A new weapon in the fight against skin cancer is being championed by scientists, who say a landmark trial of a genetically-modified cold sore virus have yielded “exciting” results.
Scientists from the Institute for Cancer Research (ICR) in London trialled the modified herpes virus on patients with aggressive, inoperable skin cancer.
Of the 26 per cent of patients who responded to the herpes virus treatment, known as T-Vec, one in ten saw their tumours vanish completely.
Another 16 per cent of patients who responded to the treatment saw their tumours reduce in size by more than 50 per cent.
Professor Kevin Harrington from the ICR led the Phase III trial, which involved 436 patients (some of whom were given the treatment and others who were given a control immunotherapy) across 64 research centres in the UK, US, Canada and South Africa.
“It’s not an exaggeration to say this is a first-in-class agent, an entirely new type of anti-cancer treatment,” he said.
“There will have to be discussions about cost effectiveness but we hope to see this agent receive approval in about the next 12 months, making it possible to prescribe it for cancer.”
The treatment works by targeting cancer cells with the modified herpes virus. The virus infects the cancer cells and multiplies inside – “bursting them from within”.
The virus has been modified to remove two key genes meaning it cannot multiply inside healthy cells. It has also been modified to produce a molecule – GM-CSFG – which stimulates the body’s immune system to also attack and destroy any remaining tumour proteins left after the cancer cells have been exploded.
ICR said one significant discovery from the trial was that T-Vec was most effective in patients with less advanced cancers and those who were yet to receive any treatment.
The scientists said this underlines the benefits of T-Vec as a first-line treatment for metastatic melanomas (skin cancer that spreads to other parts of the body) which cannot be surgically removed.
Professor Paul Workman, chief executive of the ICR, said: “We may normally think of viruses as the enemies of mankind, but it’s their very ability to specifically infect and kill human cells that can make them such promising cancer treatments.
“In this case we are harnessing the ability of an engineered virus to kill cancer cells and stimulate an immune response. It’s exciting to see the potential of viral treatment realised in a Phase III trial, and there is hope that therapies like this could be even more effective when combined with targeted cancer drugs to achieve long term control and cure.”