The Schall Law Firm is organizing a class action lawsuit against Ultragenyx Pharmaceutical Inc., seeking investors who acquired company securities between August 3, 2023 and December 26, 2025. The litigation centers on allegations that the company made materially false and misleading statements regarding the efficacy of its investigational treatment for Osteogenesis Imperfecta, a rare genetic disorder affecting bone density and strength.
At the heart of the complaint is the Phase III ORBIT clinical trial, which failed to meet its primary endpoint of demonstrating statistically significant reduction in fracture rates. Ultragenyx's prior representations about the drug candidate's effectiveness reportedly contradicted the trial's actual results, prompting investors to file for securities fraud relief. The extended investment window reflects the time between initial claims and the public disclosure of the negative trial outcome.
Investors meeting the criteria are being invited to serve as lead plaintiffs in the consolidated action. Such positions typically involve greater involvement in case proceedings and potential recovery decisions, though participation in class actions remains available to all qualifying security holders regardless of lead plaintiff status.