A class action lawsuit has been filed against Ultragenyx Pharmaceutical Inc., a biopharmaceutical company specializing in treatments for rare diseases, on behalf of investors who purchased the company's common stock between August 3, 2023, and December 26, 2025. The lawsuit alleges that Ultragenyx misled investors about the effectiveness of its ORBIT and COSMIC studies, which tested setrusumab as a treatment for Osteogenesis Imperfecta, by concealing that neither study significantly reduced clinical fracture rates compared to control groups. Following the disclosure of this information, Ultragenyx's share price dropped by more than 42%, from $34.19 on December 26, 2025, to $19.72 on December 29, 2025. Investors who acquired Ultragenyx securities during the class period have until April 6, 2026, to seek appointment as lead plaintiff in the case.

Disclaimer: This news brief was created by Public Technologies (PUBT) using generative artificial intelligence. While PUBT strives to provide accurate and timely information, this AI-generated content is for informational purposes only and should not be interpreted as financial, investment, or legal advice. Ultragenyx Pharmaceutical Inc. published the original content used to generate this news brief via Newsfile (Ref. ID: 283209) on February 10, 2026, and is solely responsible for the information contained therein.