Denali Therapeutics Announces FDA Acceptance and Priority Review of Biologics License Application (BLA) for Tividenofusp Alfa for Hunter Syndrome (MPS II)

Core Insights - Denali Therapeutics Inc. announced that the FDA has accepted the Biologics License Application (BLA) for tividenofusp alfa, seeking accelerated approval for the treatment of Hunter syndrome, with a target action date of January 5, 2026 [1][7]. Company Overview - Denali Therapeutics is a biotechnology company focused on developing therapies that can cross the blood-brain barrier (BBB) for neurodegenerative and lysosomal storage diseases [9]. - The company utilizes a proprietary TransportVehicle™ platform designed to deliver large therapeutic molecules across the BBB, enhancing drug efficacy [8]. Product Details - Tividenofusp alfa is an investigational enzyme replacement therapy designed to address both neurological and physical symptoms of Hunter syndrome by delivering the iduronate 2-sulfatase (IDS) enzyme into the brain and body [2][4]. - The therapy has received Fast Track and Breakthrough Therapy designations from the FDA, as well as Priority Medicines designation from the European Medicines Agency [4]. Clinical Studies - The BLA submission is supported by data from a Phase 1/2 study involving 47 participants with Hunter syndrome [3]. - Denali is conducting an ongoing Phase 2/3 COMPASS study to support global regulatory approvals, with participants randomized to receive either tividenofusp alfa or idursulfase [5]. Disease Context - Hunter syndrome (MPS II) is a rare genetic disorder caused by a deficiency in the IDS enzyme, leading to the accumulation of glycosaminoglycans and resulting in cognitive decline, behavioral issues, and physical complications [6]. - Current therapies do not effectively address neurological symptoms due to their inability to cross the BBB, highlighting the unmet need for new treatments [6].