New York, New York--(Newsfile Corp. - January 26, 2026) - Levi & Korsinsky notifies investors that it has commenced an investigation into Ultragenyx Pharmaceutical Inc. ("Ultragenyx Pharmaceutical Inc.") (NASDAQ: RARE) concerning potential violations of the federal securities laws.

Ultragenyx reported the study results on December 29, 2025. Both studies failed to achieve their primary endpoint of a reduction in annualized clinical fracture rate against placebo in the Orbit study and against biophosphonates, the standard care, in the Cosmic study.

The Phase III studies also failed to correlate the secondary result to a reduction in fracture rate, despite successfully showing an improvement in the tested patients' bone density. Ultragenyx had previously relied on the results Phase II of the Orbit study to claim a causal link between improved bone density and a reduction in annualized fracture rate.

In announcing the results, the company pointed to a "low fracture rate in the placebo group" as a justification for Orbit's failed results. Management had previously highlighted there were no "uncontrolled factors" in the study and they had crafted the study in such a way to "actually increase their fractures, which would give [them] more opportunities to see the difference between [the test groups]."

Analyst coverage following the results turned cautious as analysts quickly began slashing their price targets. Barclays noted it now sees "limited opportunity for drug approval despite some trend of clinical benefit."

If you suffered a loss on your Ultragenyx Pharmaceutical Inc. securities and would like to explore a potential recovery under the federal securities laws, Learn More About the Investigation or contact Joseph E. Levi, Esq. via email at jlevi@levikorsinsky.com or call (212)363-7500 to speak to our team of experienced shareholder advocates.

WHY LEVI & KORSINSKY: Over the past 20 years, Levi & Korsinsky LLP has established itself as a nationally-recognized securities litigation firm that has secured hundreds of millions of dollars for aggrieved shareholders and built a track record of winning high-stakes cases. The 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. Attorney Advertising. Prior results do not guarantee similar outcomes.

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Source: Levi & Korsinsky, LLP