Ultragenyx stock plummets after OI drug study continues to final analysis

Published 09/07/2025, 21:18
© Reuters.

Investing.com -- Ultragenyx Pharmaceutical (TADAWUL:2070) Inc. (NASDAQ:RARE) stock plummeted 33% after the company announced its Phase 3 Orbit study for UX143 (setrusumab) in osteogenesis imperfecta patients will continue to final analysis rather than stopping early for efficacy.

Mereo BioPharma Group plc (NASDAQ:MREO), Ultragenyx’s partner in developing the treatment, saw its shares sink 40% following the news. The companies revealed that the Data Monitoring Committee reviewed interim data and recommended the study continue to its planned conclusion around year-end, indicating the results did not meet the threshold for early stoppage.

"Based on the feedback we hear from investigators and families who participated in the studies, we are confident that increasing bone mass leads to stronger bone, less fractures, and improved physical abilities," said Emil D. Kakkis, M.D., Ph.D., chief executive officer and president of Ultragenyx. "While we had hoped to be able to stop the study early, we look forward to having results from both Orbit and Cosmic around the end of this year."

The Phase 3 Orbit study is evaluating UX143 in pediatric and young adult patients with osteogenesis imperfecta, a rare genetic disorder characterized by fragile bones. According to the announcement, the DMC confirmed that UX143 demonstrates an acceptable safety profile.

The companies noted that data from the companion Cosmic study, which examines the drug in younger patients, were not analyzed at this interim timepoint. Both studies will continue with final analyses planned after patients have been on therapy for at least 18 months.

This article was generated with the support of AI and reviewed by an editor. For more information see our T&C.

Latest comments

Risk Disclosure: Trading in financial instruments and/or cryptocurrencies involves high risks including the risk of losing some, or all, of your investment amount, and may not be suitable for all investors. Prices of cryptocurrencies are extremely volatile and may be affected by external factors such as financial, regulatory or political events. Trading on margin increases the financial risks.
Before deciding to trade in financial instrument or cryptocurrencies you should be fully informed of the risks and costs associated with trading the financial markets, carefully consider your investment objectives, level of experience, and risk appetite, and seek professional advice where needed.
Fusion Media would like to remind you that the data contained in this website is not necessarily real-time nor accurate. The data and prices on the website are not necessarily provided by any market or exchange, but may be provided by market makers, and so prices may not be accurate and may differ from the actual price at any given market, meaning prices are indicative and not appropriate for trading purposes. Fusion Media and any provider of the data contained in this website will not accept liability for any loss or damage as a result of your trading, or your reliance on the information contained within this website.
It is prohibited to use, store, reproduce, display, modify, transmit or distribute the data contained in this website without the explicit prior written permission of Fusion Media and/or the data provider. All intellectual property rights are reserved by the providers and/or the exchange providing the data contained in this website.
Fusion Media may be compensated by the advertisers that appear on the website, based on your interaction with the advertisements or advertisers
© 2007-2025 - Fusion Media Limited. All Rights Reserved.