Ultragenyx Pharmaceutical Faces Class Action Lawsuit
Written by Emily J. Thompson, Senior Investment Analyst
Updated: Feb 11 2026
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Should l Buy RARE?
Source: Globenewswire
- Class Action Initiated: Bronstein, Gewirtz & Grossman, LLC has filed a class action lawsuit against Ultragenyx Pharmaceutical and certain officers, seeking damages for investors who purchased securities between August 3, 2023, and December 26, 2025, reflecting significant investor dissatisfaction with the company's transparency.
- Allegations of Misrepresentation: 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 on Osteogenesis Imperfecta patients, potentially misleading investors and impacting stock prices.
- Investor Action Deadline: Affected investors have until April 6, 2026, to request to be appointed as lead plaintiff, indicating the urgency for investors to engage in the legal process to recover potential losses.
- Law Firm Credentials: Bronstein, Gewirtz & Grossman, LLC is a nationally recognized firm specializing in securities fraud class actions, having recovered hundreds of millions for investors, underscoring its critical role in upholding market integrity and investor rights.
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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: 20.950
Low
35.00
Averages
61.65
High
120.00
Current: 20.950
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.
Ultragenyx Pharmaceutical Faces Class Action Lawsuit
- Lawsuit Background: National plaintiffs’ law firm Berger Montague PC has announced a class action lawsuit against Ultragenyx Pharmaceutical, representing investors who purchased stock from August 3, 2023, to December 26, 2025, alleging misleading information regarding clinical trials.
- Stock Price Plunge: Following the disclosure that the ORBIT and COSMIC studies did not significantly reduce clinical fracture rates for Osteogenesis Imperfecta, Ultragenyx's stock price plummeted from $34.19 on December 26, 2025, to $19.72, erasing over 42% of its value in a single day, severely impacting investor confidence.
- Investor Rights: Investors must apply by April 6, 2026, to be appointed as lead plaintiff representatives in the class action, highlighting the importance of legal processes in protecting investor rights.
- Law Firm's Strength: Berger Montague, a leading law firm specializing in complex civil litigation and class actions, has recovered over $50 billion for clients over the past 55 years, demonstrating its significant influence in the legal field.
See More
Ultragenyx Pharmaceutical Faces Class Action Lawsuit Over Securities Fraud
- Lawsuit Background: Kahn Swick & Foti LLC has initiated a class action lawsuit against Ultragenyx Pharmaceutical, alleging securities fraud affecting investors from August 3, 2023, to December 26, 2025, aiming to recover losses for impacted shareholders.
- Study Failure Impact: On December 26, 2025, Ultragenyx disclosed that its Phase 3 studies for setrusumab in Osteogenesis Imperfecta failed to show a statistically significant reduction in fracture rates, resulting in a dramatic 42% drop in share price within three days.
- Stock Price Volatility: Following the announcement, Ultragenyx's stock plummeted from $34.19 to $19.72 per share, indicating severe market concerns regarding the company's operational and financial outlook, prompting management to consider significant expense reductions.
- Investor Action: Affected investors have until April 6, 2026, to request lead plaintiff status, although eligibility for any recovery does not require serving as lead plaintiff, highlighting the legal avenues available for investor protection.
See More
Reminder of Class Action Lawsuits Against Mereo BioPharma and Others
- Lawsuit Overview: Holzer & Holzer LLC reminds investors of a class action lawsuit against Mereo BioPharma Group plc (NASDAQ: MREO) for failing to disclose material facts regarding setrusumab from June 2023 to December 2025, with a deadline of April 6, 2026, for investors to apply as lead plaintiffs if they suffered significant losses.
- Pomdoctor Case: The class action against Pomdoctor Limited (NASDAQ: POM) alleges fraudulent stock promotion through social media misinformation between October 2025 and December 2025, with a similar deadline of April 6, 2026, for affected investors to seek lead plaintiff status.
- Ultragenyx Lawsuit: Ultragenyx Pharmaceutical Inc. (NASDAQ: RARE) faces a class action lawsuit for not disclosing expected results of its Phase III Orbit and Cosmic studies from August 2023 to December 2025, urging impacted investors to act by April 6, 2026.
- Legal Services Background: Holzer & Holzer LLC, recognized as a top-rated securities litigation firm, has been dedicated to representing shareholders since 2000, recovering hundreds of millions for victims of corporate misconduct, highlighting its expertise and influence in the securities litigation field.
See More
Ultragenyx Pharmaceutical Class Action Notice Issued
- 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 participate in the class action and seek compensation.
- Lawsuit Background: The lawsuit alleges that defendants provided false and misleading information regarding setrusumab's (UX 143) efficacy in reducing annual fracture rates in Osteogenesis Imperfecta patients during Phase III Orbit and Cosmic studies, leading investors to purchase shares at inflated prices.
- Legal Representation Choice: Investors are encouraged to select experienced legal counsel, with Rosen Law Firm recognized for its successful track record in securities class actions, having recovered over $438 million for investors in 2019 alone.
- Potential Impact: If the lawsuit is successful, Ultragenyx shareholders may receive compensation; however, until the class is certified, investors must choose their legal representation, and those opting out may still share in any future recovery.
See More
Ultragenyx Pharmaceutical Class Action Notice Issued
- Class Action Initiation: Rosen Law Firm reminds investors who purchased Ultragenyx Pharmaceutical Inc. (NASDAQ: RARE) common stock between August 3, 2023, and December 26, 2025, to apply as lead plaintiffs by April 6, 2026, to potentially receive compensation without any out-of-pocket costs.
- Lawsuit Background: The lawsuit alleges that Ultragenyx provided overly optimistic expectations regarding its clinical trials for Osteogenesis Imperfecta, claiming that setrusumab would significantly reduce fracture rates, which was not supported by actual results.
- Investor Losses: The defendants are accused of misleading investors by disseminating positive statements while concealing critical risks associated with setrusumab, leading to inflated stock purchases and subsequent losses when the truth emerged.
- Law Firm's Credentials: Rosen Law Firm specializes in securities class actions, having recovered over $438 million for investors in 2019 alone, and was ranked first in 2017 for the number of securities class action settlements, showcasing its extensive experience and success in this field.
See More
FDA Approves Ultragenyx's UX016 for GNE Myopathy
- New Drug Approval: The US FDA has cleared Ultragenyx Pharmaceutical (RARE) for its Investigational New Drug application for UX016, aimed at treating the rare inherited neuromuscular disorder GNE myopathy, marking a significant advancement for the company in the rare disease sector.
- Innovative Treatment Mechanism: UX016, as a prodrug of sialic acid, offers a substrate replacement therapy targeting the condition characterized by insufficient sialic acid production, indicating a potential new treatment option that could enhance patient quality of life.
- Clinical Trial Plans: A phase 1/2 study for the drug is slated to commence in the second half of 2026, which is expected to provide critical data for further validating its safety and efficacy, thereby facilitating future market access.
- Broad Market Potential: With the FDA's approval, Ultragenyx's market potential in the rare disease space significantly increases, likely attracting more investor interest and laying the groundwork for future product line expansions.
See More
Ultragenyx Pharmaceutical Faces Class Action Lawsuit
- Lawsuit Background: National plaintiffs’ law firm Berger Montague PC has announced a class action lawsuit against Ultragenyx Pharmaceutical, representing investors who purchased stock from August 3, 2023, to December 26, 2025, alleging misleading information regarding clinical trials.
- Stock Price Plunge: Following the disclosure that the ORBIT and COSMIC studies did not significantly reduce clinical fracture rates for Osteogenesis Imperfecta, Ultragenyx's stock price plummeted from $34.19 on December 26, 2025, to $19.72, erasing over 42% of its value in a single day, severely impacting investor confidence.
- Investor Rights: Investors must apply by April 6, 2026, to be appointed as lead plaintiff representatives in the class action, highlighting the importance of legal processes in protecting investor rights.
- Law Firm's Strength: Berger Montague, a leading law firm specializing in complex civil litigation and class actions, has recovered over $50 billion for clients over the past 55 years, demonstrating its significant influence in the legal field.
See More
Ultragenyx Pharmaceutical Faces Class Action Lawsuit Over Securities Fraud
- Lawsuit Background: Kahn Swick & Foti LLC has initiated a class action lawsuit against Ultragenyx Pharmaceutical, alleging securities fraud affecting investors from August 3, 2023, to December 26, 2025, aiming to recover losses for impacted shareholders.
- Study Failure Impact: On December 26, 2025, Ultragenyx disclosed that its Phase 3 studies for setrusumab in Osteogenesis Imperfecta failed to show a statistically significant reduction in fracture rates, resulting in a dramatic 42% drop in share price within three days.
- Stock Price Volatility: Following the announcement, Ultragenyx's stock plummeted from $34.19 to $19.72 per share, indicating severe market concerns regarding the company's operational and financial outlook, prompting management to consider significant expense reductions.
- Investor Action: Affected investors have until April 6, 2026, to request lead plaintiff status, although eligibility for any recovery does not require serving as lead plaintiff, highlighting the legal avenues available for investor protection.
See More
Reminder of Class Action Lawsuits Against Mereo BioPharma and Others
- Lawsuit Overview: Holzer & Holzer LLC reminds investors of a class action lawsuit against Mereo BioPharma Group plc (NASDAQ: MREO) for failing to disclose material facts regarding setrusumab from June 2023 to December 2025, with a deadline of April 6, 2026, for investors to apply as lead plaintiffs if they suffered significant losses.
- Pomdoctor Case: The class action against Pomdoctor Limited (NASDAQ: POM) alleges fraudulent stock promotion through social media misinformation between October 2025 and December 2025, with a similar deadline of April 6, 2026, for affected investors to seek lead plaintiff status.
- Ultragenyx Lawsuit: Ultragenyx Pharmaceutical Inc. (NASDAQ: RARE) faces a class action lawsuit for not disclosing expected results of its Phase III Orbit and Cosmic studies from August 2023 to December 2025, urging impacted investors to act by April 6, 2026.
- Legal Services Background: Holzer & Holzer LLC, recognized as a top-rated securities litigation firm, has been dedicated to representing shareholders since 2000, recovering hundreds of millions for victims of corporate misconduct, highlighting its expertise and influence in the securities litigation field.
See More
Ultragenyx Pharmaceutical Class Action Notice Issued
- 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 participate in the class action and seek compensation.
- Lawsuit Background: The lawsuit alleges that defendants provided false and misleading information regarding setrusumab's (UX 143) efficacy in reducing annual fracture rates in Osteogenesis Imperfecta patients during Phase III Orbit and Cosmic studies, leading investors to purchase shares at inflated prices.
- Legal Representation Choice: Investors are encouraged to select experienced legal counsel, with Rosen Law Firm recognized for its successful track record in securities class actions, having recovered over $438 million for investors in 2019 alone.
- Potential Impact: If the lawsuit is successful, Ultragenyx shareholders may receive compensation; however, until the class is certified, investors must choose their legal representation, and those opting out may still share in any future recovery.
See More
Ultragenyx Pharmaceutical Class Action Notice Issued
- Class Action Initiation: Rosen Law Firm reminds investors who purchased Ultragenyx Pharmaceutical Inc. (NASDAQ: RARE) common stock between August 3, 2023, and December 26, 2025, to apply as lead plaintiffs by April 6, 2026, to potentially receive compensation without any out-of-pocket costs.
- Lawsuit Background: The lawsuit alleges that Ultragenyx provided overly optimistic expectations regarding its clinical trials for Osteogenesis Imperfecta, claiming that setrusumab would significantly reduce fracture rates, which was not supported by actual results.
- Investor Losses: The defendants are accused of misleading investors by disseminating positive statements while concealing critical risks associated with setrusumab, leading to inflated stock purchases and subsequent losses when the truth emerged.
- Law Firm's Credentials: Rosen Law Firm specializes in securities class actions, having recovered over $438 million for investors in 2019 alone, and was ranked first in 2017 for the number of securities class action settlements, showcasing its extensive experience and success in this field.
See More
FDA Approves Ultragenyx's UX016 for GNE Myopathy
- New Drug Approval: The US FDA has cleared Ultragenyx Pharmaceutical (RARE) for its Investigational New Drug application for UX016, aimed at treating the rare inherited neuromuscular disorder GNE myopathy, marking a significant advancement for the company in the rare disease sector.
- Innovative Treatment Mechanism: UX016, as a prodrug of sialic acid, offers a substrate replacement therapy targeting the condition characterized by insufficient sialic acid production, indicating a potential new treatment option that could enhance patient quality of life.
- Clinical Trial Plans: A phase 1/2 study for the drug is slated to commence in the second half of 2026, which is expected to provide critical data for further validating its safety and efficacy, thereby facilitating future market access.
- Broad Market Potential: With the FDA's approval, Ultragenyx's market potential in the rare disease space significantly increases, likely attracting more investor interest and laying the groundwork for future product line expansions.
See More
