Recent Updates
Recently added Catalysts
RARE Negative Sentiment Score: 20/100

Ultragenyx Pharmaceutical Inc. Class Action: Levi & Korsinsky Reminds Ultragenyx Investors of the Pending Class Action Lawsuit with a Lead Plaintiff Deadline of April 6, 2026 – RARE

Key Takeaway: Levi & Korsinsky, LLP has announced a class action lawsuit against Ultragenyx Pharmaceutical Inc. for securities fraud, focusing on the company's misleading statements regarding the efficacy of its drug setrusumab. The lawsuit seeks to recover losses incurred by investors between August 3, 2023, and December 26, 2025. Following the announcement that the Phase III studies did not meet primary endpoints, Ultragenyx's stock experienced a dramatic decline of 42.32% in one day. Investors have until April 6, 2026, to file for lead plaintiff status in the class action.

Market Sentiment Analysis

CONCERNS & RISKS

  • Allegations of securities fraud against Ultragenyx Pharmaceutical Inc.
  • The company's Phase III Orbit and Cosmic Studies failed to achieve statistical significance.
  • Ultragenyx's stock price plummeted by about 42.32% in a single day due to study failure.

Full Press Release Details

NEW YORK, April 06, 2026 (GLOBE NEWSWIRE) -- Levi & Korsinsky, LLP notifies investors in Ultragenyx Pharmaceutical Inc. ("Ultragenyx" or the "Company") (NASDAQ: RARE) of a class action securities lawsuit.
CLASS DEFINITION: The lawsuit seeks to recover losses on behalf of Ultragenyx investors who were adversely affected by alleged securities fraud between August 3, 2023 and December 26, 2025. Follow the link below to get more information and be contacted by a member of our team:
RARE investors may also contact Joseph E. Levi, Esq. via email at jlevi@levikorsinsky.com or by telephone at (212) 363-7500.
CASE DETAILS: According to the complaint, defendants provided 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. 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. Following this news, the price of Ultragenyx’s common stock declined dramatically. From a closing market price of $34.19 per share on December 26, 2025, Ultragenyx’s stock price fell to $19.72 per share on December 29, 2025, a decline of about 42.32% in the span of just a single day.
WHAT'S NEXT? If you suffered a loss in Ultragenyx during the relevant time frame, you have until April 6, 2026 to request that the Court appoint you as lead plaintiff. Your ability to share in any recovery doesn't require that you serve as a lead plaintiff.
NO COST TO YOU: If you are a class member, you may be entitled to compensation without payment of any out-of-pocket costs or fees. There is no cost or obligation to participate.
WHY LEVI & KORSINSKY: Over the past 20 years, the team at Levi & Korsinsky has secured hundreds of millions of dollars for aggrieved shareholders and built a track record of winning high-stakes cases. Our firm has extensive expertise representing investors in complex securities litigation and a team of over 70 employees to serve our clients. For seven years in a row, Levi & Korsinsky has ranked in ISS Securities Class Action Services’ Top 50 Report as one of the top securities litigation firms in the United States.
Levi & Korsinsky, LLP
Joseph E. Levi, Esq.
33 Whitehall Street, 27th Floor

Tags

Frequently Asked Questions

What is the class action lawsuit against Ultragenyx about?

The lawsuit aims to recover losses for Ultragenyx investors due to alleged securities fraud from August 3, 2023, to December 26, 2025.

How much did Ultragenyx's stock fall after the study results?

Ultragenyx's stock price dropped about 42.32%, from $34.19 to $19.72 per share.

Who can participate in the class action lawsuit?

Any investor who experienced losses in Ultragenyx during the relevant period can join the lawsuit.

Is there any cost to participate in the lawsuit?

No, class members may be entitled to compensation without any out-of-pocket costs.

How can I become a lead plaintiff in the lawsuit?

You can request to be appointed as lead plaintiff until April 6, 2026, if you suffered losses.

Last updated: Apr 6, 2026