LEVI & KORSINSKY, LLP: RARE STOCK DECLINED OVER 42% FOLLOWING PHASE III STUDY FAILURE DISCLOSURE

Levi & Korsinsky, LLP is currently representing investors in a class action lawsuit against Ultragenyx Pharmaceutical Inc. (NASDAQ: RARE) following a significant decline in the company's stock price. On December 29, 2025, Ultragenyx shares fell sharply from $34.19 to $19.72, marking a drastic decline of approximately 42.32% within a single day. This drop was triggered by the disclosure that both the Phase III Orbit and Cosmic studies of its drug candidate, setrusumab, failed to meet their primary endpoints for reducing annualized fracture rates.

The lawsuit, which seeks damages for shareholders who acquired Ultragenyx securities between August 3, 2023, and December 26, 2025, alleges that the company misled investors about the efficacy of setrusumab. Prior to the December disclosure, the stock had already experienced significant volatility, having dropped by over 25% in July 2025 after interim study results were announced. Following the December report, analysts reportedly slashed their price targets for Ultragenyx by more than 30%, acknowledging the substantial loss of investor confidence.

The allegations claim that while setrusumab exhibited improvements in bone mineral density, these benefits did not translate into decreased fracture rates, raising concerns about the accuracy of information provided to investors about the trials. The lawsuit accuses Ultragenyx of concealing crucial data that potentially impacted investment decisions.

Levi & Korsinsky is facilitating the claims process for affected investors, offering opportunities for compensation without upfront fees. The deadline to seek lead plaintiff status is April 6, 2026. Investors can contact the firm for further assistance. The firm, recognized as a leading player in securities litigation, aims to hold companies accountable for misrepresentations affecting shareholder value.

Following Ultragenyx Pharmaceutical Inc.'s significant stock drop of over 42% after disclosing the failure of its Phase III studies for setrusumab, investors are reminded of the volatility inherent in biopharmaceutical stocks, particularly those tied to clinical outcomes. The stock fell from $34.19 to $19.72 on December 29, 2025, leading to immediate calls for legal action against the company for alleged misrepresentation of efficacy potential. In the turbulent landscape of biopharma investments, the repercussions of missed clinical endpoints can be severe and swift, often erasing substantial shareholder value.

For current and potential investors, it is critical to assess both the short-term implications of these clinical setbacks and the long-term trajectory of the company's pipeline. The interim results had already indicated signs of weakening investor confidence, as evidenced by a previous 25.12% decline in July 2025 after interim results failed to impress the market. The substantial price target cuts from analysts, also over 30%, reflect caution and reevaluation of the company’s future prospects.

Going forward, investors should closely monitor Ultragenyx's strategic response to this setback, particularly the promised "significant expense reductions." These measures could help stabilize the company’s financials and potentially set the stage for recovery. However, caution is warranted; investments should be based on a thorough analysis of the company’s remaining assets, ongoing studies, and the management’s capability to navigate this crisis.

Participating in any legal actions, such as the pending class action filed by Levi & Korsinsky LLP, may be worth considering for impacted investors seeking to recover losses. Ultimately, due diligence remains key—understanding the high-risk nature of this investment category can inform better decision-making as the situation evolves.