Ultragenyx Announces the Marketing Authorisation Application (MAA) for its Investigational Gene Therapy for MPS IIIA (Sanfilippo syndrome Type A) is Under Review with the UK Medicines and Healthcare Products Regulatory Agency (MHRA)

Ultragenyx (NASDAQ:RARE), a biopharmaceutical company focused on the development and commercialisation of novel therapies for rare and ultra-rare genetic diseases, today announced that the UK Medicines and Healthcare products Regulatory Agency (MHRA) accepted on 28 th October 2026 the Company’s Marketing Authorisation Application (MAA) for rebisufligene etisparvovec (also known as rebi-vec or UX111), an investigational gene therapy for the treatment of mucopolysaccharidosis Type IIIA (MPS IIIA), also known as Sanfilippo syndrome Type A.