Replimune Group Inc. shares plunged 34% after FDA staff said the company's lead skin cancer drug trial data was "not interpretable."
"The overall survival analysis from the single-arm IGNYTE study is not interpretable," the FDA wrote in briefing documents released ahead of a July 30 advisory committee meeting. The agency said the response assessment used in the Phase 1/2 trial "confounds interpretation of the reported efficacy results and limits FDA's ability to verify the reported results."
Replimune is seeking accelerated approval for RP1 (vusolimogene oderparepvec) in combination with Bristol-Myers Squibb Co.'s Opdivo (nivolumab) for advanced melanoma. The IGNYTE trial showed a 34% response rate in patients who had progressed on prior anti-PD-1 therapies, with a median duration of response of 24.8 months. The FDA said those results "are not of sufficient magnitude to overcome concerns about the contribution of effect" without a reliable historical control, adding that "it cannot be determined whether RP1 contributes to any observed effect" when combined with Opdivo.
The FDA previously issued a Complete Response Letter for RP1 in June 2025 and rejected the application again in April 2026. The agency accepted a resubmission in June with a decision date of Aug. 2, while also scheduling the advisory committee meeting for July 30. Replimune had argued the dataset supporting its breakthrough therapy designation should have been sufficient for accelerated approval.
The stock closed at $5.65, its lowest level since the initial CRL in June 2025. The negative FDA review significantly reduces the probability of RP1 approval ahead of the Aug. 2 PDUFA date. Investors will watch the advisory committee vote on July 30 for the panel's recommendation on whether the data support accelerated approval.
This article is for informational purposes only and does not constitute investment advice.