Company Announcements

Time-Sensitive: Allegations Focus on Repeated Assurances Regarding Setrusumab Efficacy

RARE INVESTOR ALERT

"Investors deserve transparency about material risks that could affect their investments," stated Joseph E. Levi, Esq., managing partner of Levi & Korsinsky, LLP. "The adequacy of clinical trial risk disclosures is a fundamental issue for biopharmaceutical investors."

NEW YORK , Feb. 25, 2026 /PRNewswire/ -- Levi & Korsinsky, LLP alerts investors in Ultragenyx Pharmaceutical Inc. (NASDAQ: RARE) of a pending securities class action. The Court has set April 6, 2026 as the deadline to apply for lead plaintiff appointment.

• Class Period: August 3, 2023 through December 26, 2025

Submit your information to join this case or contact Joseph E. Levi, Esq. at jlevi@levikorsinsky.com | (212) 363-7500.

What Management Allegedly Knew

Throughout the Class Period, the lawsuit asserts that management made numerous public statements expressing "high confidence" that setrusumab's ability to increase bone mineral density would translate to reduced fracture rates. As alleged, these statements created the impression that the Company possessed reliable scientific information supporting this confidence when, in reality, significant uncertainties existed.

Patterns in Alleged Confidence Representations

The action claims that during earnings calls and investor presentations spanning more than two years, management repeatedly assured investors of positive outcomes. These assurances allegedly included statements that the Company "did not see any uncontrolled factors" in the Phase III protocols, that increased patient activity would not cause problems because bones would be "strong enough," and that the studies were "well powered to succeed."

Industry Context: Surrogate Endpoints in Rare Disease Trials

• Surrogate endpoints like bone mineral density changes are commonly used in drug development when clinical endpoints are difficult to measure
• The relationship between surrogate and clinical endpoints must be scientifically validated to support regulatory approval
• Rare disease populations present challenges due to patient heterogeneity and limited sample sizes
• As alleged, management's confidence statements may have understated the scientific uncertainty in the BMD-to-fracture relationship
• The lawsuit asserts that prior bisphosphonate treatment in most Phase II patients complicated interpretation of setrusumab's standalone efficacy

Why Confidence Adequacy Allegedly Matters to Investors

The action claims that investors relied on management's confidence statements in making investment decisions. When the Phase III studies failed to achieve their primary endpoints, shareholders allegedly suffered significant losses as the market recalibrated expectations.

Speak with an attorney about your options contact Joseph E. Levi, Esq. at (212) 363-7500.

WHY LEVI & KORSINSKY

Ranked in ISS Securities Class Action Services' Top 50 Report for seven consecutive years, Levi & Korsinsky, LLP is a nationally recognized leader in shareholder rights litigation. With a team of over 70 professionals, the firm has recovered hundreds of millions of dollars for investors across the country.

CONTACT:
Levi & Korsinsky, LLP
Joseph E. Levi, Esq.
33 Whitehall Street, 27th Floor
New York, NY 10004
(212) 363-7500
jlevi@levikorsinsky.com
www.zlk.com

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SOURCE Levi & Korsinsky, LLP