Scientists in the UK have identified a cancer-killing virus involving therapy that uses a common virus to infect and destroy harmful cells. Early trials of the virus therapy on patients have been especially promising.
The drug is a weakened form of the cold sore virus, herpes simplex, that has been modified to kill tumors. A trial on one patient witnessed the cancer vanishing while others saw their tumors shrink.
Experts say the injection might ultimately offer a lifeline to more people with advanced cancers although larger and longer studies will be required.
A 39-year-old man from west London, Krzysztof Wojkowski, is one of the patients who took part in the ongoing phase one safety trial run by the Institute of Cancer Research and the Royal Marsden NHS Foundation Trust.
Mr. Wojkowski was diagnosed in 2017 with cancer of the salivary glands near the mouth, and, despite surgery and other treatments at the time, his cancer continued to grow.
“I was told there [were] no options left for me and I was receiving end-of-life care,” he reported. “It was devastating, so it was incredible to be given the chance to join the trial.”
Short course therapy of the virus appeared to clear the cancer
A short course of the virus therapy, which is a specially modified version of the herpes virus that usually causes cold sores, appears to have cleared his cancer.
Wojkowski said, “I had injections every two weeks for five weeks which completely eradicated my cancer. I’ve been cancer-free for two years now.”
The injections, administered directly into tumors, attack cancer in two ways—first of all, by invading the cancerous cells and making them burst and, secondly, by activating the immune system.
As part of the trial, about forty patients took advantage of the treatment. Some were given the virus injection called RP2 on its own while others also received another cancer drug, called nivolumab.
During a presentation at a medical conference in Paris, France, the findings indicated that three out of nine patients given RP2 only, which included Krzysztof, saw their tumors shrink.
Seven out of thirty who had combined treatment also appeared to benefit, and side effects, such as tiredness, were generally mild.
Treatment responses “truly impressive” on advanced cancers
Professor Kevin Harrington, the lead researcher, said the treatment responses seen were “truly impressive” across a range of advanced cancers, including cancer of the gullet (oesophagus) and a rare type of eye cancer.
“It is rare to see such good response rates in early stage clinical trials, as their primary aim is to test treatment safety, and they involve patients with very advanced cancers for whom current treatments have stopped working,” he said.
“I am keen to see if we continue to see benefits as we treat increased numbers of patients,” he said with hope.
“Scientists discovered that viruses could help treat cancer one hundred years ago, but harnessing them safely and effectively has been challenging,” said Dr. Marianne Baker from Cancer Research UK.
“This new viral therapy shows promise in a small-scale early trial,” Dr. Baker said. “Now we need more studies to find out how well it works.”
Dr. Baker further noted, “Research suggests that combining multiple treatments is a powerful strategy, and virus therapies like this one could become a part of our toolkit for beating cancer.”