Gleevec

Gleevec is the brand name for imatinib mesylate, a first-in-class tyrosine kinase inhibitor used to treat certain cancers characterized by abnormal tyrosine kinase activity. It binds selectively to the ATP-binding site of BCR-ABL, the abnormal fusion protein produced by the Philadelphia chromosome in chronic myeloid leukemia (CML) and in some cases of acute lymphoblastic leukemia (ALL). Imatinib also inhibits other tyrosine kinases including PDGF receptor alpha and beta, c-KIT, and ABL2, limiting malignant cell proliferation and survival.

Approved indications include chronic myeloid leukemia in the chronic phase, accelerated phase, or blast crisis; Philadelphia chromosome-positive ALL; unresectable or metastatic gastrointestinal stromal tumors; and certain myeloid neoplasms with PDGFR or KIT alterations, such as hypereosinophilic syndrome with FIP1L1-PDGFRA fusion and dermatofibrosarcoma protuberans (DFSP).

Imatinib is administered orally as tablets. Dosing varies by condition; a common starting dose for CML is 400 mg per day, with adjustments based on response and tolerability.

Common side effects include edema, nausea, muscle cramps, rash, fatigue, diarrhea, and abdominal pain. Serious adverse effects can include hepatotoxicity, congestive heart failure, severe cytopenias, and skin reactions. It can interact with other drugs metabolized by CYP3A4.

Developed by scientists at Ciba-Geigy (now Novartis) and approved by the U.S. FDA in 2001, imatinib transformed CML from a fatal disease to a manageable chronic condition for many patients and is now available as a generic medication in many markets.