Key Takeaways
- Replimune’s melanoma immunotherapy RP1 received its second FDA rejection
- The therapy was under review for use with Bristol Myers Squibb’s (BMY) Opdivo
- FDA maintained its position that the clinical trial lacked adequate controls
- Shares of REPL plummeted approximately 19% to $4.76, with two trading halts implemented
- The current price represents a significant decline from the 52-week peak of $13.24
Replimune (REPL) has encountered its second regulatory roadblock as the FDA maintains its position on concerns regarding the clinical trial methodology supporting the RP1 drug application.
The regulatory agency delivered a complete response letter rejecting the approval of RP1, scientifically designated as vusolimogene oderparepvec, for combination therapy with Bristol Myers Squibb’s (BMY) Opdivo in treating advanced melanoma patients previously treated with anti-PD-1 therapies.
In correspondence directed to Kari Jeschke, Replimune’s senior vice president of regulatory affairs, the FDA stated that supplementary exploratory data analyses failed to change its prior determination. The RPL-001-16 clinical trial was judged insufficient as an adequate and well-controlled study.
Safety issues were not flagged by the FDA — the primary obstacle continues to be the strength of efficacy data.
This marks the second time the agency has declined approval. The initial rejection occurred in July 2025, following Vinay Prasad’s appointment to head the FDA’s Center for Biologics Evaluation and Research by two months. The company resubmitted its Biologics License Application, which received acceptance for review in October 2025.
Shares of REPL declined roughly 19% to $4.76 following the announcement. The stock experienced two volatility-triggered trading halts during the session. Based on Dow Jones Market Data, this decline positions the stock toward its lowest closing price since October.
At the current valuation, REPL trades substantially below its 52-week peak of $13.24.
Understanding RP1 Technology
RP1 represents a genetically modified variant of Herpes Simplex Virus type 1 — the identical virus responsible for cold sores. The company engineered it to selectively replicate within cancerous cells, causing cellular rupture while simultaneously stimulating enhanced immune system responses through white blood cell activation.
This therapy serves as the flagship candidate within Replimune’s RPx platform, which concentrates on developing oncolytic immunotherapies targeting solid tumors.
The biotechnology firm currently maintains a market capitalization of approximately $393 million. No P/E ratio exists due to negative earnings — a typical characteristic of clinical-stage biotechnology companies developing their therapeutic pipelines.
Stock Performance and Company Metrics
Replimune’s GF Score registers at 40 out of 100, with profitability scoring merely 1 out of 10. The company’s financial strength receives a 6 out of 10 rating.
During the previous three-month period, company insiders divested $0.1 million in shares, while no insider purchases were documented.
The stock currently trades at $4.76, representing a substantial discount from the year’s 52-week high of $13.24 achieved earlier this year.
