Replimune announced FDA's Cellular, Tissue, and Gene Therapies Advisory Committee (CTGTAC) voted 10 to 3 that the efficacy results from the Ignyte study are evaluable and clinically meaningful.

The vote came out of a July 30 committee meeting called to discuss Replimune's Biologics License Application resubmission for RP1 (vusolimogene oderparepvec) in combination with nivolumab for advanced melanoma patients who have progressed on prior anti-PD-1 therapy.¹

During the meeting, the committee considered two questions during the session: whether the single-arm Ignyte study, as designed and conducted, allows for a reliable determination of the expected response rate and durability of response in the proposed patient population, and whether the response rate and duration of response reported in the study are clinically meaningful and indicative of systemic antitumor activity attributable to RP1.¹

The panel then voted 10 to 3 on the central question of whether the efficacy results from Ignyte are evaluable as well as clinically meaningful.¹ The vote comes just days after the company saw its shares drop nearly 32% after the agency’s reviews said the company had not provided clear evidence the drug worked as claimed.

How did the application get to this point?

The vote follows two earlier rejections of the RP1 application. Replimune first submitted the BLA for RP1 plus nivolumab in late 2024, and FDA issued its first complete response letter on July 22, 2025, stating that the single-arm Ignyte trial was not an adequate and well-controlled study capable of providing substantial evidence of effectiveness and that heterogeneity in the patient population complicated interpretation of the results.

Replimune's first resubmission was accepted in October 2025 under a Class II review with a target action date of April 10, 2026, but FDA issued a second complete response letter on that date, again citing trial design and tumor assessment methodology and stating that the data submitted did not provide substantial evidence of effectiveness. Replimune said it disagreed with FDA's position given that the same Ignyte data set had previously supported RP1's

breakthrough therapy designation, and the company resubmitted the BLA a third time. FDA accepted that resubmission under a Class 1 review, setting the August 2, 2026 target action date and scheduling Friday's advisory committee meeting.¹

Why does this vote matter?

An advisory committee vote is non-binding, but it signals how outside reviewers weigh the strength of a single-arm data package supporting an accelerated pathway.¹ The 10-3 outcome on evaluability and clinical meaningfulness gives Replimune a favorable read heading into FDA's own review of the resubmitted application. The company says patients and physicians spoke at the meeting about the unmet need in advanced melanoma in patients who have already progressed on anti-PD-1 therapy, a population with limited treatment options.¹

"We are encouraged by today's outcome and would like to thank the committee for its thoughtful discussion of the Ignyte data," said Sushil Patel, Ph.D., chief executive officer of Replimune. "We are grateful to the patients and physicians who took the time to speak today and so clearly articulate the high unmet need in advanced melanoma and importance of new treatment options such as RP1 for the community. This is an important step forward for patients with advanced melanoma who have progressed on anti-PD-1 therapy. We look forward to continuing to work with the FDA as it completes its review of the BLA ahead of the action date."

Previously Replimune

What is RP1?

RP1 is Replimune's lead product candidate, built on a proprietary strain of herpes simplex virus. The virus is engineered and genetically armed with a fusogenic protein, GALV-GP R-, and GM-CSF, with the intent of maximizing tumor killing potency, the immunogenicity of tumor cell death, and the activation of a systemic anti-tumor immune response.¹ In the BLA resubmission under review, RP1 is being evaluated in combination with nivolumab.

What is the Ignyte study?

Ignyte is an open-label, multicenter Phase I/II study evaluating RP1 as a single agent and in combination with PD-1 blockade in patients with solid tumors.² Replimune sponsors the study with Bristol-Myers Squibb as a collaborator, and the trial has enrolled 340 participants across sites in the United States, France, Germany, Spain, and the United Kingdom.²

The study's primary outcome measures include the percentage of adverse events, serious adverse events, and dose-limiting toxicities, along with overall response rate and the maximum tolerated dose and recommended Phase II dose established during the Phase I escalation portion.² Secondary measures track complete response rate, duration of response, progression-free survival, and overall survival, along with biomarker and viral shedding data collected from tumor biopsies, blood, urine, and other samples.

What happens next?

FDA's target action date for the Class 1 resubmission is August 2, 2026, with Replimune saying it will continue working with the agency as it completes its review of the BLA, with the advisory committee's favorable vote now part of the record FDA will weigh before that decision.

Sources

1. Replimune Announces Favorable Outcome of FDA's Cellular, Tissue, and Gene Therapies Advisory Committee Meeting for RP1 in Advanced Melanoma Replimune July 30, 2026, https://ir.replimune.com/news-releases/news-release-details/replimune-announces-favorable-outcome-fdas-cellular-tissue-and
2. Study of RP1 Monotherapy and RP1 in Combination With Nivolumab (IGNYTE) (IGNYTE) National Library of Medicine February 13, 2026, https://clinicaltrials.gov/study/NCT03767348