Replimune's 101% Stock Surge Driven by $1.37B Volume Ranks 63rd Amid FDA Rejection and Securities Lawsuits

On July 30, 2025, Replimune Group (REPL) surged 101.33% with a trading volume of $1.37 billion, ranking 63rd in market activity. The spike followed a 77% plunge on July 22 after the FDA rejected its Biologics License Application for RP1, citing inadequacies in the IGNYTE trial’s design and execution. The agency highlighted inconsistent patient demographics and methodological flaws that undermined the study’s reliability, triggering a sharp sell-off.

Two securities class action lawsuits now allege Replimune misled investors by overstating the IGNYTE trial’s potential and downplaying regulatory risks. Firms Hagens Berman and Bleichmar Fonti & Auld LLP claim the company failed to disclose flaws in the trial, including insufficient controls and uninterpretable data. Investors who purchased shares between November 2024 and July 2025 face potential legal recourse, with a lead plaintiff deadline set for September 22, 2025.

The FDA’s rejection underscored broader concerns about the trial’s validity. The agency noted the patient population’s heterogeneity made it impossible to draw reliable conclusions about RP1’s efficacy when combined with nivolumab. Additionally, the confirmatory trial’s design raised questions about how individual treatment components contributed to outcomes. These findings have cast doubt on Replimune’s ability to secure regulatory approval for its lead candidate, heightening scrutiny over its development strategies.

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