Kahn Swick & Foti, LLC (“KSF”), along with its partner and former Louisiana Attorney General Charles C. Foti, Jr., has alerted investors of Ultragenyx Pharmaceutical Inc. (“Ultragenyx” or the “Company”) about a filed class action securities lawsuit.
Class Definition: The legal action aims to recover losses for investors who purchased Ultragenyx securities and were negatively impacted by alleged securities fraud occurring between August 3, 2023, and December 26, 2025. Additional details are available at: https://www.ksfcounsel.com/cases/nasdaqgs-rare/
Investors can reach out to KSF Managing Partner Lewis Kahn by calling 1-877-515-1850 or by emailing lewis.kahn@ksfcounsel.com . More information can also be found on the case webpage linked above.
Case Details: On December 26, 2025, Ultragenyx released results from its Phase 3 Orbit and Cosmic trials evaluating setrusumab (UX143) for the treatment of osteogenesis imperfecta. The company reported that neither study achieved a statistically significant reduction in annualized fracture rates. Following this outcome, Ultragenyx stated it would reassess its operational plans and implement substantial cost-cutting measures.
After the announcement, Ultragenyx’s stock price dropped sharply—falling about 42% from $34.19 per share on December 26, 2025, to $19.72 per share on December 29, 2025.
The lawsuit is titled Steven Bailey v. Ultragenyx Pharmaceutical Inc., et al., Case No. 26-cv-01097.
What to Do: Investors who experienced losses during the specified period may seek appointment as lead plaintiff by April 6, 2026. However, participation in any potential recovery does not depend on serving in that role.