overview - Ultragenyx is a biopharmaceutical company focused on developing therapies for serious rare and ultra-rare genetic diseases, with a diverse portfolio of approved medicines and treatment candidates [5][6] - The management team has extensive experience in the development and commercialization of rare disease therapeutics, emphasizing efficient drug development to deliver safe and effective therapies urgently [6] Product Information - DTX401 is an investigational AAV8 gene therapy designed to provide stable expression of G6Pase-α, allowing liver cells to manage glucose levels effectively [3] - The therapy is administered as a single intravenous infusion and has shown promise in preclinical studies by improving G6Pase-α activity and reducing hepatic glycogen levels [3] Disease Context - Glycogen Storage Disease Type Ia (GSDIa) is a serious inherited condition caused by a defective gene affecting blood sugar regulation, leading to life-threatening hypoglycemia and potential organ dysfunction [4] - Approximately 6,000 individuals are estimated to be affected by GSDIa in commercially accessible regions, highlighting the unmet medical need for effective treatments [4] Clinical Development - The BLA for DTX401 includes data from a 96-week randomized, placebo-controlled Phase 3 study, showing significant reductions in daily cornstarch intake by 60% in the DTX401 group and 64% in the crossover group compared to baseline [2] - The company plans to address FDA observations from the UX111 program while completing the BLA submission [2]