NRAS and metastatic melanoma: Pimasertib, a non-competitive MEK1/MEK2 inhibitor, was also efficient in all our cell lines and a phase I dose-escalation study performed with this drug in 89 patients with metastatic melanoma revealed a complete response in a melanoma with the NRAS mutation, an objective response in 12.4% of the patients, and stable disease in 55% of the patients [46].