Rosen Law Firm Encourages Ultragenyx Investors to Secure Counsel Before Deadline

Investors who purchased Ultragenyx stock between August 2023 and December 2025 may be eligible for compensation.

Published on Mar. 2, 2026

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Rosen Law Firm, a global investor rights law firm, is reminding purchasers of Ultragenyx Pharmaceutical Inc. common stock between August 3, 2023 and December 26, 2025 of the important April 6, 2026 lead plaintiff deadline in a securities class action lawsuit against the company. The lawsuit alleges that Ultragenyx provided investors with materially false and misleading information about the potential of its drug setrusumab to reduce fracture rates in patients with Osteogenesis Imperfecta.

Why it matters

This case highlights the importance of transparency and accurate disclosures from pharmaceutical companies, especially when it comes to the potential efficacy of their drug candidates. Investors rely on this information to make informed decisions, and any misleading statements can lead to significant financial losses.

The details

The lawsuit claims that Ultragenyx provided overwhelmingly positive statements to investors about setrusumab's ability to reduce fracture rates in OI patients, while simultaneously concealing material adverse facts about the drug's true potential and the limitations of the study protocols. When the true details entered the market, the lawsuit alleges that investors suffered damages.

  • The class period is from August 3, 2023 to December 26, 2025.
  • The lead plaintiff deadline is April 6, 2026.

The players

Ultragenyx Pharmaceutical Inc.

A biopharmaceutical company that develops therapies for rare and ultra-rare genetic diseases.

Rosen Law Firm

A global investor rights law firm that is representing investors in the securities class action lawsuit against Ultragenyx.

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What they’re saying

“We encourage investors to select qualified counsel with a track record of success in leadership roles. Often, firms issuing notices do not have comparable experience, resources, or any meaningful peer recognition.”

— Laurence Rosen, Founding Partner, Rosen Law Firm (Newsfilecorp)

What’s next

Investors who purchased Ultragenyx stock during the class period have until April 6, 2026 to move the court to serve as lead plaintiff in the class action lawsuit.

The takeaway

This case underscores the importance of pharmaceutical companies providing accurate and transparent information to investors about the potential of their drug candidates. Investors should be cautious and thoroughly research any investment opportunities, especially in the biotech and pharmaceutical sectors, to avoid potential financial losses due to misleading disclosures.