The Food and Drug Administration (FDA) has granted Orphan Drug designation to UX701 (Ultragenyx Pharmaceutical) for the treatment of Wilson disease.

Wilson disease is a rare inherited disorder caused by mutations in the ATP7B gene which leads to a lack of ATP7B production, a protein responsible for transporting copper. This results in the accumulation of copper in various body tissues, particularly the liver and central nervous system. 

UX701 is an investigational adeno-associated virus type 9 gene therapy that works by stabilizing the expression of the ATP7B copper transporter after a single intravenous infusion. In preclinical studies, UX701 has shown to normalize copper trafficking and excretion from the body. The Company is expected to file an Investigational New Drug application with the FDA by the end of the year.

The FDA’s Orphan Drug designation is granted to medicines intended to treat or prevent rare diseases or disorders that affect fewer than 200,000 individuals. 

Eric Crombez, MD, Chief Medical Officer of the Ultragenyx Gene Therapy development unit, said, “By correcting copper trafficking and removal, this one-time treatment has the potential to better address the many serious effects of this disease and improve the lives of patients.”

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Ultragenyx announces Orphan Drug designation for UX701 for the treatment of Wilson disease. [press release]. Novato, CA: Ultragenyx Pharmaceutical Inc; December 9, 2020.