FDA approves Amgen's first-of-its-kind product for treatment of melanoma

The injection, called talimogene laherparepvec, is a so-called oncolytic immunotherapy, using a genetically modified strain of the herpes virus to invade tumors and replicate itself, thereby killing cancer and spurring an immune response to multiply its effect.

The drug, Imlygic (em-LYE'-gick), is injected directly into tumor tissue, where it uses herpes as a Trojan horse to slip past and rupture cancer cells.

It is meant for patients with hard-to-treat melanoma, the deadliest form of skin cancer.

DRR was 16.3% with T-VEC compared with 2.1% for GM-CSF. "Immunotherapy is an exciting area for cancer research, and we are now studying IMLYGIC in combination with other immunotherapies in advanced melanoma and other solid tumors".

The primary safety analysis for the approval was based on findings from 292 patients in the Imlygic arm and 127 patients in the GM-CSF arm of the OPTiM study. The most frequently occurring all-grade adverse events for patients receiving Imlygic included fatigue (50.3 percent vs 36.2 percent with GM-CSF), chills (48.6 percent vs 8.7 percent), pyrexia (42.8 percent vs 8.7 percent), nausea (35.6 percent vs 19.7 percent), influenza-like illness (30.5 percent vs 15 percent) and injection site pain (27.7 percent vs 6.3 percent).

Amgen's drug was not able to improve overall survival or to have an effect on melanoma that has spread to the brain, bone, liver, lungs, or other internal organs, according to the FDA, but the palliative effects were considered significant enough to warrant approval. It can also give patients herpes - the herpes simplex 1 infection that causes cold sores. The ruptured cells then release tumor-derived antigens, along with a white blood cell growth factor called GM-CSF (granulocyte-macrophage colony-stimulating factor) that can stimulate a system-wide immune response.

Amgen said patients should be treated with the drug for at least six months, or until there are no more tumors left to treat. The company estimates one course of treatment will cost about $65,000, depending on the length of treatment.

"This approval provides patients and healthcare providers with a novel treatment for melanoma", she added.

Amgen acquired the drug as part of its takeover of BioVex in 2011, valued at up to $1bn with $425m paid upfront.