Federal regulators have approved a therapy that treats advanced skin cancer with a living, genetically modified virus injected straight into tumors. The Food and Drug Administration granted accelerated approval in early August 2026 to a reengineered herpes virus, given alongside an established immunotherapy drug, for patients whose melanoma has kept spreading despite earlier treatment. It is the first therapy of its kind cleared in the United States in more than a decade.
The decision matters because the patients it targets have historically had few good options. Once melanoma stops responding to the immunotherapy drugs that transformed the disease over the past ten years, remaining choices narrow sharply. The new approval offers a mechanism that works differently, turning a virus into a tool that both destroys cancer cells directly and rallies the body’s immune defenses against the tumor.
How the Tudriqev-nivolumab combination won approval
The FDA granted accelerated approval to vusolimogene oderparepvec-wtpg, sold as Tudriqev and developed by Replimune, in combination with the immunotherapy nivolumab, for adults with unresectable advanced cutaneous melanoma that progressed on a PD-1-blocking treatment regimen, according to the agency’s drug approval notice. Unresectable means the cancer cannot be fully removed by surgery, and the PD-1 requirement limits the therapy to patients who have already exhausted a mainstay class of immunotherapy.
The regulatory path was unusually contentious. The clearance followed a public meeting of the FDA’s advisory committee on cellular, tissue, and gene therapies, whose members voted in favor of accelerated approval after weighing the trial data, and it arrived only after earlier setbacks in the review process. The company confirmed the clearance in a corporate announcement describing the combination as a new option for a difficult-to-treat population.
An engineered herpes virus turned against tumors
The active agent is a modified strain of herpes simplex virus type 1, the same family of virus responsible for cold sores, altered so that it replicates inside tumor tissue rather than causing ordinary infection. Injected directly into a melanoma lesion, the virus multiplies within cancer cells and ruptures them, a process that spills tumor debris and signaling molecules into the surrounding tissue. That release is designed to flag the cancer for the immune system, prompting a broader attack that can reach tumors beyond the injection site.
This category of treatment is known as oncolytic viral therapy, a name that combines the Greek roots for tumor and dissolving. Pairing the virus with nivolumab, an antibody that releases a molecular brake on immune cells, is meant to amplify the effect: the virus exposes the tumor, and the immunotherapy helps sustain the immune response the virus provokes. The FDA framed the clearance as an addition to the toolkit for treatment-resistant disease in its announcement of the approval.
What the IGNYTE trial showed
The approval rested on a single-arm study called IGNYTE, which enrolled adults with stage III or stage IV unresectable melanoma who had progressed after at least eight consecutive weeks of prior anti-PD-1 therapy. In the trial, the combination produced an objective response rate of about 24 percent, meaning roughly a quarter of participants saw their tumors shrink measurably, with a median duration of response exceeding a year, according to the study’s registry entry. For a population with limited alternatives, responses that last are a meaningful benchmark.
A single-arm design, without a comparison group receiving a different treatment, is common when an unmet need is severe and a placebo would be hard to justify, but it also leaves open questions that a randomized trial answers more cleanly. Response rate and duration are the measures the FDA used to judge the therapy, rather than direct evidence that patients lived longer, which is why the clearance came through the accelerated pathway rather than a standard full approval.
The first engineered oncolytic virus cleared since 2015
The approval revives a field that had produced only one prior U.S. product. Talimogene laherparepvec, also a modified herpes virus for melanoma, was cleared in 2015 and stood alone for years as the only genetically engineered oncolytic virus on the American market. The long gap reflected the difficulty of proving that injected viruses could deliver reliable, durable benefit across large groups of patients, a hurdle that stalled several other candidates.
Melanoma has been a natural proving ground for the approach because tumors often sit in or near the skin, making them accessible to direct injection, and because the disease has proven responsive to immune-based treatments in general. Researchers are studying whether oncolytic viruses can be extended to cancers deeper in the body, where reaching the tumor with a needle is harder, but the melanoma clearance gives the strategy a concrete, regulated foothold to build on.
Conditions attached to the accelerated approval
Accelerated approval is not the end of the review. As a condition of the clearance, the manufacturer is required to run confirmatory trials to verify that the therapy delivers real clinical benefit, and continued approval can depend on those results. If the follow-up studies fail to confirm the expected benefit, the FDA retains the ability to pull the therapy from the market.
For now, the clearance gives oncologists a new option for a specific group of patients who have run out of standard immunotherapy, delivered as a direct injection into tumors rather than an infusion or a pill. Whether the approach expands to other cancers, and whether the confirmatory data hold up, will determine how large a role engineered viruses ultimately play in cancer care.
This article was produced with AI assistance and reviewed by Morning Overview editors.
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