Replimune Group Inc. received a Complete Response Letter from the U.S. Food and Drug Administration (FDA) rejecting its Biologics License Application for RP1, an oncolytic virus treatment intended for advanced melanoma. The FDA's decision was based on the inadequacy and heterogeneity of data from the IGNYTE trial and issues with the confirmatory study design, although no safety concerns were cited. The rejection reflects a stricter regulatory approach by the FDA's cell and gene therapy division. Following the announcement, Replimune's shares plummeted approximately 75%, falling from around $12.32 to near $3 per share. The company plans to request a Type A meeting with the FDA to discuss a path forward. At the time of the announcement, Replimune reported cash reserves equivalent to $8.19 per share.