Replimune (REPL) Faces Investor Lawsuit After FDA Blocks Cancer Drug Approval - Hagens Berman

Core Viewpoint - Replimune Group Inc. faces significant backlash from investors following a regulatory setback that has led to a dramatic decline in its stock price, primarily due to allegations of misrepresentation regarding its cancer therapy RP1 and its clinical trial data [1][4]. Regulatory Setback - On July 22, 2025, Replimune announced that the FDA issued a Complete Response Letter (CRL) for its Biologics License Application for RP1, halting the drug's approval process due to concerns about the adequacy of the clinical data [3][6]. - The stock price plummeted by 77% in a single trading session, resulting in billions in lost market capitalization [4]. Legal Allegations - A class action lawsuit has been filed on behalf of investors who purchased Replimune stock between November 22, 2024, and July 21, 2025, claiming that the company misrepresented the likelihood of regulatory success and failed to disclose material deficiencies in its trial design [2][3]. - The lawsuit highlights that Replimune emphasized RP1's "durable response" data while allegedly concealing critical information regarding the trial's design flaws [5]. FDA Concerns - The FDA's rejection was based on two main issues: the trial's design was not sufficiently rigorous to meet FDA standards, and the patient population was deemed too heterogeneous, complicating the assessment of RP1's efficacy [7][8]. - The agency also raised questions about the ability to isolate the effects of RP1 from other drugs used in combination during the trial [8]. Investor Investigation - Hagens Berman Sobol Shapiro LLP is investigating whether Replimune misled investors about regulatory risks and trial limitations, emphasizing the importance of transparency in clinical trial data [7].