FDA Priority Review for Hunter Syndrome Therapy

FDA has accepted for priority review a Denali Therapeutics’ BLA for tividenofusp alfa and its use for treating Hunter syndrome. The agency has set a user fee review action target date of 1/5/2026.

Tividenofusp alfa is described by the company as a next-generation enzyme replacement therapy designed to address both the cognitive and physical manifestations of Hunter syndrome, also known as mucopolysaccharidosis Type II. The rare genetic disorder is caused by a deficiency of the iduronate 2-sulfatase (IDS) enzyme, leading to the accumulation of harmful complex sugars in the body and brain, it says. The therapy uses the company’s proprietary TransportVehicle platform to deliver IDS throughout the body and into the brain.

The submission is based on data from a Phase 1/2 open-label study involving 47 patients with Hunter syndrome. A Phase 2/3 study (COMPASS) is currently underway to further support global regulatory submissions, the company says.