Imatinib (originally STI571) is a drug used to treat certain cancers. It is marketed by Novartis as Gleevec (USA) or Glivec (Europe/Australia/Latin America) as its mesylate salt, imatinib mesilate (INN).
Imatinib is the first of a new class of drugs that act by specifically inhibiting a certain enzyme (a receptor tyrosine kinase) that is characteristic of a particular cancer cell, rather than non-specifically inhibiting and killing all rapidly dividing cells. Imatinib was a model for other targeted therapies that inhibited this class of enzymes.
It is used in treating chronic myelogenous leukemia (CML), gastrointestinal stromal tumors (GISTs) and some other diseases. By 2011, Gleevec has been FDA approved to treat ten different cancers.
In CML, the tyrosine kinase enzyme ABL in white blood cells is constantly (constitutively) expressed. This causes the excessive proliferation and high white blood cell count which is characteristic of CML. Imatinib binds to the site of tyrosine kinase activity, and prevents its activity, causing tumor cell death (apoptosis).
The developers of imatinib won the Lasker Award in 2009 and the Japan Prize in 2012.
Read more about Imatinib: History, Adverse Effects, Interactions, Costs