Rosen Law Firm, a global investor rights law firm, announces a class action lawsuit on behalf of purchasers of common stock of Ultragenyx Pharmaceutical Inc. (NASDAQ: RARE) between August 3, 2023 and December 26, 2025. Ultragenyx describes itself as a “biopharmaceutical company focused on rare and ultrarare genetic disorders.”

For more information, submit a form, email attorney Phillip Kim, or give us a call at 866-767-3653.

The Allegations: Rosen Law Firm is Investigating the Allegations that Ultragenyx Pharmaceutical Inc. (NASDAQ: RARE) Misled Investors Regarding its Business Operations.

According to the lawsuit, defendants made false and/or misleading statements and/or concealed 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. When the true details entered the market, the lawsuit claims that investors suffered damages.

What Now: You may be eligible to participate in the class action against Ultragenyx Pharmaceutical Inc. Shareholders who want to serve as lead plaintiff for the class must file their motions with the court by April 6, 2026. A lead plaintiff is a representative party who acts on behalf of other class members in directing the litigation. You do not have to participate in the case to be eligible for a recovery. If you choose to take no action, you can remain an absent class member. For more information, click here.

All representation is on a contingency fee basis. Shareholders pay no fees or expenses.

About Rosen Law Firm: Some law firms issuing releases about this matter do not actually litigate securities class actions. Rosen Law Firm does. Rosen Law Firm is a recognized leader in shareholder rights litigation, dedicated to helping shareholders recover losses, improving corporate governance structures, and holding company executives accountable for their wrongdoing. Since its inception, Rosen Law Firm has obtained over $1 billion for shareholders.

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