Imatinib, sold under the brand names Gleevec among others, is a medication used to treat cancer. Specifically, it is used for chronic myelogenous leukemia (CML) and acute lymphocytic leukemia (ALL) that is Philadelphia chromosome-positive (Ph+) and certain types of gastrointestinal stromal tumors (GIST), systemic mastocytosis, and myelodysplastic syndrome.

Imatinib is a 2-phenyl amino pyrimidine derivative that functions as a specific inhibitor of a number of tyrosine kinase enzymes. It occupies the TK active site, leading to a decrease in activity. There are a large number of TK enzymes in the body, including the insulin receptor. Imatinib is specific for the TK domain in abl (the Abelson proto-oncogene), c-kit and PDGF-R (platelet-derived growth factor receptor). In chronic myelogenous leukemia, the Philadelphia chromosome leads to a fusion protein of abl with bcr (breakpoint cluster region), termed bcr-abl. As this is now a constitutively active tyrosine kinase, imatinib is used to decrease bcr-abl activity.

Imatinib was developed by rational drug design. After the Philadelphia chromosome mutation and hyperactive bcr-abl protein were discovered, the investigators screened chemical libraries to find a drug that would inhibit that protein. With high-throughput screening, they identified 2-phenylaminopyrimidine. This lead compound was then tested and modified by the introduction of methyl and benzamide groups to give it enhanced binding properties, resulting in imatinib. Imatinib was invented in the late 1990s by scientists at Ciba-Geigy (which merged with Sandoz in 1996 to become Novartis), in a team led by biochemist Nicholas Lydon and that included Elisabeth Buchdunger and Jürg Zimmermann.

Formal Chemical Name (IUPAC)
N-(4-methyl-3-((4-(pyridin-3-yl)pyrimidin-2-yl)amino)phenyl)-4-((4-methylpiperazin-1-yl)methyl)benzamide

References

https://en.wikipedia.org/wiki/Imatinib