Imatinib mesylate. Molecular model of the drug imatinib mesylate (C29.H31.N7.O?C.H4.S.O3). This tyrosine-kinase inhibitor is sold under the brand name Gleevec. It is used in the treatment of multiple cancers, most notably Philadelphia chromosome-positive (Ph+) chronic myelogenous leukemia (CML). Atoms are represented as spheres and are colour-coded: carbon (grey), hydrogen (white), nitrogen (blue), oxygen (red) and sulfur (yellow).