Mereo BioPharma Group PLC faces significant decline amid market weakness
Written by Emily J. Thompson, Senior Investment Analyst
Updated: Jan 12 2026
0mins
Should l Buy MREO?
Source: 8-K
Mereo BioPharma Group PLC's stock has plummeted by 89.61% in pre-market trading, crossing below the 5-day SMA. This drastic drop occurs in the context of broader market weakness, with the Nasdaq-100 down 0.69% and the S&P 500 down 0.43%. The stock's decline is attributed to sector rotation as investors react to the overall market conditions.
The significant price movement reflects a lack of positive catalysts specific to Mereo BioPharma Group PLC, as no recent news or developments have been reported that could have influenced investor sentiment. The broader market's downturn has likely led to a shift in investor focus, contributing to the stock's steep decline. This situation highlights the vulnerability of Mereo BioPharma Group PLC in the current market environment.
Investors may need to reassess their positions in Mereo BioPharma Group PLC, especially given the lack of supportive news. The stock's performance will likely continue to be influenced by overall market trends and investor sentiment in the biotech sector.
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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: 0.416
Low
0.50
Averages
2.08
High
5.00
Current: 0.416
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 Reminder for Mereo BioPharma Shareholders
- 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.
See More
Mereo BioPharma Faces Class Action Lawsuit
- Class Action Initiated: Berger Montague PC has filed a class action lawsuit against Mereo BioPharma on behalf of investors who purchased American Depositary Shares between June 5, 2023, and December 26, 2025, indicating significant investor disappointment regarding the company's outlook.
- Stock Price Plunge: Following Mereo's disclosure on December 29, 2025, that its ORBIT and COSMIC Phase 3 trials failed to meet primary endpoints, the ADS price plummeted over 87% from $2.31 on December 26, 2025, to $0.29, reflecting market pessimism about the company's future.
- Investor Rights: Investors must apply by April 6, 2026, to be appointed as lead plaintiffs in the class action, highlighting the urgency of the legal action and its potential impact on investors.
- Company Background: Mereo is a biopharmaceutical company focused on developing therapies for rare and serious diseases, headquartered in London, UK, and the legal challenges it faces may affect its future financing and R&D capabilities.
See More
Ultragenyx and Mereo Face Class Action Lawsuits
- Lawsuit Background: Bragar Eagel & Squire, P.C. has alerted investors that Ultragenyx Pharmaceutical Inc. and Mereo BioPharma Group plc are facing class action lawsuits, with a deadline of April 6, 2026, for investors to apply as lead plaintiffs, indicating significant investor concern over potential risks associated with these companies.
- Ultragenyx Lawsuit Details: On December 29, 2025, Ultragenyx announced that its Phase III Orbit and Cosmic studies failed to achieve statistical significance in reducing fracture rates, causing its stock price to plummet from $34.19 to $19.72, a decline of 42.32%, reflecting market disappointment in the study results.
- Mereo Lawsuit Details: Mereo BioPharma faces similar allegations as its Phase 3 ORBIT and COSMIC studies did not meet the primary endpoint of reducing annualized fracture rates, leading to a drastic drop in its stock price from $2.31 to $0.29, a decline of over 87.7%, showcasing extreme investor pessimism regarding its prospects.
- Investor Impact: Both companies are accused of failing to disclose research risks adequately, resulting in shareholders purchasing stocks at inflated prices; the initiation of class action lawsuits may severely impact their future financing and market confidence, exacerbating investor anxiety.
See More
Class Action Lawsuit Filed Against Mereo BioPharma Group plc
- Class Action Initiation: Pomerantz LLP has announced a class action lawsuit against Mereo BioPharma, alleging securities fraud by the company and certain executives, with investors advised to apply as Lead Plaintiff by April 6, 2026, indicating significant legal risks that could impact stock price and market confidence.
- Stock Price Plunge: On December 29, 2025, Mereo disclosed that neither the Orbit nor Cosmic Phase 3 studies achieved statistical significance, resulting in an 87.7% drop in its American Depositary Receipt (ADR) price to $0.29, reflecting extreme investor pessimism regarding the company's future prospects.
- Poor Research Outcomes: Although Mereo and its partner Ultragenyx reported progress in July 2025, the final analysis revealed failure to meet primary endpoints, indicating major setbacks in critical R&D projects that could affect future financing and partnership opportunities.
- Law Firm Background: Pomerantz LLP, a leading firm in securities class litigation with over 85 years of experience, focuses on the rights of victims of securities fraud and corporate misconduct, highlighting the potential impact and complexity of this case, which may attract further investor attention.
See More
Class Action Filed Against Mereo BioPharma Group plc for Securities Violations
- Class Action Initiated: Bronstein, Gewirtz & Grossman, LLC has announced a class action lawsuit against Mereo BioPharma Group plc, aiming to recover damages for investors who purchased securities between June 5, 2023, and December 26, 2025, reflecting strong investor concerns over potential fraud.
- Allegations of False Statements: The complaint alleges that throughout the class period, defendants made overly positive statements while concealing significant adverse facts regarding the Phase 3 ORBIT and COSMIC programs, leading to investor misconceptions about the company's true condition, which could impact stock prices.
- Investor Action Deadline: Affected investors have until April 6, 2026, to request appointment as lead plaintiff to share in any potential recovery, highlighting the legal system's role in protecting investor rights.
- No-Cost Legal Representation: Bronstein, Gewirtz & Grossman, LLC offers contingency fee-based legal services, charging only if successful in claims, ensuring that investors can pursue justice without incurring additional financial burdens.
See More
Class Action Lawsuit Announced for Mereo BioPharma
- Class Action Initiation: Rosen Law Firm has announced a class action lawsuit against Mereo BioPharma Group plc for purchasers of American Depositary Shares between June 5, 2023, and December 26, 2025, indicating potential investor losses.
- Compensation Structure: Investors joining the lawsuit may receive compensation without any out-of-pocket costs, demonstrating the law firm's commitment to protecting investor rights, which could also impact Mereo's stock performance.
- False Statement Allegations: The lawsuit alleges that defendants provided misleading information regarding the Phase 3 Orbit and COSMIC studies, leading investors to purchase Mereo ADS at artificially inflated prices, reflecting potential issues in the company's clinical trials.
- Law Firm Credentials: Rosen Law Firm is renowned for its successful securities class actions, having recovered over $438 million for investors in 2019 alone, showcasing its strength and experience in handling similar cases.
See More
Class Action Reminder for Mereo BioPharma Shareholders
- 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.
See More
Mereo BioPharma Faces Class Action Lawsuit
- Class Action Initiated: Berger Montague PC has filed a class action lawsuit against Mereo BioPharma on behalf of investors who purchased American Depositary Shares between June 5, 2023, and December 26, 2025, indicating significant investor disappointment regarding the company's outlook.
- Stock Price Plunge: Following Mereo's disclosure on December 29, 2025, that its ORBIT and COSMIC Phase 3 trials failed to meet primary endpoints, the ADS price plummeted over 87% from $2.31 on December 26, 2025, to $0.29, reflecting market pessimism about the company's future.
- Investor Rights: Investors must apply by April 6, 2026, to be appointed as lead plaintiffs in the class action, highlighting the urgency of the legal action and its potential impact on investors.
- Company Background: Mereo is a biopharmaceutical company focused on developing therapies for rare and serious diseases, headquartered in London, UK, and the legal challenges it faces may affect its future financing and R&D capabilities.
See More
Ultragenyx and Mereo Face Class Action Lawsuits
- Lawsuit Background: Bragar Eagel & Squire, P.C. has alerted investors that Ultragenyx Pharmaceutical Inc. and Mereo BioPharma Group plc are facing class action lawsuits, with a deadline of April 6, 2026, for investors to apply as lead plaintiffs, indicating significant investor concern over potential risks associated with these companies.
- Ultragenyx Lawsuit Details: On December 29, 2025, Ultragenyx announced that its Phase III Orbit and Cosmic studies failed to achieve statistical significance in reducing fracture rates, causing its stock price to plummet from $34.19 to $19.72, a decline of 42.32%, reflecting market disappointment in the study results.
- Mereo Lawsuit Details: Mereo BioPharma faces similar allegations as its Phase 3 ORBIT and COSMIC studies did not meet the primary endpoint of reducing annualized fracture rates, leading to a drastic drop in its stock price from $2.31 to $0.29, a decline of over 87.7%, showcasing extreme investor pessimism regarding its prospects.
- Investor Impact: Both companies are accused of failing to disclose research risks adequately, resulting in shareholders purchasing stocks at inflated prices; the initiation of class action lawsuits may severely impact their future financing and market confidence, exacerbating investor anxiety.
See More
Class Action Lawsuit Filed Against Mereo BioPharma Group plc
- Class Action Initiation: Pomerantz LLP has announced a class action lawsuit against Mereo BioPharma, alleging securities fraud by the company and certain executives, with investors advised to apply as Lead Plaintiff by April 6, 2026, indicating significant legal risks that could impact stock price and market confidence.
- Stock Price Plunge: On December 29, 2025, Mereo disclosed that neither the Orbit nor Cosmic Phase 3 studies achieved statistical significance, resulting in an 87.7% drop in its American Depositary Receipt (ADR) price to $0.29, reflecting extreme investor pessimism regarding the company's future prospects.
- Poor Research Outcomes: Although Mereo and its partner Ultragenyx reported progress in July 2025, the final analysis revealed failure to meet primary endpoints, indicating major setbacks in critical R&D projects that could affect future financing and partnership opportunities.
- Law Firm Background: Pomerantz LLP, a leading firm in securities class litigation with over 85 years of experience, focuses on the rights of victims of securities fraud and corporate misconduct, highlighting the potential impact and complexity of this case, which may attract further investor attention.
See More
Class Action Filed Against Mereo BioPharma Group plc for Securities Violations
- Class Action Initiated: Bronstein, Gewirtz & Grossman, LLC has announced a class action lawsuit against Mereo BioPharma Group plc, aiming to recover damages for investors who purchased securities between June 5, 2023, and December 26, 2025, reflecting strong investor concerns over potential fraud.
- Allegations of False Statements: The complaint alleges that throughout the class period, defendants made overly positive statements while concealing significant adverse facts regarding the Phase 3 ORBIT and COSMIC programs, leading to investor misconceptions about the company's true condition, which could impact stock prices.
- Investor Action Deadline: Affected investors have until April 6, 2026, to request appointment as lead plaintiff to share in any potential recovery, highlighting the legal system's role in protecting investor rights.
- No-Cost Legal Representation: Bronstein, Gewirtz & Grossman, LLC offers contingency fee-based legal services, charging only if successful in claims, ensuring that investors can pursue justice without incurring additional financial burdens.
See More
Class Action Lawsuit Announced for Mereo BioPharma
- Class Action Initiation: Rosen Law Firm has announced a class action lawsuit against Mereo BioPharma Group plc for purchasers of American Depositary Shares between June 5, 2023, and December 26, 2025, indicating potential investor losses.
- Compensation Structure: Investors joining the lawsuit may receive compensation without any out-of-pocket costs, demonstrating the law firm's commitment to protecting investor rights, which could also impact Mereo's stock performance.
- False Statement Allegations: The lawsuit alleges that defendants provided misleading information regarding the Phase 3 Orbit and COSMIC studies, leading investors to purchase Mereo ADS at artificially inflated prices, reflecting potential issues in the company's clinical trials.
- Law Firm Credentials: Rosen Law Firm is renowned for its successful securities class actions, having recovered over $438 million for investors in 2019 alone, showcasing its strength and experience in handling similar cases.
See More
