A new type of cancer treatment that uses a common virus to infect and destroy harmful cells is showing great promise in early human trials, UK scientists say.
One patient’s cancer disappeared, while others saw their tumors shrink.
The drug is a weakened form of the herpes virus — herpes simplex — that has been modified to kill tumors.
Larger, longer-term studies are needed, but experts say the injection may ultimately offer a lifeline for more patients with advanced cancer.
Krzysztof’s cancer is no longer detectable — Photo: KRZYSZTOF WOJKOWSKI/BBC
Krzysztof Wojkowski, a 39-year-old builder from west London, is one of the patients who participated in phase 1 of the ongoing safety trial, run by the Cancer Research Institute of the Royal Marsden NHS Foundation Trust.
He was diagnosed in 2017 with cancer of the salivary glands near his mouth. Despite surgery and other treatments at the time, her cancer continued to grow.
“I was told there were no more options for me, and that I was receiving end-of-life care. It was devastating, so it was amazing to have the chance to participate in the study.”
A short course of virus-based therapy — which is a specially modified version of the herpes virus that normally causes cold sores — appears to have eliminated the tumor.
“I had injections every two weeks for five weeks that completely eradicated my cancer. I’ve been cancer free for two years.”
The injections, given directly into the tumor, attack the cancer in two ways — by invading cancer cells and causing them to rupture, and activating the immune system.
About 40 patients tried treatment as part of the study. Some took just the virus injection, called RP2. Others took yet another cancer drug — called nivolumab.
The results, presented at a medical conference in Paris, France, show that:
- Three out of nine patients who took RP2 alone, including Krzysztof, saw their tumors shrink;
- Seven in 30 who received combination treatment also appeared to benefit;
- Side effects such as tiredness were mild overall.
The study’s lead researcher, Kevin Harrington, told the BBC that the observed treatment responses were “truly impressive” in a range of advanced cancers, including esophageal cancer and a rare type of eye cancer.
“It’s rare to see such good response rates in early-stage clinical trials, as their primary purpose is to test the safety of the treatment, and it involves patients with very advanced cancer for whom current treatments have stopped working,” he said.
“I look forward to seeing if we will continue to see benefits as we treat more patients.”
It’s not the first time scientists have used a virus to fight cancer. The NHS, the UK public health system, approved a cold virus-based treatment called T-Vec for advanced skin cancer a few years ago.
Harrington calls the RP2 a turbocharged version of the T-Vec.
“There were other modifications to the virus so that when it enters cancer cells, it effectively signs its death sentence.”
Marianne Baker, from Cancer Research UK, said the encouraging findings could change the course of cancer treatment.
“Scientists discovered that viruses can help treat cancer 100 years ago, but harnessing them safely and effectively has been a challenge.”
“This new viral therapy showed promise in an initial small-scale trial — now we need more studies to find out how it works.”
“Research suggests that combining multiple treatments is a powerful strategy, and virus therapies like this could become part of our toolkit for beating cancer.”