Amgen’s closely-watched Imlygic has become the first oncolytic immunotherapy approved in the European Union for patients with metastatic melanoma.

The therapy, which is also known as T-Vec (talimogene laherparepvec), can be used to treat adults with unresectable melanoma that is regionally or distantly metastatic (Stage IIIB, IIIC and IVM1a), with no bone, brain, lung or other visceral disease.

T-Vec is an oncolytic immunotherapy which is injected directly into tumour tissue and then replicates until the membrane of the cancer cells rupture, thereby destroying them. The virus contained in these cells is then released locally in the tumour tissue along with granulocyte-macrophage colony-stimulating factor (GM-CSF), a white blood cell growth factor that the virus is engineered to express, which kill tumour cells throughout the body.

"By igniting the body's own immune system Imylgic can initiate an anti-tumour immune response, providing meaningful and durable response rates in the early stage metastatic melanoma patient,” said Sean Harper, who heads up Research and Development at Amgen.

Data from one clinical trial showed a 50% or greater reduction in size in 64% of injected tumours, one-third of uninjected non-visceral tumours, and 15% of visceral tumours were also reduced by at least 50%. Also, there were 35 melanoma-related surgeries performed during this trial of which 30% successfully removed all residual disease.

In Study 005/05, patients achieved an overall response rate of 40.5 percent when treated with Imylgic compared to 2.3 percent with GM-CSF, while median overall survival was 41.1 months versus 21.5 months, respectively. On the safety side, fatigue, chills, pyrexia, nausea, influenza-like illness and injection-site pain were the most frequently-reported adverse events,   98 percent of which were considered mild or moderate in severity.

While melanoma is curable when detected in the early stages, metastatic melanoma continues to be one of the most difficult-to-treat cancers because it is highly aggressive and complex. Even with recent new options in immune-oncology, a large number of patients still fail to respond to treatment, highlighting the remaining unmet need.