Ultragenyx Pharmaceutical Faces Class Action Lawsuit Deadline

Investors have until April 6, 2026 to apply for lead plaintiff status in case against Ultragenyx

Mar. 25, 2026 at 2:35am

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Kahn Swick & Foti, LLC, a leading securities litigation law firm, has notified investors in Ultragenyx Pharmaceutical Inc. (NasdaqGS: RARE) of a class action securities lawsuit. The lawsuit seeks to recover losses on behalf of investors who were adversely affected by alleged securities fraud between August 3, 2023 and December 26, 2025. Ultragenyx investors have until April 6, 2026 to request to be appointed as lead plaintiff in the case.

Why it matters

This case highlights the importance of investor protections and the role of securities litigation in holding publicly traded companies accountable for alleged fraud or malfeasance. The outcome could have significant financial implications for Ultragenyx and its investors.

The details

The lawsuit alleges that on December 26, 2025, Ultragenyx announced that its Phase 3 Orbit and Cosmic studies for setrusumab (UX143) in Osteogenesis Imperfecta failed to demonstrate a statistically significant reduction in annualized fracture rates. As a result, the company said it would be implementing 'significant expense reductions.' This news caused Ultragenyx's stock price to drop approximately 42% from $34.19 per share to $19.72 per share.

  • The class period is from August 3, 2023 to December 26, 2025.
  • Ultragenyx made its announcement on December 26, 2025.
  • Investors have until April 6, 2026 to apply for lead plaintiff status.

The players

Kahn Swick & Foti, LLC

A leading securities litigation law firm that has notified Ultragenyx investors of the class action lawsuit.

Charles C. Foti, Jr.

Former Attorney General of Louisiana and partner at Kahn Swick & Foti, LLC.

Ultragenyx Pharmaceutical Inc.

A biopharmaceutical company that is facing a class action lawsuit from investors over alleged securities fraud.

Steven Bailey

The plaintiff in the class action lawsuit against Ultragenyx Pharmaceutical Inc.

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What they’re saying

“Ultragenyx investors should contact KSF Managing Partner Lewis Kahn toll-free at 1-877-515-1850 or via email (lewis.kahn@ksfcounsel.com), or visit https://www.ksfcounsel.com/cases/nasdaqgs-rare/ to learn more.”

— Lewis Kahn, Managing Partner, Kahn Swick & Foti, LLC

What’s next

The judge in the case will decide on whether to allow the class action lawsuit to proceed.

The takeaway

This case highlights the importance of investor protections and the role of securities litigation in holding publicly traded companies accountable for alleged fraud or malfeasance. The outcome could have significant financial implications for Ultragenyx and its investors.