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The Food and Drug Administration granted accelerated approval on August 6 to Tudriqev, a genetically engineered herpes-virus therapy for advanced melanoma, capping a saga that included two earlier rejections and a wholesale change in the agency's review team. The decision, from the FDA's own announcement, clears the drug, made by Massachusetts-based Replimune, for adults whose cutaneous melanoma has progressed despite prior treatment with a PD-1-blocking immunotherapy — a population of roughly 112,000 Americans diagnosed with invasive melanoma each year, according to American Cancer Society projections. In the pivotal trial that supported approval, 91 evaluable patients treated with the combination achieved an objective response rate of 24.2%, with responses lasting a median of 14.1 months. Replimune has set a list price of $450,000 per course of therapy before rebates and discounts.
A Data Package That Divided Reviewers Before It Won Over Advisers
The approval followed an unusually contentious regulatory path. Replimune's application, formally known as RP1, had already drawn two complete response letters — rejections issued in July 2025 and again in April 2026 — with the agency citing insufficient data to determine whether tumor shrinkage came from the experimental virus or from the nivolumab it was paired with. That skepticism persisted into the drug's advisory committee hearing on July 30, when FDA staff reviewers raised concerns about the trial's single-arm design, yet the Cellular, Tissue, and Gene Therapies Advisory Committee ultimately voted 10-3 that the data showed a meaningful clinical benefit. Reuters reported that Replimune's shares more than doubled in premarket trading after that vote, following a stretch in which the stock had fallen more than 37% amid doubts about a third rejection. Replimune has said the FDA assigned a new review team ahead of the second rejection and later signaled a more collaborative posture following leadership changes at the agency, though the company did not attribute the reversal to any single factor.
Response Rates Vary Depending on Which Numbers Are Cited
Coverage of the trial results has not been entirely consistent, a reflection of the different analysis methods applied to the same dataset. The FDA's own approval documents and Replimune's press release point to a 24.2% objective response rate among the 91 core efficacy-evaluable patients, with a 14.1-month median duration of response. Separate reporting on the underlying IGNYTE trial has cited a higher confirmed overall response rate of 33.6% by independent central review using modified RECIST criteria, with durations exceeding 35 months in some analyses — while trade press covering the international rollout cited a 34% response rate with a 24.8-month median duration. The discrepancies largely stem from differences between the full trial population, the label-specific efficacy population, and the endpoints regulators ultimately relied on for the accelerated approval decision. Because the approval was granted on the accelerated pathway, it is explicitly conditional: Replimune must complete the ongoing IGNYTE-3 confirmatory trial, with overall survival as the eventual measure of benefit, or risk having the approval withdrawn.
Filling a Gap for Patients Who No Longer Respond to Standard Immunotherapy
Physicians describe the approval as addressing a genuine treatment gap. An estimated half of advanced melanoma patients do not respond to, or eventually progress on, standard checkpoint-inhibitor therapy, and until now the only FDA-approved option specifically for this post-PD-1 population was tumor-infiltrating lymphocyte therapy, according to commentary from a Roswell Park oncologist published by OncLive. Tudriqev works differently than most approved cancer drugs: it is a modified herpes simplex virus injected directly into tumors, engineered to destroy cancer cells while triggering an immune response that Replimune says can also affect untreated lesions elsewhere in the body. The therapy carries breakthrough therapy designation and priority review, reflecting the FDA's own recognition of unmet need in this population, even as reviewers debated the strength of the supporting evidence.
Cost and Confirmatory Trial Timeline Leave Questions Unresolved
Two open questions will shape how the approval is ultimately judged. The first is cost: a $450,000 list price for a single course of therapy, on top of the co-administered nivolumab, raises affordability and insurance-coverage questions common to newer cancer immunotherapies, though actual patient costs will depend on rebates, discounts, and individual insurance arrangements not yet public. The second is durability of evidence. The confirmatory IGNYTE-3 trial comparing the combination against physician's choice of treatment is not expected to read out until 2030, meaning patients and clinicians will use the therapy for years before overall-survival data confirms whether the response rates observed in the smaller trial translate into a durable survival benefit. The FDA's approval letter itself notes that continued marketing authorization depends on that trial's outcome, underscoring that Thursday's decision — while a milestone for a company on its third attempt — is not the final word on the drug's long-term value to patients with treatment-resistant melanoma.
