Ultragenyx Shares Plunge 42% Following Phase 3 Study Failures for Setrusumab
Written by Emily J. Thompson, Senior Investment Analyst
Updated: Dec 29 2025
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Source: Benzinga
- Stock Plunge: Ultragenyx Pharmaceutical's shares fell sharply by 42% to $19.84 on Monday, primarily due to the failure of its Phase 3 Orbit and Cosmic studies for setrusumab (UX143) in Osteogenesis Imperfecta, leading to a significant decline in market confidence.
- Clinical Trial Failure: The results from Mereo BioPharma and Ultragenyx indicated that setrusumab did not achieve statistical significance in reducing the annualized clinical fracture rate, which not only impacts the company's short-term financial performance but may also have long-term negative implications for its future R&D investments and market competitiveness.
- Severe Market Reaction: The disappointing trial results raised investor concerns about Ultragenyx's future prospects, resulting in a substantial decrease in its market capitalization, reflecting the high sensitivity of investors to the success or failure of clinical trials in the biopharmaceutical sector.
- Industry Impact: Ultragenyx's failure could have a ripple effect across the biopharmaceutical industry, particularly in the bone metabolism disease space, as investors may adopt a more cautious approach towards similar product developments, potentially affecting financing and R&D strategies of related companies.
About the author
Emily J. Thompson
Emily J. Thompson, a Chartered Financial Analyst (CFA) with 12 years in investment research, graduated with honors from the Wharton School. Specializing in industrial and technology stocks, she provides in-depth analysis for Intellectia’s earnings and market brief reports.
