A member of the class of N-acylazetidines obtained by selective formal condensation of the carboxy group of 3,4-difluoro-2-(2-fluoro-4-iodoanilino)benzoic acid with the secondary amino group from the azetidine ring of 3-[(2S)-piperidin-2-yl]azetidin-3-ol. An inhibitor of mitogen-activated protein kinase that is used (as its fumarate salt) in combination with vemurafenib for the treatment of patients with unresectable or metastatic melanoma.