Replimune Group Faces Investor Lawsuit After FDA Denies Cancer Drug Approval

Replimune Group Faces Serious Legal Challenges

In a considerable turn of events for Replimune Group Inc. (NASDAQ: REPL), the biotechnology firm has landed in hot water with its investors after the FDA's recent refusal to approve its cancer drug, RP1. The setback has triggered a sharp decline in the company's stock value, leading to the filing of a class action lawsuit against Replimune and its executives.

Background of the Lawsuit

The litigation, initiated by Hagens Berman Sobol Shapiro LLP on behalf of investors, alleges that Replimune misrepresented information critical to the FDA approval process. It accuses the firm of downplaying associated risks linked to its flagship cancer therapy while overstating the success of clinical trials that were purportedly critical to the FDA application. The class action covers all investors who purchased Replimune stock from November 22, 2024, to July 21, 2025. The lawsuit argues that Replimune's public disclosures did not accurately reflect the potential for regulatory success and failed to highlight significant deficiencies in the trial's design.

The Regulatory Setback

The troubles began on July 22, 2025, when Replimune announced that the FDA issued a Complete Response Letter (CRL) concerning the Biologics License Application for RP1, an immunotherapy intended for advanced melanoma treatment. The FDA's letter halted the approval process, citing issues related to the quality and sufficiency of the clinical data provided by Replimune.

This news led to an unprecedented 77% drop in Replimune's stock price in just one trading session, erasing billions from the company’s market capitalization and prompting a wave of panic among investors. Hagens Berman recommends that any investors who have incurred serious losses take action and register with the firm to potentially receive compensation.