Ultragenyx cuts workforce, assets in R&D overhaul

Ultragenyx is reducing its workforce by approximately 20% and discontinuing two investigational programs as part of a broad cost-cutting initiative expected to reduce its 2027 R&D spending by at least 50% compared with 2025.

The restructuring, announced alongside the company's third-quarter financial results, is expected to leave Ultragenyx with approximately 1,000 employees. The reduction in force is should be substantially completed by the end of 2026 and will generate approximately $25 million in severance and other non-recurring restructuring charges, which the company expects to recognize in the fourth quarter.

The cuts also include winding down all ongoing studies of GTX-102, an investigational antisense oligonucleotide for Angelman syndrome, and terminating development of UX701, an AAV9 gene therapy candidate for Wilson disease. Ultragenyx will also reduce expenses across the company, including its real estate footprint.

The decision to discontinue GTX-102 follows the September failure of the phase 3 Aspire study, which did not meet its primary or secondary endpoints. CEO Emil Kakkis attributed the outcome to substantial variability in the control group across multiple endpoints, making it difficult to distinguish treatment effects.

For UX701, additional data from the dose-finding portion of the phase 1/2 Cyprus2+ study showed clinical activity in some patients but failed to meet the company's criteria for advancing the program to pivotal development. Specifically, the majority of patients did not achieve the targeted biochemical response and elimination of standard-of-care treatment.

This is the second round of layoffs this year, with Ultragenyx announcing a 10% workforce reduction back in February 2026.

The recent reduction comes despite back-to-back approvals for the drugmaker this year. In August the FDA approved Genglycos, a one-time AAV8 based gene therapy, marking the first treatment designed to address the underlying cause of glycogen storage disease type Ia. A month later, the agency approvedFayuvi, an AAV9 gene therapy for the treatment of pediatric patients with mucopolysaccharidosis type IIIA (MPS IIIA, Sanfilippo syndrome Type A). The approval marked the first-ever FDA-approved treatment for the indication.

Both of Genglycos and Fayuvi approvals came with rare pediatric disease priority review vouchers, which the company recently sold for $210 million and $203 million, respectively.