Cold Sore Virus Can Kill Skin Cancer?
If any of you suffer from the occasional cold sore, it might be hard to imagine how such an annoying mark on your face could possibly be of benefit to anyone. It’s even more irritating when you consider that cold sores are a variation of the herpes virus.
But a genetically engineered version of this virus has shown real promise for treating malignant melanoma – skin cancer.
Using a virus to treat another illness is called viral immunotherapy. In this case, the cold sore virus has been modified so that it can’t replicate in healthy cells, leaving only cancer cells to focus on. This new cancer-fighting virus is called Talimogene Laherparepvec, or T-Vec for short.
When T-Vec is injected into a tumour, it replicates in the cancer cells and releases substances that fight cancer. This has already been shown in phase-3 trial results, which have been published in Journal of Clinical Oncology.
The results are from the largest ever randomised trial of virus immunotherapy in the fight against skin cancer. They showed that some melanoma patients could have years more survival than without the therapy.
All of the 436 patients in the study had aggressive and inoperable skin cancer. However, those treated early on in their disease’s progression survive an average of 20 months longer than those participants who were given an alternative treatment.
The international trial, which covered the South Africa, the US and Canada, as well as the UK, yielded such positive results that T-Vec could become widely available from next year.
Professor Kevin Harrington from the Institute of Cancer Research in London is the trial leader in the UK. He said that using treatments like T-Vec for cancer is exciting because of the so-called “two-pronged attack” against the disease. T-Vec not only directly kills cancer cells, it also boosts the immune system against them as well.
“And because viral treatment can target cancer cells specifically,” he explained, “it tends to have fewer side effects than traditional chemotherapy.”
Professor Harrington added that he and other experts in the field hope T-Vec is just the start of a new development of cancer-fighting treatments that we’ll be hearing about over the 10 years or so.
Dr Hayley Frend, Cancer Research UK’s Science Information Manager, said that T-Vec had already been shown to benefit some people with skin cancer in previous trials. However, this is the first study – in the world – to have shown to increase the length of patient survival.
“The next step will be to understand why only some patients respond to T-Vec,” she added, “to help better identify which patients might benefit from it.”