Scientists have genetically modified a strain of the herpes virus to act as a cancer-killing agent in humans. Findings from an initial human trial are encouraging, with the experimental treatment proving safe and promisingly effective.
“Viruses are one of humanity’s oldest enemies, as we have all seen over the pandemic,” explained Kristian Helen from the Institute of Cancer Research. “But our new research suggests we can exploit some of the features that make them challenging adversaries to infect and kill cancer cells.”
Called oncolytic viruses, researchers have long explored the potential for these tiny invaders to be recruited as cancer-killing soldiers. With the advent of genetic engineering over recent years scientists have finally been able to engineer viruses so they help instead of harm.
In this new research scientists have looked to modify a strain of the herpes simplex virus. The genetically modified virus, called RP2, has been engineered to only multiply within cancer cells, causing them to essentially inflate and explode.
The virus is designed to be directly injected into tumors and also act as an immune system alarm, attracting the body’s own cancer-killing cells by producing molecules that spark immune activity.
“Our study shows that a genetically engineered, cancer-killing virus can deliver a one-two punch against tumors – directly destroying cancer cells from within while also calling in the immune system against them,” said Kevin Harrington, a researcher working on the project.
Initial findings from the first Phase 1 trial testing the oncolytic therapy in 39 patients were announced at a recent medical conference in Europe. Three of nine patients testing the viral therapy on its own saw their tumors shrink, while seven of the remaining 30 saw treatment benefits in combination with other immunotherapy.
This Phase 1 trial was primarily focused on establishing whether the treatment is safe, and no serious adverse effects were detected. Because it was just a safety trial the patients recruited spanned a number of different cancer types, so future trials will better target the most effective cancers for this therapy.
“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,” said Harrington. “I am keen to see if we continue to see benefits as we treat increased numbers of patients.”
New Atlas, 26 September 2022