Ultragenyx Pharmaceutical(US:RARE) Globenewswire·2026-03-04 15:33Core Viewpoint - Ultragenyx Pharmaceuticals is facing a federal securities class action lawsuit due to allegations of misleading statements regarding the efficacy of its drug setrusumab in treating Osteogenesis Imperfecta, leading to significant stock price declines [4][6][8]. Group 1: Legal Investigation and Class Action - Faruqi & Faruqi, LLP is investigating potential claims against Ultragenyx and has set an April 6, 2026 deadline for investors to seek the role of lead plaintiff in the class action [4]. - The lawsuit alleges that Ultragenyx and its executives violated federal securities laws by making false statements about the reliability of data from the Phase III Orbit study [6]. - Investors who purchased Ultragenyx securities between August 3, 2023, and December 26, 2025, are encouraged to discuss their legal rights with the law firm [1][4]. Group 2: Study Results and Stock Impact - On July 9, 2025, Ultragenyx disclosed that the Phase III Orbit study did not achieve statistical significance for its second interim analysis, resulting in a stock price drop of over 25% [7]. - Following a December 29, 2025 announcement that both the Phase III Orbit and Cosmic studies failed to meet primary endpoints, Ultragenyx's stock fell more than 42% [8][9]. - The company attributed the study failures to a low fracture rate in the placebo group and a trend that did not reach statistical significance [8].