Mekinist (trametinib) is used in treating patients with unresectable or metastatic melanoma with BRAF (a gene) V600 mutation.

Trametinib has not demonstrated clinical activity in patients who have progressed on a prior BRAF inhibitor therapy.

Before taking trametinib, patients must have confirmation of a BRAF V600 mutation using a validated test.

Trametinib is a MEK inhibitor which blocks the activity of a protein kinase called MEK-1. This protein is present in the MAPK pathway, which regulates the normal growth and death of cells and plays a role in metastatic melanoma development.

Some mutations in the BRAF gene can cause the MEK protein to stimulate cancer cell growth and survival; therefore, inhibiting MEK can potentially slow down the growth of tumors in BRAF-mutant metastatic melanoma.

Dr Paolo Paoletti, president of oncology, GSK said: "We welcome today's decision of the European Commission. MEK has been pursued as a therapeutic target in cancer for more than a decade, and Mekinist is the first medicine in this class to be licensed in Europe."