Trametinib had good results for V600E mutated metastatic melanoma in a phase III clinical trial. In this mutation, the amino acid valine at position 600 is replaced by glutamic acid.
In May 2013, trametinib was approved as a single-agent by the Food and Drug Administration for the treatment of patients with V600E mutated metastatic melanoma. Clinical trial data demonstrated that progression on single-agent trametinib occurs within 6 to 7 months. To overcome this, trametinib was combined with the BRAF inhibitor dabrafenib. As a result of this research, on January 8, 2014, the FDA approved the combination of dabrafenib and trametinib for the treatment of patients with BRAF V600E/K-mutant metastatic melanoma.