Scientists have developed a virus specifically designed to target cancer tissue while not affecting normal healthy tissue.
The virus, NV1020, is a type of herpes simplex virus which has been modified so that it selectively replicates in virus cells, killing them in the process.
The researchers say NV1020 is deadly to cancer and has shown promise in a preliminary study and they hope it will help fight cancers without causing side-effects in the rest of the body.
The researchers believe viruses which are skilled at killing cells could eventually become a valuable addition in the fight against cancer.
The German biotech company MediGene who developed the virus had already announced positive results from an interim analysis of a 13-patient Phase I/II study of NV1020 in September, but data from a case study was unveiled for the first time at the annual European Society for Medical Oncology conference in Lugano, Switzerland.
The study was conducted on one very late-stage patient whose cancer had spread to 10 different places around the liver and four areas in the lungs.
He was given four weekly infusions of the virus followed by two cycles of chemotherapy, and six months after treatment scans showed that his liver tumours had almost disappeared.
The man survived for 12 months following the intervention and Dr. Axel Mescheder head of research at MediGene's says the reduction in the tumour masses was really impressive and are very encouraging.
Treating cancer in the liver is very difficult, and the prognosis for patients is poor; many people with colorectal cancer face the risk that their cancer will spread to the liver.
The encouraging results with the virus in the early human studies follows tests in animals, which showed that NV1020 was effective at killing colorectal and liver cancer cells.
Dr. Mescheder says a current study is testing the treatment in patients with colorectal cancer that have not responded to chemotherapy, where the cancer has spread to the liver and the scientists are optimistic they will be able to extend the overall survival time.