UK News

A new genetically engineered virus has delivered a one-two punch against advanced cancers in initial findings from a Phase I trial. Scientists found that RP2 – amodified version of the herpes simplex virus – showed signs of effectiveness in a quarter of patients with a range of advanced cancers.

The early findings were presented at the European Society for Medical Oncology Congress (ESMO) on Saturday, and suggest cancer-killing viruses could potentially offer hope to patients where other forms of immunotherapy have not worked.

Researchers from The Institute of Cancer Research, London, and the Royal Marsden NHS Foundation Trust, assessed the cancer-killing virus on its own in nine patients, and, in combination with the immunotherapy nivolumab, in an initial 30 patients in the ongoing Phase I trial.

The early-stage study, sponsored by the drug’s manufacturer Replimune, is testing the safety and dosage of RP2, as well as evaluating its ability to shrink tumours.

The genetically-engineered RP2 virus, which is injected directly into the tumours, is designed to have a dual action against tumours. It multiplies inside cancer cells to burst them from within, and also blocks a protein known as CTLA-4 – which releases the brakes on the immune system and increases its ability to kill cancer cells.

Study leader Professor Kevin Harrington, Professor of Biological Cancer Therapies at The Institute of Cancer Research, London, and Consultant Oncologist at The Royal Marsden NHS Foundation Trust, said: “Our study shows that a genetically engineered, cancer-killing virus can deliver a one-two punch against tumours – directly destroying cancer cells from within while also calling in the immune system against them.

“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.

“Our initial trial findings 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 haven’t responded to other forms of immunotherapy. I am keen to see if we continue to see benefits as we treat increased numbers of patients.”