imatinib

noun

imat·​i·​nib i-ˈma-tə-ˌnib 

variants or imatinib mesylate

: an anticancer drug taken orally in the form of its mesylate C₂₉H₃₁N₇O·CH₄O₃S to treat chronic myelogenous leukemia and metastatic or unresectable gastrointestinal stromal tumors

Note: Imatinib acts by inhibiting the abnormal tyrosine kinase produced by the Philadelphia chromosome. It is marketed under the trademark Gleevec.