Ultragenyx Pharmaceutical Inc. Notice of April 6, 2026 Application Deadline for Class Action Lawsuit – Contact Lewis Kahn, Esq. at Kahn Swick & Foti, LLC, Before Application Deadline

NEW YORK & NEW ORLEANS–(BUSINESS WIRE)–Kahn Swick & Foti, LLC (“KSF”) and KSF partner, former Attorney General of Louisiana, Charles C. Foti, Jr., notifies investors in Ultragenyx Pharmaceutical Inc. (“Ultragenyx” or the “Company”) (NasdaqGS: RARE) of a class action securities lawsuit.

CLASS DEFINITION: The lawsuit seeks to recover losses on behalf of investors of Ultragenyx 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:

https://www.ksfcounsel.com/cases/nasdaqgs-rare/

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.

CASE DETAILS: On December 26, 2025, the Company announced the “results from the Phase 3 Orbit and Cosmic studies for setrusumab (UX143) in Osteogenesis Imperfecta” disclosing that both its Phase III Orbit and Cosmic studies failed to demonstrate that setrusumab triggered a statistically significant reduction in annualized fracture rates for patients with osteogenesis imperfecta, and, as a result the Company “is evaluating its planned operations and will promptly define and implement significant expense reductions.” On this news, the price of Ultragenyx’s shares fell approximately 42%, from $34.19 per share on December 26, 2025 to $19.72 per share on December 29, 2025.

The case is Steven Bailey v. Ultragenyx Pharmaceutical Inc., et al., No. 26-cv-01097.

WHAT TO DO? If you invested in Ultragenyx and suffered a loss during the relevant time frame, you have until April 6, 2026 to request that the Court appoint you as lead plaintiff; however, your ability to share in any recovery does not require that you serve as a lead plaintiff.

About Kahn Swick & Foti, LLC

KSF, whose partners include former Louisiana Attorney General Charles C. Foti, Jr., is one of the nation’s premier boutique securities litigation law firms. This past year, KSF was ranked by SCAS among the top 10 firms nationally based upon total settlement value. KSF serves a variety of clients, including public and private institutional investors, and retail investors – in seeking recoveries for investment losses emanating from corporate fraud or malfeasance by publicly traded companies. KSF has offices in New York, Delaware, California, Louisiana, Chicago, and a representative office in Luxembourg.

TOP 10 Plaintiff Law Firms – According to ISS Securities Class Action Services

To learn more about KSF, you may visit www.ksfcounsel.com.

Contacts

Kahn Swick & Foti, LLC
Lewis Kahn, Managing Partner
lewis.kahn@ksfcounsel.com
1-877-515-1850
1100 Poydras St., Suite 960
New Orleans, LA 70163

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