ROSEN Law Firm Encourages Mereo BioPharma Investors to Secure Counsel Before Deadline

Investors have until April 6, 2026 to join securities class action lawsuit against Mereo BioPharma Group plc

Published on Mar. 8, 2026

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The Rosen Law Firm, a global investor rights law firm, is reminding purchasers of American Depositary Shares (ADSs) of Mereo BioPharma Group plc (NASDAQ: MREO) between June 5, 2023 and December 26, 2025 to secure counsel before the April 6, 2026 lead plaintiff deadline in a securities class action lawsuit against the company.

Why it matters

The lawsuit alleges that Mereo BioPharma provided investors with materially false and misleading information about the expected results of its Phase 3 Orbit and COSMIC studies for its drug setrusumab in treating Osteogenesis Imperfecta (OI). This allegedly caused investors to purchase Mereo's ADSs at artificially inflated prices, resulting in damages when the true details emerged.

The details

According to the lawsuit, Mereo BioPharma made positive statements to investors about setrusumab's ability to reduce annualized fracture rates in OI patients, while concealing the fact that neither the Orbit nor COSMIC studies had hit their primary endpoints of reducing annualized clinical fracture rate compared to placebo or bisphosphonate control groups.

  • The class period is from June 5, 2023 to December 26, 2025.
  • The lead plaintiff deadline is April 6, 2026.

The players

Mereo BioPharma Group plc

A biopharmaceutical company focused on developing and commercializing innovative therapeutics.

The Rosen Law Firm, P.A.

A global investor rights law firm that concentrates its practice in securities class actions and shareholder derivative litigation.

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What they’re saying

“Rosen Law Firm has achieved, at that time, the largest ever securities class action settlement against a Chinese Company. Rosen Law Firm was Ranked No. 1 by ISS Securities Class Action Services for number of securities class action settlements in 2017. The firm has been ranked in the top 4 each year since 2013 and has recovered hundreds of millions of dollars for investors. In 2019 alone the firm secured over $438 million for investors. In 2020, founding partner Laurence Rosen was named by law360 as a Titan of Plaintiffs' Bar.”

— The Rosen Law Firm (The Rosen Law Firm)

What’s next

Investors have until April 6, 2026 to join the Mereo BioPharma securities class action lawsuit as lead plaintiff. To join, investors can go to https://rosenlegal.com/submit-form/?case_id=52452 or call Phillip Kim, Esq. toll-free at 866-767-3653.

The takeaway

This case highlights the importance for investors to carefully scrutinize public statements made by biopharmaceutical companies about their drug development programs, and to seek qualified legal counsel if they believe they have been misled and suffered losses as a result.