Class Action Reminder for Mereo BioPharma Shareholders
Written by Emily J. Thompson, Senior Investment Analyst
Updated: Feb 18 2026
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Should l Buy MREO?
Source: Globenewswire
- Lawsuit Background: Robbins LLP reminds all investors who purchased Mereo BioPharma Group plc (NASDAQ: MREO) American Depository Shares between June 5, 2023, and December 26, 2025, that a class action has been filed, alleging the company misled investors regarding clinical trial results.
- Study Failures: The complaint indicates that Mereo failed to meet the primary endpoint of reducing clinical fracture rates in its Phase 3 ORBIT and COSMIC studies, despite previously optimistic statements about the drug setrusumab, leading investors to buy shares at artificially inflated prices.
- Stock Price Plunge: Following the announcement on December 29, 2025, that the studies did not meet their endpoints, Mereo's ADS price plummeted from $2.31 on December 26, 2025, to $0.29, representing a decline of over 87.7%, severely impacting shareholder value.
- Next Steps: Shareholders wishing to serve as lead plaintiffs in the class action must submit their papers by April 6, 2026; Robbins LLP offers contingency fee representation, ensuring shareholders can recover losses without upfront costs.
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Analyst Views on MREO
Wall Street analysts forecast MREO stock price to rise
8 Analyst Rating
6 Buy
2 Hold
0 Sell
Strong Buy
Current: 0.392
Low
0.50
Averages
2.08
High
5.00
Current: 0.392
Low
0.50
Averages
2.08
High
5.00
About MREO
Mereo BioPharma Group plc is a biopharmaceutical company focused on the development of therapeutics for rare diseases. The Company has developed a portfolio of late-stage clinical product candidates, and its two rare disease product candidates are setrusumab for the treatment of osteogenesis imperfecta (OI) and alvelestat primarily for the treatment of severe alpha-1 antitrypsin deficiency-associated lung disease (AATD-LD). In addition to the rare disease programs, it has two oncology product candidates in clinical development, which include Etigilimab, an IgG1 monoclonal antibody which binds to the human T-cell immunoreceptor with Ig and ITIM domains (TIGIT) receptor on immune cells to improve the activation and effectiveness of T-cell and NK cell antitumor activity and Navicixizumab is a bispecific antibody that inhibits delta-like ligand 4 (DLL4) and vascular endothelial growth factor (VEGF). Navicixizumab is developed for the treatment of late-line ovarian cancer.
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 Notice: Rosen Law Firm reminds investors who purchased Mereo BioPharma ADS between June 5, 2023, and December 26, 2025, to apply as lead plaintiffs by April 6, 2026, to participate in the class action and potentially receive compensation.
- Lawsuit Background: The lawsuit alleges that defendants provided misleading information regarding the expected results of the Phase 3 Orbit and COSMIC studies for setrusumab, leading investors to purchase ADS at artificially inflated prices, resulting in financial losses when the truth emerged.
- Law Firm Credentials: Rosen Law Firm specializes in securities class actions and has recovered over $438 million for investors in 2019 alone, being ranked first in 2017 for the number of securities class action settlements, demonstrating its expertise and success in this field.
- Investor Guidance: Investors are advised to select counsel with a proven track record to ensure effective legal support in the class action, avoiding firms that merely act as intermediaries without substantial litigation experience.
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- Class Action Notice: Rosen Law Firm reminds investors who purchased Mereo BioPharma ADS between June 5, 2023, and December 26, 2025, to apply to be lead plaintiff by April 6, 2026, to potentially receive compensation without any out-of-pocket costs.
- Case Background: The lawsuit alleges that defendants provided false and misleading information regarding the Phase 3 Orbit and COSMIC studies, claiming setrusumab could significantly reduce annual fracture rates in Osteogenesis Imperfecta patients, while the studies failed to meet primary endpoints, leading investors to purchase ADS at inflated prices.
- Law Firm Credentials: Rosen Law Firm specializes in securities class actions and has achieved the largest settlement against a Chinese company, recovering over $438 million for investors in 2019 alone, demonstrating its strong track record and expertise in this field.
- Investor Advisory: Investors are advised to choose legal counsel carefully, as Rosen Law Firm emphasizes the importance of selecting experienced attorneys to ensure effective legal representation in class actions.
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- Class Action Notice: The Portnoy Law Firm advises Mereo BioPharma Group plc investors of a class action for those who purchased securities between June 5, 2023, and December 26, 2025, with a deadline of April 6, 2026, to file a lead plaintiff motion to protect their legal rights.
- False Statements Allegations: The complaint alleges that defendants provided overly positive statements while concealing significant adverse facts regarding the true status of the Phase 3 ORBIT and COSMIC programs, misleading investors about the company's actual condition.
- Clinical Trial Failures: On December 29, 2025, Mereo announced that neither the ORBIT nor COSMIC Phase 3 studies achieved statistical significance, failing to meet their primary endpoint of reducing annualized clinical fracture rates compared to placebo or bisphosphonates, despite improvements in bone mineral density.
- Stock Price Collapse: Following this announcement, Mereo's ADS price plummeted from $2.31 per share on December 26, 2025, to $0.29 per share on December 29, 2025, representing a dramatic decline of over 87.7%, severely impacting investor asset values.
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- Lawsuit Initiation: Bragar Eagel & Squire law firm has commenced class actions on behalf of shareholders of Ultragenyx Pharmaceutical (NASDAQ:RARE) and Mereo BioPharma (NASDAQ:MREO), with a lead plaintiff deadline of April 6, 2026, indicating significant investor concern regarding potential risks associated with these companies.
- Study Result Failures: On December 29, 2025, Ultragenyx announced that its Phase III Orbit and Cosmic studies failed to achieve statistical significance in reducing annualized fracture rates, causing its stock price to plummet by approximately 42.32% in a single day, from $34.19 to $19.72, reflecting market disappointment in the study outcomes.
- Mereo BioPharma's Reaction: Similarly, Mereo BioPharma announced on December 29, 2025, that its ORBIT and COSMIC studies did not meet the primary endpoint of reducing annualized clinical fracture rates, despite improved bone mineral density, leading to a dramatic decline in its ADS price from $2.31 to $0.29, a drop of over 87.7%, highlighting severe investor confidence erosion.
- Disclosure Issues: The lawsuits allege that both companies provided overly optimistic projections to investors while concealing significant adverse facts related to the study protocols, resulting in shareholders purchasing stocks at artificially inflated prices, raising concerns about corporate governance and transparency.
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- Class Action Deadline: Investors in Mereo BioPharma Group plc must apply to be lead plaintiffs by April 6, 2026, to potentially receive compensation without any out-of-pocket costs, indicating a significant impact on investor confidence regarding the company's future.
- False Statements Allegations: The lawsuit alleges that the company misrepresented the expected outcomes of the Phase 3 Orbit and COSMIC studies for setrusumab, leading investors to purchase ADS at inflated prices, highlighting serious deficiencies in the company's transparency and information disclosure practices.
- Law Firm Credentials: The Rosen Law Firm specializes in securities class actions and has recovered over $438 million for investors in 2019 alone, showcasing its proven track record and expertise in handling similar cases, which enhances investor trust in their representation.
- Investor Guidance: The law firm advises investors to select qualified counsel with a successful track record to avoid partnering with inexperienced intermediaries, ensuring they receive the best legal support and potential compensation in the class action.
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- Class Action Initiated: Bronstein, Gewirtz & Grossman LLC has filed a class action lawsuit against Mereo BioPharma Group, seeking damages for investors who purchased securities between June 5, 2023, and December 26, 2025, reflecting strong investor response to potential fraud allegations.
- Allegations of False Statements: The complaint alleges that Mereo provided overly positive statements to investors while concealing significant adverse facts regarding the Phase 3 ORBIT and COSMIC programs, which failed to meet their primary endpoints, potentially undermining investor confidence.
- Call to Action for Investors: Affected investors are encouraged to apply to be lead plaintiffs by April 6, 2026, to share in any potential recovery from the lawsuit, indicating the legal team's commitment to protecting investor rights.
- No-Cost Legal Services: The law firm offers legal representation on a contingency fee basis, meaning they will only charge fees if they successfully recover funds, thereby reducing the legal risk for investors and enhancing the appeal of participating in the lawsuit.
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