This referred to the Crystalline fumarate Salt of (S) - 3,4 - difluoro - [2 - (4 - fluoro - yodofenilamino) phenyl] [3 - hydroxy - 3 - (2 - azetidin piperidin yl) - triazin-1-yl] - methanone In addition,The pharmaceutical compositions comprising the Salt thereof.It also relates to the use of this salt in Methods to treat cancers such as melanoma, colorectal cancer, Lung Cancer, among othersEsta referido a la sal de fumarato cristalina de (S)-[3,4-difluoro-2-(2-fluoro-4-yodofenilamino)fenil] [3-hidroxi-3-(piperidin-2-il)azetidin-1-il]-metanona ademas, a sus composiciones farmaceuticas que comprende la sal del mismo. Tambien se refiere al uso de esta sal en metodos para tratar canceres como melanoma, cancer colorrectal, cancer de pulmon, entre otras