Ultragenyx wins FDA nod for first gene therapy targeting Sanfilippo syndrome

The U.S. Food and Drug Administration granted accelerated approval to Ultragenyx's gene therapy UX111, now branded Fayuvi, for Sanfilippo syndrome type A. The decision provides a significant regulatory win for the company amid a challenging year. The therapy is designed to address the underlying genetic cause of the rare lysosomal storage disease.

This approval marks the first gene therapy cleared by the FDA for Sanfilippo syndrome, a rare inherited disorder that progressively damages the nervous system. Fayuvi works by delivering a functional copy of the gene responsible for producing a crucial enzyme, targeting the root cause of the disease rather than merely managing symptoms. The accelerated approval pathway reflects the therapy's promise in addressing a condition with few existing treatment options.

For Ultragenyx, the decision arrives as a pivotal achievement after a difficult period for the company. Sanfilippo syndrome type A is one of several lysosomal storage diseases, a family of disorders characterized by the body's inability to break down certain molecules. The regulatory green light validates the company's gene therapy platform and could strengthen its position in the rare disease space.