Researchers have conducted an experiment in which they used the modified herpes virus in order to treat melanoma, one of the most common and deadly forms of cancer. The genetically engineered virus proved to be efficient in slowing down the progression of melanoma.
According to the research which was published in the Journal of Clinical Oncology the treatment kills cancer cells and triggers the immune system to attack tumors. The study was funded by drug maker Amgen, but the therapy is not yet licensed. This was a Phase III clinical trial which involved human testing. It is the final step before the treatment can receive FDA (the US Food and Drug Administration) approval. The approach used is called viral immunotherapy, which is a form of experimenting which involves the use of viruses.
The study was conducted on 436 patients who had aggressive melanoma, which could not be treated. Each patient received a control immunotherapy or a T-VEC (Talimogene Laherparepvec), which is the injection of the viral therapy. The drug did not have effect in all of the patients. 16% of the participants who were injected with T-VEC responded to the treatment in more than six months. Some patients had a response which lasted longer than three years. The result was good when compared to the control group in which only 2% of the participants responded to the treatment.
T-VEC is a genetically modified form of the herpes simplex virus type 1. According to the research team two of its genes were removed so that the virus could not replicate in healthy cells. What T-VEC does is multiply inside cancer cells and attacks them from within. In addition it produces a molecule which makes the immune system destroy the tumors.
The lead author of the study, Professor Kevin Harrington of the Institute of Cancer Research in London, remarked:
“There is increasing excitement over the use of viral treatments like T-VEC for cancer, because they can launch a two-pronged attack on tumors — both killing cancer cells directly and marshalling the immune system against them.”
Moreover, since this therapy targets the cancer cells particularly it does not have as many side effects as other immunotherapies or chemotherapy have.
Dr. Hayley Frend from Cancer Research UK said that the next step is to find out why only some of the patients responded to the T-VEC treatment and also to discover which patients could benefit from using this treatment.
Image Source: microscopyu.com