“I received injections every two weeks for five weeks that completely eradicated my cancer.
“I have been cancer free for two years now, it is a true miracle, there is no other word to describe it. I’ve been able to work as a contractor again and spend time with my family, there’s nothing I can’t do.”
Virus causes cancer cells to burst
The genetically engineered virus – called RP2 – is injected directly into the tumor where it multiplies, causing cancer cells to burst from within.
It also blocks a protein called CTLA-4 that lowers the immune system, making the body more likely to fight the cancer. In addition, the virus also produces molecules that trigger the immune system to take action against cancer.
The therapy was tested in 39 patients with cancers, including skin, esophageal and head and neck cancer, who had exhausted all other treatments.
The results showed that about a quarter saw a benefit.
The herpes simplex virus is a very common infection, which many people already carry with them latently without any problems.
Researchers looked at patient biopsies before and after RP2 injections and found positive changes in the tumor’s “immune microenvironment” — the area immediately surrounding the tumor. Injections led to more immune cells in the area, including CD8+ T cells, and ‘switched on’ genes related to the ‘anticancer’ immune response.
The team found that most of the side effects of RP2 were mild — some of the most common were fever, chills and fatigue. None of the side effects were serious enough to require medical intervention.
Professor Kristian Helin, chief executive of The Institute of Cancer Research, London, said: “Viruses are one of humanity’s oldest enemies, as we have all seen during the pandemic. But our new research suggests we may be able to leverage some of the functions that make them challenge adversaries to infect and kill cancer cells.
“It’s a small study, but the initial findings are promising. I sincerely hope that as this research expands, we see patients continue to benefit.”
Potential to become a new treatment option
Study leader Kevin Harrington, professor of biological cancer therapies at the Institute of Cancer Research, said: “Our study shows that a genetically engineered, cancer-destroying virus can deliver a one-two punch against tumors — destroying cancer cells directly from within and also calling the immune system against them.
“It’s rare to see such good response rates in early stage clinical trials because their primary goal is to test the safety of the treatment and it involves patients with very advanced cancers for whom current treatments are no longer working.
“Our initial research results 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 failed to respond to other forms of immunotherapy.
“I’m curious to see if we continue to see benefits as we treat a larger number of patients.”
The research was presented at the European Society for Medical Oncology Congress (ESMO) in 2022 and the team hopes to move on to larger studies.