US FDA approves drug that uses engineered virus to destroy melanoma tumours

The US Food and Drug Administration approved a new drug on Tuesday that uses a genetically engineered cold sore virus to destroy melanoma skin cancer tumors.

The first drug of its type to get FDA approval, it uses a genetically engineered herpes virus - the same kind that causes cold sores. It carries an immune system compound into tumours, causing them to burst apart.

The drug, called Imlygic, does not cure the patient and it had not been show to help patients live longer, though, it provides relief from melanoma, the deadliest form of skin cancer.

The FDA approved the drug on the basis of a study of 436 people with advanced melanoma that had spread, into which the drug was injected.

"The study showed that 16.3 percent of the study participants who received Imlygic experienced a decrease in size of their skin and lymph node lesions, lasting for a minimum of six months," the FDA said in a statement. That compared to 2.1 per cent patients who did not get the drug.

"However, Imlygic has not been shown to improve overall survival or to have an effect on melanoma that has spread to the brain, bone, liver, lungs, or other internal organs," the FDA noted.

In clinical trials, Imylgic had helped cancer patients achieve remission with few of the side effects common to existing treatments. According to experts, as the first tumour-killing virus to receive the FDA's approval, Imlygic could accelerate the development of other viral therapies.

''This is huge for the whole field, and for cancer patients,'' said John Bell, a senior scientist at the Ottawa Hospital Research Institute in Canada, The Boston Globe's online edition reported. ''The field is exploding, and this would be another arrow in the quiver that oncologists use.''

Imlygic formed part of a new group of immune-stimulating viral therapies that could radically change the management and treatment of cancer.

''It's a low-toxicity treatment, and for the right patients you see quite stunning results,'' said Robert Coffin, a virologist who created Imlygic at BioVex, the Woburn-based company he founded.

BioVex was acquired in 2011 by the California biotech giant Amgen along with the rights to Imlygic, known generically as talimogene laherparepvec, or T-VEC, in a deal worth up to $1 billion. Amgen would charge patients $65,000 for a course of treatment, which, according to analysts was in line with expectations.

''These days in oncology we've seen some prices quite a bit higher than that,'' said Eric Schmidt, an analyst with Cowen & Company. ''And Amgen's not a company that likes to price gouge.''