Mereo BioPharma Shares Plunge After Phase 3 Trial Failures
Written by Emily J. Thompson, Senior Investment Analyst
Updated: Dec 30 2025
0mins
Should l Buy MREO?
Source: Globenewswire
Mereo BioPharma Group PLC's stock price fell by 18.46%, crossing below the 5-day SMA, following a significant announcement regarding its clinical trials.
The decline is attributed to Mereo BioPharma's announcement on December 29, 2025, regarding two Phase 3 studies failing to achieve statistical significance on primary endpoints, leading to a staggering 87.64% drop in stock price. This failure has severely impacted market confidence in its bone metabolism treatment, setrusumab. Additionally, a legal investigation has been initiated, further increasing the company's legal risks and affecting investor sentiment.
The implications of these trial failures are profound, as they not only reflect the challenges faced by Mereo in clinical development but also highlight the market's heightened sensitivity to success rates in biopharmaceutical trials. Investors are likely to remain cautious as the company navigates these setbacks.
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Analyst Views on MREO
Wall Street analysts forecast MREO stock price to rise over the next 12 months. According to Wall Street analysts, the average 1-year price target for MREO is 2.08 USD with a low forecast of 0.50 USD and a high forecast of 5.00 USD. However, analyst price targets are subjective and often lag stock prices, so investors should focus on the objective reasons behind analyst rating changes, which better reflect the company's fundamentals.
8 Analyst Rating
6 Buy
2 Hold
0 Sell
Strong Buy
Current: 0.375
Low
0.50
Averages
2.08
High
5.00
Current: 0.375
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 Lawsuit Announced for Mereo BioPharma
- Class Action Initiation: Rosen Law Firm has announced a class action lawsuit against Mereo BioPharma Group plc, covering purchasers of American Depositary Shares from June 5, 2023, to December 26, 2025, aiming to seek compensation for affected investors, indicating significant legal risks for the company.
- Lawsuit Background: The lawsuit alleges that defendants made false or misleading statements regarding the Phase 3 ORBIT and COSMIC programs, which failed to meet primary endpoints for reducing clinical fracture rates, resulting in investor losses when the truth emerged, highlighting major failures in the company's R&D efforts.
- Investor Rights Protection: Investors joining the class action will incur no upfront costs, as the law firm operates on a contingency fee basis, thereby reducing legal risks for investors and encouraging more affected parties to participate.
- Law Firm's Strengths: 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 advantages in handling similar cases.
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 investors who purchased American Depositary Shares between June 5, 2023, and December 26, 2025, indicating significant legal risks that could undermine shareholder confidence.
- Compensation Mechanism: Investors participating in the lawsuit may receive compensation without any out-of-pocket costs, suggesting that the lawsuit could attract a large number of affected investors, thereby increasing the company's potential financial liabilities.
- Lawsuit Background: The lawsuit alleges that Mereo BioPharma concealed the true status of its Phase 3 ORBIT and COSMIC programs, which failed to meet primary clinical trial endpoints, leading to investor losses and highlighting the company's lack of transparency in R&D.
- Law Firm's Credentials: Rosen Law Firm is renowned for its successful track record in securities class actions, having secured hundreds of millions in settlements, which may further impact Mereo BioPharma's reputation as it navigates this legal challenge.
See More
Class Action Filed Against Mereo BioPharma Group plc
- Class Action Initiated: Bronstein, Gewirtz & Grossman, LLC has announced a class action lawsuit against Mereo BioPharma Group plc, seeking damages for investors who acquired Mereo securities between June 5, 2023, and December 26, 2025, indicating significant legal risks for the company.
- Allegations of False Statements: The complaint alleges that Mereo provided overly positive statements to investors while concealing material adverse facts regarding the Phase 3 ORBIT and COSMIC programs, leading to investor misconceptions about the company's prospects.
- Clinical Trial Failures: The lawsuit highlights that Mereo's two critical clinical trials failed to meet their primary endpoints, failing to effectively reduce the annualized clinical fracture rate compared to placebo or bisphosphonate control groups, which could negatively impact the company's future market performance.
- Investor Action Deadline: Affected investors have until April 6, 2026, to request to be appointed as lead plaintiff, demonstrating the urgency and proactive nature of investors in the legal proceedings.
See More
Faruqi & Faruqi Investigates Potential Claims Against Mereo BioPharma
- Legal Investigation Initiated: Faruq & Faruqi, LLP is investigating potential claims against Mereo BioPharma Group plc, specifically targeting investors who purchased or acquired securities between June 5, 2023, and December 26, 2025.
- Investor Rights Reminder: The firm reminds investors that April 6, 2026, is the deadline to seek the role of lead plaintiff in a federal securities class action, indicating that legal proceedings are accelerating.
- Contact Information Provided: Investors who have suffered losses are encouraged to contact Faruqi & Faruqi partner Josh Wilson directly, with multiple contact numbers provided to facilitate legal consultations.
- Securities Law Firm Role: As a leading national securities law firm, Faruqi & Faruqi's investigation may negatively impact Mereo's stock price and investor confidence, reflecting market concerns about the company's future.
See More
Mereo BioPharma Group Faces Class Action for Securities Fraud
- Lawsuit Background: DJS Law Group reminds investors of a class action lawsuit against Mereo BioPharma Group for violations of §§10(b) and 20(a) of the Securities Exchange Act, concerning shareholders who purchased shares from June 5, 2023, to December 26, 2025.
- False Statements: The complaint alleges that Mereo made false and misleading statements regarding its Phase 3 ORBIT and COSMIC programs, both of which failed to meet their endpoints against placebo or bisphosphonate control groups, misleading investors throughout the class period.
- Investor Losses: Affected shareholders are encouraged to contact DJS Law Group to participate in the lawsuit and potentially serve as lead plaintiffs, although such an appointment is not required to partake in any recovery, indicating the company may face significant financial liabilities.
- Legal Service Commitment: DJS Law Group focuses on enhancing investor returns through balanced counseling and aggressive advocacy, specializing in securities class actions and corporate governance litigation, aiming to provide high-value legal services to its clients.
See More
Class Action Lawsuit Reminder Against Mereo BioPharma Group plc
- Lawsuit Background: DJS Law Group reminds investors of a class action lawsuit against Mereo BioPharma Group for violations of §§10(b) and 20(a) of the Securities Exchange Act, covering the period from June 5, 2023, to December 26, 2025, with a deadline of April 6, 2026.
- False Statement Allegations: The complaint alleges that Mereo made false and misleading statements regarding its Phase 3 ORBIT and COSMIC programs, which failed to meet endpoints against placebo or bisphosphonate control groups, misleading investors throughout the class period.
- Investor Participation: Shareholders who suffered losses are encouraged to contact DJS Law Group to participate in the lawsuit, with the flexibility that appointment as lead plaintiff is not required for recovery, allowing broader investor engagement.
- Law Group Expertise: DJS Law Group focuses on enhancing investor returns through balanced counseling and aggressive advocacy, specializing in securities class actions and corporate governance litigation, serving some of the largest hedge funds and alternative asset managers globally.
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, covering purchasers of American Depositary Shares from June 5, 2023, to December 26, 2025, aiming to seek compensation for affected investors, indicating significant legal risks for the company.
- Lawsuit Background: The lawsuit alleges that defendants made false or misleading statements regarding the Phase 3 ORBIT and COSMIC programs, which failed to meet primary endpoints for reducing clinical fracture rates, resulting in investor losses when the truth emerged, highlighting major failures in the company's R&D efforts.
- Investor Rights Protection: Investors joining the class action will incur no upfront costs, as the law firm operates on a contingency fee basis, thereby reducing legal risks for investors and encouraging more affected parties to participate.
- Law Firm's Strengths: 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 advantages in handling similar cases.
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 investors who purchased American Depositary Shares between June 5, 2023, and December 26, 2025, indicating significant legal risks that could undermine shareholder confidence.
- Compensation Mechanism: Investors participating in the lawsuit may receive compensation without any out-of-pocket costs, suggesting that the lawsuit could attract a large number of affected investors, thereby increasing the company's potential financial liabilities.
- Lawsuit Background: The lawsuit alleges that Mereo BioPharma concealed the true status of its Phase 3 ORBIT and COSMIC programs, which failed to meet primary clinical trial endpoints, leading to investor losses and highlighting the company's lack of transparency in R&D.
- Law Firm's Credentials: Rosen Law Firm is renowned for its successful track record in securities class actions, having secured hundreds of millions in settlements, which may further impact Mereo BioPharma's reputation as it navigates this legal challenge.
See More
Class Action Filed Against Mereo BioPharma Group plc
- Class Action Initiated: Bronstein, Gewirtz & Grossman, LLC has announced a class action lawsuit against Mereo BioPharma Group plc, seeking damages for investors who acquired Mereo securities between June 5, 2023, and December 26, 2025, indicating significant legal risks for the company.
- Allegations of False Statements: The complaint alleges that Mereo provided overly positive statements to investors while concealing material adverse facts regarding the Phase 3 ORBIT and COSMIC programs, leading to investor misconceptions about the company's prospects.
- Clinical Trial Failures: The lawsuit highlights that Mereo's two critical clinical trials failed to meet their primary endpoints, failing to effectively reduce the annualized clinical fracture rate compared to placebo or bisphosphonate control groups, which could negatively impact the company's future market performance.
- Investor Action Deadline: Affected investors have until April 6, 2026, to request to be appointed as lead plaintiff, demonstrating the urgency and proactive nature of investors in the legal proceedings.
See More
Faruqi & Faruqi Investigates Potential Claims Against Mereo BioPharma
- Legal Investigation Initiated: Faruq & Faruqi, LLP is investigating potential claims against Mereo BioPharma Group plc, specifically targeting investors who purchased or acquired securities between June 5, 2023, and December 26, 2025.
- Investor Rights Reminder: The firm reminds investors that April 6, 2026, is the deadline to seek the role of lead plaintiff in a federal securities class action, indicating that legal proceedings are accelerating.
- Contact Information Provided: Investors who have suffered losses are encouraged to contact Faruqi & Faruqi partner Josh Wilson directly, with multiple contact numbers provided to facilitate legal consultations.
- Securities Law Firm Role: As a leading national securities law firm, Faruqi & Faruqi's investigation may negatively impact Mereo's stock price and investor confidence, reflecting market concerns about the company's future.
See More
Mereo BioPharma Group Faces Class Action for Securities Fraud
- Lawsuit Background: DJS Law Group reminds investors of a class action lawsuit against Mereo BioPharma Group for violations of §§10(b) and 20(a) of the Securities Exchange Act, concerning shareholders who purchased shares from June 5, 2023, to December 26, 2025.
- False Statements: The complaint alleges that Mereo made false and misleading statements regarding its Phase 3 ORBIT and COSMIC programs, both of which failed to meet their endpoints against placebo or bisphosphonate control groups, misleading investors throughout the class period.
- Investor Losses: Affected shareholders are encouraged to contact DJS Law Group to participate in the lawsuit and potentially serve as lead plaintiffs, although such an appointment is not required to partake in any recovery, indicating the company may face significant financial liabilities.
- Legal Service Commitment: DJS Law Group focuses on enhancing investor returns through balanced counseling and aggressive advocacy, specializing in securities class actions and corporate governance litigation, aiming to provide high-value legal services to its clients.
See More
Class Action Lawsuit Reminder Against Mereo BioPharma Group plc
- Lawsuit Background: DJS Law Group reminds investors of a class action lawsuit against Mereo BioPharma Group for violations of §§10(b) and 20(a) of the Securities Exchange Act, covering the period from June 5, 2023, to December 26, 2025, with a deadline of April 6, 2026.
- False Statement Allegations: The complaint alleges that Mereo made false and misleading statements regarding its Phase 3 ORBIT and COSMIC programs, which failed to meet endpoints against placebo or bisphosphonate control groups, misleading investors throughout the class period.
- Investor Participation: Shareholders who suffered losses are encouraged to contact DJS Law Group to participate in the lawsuit, with the flexibility that appointment as lead plaintiff is not required for recovery, allowing broader investor engagement.
- Law Group Expertise: DJS Law Group focuses on enhancing investor returns through balanced counseling and aggressive advocacy, specializing in securities class actions and corporate governance litigation, serving some of the largest hedge funds and alternative asset managers globally.
See More
