Key Takeaways
- Replimune received a second FDA rejection for its RP1 cancer treatment targeting advanced melanoma
- The therapy was proposed for use with Bristol Myers Squibb’s (BMY) Opdivo medication
- Regulators maintained their position that the clinical trial design lacked adequate controls
- Shares of REPL plummeted approximately 19% to $4.76, with two volatility-triggered trading pauses
- Current trading levels remain significantly beneath the 52-week peak of $13.24
The FDA has delivered a second complete response letter to Replimune (REPL) regarding its experimental RP1 therapy, maintaining its original stance on clinical trial methodology concerns.
Regulatory authorities declined approval for vusolimogene oderparepvec (RP1) as a combination therapy with Bristol Myers Squibb’s (BMY) Opdivo for treating advanced melanoma in patients who had received prior anti-PD-1 therapies.
The FDA communicated to Kari Jeschke, Replimune’s senior vice president of regulatory affairs, that supplementary exploratory analyses submitted by the company failed to address the agency’s original determination. The RPL-001-16 clinical study continued to fall short of meeting adequate and well-controlled investigation standards.
Safety profiles for the treatment raised no red flags with regulators — the challenge centers entirely on demonstrating efficacy through acceptable trial methodology.
The initial rejection occurred in July 2025, coming two months following Vinay Prasad’s appointment to head the FDA’s Center for Biologics Evaluation and Research. Following that decision, Replimune submitted a revised Biologics License Application, which gained acceptance for regulatory review in October 2025.
Shares experienced an approximately 19% decline to $4.76 following the announcement. Market exchanges implemented two trading halts throughout the session due to price volatility. Based on Dow Jones Market Data, this decline positioned the stock toward its weakest closing level since October.
Current pricing places REPL significantly beneath its 52-week peak of $13.24.
Understanding RP1 Therapy
RP1 represents a genetically modified variant of Herpes Simplex Virus type 1 — the identical virus responsible for cold sores. Replimune engineered the virus to selectively replicate within cancerous tumor cells, leading to cellular destruction while simultaneously activating enhanced immune responses from the body’s white blood cell populations.
The treatment serves as the flagship candidate within Replimune’s RPx platform, dedicated to developing oncolytic immunotherapies targeting solid tumor cancers.
The biotechnology company currently maintains a market capitalization approaching $393 million. Due to ongoing negative earnings — typical for clinical-stage biotech firms developing their therapeutic pipelines — the company lacks a P/E ratio.
Recent Trading Activity and Company Financials
Replimune holds a GF Score of 40 out of 100, with profitability metrics scoring just 1 out of 10. Financial strength indicators register at 6 out of 10.
During the most recent three-month period, company insiders divested $0.1 million in shares, while no insider purchases were documented.
Current share pricing stands at $4.76, representing a substantial discount from the $13.24 peak recorded earlier this year.
