Lead Plaintiff Deadline is April 6, 2026

NEW YORK , Feb. 18, 2026 /PRNewswire/ -- Wolf Haldenstein Adler Freeman & Herz LLP announces that a class action lawsuit has been filed against Mereo BioPharma Group PLC (NASDAQ: MREO) ("Mereo" or the "Company") inclusive on behalf of all persons and entities that purchased or otherwise acquired Mereo American Depositary Shares ("ADS's") between June 5, 2023 and December 26, 2025, both dates inclusive (the "Class Period"). Investors have until April 6, 2026, to seek appointments as lead plaintiff.

PLEASE CLICK HERE TO JOIN THE CASE AND SUBMIT CONTACT INFORMATION

Investors allege that Mereo and certain executives made materially false and misleading statements about the likelihood of success of its Phase 3 clinical trials for setrusumab, a treatment for Osteogenesis Imperfecta (OI).

Specifically, defendants repeatedly expressed confidence that:

• The ORBIT and COSMIC Phase 3 trials would
• Achieve statistical significance in reducing annualized fracture rates (AFR)
• Position setrusumab for regulatory success

While promoting these optimistic projections, the complaint claims the company concealed adverse facts showing:

• Neither Phase 3 study was on track to meet its primary endpoint
• The trials ultimately failed to demonstrate AFR reduction versus control groups

Corrective Disclosure & Stock Collapse
On December 29, 2025, Mereo issued a press release revealing that:

• Neither ORBIT nor COSMIC achieved statistical significance
• The primary endpoint — reduction in AFR — was not met
• Improvements in bone mineral density did not offset failure of core efficacy goals

Following this disclosure:

• Share price fell from $2.31 to $0.29 in one trading session
• Representing a loss of over 87% of shareholder value

Investors seeking appointment as Lead Plaintiff may file a motion with the court no later than April 6, 2026.

Why  Wolf Haldenstein Adler Freeman & Herz LLP?:

This illustrious firm, founded in 1888, is steadfast in their pursuit of justice for investors who have suffered financial harm due to these misrepresented statements. The law firm brings to the fore over 125 years of legal expertise in securities litigation and has a proven track record of protecting the rights of investors.

We encourage all investors who have been affected or have information that will assist in our investigation, to contact Wolf Haldenstein Adler Freeman & Herz LLP.

Contact:

• Phone: (800) 575-0735 or (212) 545-4774
• Email:  classmember@whafh.com
• Contact Person: Gregory Stone, Director of Case and Financial Analysis

Firm Website:  Wolf Haldenstein Adler Freeman & Herz LLP

This press release may be considered Attorney Advertising in some jurisdictions under the applicable law and ethical rules.

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SOURCE Wolf Haldenstein Adler Freeman & Herz LLP