Portnoy Law Firm Announces Class Action On Behalf Of Ultragenyx Pharmaceutical, Inc. Investors

(MENAFN- GlobeNewsWire - Nasdaq) LOS ANGELES, Feb. 26, 2026 (GLOBE NEWSWIRE) -- The Portnoy Law Firm advises Ultragenyx Pharmaceutical, Inc., (“Ultragenyx” or the "Company") (NASDAQ: RARE) investors of a class action on behalf of investors that bought securities between August 3, 2023 and December 26, 2025, inclusive (the“Class Period”). Ultragenyx investors have until April 6, 2026 to file a lead plaintiff motion.

Investors are encouraged to contact attorney Lesley F. Portnoy, by phone 844-767-8529 or email:..., to discuss their legal rights, or join the case via . The Portnoy Law Firm can provide a complimentary case evaluation and discuss investors' options for pursuing claims to recover their losses.

The complaint alleges that, throughout the Class Period, Defendants made false and/or misleading statements and/or failed to disclose that: (1) Ultragenyx created the false impression that they possessed reliable information pertaining to the effects of the company's drug, setrusumab, on patients with variable types of Osteogenesis Imperfecta, while also minimizing risk that patients in Ultragenyx's Phase III Orbit study would fail to achieve a statistically significant reduction in annualized fracture rate (“AFR”), such that the second interim analysis could be performed and presented to the investing public; (2) in truth, Ultragenyx's optimism in the Phase III Orbit study's results and interim analysis benchmark were misplaced because Ultragenyx failed to convey the risk associated with basing such threshold figures on Phase II results that had no placebo control group for appropriate comparison and thus had not ruled out that the reduction in AFR from that study could merely be triggered by an increased standard of care and the placebo effect of being provided a novel treatment; and (3) as a result, Defendants' positive statements about the company's business, operations, and prospects were materially misleading and/or lacked a reasonable basis.

The Portnoy Law Firm represents investors in pursuing claims caused by corporate wrongdoing. The Firm's founding partner has recovered over $5.5 billion for aggrieved investors. Attorney advertising. Prior results do not guarantee similar outcomes.

Lesley F. Portnoy, Esq.
Admitted CA, NY and TX Bar
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310-692-8883

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