Cold sore virus may be the key to treating skin cancer

BBC News online reports this week on a revolutionary new treatment for skin cancer, using a genetically engineered version of herpes – the virus responsible for cold sores.

The research, published in full in the Journal of Clinical Oncology, was based on the largest ever randomised trial of an anti-cancer virus. 436 patients from 64 centres in the US, the UK, Canada and South Africa who had inoperable malignant melanoma took part, and according to the researchers the results showed real promise, having the potential to increase survival of some melanoma sufferers by years.

 The treatment – called T-Vec – works by the modified herpes virus being injected directly into tumours. It is harmless to normal cells, but releases substances to help fight the cancer, replicating itself as it does so. While the treatment is not yet licensed, similar immunotherapy treatments for melanoma are already available in the US and in Europe. However, this would be the first melanoma treatment to use a virus.

The BBC quoted UK trial leader Prof Kevin Harrington, from the Institute of Cancer Research, London, as saying: "There is increasing excitement over the use of viral treatments like T-Vec for cancer, because they can launch a two-pronged attack on tumours – both killing cancer cells directly and marshalling the immune system against them. And because viral treatment can target cancer cells specifically, it tends to have fewer side effects than traditional chemotherapy or some of the other new immunotherapies."

Dr Hayley Frend, science information manager at Cancer Research UK, commented: "Previous studies have shown T-Vec could benefit some people with advanced skin cancer, but this is the first study to prove an increase in survival. The next step will be to understand why only some patients respond to T-Vec, in order to help better identify which patients might benefit from it."

Researchers aim to run further studies to answer these questions and determine whether it should be used alongside other melanoma drugs that are already approved. Earlier this year another immunotherapy drug, pembrolizumab, became the first treatment fast-tracked for NHS patients in England with advanced melanoma, under the government’s new Early Access to Medicines scheme, launched in April 2014.

Per Hall, Clinical Director at Check4Cancer and a pioneer in the early detection of melanoma, comments: “If the trials of T-Vec show further positive results then this creates hope for melanoma sufferers whose disease has reached an advanced stage. But whilst I am cautiously optimistic about this research we really do not want melanoma patients to present so late as to need these sorts of treatments. The key advice for those worried about melanoma remains the same: limit sun exposure, use high factor sun block and if you are in a high risk group and/or spend a large amount of time outdoors, get checked on a regular basis. Melanoma is the sixth most common cancer in the UK, killing over 2,000 people in Britain each year, but as with all cancers, early detection remains the single most effective method for increasing chances of survival. If caught at stage 0 or stage 1 a simple surgical procedure may be all that is required, with no need for other treatment.”