Kuznicki Law PLLC notifies investors that a class action has commenced in the United States District Court for the Northern District of California on behalf of shareholders of Ultragenyx Pharmaceutical Inc. who purchased shares between August 3, 2023 and December 26, 2025.
On December 26, 2025, the Company announced the “results from the Phase 3 Orbit and Cosmic studies for setrusumab (UX143) in Osteogenesis Imperfecta” disclosing that both its Phase III Orbit and Cosmic studies failed to demonstrate that setrusumab triggered a statistically significant reduction in annualized fracture rates for patients with osteogenesis imperfecta, and, as a result the Company “is evaluating its planned operations and will promptly define and implement significant expense reductions.” On this news, the price of Ultragenyx’s shares fell approximately 42%, from $34.19 per share on December 26, 2025 to $19.72 per share on December 29, 2025.
If you wish to choose counsel to represent you and the class, you must apply to be appointed lead plaintiff and be selected by the Court. The lead plaintiff will direct the litigation and participate in important decisions including whether to accept a settlement for the class in the action. The lead plaintiff will be selected from among applicants claiming the largest loss from investment in the respective securities during the class periods. Members of the class will be represented by the lead plaintiff and counsel chosen by the lead plaintiff. No class has yet been certified in the above action. Appointment as Lead Plaintiff is not required to partake in any recovery.
Shareholders have until April 6, 2026 to request that the court appoint them lead plaintiff.