Ultragenyx to cut about 20% of staff and discontinue Wilson disease gene therapy

On November 3, 2026, Ultragenyx said it plans to cut about 20% of its workforce, leaving roughly 1,000 employees. The company expects the reductions to be largely complete by year-end.

The company is ending development of UX701, its investigational AAV9 gene therapy for Wilson disease. In the Cyprus2+ dose-finding study, some patients showed clinical activity, but the results did not meet the company’s goal for most patients to achieve a biochemical response and stop standard treatment.

Ultragenyx said UX701 had a favorable safety profile; the decision was based on not meeting efficacy goals, not a safety concern. The company plans to share study results at a future scientific meeting.

The cuts are part of a broader cost-reduction push as Ultragenyx shifts toward commercial execution and aims for profitability in 2027. Other measures include winding down ongoing GTX-102 studies for Angelman syndrome and reducing real-estate and other expenses.

Ultragenyx estimated about $25 million in severance and other one-time restructuring charges in the fourth quarter of 2026.