Replimune Group Hit with Securities Class Action Over Stock Price Collapse.

Replimune Group has been sued in a securities class action over its recent stock price collapse, which plummeted by 77% after the FDA issued a "Complete Response Letter" for its Biologics License Application for RP1, an investigational drug for advanced melanoma. The lawsuit seeks damages on behalf of investors who bought Replimune securities between November 2024 and July 2025. Hagens Berman is investigating potential violations of the Securities Act.

Replimune Group, Inc. (NASDAQ: REPL) is facing a securities class action lawsuit following a dramatic 77% drop in its stock price on July 22, 2025. The lawsuit, officially known as Jboor v. Replimune Group, Inc., et al., No. 1:25-cv-12085 (D. Mass.), is on behalf of investors who acquired Replimune securities between November 22, 2024, and July 21, 2025.

The legal action stems from the company's stock price collapse, which was triggered by the U.S. Food and Drug Administration (FDA) issuing a "Complete Response Letter" (CRL) for its Biologics License Application (BLA) for RP1, an investigational drug intended to treat advanced melanoma in combination with nivolumab. The FDA's rejection halted the drug's approval path, sending shockwaves through the market.

The lawsuit alleges that Replimune misrepresented the strength of the clinical data supporting its RP1 application. Throughout the designated class period, the company had consistently projected a positive outlook, citing the FDA's Breakthrough Therapy and Accelerated Approval designations and data from the IGNYTE study. The lawsuit contends that these statements fostered a misleading sense of confidence among investors.

The core claims of the lawsuit assert that Replimune made false and misleading statements by recklessly overstating the likelihood of success for the IGNYTE trial and failing to disclose that the FDA was likely to find the IGNYTE trial's design and data inadequate. The FDA's CRL confirmed these concerns, stating that the IGNYTE trial was not considered a "sufficiently well-designed or controlled investigation to provide substantial evidence of effectiveness."

The FDA's rejection was based on several critical issues identified in the CRL. Beyond the overall inadequacy of the IGNYTE trial, the agency noted that the patient population in the study was too varied, making it difficult to draw reliable conclusions about the drug’s efficacy. Additionally, the FDA questioned the proposed design of the necessary confirmatory trial, specifically how the individual contributions of each component in the combination therapy could be properly evaluated.

Prominent shareholder rights firm Hagens Berman is investigating whether Replimune may have violated the U.S. securities laws. The firm is urging Replimune investors who suffered substantial losses to submit their losses now. If you invested in Replimune and have substantial losses or have knowledge that may assist the firm’s investigation, submit your losses now. Whistleblowers with non-public information regarding Replimune should consider their options to help in the investigation or take advantage of the SEC Whistleblower program.

References:
[1] https://www.globenewswire.com/news-release/2025/08/20/3136642/0/en/Replimune-REPL-Faces-Securities-Class-Action-Following-Stock-s-Collapse-Amid-FDA-s-Rejection-of-Melanoma-Drug-Hagens-Berman.html
[2] https://www.morningstar.com/news/globe-newswire/9515635/replimune-repl-faces-securities-class-action-following-stocks-collapse-amid-fdas-rejection-of-melanoma-drug-hagens-berman