An engineered herpesvirus that provokes an immune response against cancer has become the first treatment of its kind to be approved for use in the United States, paving the way for a long-awaited class of therapies. On 27 October, the US Food and Drug Administration (FDA) approved a genetically engineered virus called talimogene laherparepvec (T-VEC) to treat advanced melanoma. Four days earlier, advisers to the European Medicines Agency had endorsed the drug.
With dozens of ongoing clinical trials of similar ‘oncolytic’ viruses, researchers hope that the approval will generate the enthusiasm and cash needed to spur further development of the approach. “The era of the oncolytic virus is probably here,” says Stephen Russell, a cancer researcher and haematologist at the Mayo Clinic in Rochester, Minnesota. “I expect to see a great deal happening over the next few years.”
Many viruses preferentially infect cancer cells. Malignancy can suppress normal antiviral responses, and sometimes the mutations that drive tumour growth also make cells more susceptible to infection. Viral infection can thus ravage a tumour while leaving abutting healthy cells untouched, says Brad Thompson, president of the pharmaceutical-development firm Oncolytics Biotech in Calgary, Canada.