Lawsuit Filed Against Ultragenyx Pharmaceutical Inc. for Securities Fraud

Ultragenyx Pharmaceutical Inc. (RARE) is facing a securities fraud class action lawsuit filed recently, with a lead plaintiff deadline set for April 6, 2026. The lawsuit, brought against the company on behalf of individuals who bought or acquired Ultragenyx common stock between August 3, 2023, and December 26, 2025, accuses Ultragenyx of making false and misleading statements about its drug, setrusumab. The lawsuit, filed in the United States District Court for the Northern District of California, states that Ultragenyx overstated the reliability of information on setrusumab’s impact on Osteogenesis Imperfecta patients. The company also allegedly downplayed the risks of patients in its Phase III Orbit study failing to achieve a statistically significant reduction in annualized fracture rate (AFR), which prevented the second interim analysis from being presented to the public.

The complaint contends that Ultragenyx’s optimism about the Phase III Orbit study’s results and interim analysis benchmarks was unwarranted. The company is accused of failing to adequately disclose the risks associated with using Phase II results, lacking a placebo control group, as a basis for comparison. This omission meant that the demonstrated reduction in AFR could have been due to an increase in the standard of care or the placebo effect from a new treatment, as opposed to the drug’s efficacy. As a result, the lawsuit claims that Ultragenyx’s positive statements regarding its business, operations, and prospects were materially misleading or without reasonable support.

Investors affected by these alleged misrepresentations have been urged to come forward and explore their recovery options by contacting Kessler Topaz Meltzer & Check, LLP at no cost. The filing for lead plaintiff status is open until April 6, 2026, for those seeking to pursue legal action. The potential lead plaintiff would represent all investors in the class action lawsuit and would direct the litigation on behalf of the group to recover losses incurred due to Ultragenyx’s purported misconduct.

Investors who wish to participate in seeking lead plaintiff status or want to learn more about the legal process should reach out to Kessler Topaz Meltzer & Check, LLP promptly. The firm specializes in securities-fraud class actions and investor protection, extending its services to individual investors and institutional clients. With a track record of securing significant recoveries in securities litigation, Kessler Topaz Meltzer & Check, LLP stands ready to assist Ultragenyx investors in pursuing their legal rights in this class action lawsuit.