A modified herpes virus has shown promise in killing cancer cells – one patient saw the disease disappear completely.
Patients were injected with a drug that was a weakened form of the cold sore virus – herpes simplex – which was modified to kill tumours.
Although more research is needed, it could offer a lifeline for people with advanced cancer.
Krzysztof Wojkowski, 39, a builder from west London, went from end-of-life care to cancer-free after joining the trial.
Mr Wojkowski was diagnosed with mucoepidermoid carcinoma, a type of salivary gland cancer, in May 2017.
Despite multiple surgeries, she was told there were no more treatment options, before she was given the opportunity to join the RP2 trial at Royal Marsden in 2020.
He said: “I was told there were no more options for me and I was receiving end-of-life care, it was devastating so it was amazing to have the chance to participating in the trial at the Royal Marsden was my last lifeline.
“I had injections every two weeks for five weeks which completely eradicated my cancer. I’ve been cancer free for two years now, it’s a real miracle, there’s no other word for it to describe it.
“I was able to work as a bricklayer again and spend time with my family, there’s nothing I can’t do.”
The genetically modified virus, which is injected directly into tumours, is designed to do double duty – it multiplies inside cancer cells to burst them from the inside and it also blocks a protein known as CTLA-4, releasing the brakes on the immune system and increasing its ability to kill cancer cells.
Rare to see such promise in the first trials
Three out of nine patients treated with RP2 saw their tumors shrink.
Seven of the 30 patients who received both RP2 and nivolumab immunotherapy also benefited from the treatment.
In this group, four out of nine patients with melanoma skin cancer, two out of eight patients with eye cancer uveal melanoma, and one out of three patients with head and neck cancer saw the growth of their cancer stop or decrease.
Of the seven patients receiving the combination who saw benefit, six remained progression-free at 14 months.
It’s rare to see such a good response rate in early-stage clinical trials, according to study leader Professor Kevin Harrington, professor of biological cancer therapies at the Institute of Cancer Research in London and Consultant Oncologist at the Royal Marsden NHS Foundation Trust. .
He said: “Our study shows that a genetically modified, cancer-killing virus can deliver a punch against tumors – directly destroying cancer cells from the inside while calling on the immune system against them.
“It’s rare to see such good response rates in early-stage clinical trials because their primary focus is to test the safety of treatments and they involve patients with very advanced cancers for whom current treatments have stopped. to work.
“Results from our early trials suggest that a genetically engineered form of the herpes virus could potentially become a new treatment option for some patients with advanced cancers – including those who have not responded to other forms. of immunotherapy.
“I look forward to seeing if we continue to see benefits as we treat increased numbers of patients.”
Exploiting the functionality of viruses
Professor Kristian Helin, chief executive of the Institute of Cancer Research in London, said it was possible to exploit some of the characteristics of viruses.
They said: “Viruses are one of humanity’s oldest enemies, as we have all seen during the pandemic. But our new research suggests we can exploit some of the characteristics that make them adversaries. difficult to infect and kill cancer cells.
“This is a small study, but the early results are promising. I really hope that as this research grows, patients will continue to benefit.”