Bragar Eagel & Squire, P.C. Litigation Partner Brandon Walker Encourages Investors Who Suffered Losses In Ultragenyx (RARE) To Contact Him Directly To Discuss Their Options

If you purchased or acquired Ultragenyx common stock between August 3, 2023, to December 26, 2025 and would like to discuss your legal rights, call Bragar Eagel & Squire partner Brandon Walker or Melissa Fortunato directly at (212) 355-4648.

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NEW YORK, Feb. 05, 2026 (GLOBE NEWSWIRE) --

What’s Happening:

• Bragar Eagel & Squire, P.C., a nationally recognized stockholder rights law firm, announces that a class action lawsuit has been filed against Ultragenyx Pharmaceutical Inc. (“Ultragenyx” or the “Company”) (NASDAQ: RARE) in the United States District Court for the Northern District of California on behalf of all persons and entities who purchased or otherwise acquired Ultragenyx common stock between August 3, 2023, to December 26, 2025, both dates inclusive (the “Class Period”). Investors have until April 6, 2026 to apply to the Court to be appointed as lead plaintiff in the lawsuit.
  
  

Allegation Details:

• According to the complaint, during the class period, defendants provided investors with material information concerning Ultragenyx’s expected results for its Phase III Orbit and Cosmic Studies, which tested setrusumab (UX 143) in patients with Osteogenesis Imperfecta (“OI”). Defendants’ statements included, among other things, confidence in setrusumab’s ability to ultimately trigger a decrease in the OI patients’ annualized fracture rate, alongside confidence in the study designs to demonstrate such ability and reduce testing variability that could interfere with such a result.
  
  
• Plaintiff alleges that defendants provided these overwhelmingly positive statements to investors while, at the same time, disseminating materially false and misleading statements and/or concealing material adverse facts concerning the true state of setrusumab’s potential and the true risk inherent in the study protocols put forth; notably, that, while setrusumab does increase material bone density, this increase does not correlate to a decrease in annualized fracture rates or otherwise the Phase III Orbit and Cosmic studies were much less likely to be able to demonstrate such a link than management claimed. Such statements absent these material facts caused Plaintiff and other shareholders to purchase Ultragenyx’s securities at artificially inflated prices.
  
  
• The complaint alleges that on December 29, 2025, Ultragenyx announced that both its Phase III Orbit and Cosmic Studies had not “achieved statistical significance against the primary endpoints of reduction in annualized clinical fracture rate compared to placebo or bisphosphonates, respectively.” The Company attributed the study failure to a “low fracture rate in the placebo group” of Orbit and a trend that fell shy of statistical significance in Cosmic. On this news, the price of Ultragenyx's stock fell from a closing market price of $34.19 per share on December 26, 2025, to $19.72 per share on December 29, 2025, a decline of about 42.32% in the span of just a single day.
  
  

Next Steps:

• If you purchased or otherwise acquired Ultragenyx shares and suffered a loss, are a long-term stockholder, have information, would like to learn more about these claims, or have any questions concerning this announcement or your rights or interests with respect to these matters, please contact Brandon Walker or Melissa Fortunato by email at investigations@bespc.com, telephone at (212) 355-4648, or by filling out this contact form. There is no cost or obligation to you.
  
  

About Bragar Eagel & Squire, P.C.:

Bragar Eagel & Squire, P.C. is a nationally recognized law firm with offices in New York, South Carolina, and California. The firm represents individual and institutional investors in securities, derivative, and commercial litigation as well as individuals in consumer protection and data privacy litigation. The firm has a nationwide practice and routinely handles cases in both federal and state courts. For more information about the firm, please visit www.bespc.com.  Attorney advertising.  Prior results do not guarantee similar outcomes.

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Contact Information:

Bragar Eagel & Squire, P.C.
Brandon Walker, Esq.
Melissa Fortunato, Esq.
(212) 355-4648
investigations@bespc.com
www.bespc.com