On August 6, 2026, the FDA granted accelerated approval to vusolimogene oderparepvec-wtpg (Tudriqev, Replimune Inc.) in combination with nivolumab for adult patients with unresectable advanced cutaneous melanoma who have progressed on an anti-PD-1-based regimen. Tudriqev is a genetically engineered oncolytic herpes simplex virus (HSV-1) immunotherapy, injected directly into accessible tumor lesions, designed to lyse tumor cells and stimulate a systemic anti-tumor immune response when combined with checkpoint blockade.
The clinically interesting part of this approval is not the mechanism. It is the regulatory path: the same application, built on the same single-arm trial, was rejected twice before it was approved — a Complete Response Letter (CRL) in July 2025 and a second CRL dated April 10, 2026 — before an FDA oncology advisory committee voted 10-3 on July 30, 2026 that the available data were evaluable and demonstrated a clinically meaningful benefit. For research offices, IRBs and clinical-trials staff, the substantive story is what changed in the FDA’s reading of a single-arm evidence package between two rejections and an approval, not the drug itself.
What the trial actually showed
Tudriqev’s efficacy and safety were evaluated in IGNYTE (NCT03767348), an open-label, multiregional, single-arm trial in 140 adult patients with Stage IIIB, IIIC or IV unresectable melanoma who had progressed on at least eight consecutive weeks of prior anti-PD-1-based therapy. In the efficacy-evaluable population, Tudriqev plus nivolumab produced an objective response rate (ORR) of 24.2%, with a median duration of response (DOR) of 14.1 months. There is no randomized comparator arm; the accelerated approval rests on ORR and DOR as surrogate endpoints considered reasonably likely to predict clinical benefit, the standard mechanism FDA uses under 21 CFR 601 Subpart E / 314 Subpart H when a single-arm response-rate trial is the basis for approval in a serious, unmet-need setting.
Two rejections, then an approval, on the same dataset
What makes this approval notable for a research-administration audience is that FDA did not ask for a new trial between the first CRL and the approval — it revisited the same IGNYTE data twice more. Public reporting places the first CRL in July 2025 and a second in April 2026, with the agency’s stated concerns centered on trial design and the strength of the evidence of effectiveness rather than safety. FDA now publishes CRLs (via openFDA), so the reasoning behind a rejected application is, for the first time in cases like this, directly readable rather than inferred from a sponsor’s press release. That transparency matters for anyone trying to understand how a single-arm oncolytic-virus trial with a protocol that permits re-injection of lesions on progression can be assessed cleanly for response attribution — a design question that recurs across single-arm oncology trials generally, and one that sits squarely in the statistical-design territory covered by ICH E9, not just this one product.
The July 30, 2026 advisory committee vote (10-3, that the data were evaluable and showed clinically meaningful benefit) is the visible pivot point. An advisory committee vote is not binding on FDA, but a split, narrowly-won vote on data adequacy — rather than on safety — is itself informative about where the agency’s internal disagreement sat. CASRAI covered FDA’s broader move to revise its draft guidance on the substantial evidence of effectiveness standard in July 2026; this approval is a live, concrete test of how that evolving standard gets applied to a real single-arm oncology package, and is worth reading alongside that piece rather than in isolation.
What Replimune must still show
As a condition of accelerated approval, Replimune is required to conduct post-approval confirmatory trial(s) verifying and describing the clinical benefit of Tudriqev plus nivolumab; continued approval is contingent on that verification. This is the standard accelerated-approval structure — approval now, on a surrogate/intermediate endpoint, with continued marketing contingent on a trial that measures a clinical outcome (survival, or a validated benefit measure) rather than tumor response alone. Confirmatory-trial non-completion or a negative confirmatory result is the mechanism by which FDA has withdrawn other accelerated approvals in recent years; research teams tracking this drug’s post-marketing commitments should expect that trial’s design and timeline to be the next disclosure point that matters.
Why this belongs on a research-administration radar
For institutions running or hosting oncology trials, three things are worth tracking directly from this case rather than from patient-facing coverage of the approval itself:
- Single-arm evidence standards are not static. A twice-rejected single-arm ORR/DOR package became approvable without a new trial. Any internal guidance describing FDA’s current posture toward single-arm accelerated-approval submissions should be checked against this outcome rather than assumed current.
- CRLs are now a primary source. openFDA’s CRL repository means the specific evidentiary objections behind a rejection are publicly readable, which changes what “verify the regulatory history of a product” can mean for a protocol or literature review.
- The confirmatory-trial obligation is the real endpoint to watch. Accelerated approval is provisional by design; the clinical-benefit question IGNYTE could not answer on its own is deferred, not resolved.
This article covers the regulatory-evidence dimension of the Tudriqev approval for a research-administration and clinical-trials audience. It is not medical guidance; patients and clinicians should consult FDA’s prescribing information and their care team.
