Could a therapeutic virus help immunotherapy work against head and neck cancer?

An intriguing new approach is being investigated for people with recurrent or metastatic head and neck squamous cell carcinoma whose cancer has stopped responding to immunotherapy.

Researchers in Spain have completed an early Phase I clinical trial combining the immunotherapy drug durvalumab with a specially engineered virus called VCN-01.

Why use a virus to treat cancer?

It sounds unusual, but scientists have been investigating oncolytic viruses as cancer treatments for some time.

VCN-01 has been genetically modified so that it preferentially replicates inside tumour cells. Once there, it can help destroy cancer cells, but researchers are interested in something else it appears to do as well: change the environment surrounding the tumour.

Tumours can create an environment that effectively protects them from the immune system. Even when immunotherapy encourages immune cells to attack the cancer, those cells may have difficulty getting inside the tumour or functioning effectively once they arrive.

The researchers hope VCN-01 can help break down some of these barriers, allowing immune cells—and immunotherapy drugs—to reach and attack the cancer more effectively.

What happened in the trial?

This was a very small Phase I study involving 20 patients, so its main purpose was to investigate whether the treatment could be given safely and to understand what it was doing biologically—not to prove that it extends people's lives.

However, researchers saw some encouraging signs.

Biopsies taken after treatment showed an increase in active immune cells inside the tumours and a reduction in biological markers associated with suppression of the immune response. In other words, the virus appeared to change previously resistant tumours into an environment where the immune system could potentially work more effectively.

There were also some encouraging clinical observations. More than 60% of participants were alive after one year of follow-up, and some survived beyond 17 months.

Perhaps one of the most intriguing findings was that some people whose cancer had previously stopped responding to immunotherapy responded again to later treatments after receiving VCN-01 and durvalumab. Researchers believe this raises the possibility that the treatment may have somehow restored the tumour's sensitivity to therapy.

Why could this matter?

Immunotherapy has changed the treatment landscape for advanced head and neck cancer, but unfortunately it doesn't work for everyone. Even when it initially works well, cancers can eventually develop resistance.

Finding ways to overcome that resistance—or potentially make immunotherapy work again—is therefore an important area of research.

This study suggests that instead of simply trying another cancer drug, researchers may be able to change the tumour itself and make it more vulnerable to the immune system.

Is this a new treatment patients can receive now?

Not yet.

This was a Phase I trial with only 20 participants. There was no large comparison group showing that people receiving VCN-01 plus immunotherapy lived longer than people receiving current standard treatments.

The researchers themselves emphasise that the findings now need to be tested in larger, controlled clinical trials.

What does this mean for our community?

For people living with recurrent or metastatic head and neck cancer, particularly when treatments have stopped working, news of experimental therapies understandably brings both hope and questions.

This research is promising rather than proven.

But it demonstrates something encouraging about where cancer research is heading. Scientists aren't only developing new drugs to attack cancer—they are learning how to change the tumour environment so that our own immune system and existing treatments may be able to work more effectively.

And for people who have exhausted conventional treatment options, finding ways to overcome treatment resistance is an especially important area of research to watch. Link https://idibell.cat/en/2026/06/therapeutic-virus-combined-with-immunotherapy-shows-promising-results-in-advanced-head-and-neck-cancer/

The takeaway: A genetically modified virus called VCN-01 appears capable of changing the environment inside some advanced head and neck cancers and potentially helping the immune system attack them. Early results are encouraging, particularly the suggestion that some cancers resistant to immunotherapy might become sensitive to treatment again—but much larger trials are needed before we know whether this approach will translate into an effective treatment for patients.