Ultragenyx Pharmaceutical Class Action Notice Issued
Written by Emily J. Thompson, Senior Investment Analyst
Updated: 1 day ago
0mins
Should l Buy RARE?
Source: PRnewswire
- Class Action Notice: Rosen Law Firm reminds investors who purchased Ultragenyx (NASDAQ:RARE) common stock between August 3, 2023, and December 26, 2025, to apply as lead plaintiffs by April 6, 2026, to protect their rights in the lawsuit.
- Fee Arrangement: Investors joining the class action will incur no out-of-pocket costs, as attorney fees will be covered through a contingency fee arrangement, thereby reducing financial barriers and encouraging broader participation from affected shareholders.
- Lawsuit Background: The lawsuit alleges that Ultragenyx made false statements regarding the efficacy of setrusumab in its Phase III Orbit and Cosmic studies, leading investors to purchase shares at artificially inflated prices, resulting in financial losses when the truth emerged.
- Law Firm's Advantage: Rosen Law Firm is renowned for its successful track record in securities class actions, having recovered over $438 million for investors in 2019 alone, demonstrating its expertise and resource capabilities in handling such cases.
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Analyst Views on RARE
Wall Street analysts forecast RARE stock price to rise
18 Analyst Rating
17 Buy
1 Hold
0 Sell
Strong Buy
Current: 22.070
Low
35.00
Averages
61.65
High
120.00
Current: 22.070
Low
35.00
Averages
61.65
High
120.00
About RARE
Ultragenyx Pharmaceutical Inc. is a biopharmaceutical company. The Company is focused on the identification, acquisition, development, and commercialization of novel products for the treatment of serious rare and ultrarare genetic diseases. Its therapies and clinical-stage pipeline consist of four product categories: biologics, small molecules, AAV gene therapy, and nucleic acid product candidates. Its four approved product candidates include Crysvita (burosumab) for the treatment of X-linked hypophosphatemia (XLH), and tumor-induced osteomalacia (TIO), Mepsevii (vestronidase alfa) for the treatment of mucopolysaccharidosis VII (MPSVII) or Sly Syndrome, Dojolvi (triheptanoin) for the treatment of long-chain fatty acid oxidation disorders (LC-FAOD), and Evkeeza (evinacumab) for the treatment of homozygous familial hypercholesterolemia (HoFH). Its clinical product candidates include DTX401, DTX301, UX701, UX143, UX111, and GTX-102. UX143 for the treatment of Osteogenesis Imperfecta.
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.
- Class Action Initiation: Robbins Geller Rudman & Dowd LLP announces that investors who purchased Ultragenyx Pharmaceutical Inc. stock between August 3, 2023, and December 26, 2025, can seek lead plaintiff status in a class action lawsuit, indicating strong investor concern over potential violations.
- Stock Price Plunge: Following the July 9, 2025, announcement that the Phase III Orbit study failed to achieve statistical significance, Ultragenyx's stock fell over 25%, and after the December 29, 2025, revelation of further study failures, the stock dropped more than 42%, reflecting a pessimistic market outlook.
- False Statement Allegations: The lawsuit alleges that Ultragenyx and its executives made false or misleading statements during the class period, failing to disclose risks associated with Osteogenesis Imperfecta studies, which may have misled investors and impacted future financing capabilities.
- Legal Process Overview: Under the Private Securities Litigation Reform Act of 1995, any investor who purchased Ultragenyx stock during the class period can apply to be the lead plaintiff, representing other investors in the lawsuit, highlighting the legal mechanisms in place to protect investor rights.
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- Class Action Initiated: Robbins LLP reminds investors of a class action filed on behalf of shareholders who purchased Ultragenyx Pharmaceutical Inc. (NASDAQ: RARE) stock between August 3, 2023, and December 26, 2025, alleging the company misled investors regarding clinical trial results.
- Study Results Failure: On December 29, 2025, Ultragenyx announced that its Phase III Orbit and Cosmic studies did not achieve statistical significance on primary endpoints, causing the stock price to plummet approximately 42.32% in a single day, from $34.19 to $19.72, severely impacting investor confidence.
- Misleading Statements: The lawsuit alleges that Ultragenyx made overly optimistic statements about setrusumab's potential while concealing the lack of correlation between increased bone density and reduced fracture rates, leading investors to purchase shares at artificially inflated prices.
- Shareholder Action Recommended: Affected shareholders are encouraged to contact Robbins LLP to participate in the class action as lead plaintiffs, representing other shareholders in the litigation without incurring any fees, demonstrating the firm's commitment to shareholder rights.
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- Lawsuit Background: Bronstein, Gewirtz & Grossman, LLC, a nationally recognized investor-rights law firm, has filed a class action lawsuit against Ultragenyx Pharmaceutical Inc. and certain officers, seeking damages for investors who purchased securities between August 3, 2023, and December 26, 2025.
- Allegations: The complaint alleges that throughout the class period, defendants made false and/or misleading statements and failed to disclose risks associated with the Phase III Orbit study's results, misleading investors about the treatment's efficacy for Osteogenesis Imperfecta patients.
- Investor Action: Affected investors are encouraged to apply to be lead plaintiffs by April 6, 2026, to share in any potential recovery, with the assurance that participation does not require serving as lead plaintiff.
- Law Firm's Reputation: Bronstein, Gewirtz & Grossman, LLC has a strong reputation in securities fraud class actions, having recovered hundreds of millions for investors nationwide, emphasizing their commitment to restoring investor capital and ensuring corporate accountability.
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- Investor Loss Warning: Faruqi & Faruqi LLP is investigating potential securities litigation against Ultragenyx Pharmaceuticals, urging investors who purchased securities between August 3, 2023, and December 26, 2025, to apply for lead plaintiff status by April 6, 2026, indicating significant legal risks for the company.
- Study Result Failures: Ultragenyx revealed on July 9, 2025, that its Phase III Orbit study failed to achieve statistical significance, causing a stock price drop of over 25%, and subsequently announced on December 29, 2025, that both Orbit and Cosmic studies did not meet primary endpoints, leading to an additional 42% decline, reflecting severe investor confidence erosion.
- False Statement Allegations: The lawsuit alleges that Ultragenyx and its executives violated federal securities laws by making false or misleading statements regarding study results, failing to disclose associated risks, which may mislead investors in their decision-making and impact their returns.
- Legal Consultation Opportunity: Faruqi & Faruqi encourages anyone with information, including former employees and shareholders, to contact the firm, highlighting the company's lack of transparency regarding legal issues, which could affect its future market performance and investor trust.
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- Lawsuit Background: Kahn Swick & Foti LLC informs investors in Ultragenyx Pharmaceutical of a class action lawsuit due to alleged securities fraud occurring between August 3, 2023, and December 26, 2025, aimed at recovering losses for affected investors.
- Study Failure Impact: On December 26, 2025, Ultragenyx announced that its Phase 3 studies for setrusumab (UX143) failed to show a statistically significant reduction in annualized fracture rates for osteogenesis imperfecta patients, prompting the company to evaluate significant expense reductions.
- Stock Price Plunge: Following the announcement, Ultragenyx's stock price fell approximately 42%, from $34.19 per share on December 26, 2025, to $19.72 per share on December 29, 2025, indicating a negative market outlook on the company's future.
- Investor Action Recommendation: Affected investors have until April 6, 2026, to request to be appointed as lead plaintiff, although they can still share in any recovery without serving in that role, highlighting ongoing opportunities for legal recourse for investors seeking compensation.
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- Regulatory Standards Controversy: Congressman Jake Auchincloss criticized FDA Commissioner Marty Makary for replacing standards of safety and efficacy with fear and favoritism, undermining patient confidence in new therapies and impacting the market launch of innovative drugs.
- Staffing Losses: The FDA has experienced significant staff reductions in its Center for Drug Evaluation and Research, with oncology review staff dropping from about 100 to below 60, which may lead to approval delays and incomplete response letters.
- Decline in Accelerated Approvals: In 2024, the FDA approved 20 drugs through the accelerated approval process, down from 9 the previous year, indicating a direct impact on drug approval efficiency due to the loss of experienced reviewers.
- New Therapy Approval Pathways: The FDA proposed a new system for approving personalized drugs aimed at rare diseases, intending to provide more flexible approval pathways, but this change has sparked widespread controversy, affecting the agency's core mission.
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