Tipifarnib

Tipifarnib (trade name Zarnestra) is a farnesyltransferase inhibitor that is being investigated in patients 65 years of age and older with newly diagnosed acute myeloid leukemia (AML). It inhibits the Ras kinase in a post translational modification step before the kinase pathway becomes hyperactive. It inhibits prenylation of the CxxX tail motif, which allows Ras to bind to the membrane where it is active. Without this step the protein cannot function.