Imatinib

What it is and how it works

Mechanism of Action Imatinib mesylate is a protein-tyrosine kinase inhibitor that inhibits the BCR-ABL tyrosine kinase, the constitutive abnormal tyrosine kinase created by the Philadelphia chromosome abnormality in CML. Imatinib inhibits proliferation and induces apoptosis in BCR-ABL positive cell lines as well as fresh leukemic cells from Philadelphia chromosome positive chronic myeloid leukemia. Imatinib inhibits colony formation in assays using ex vivo peripheral blood and bone marrow samples from CML patients. In vivo , imatinib inhibits tumor growth of BCR-ABL transfected murine myeloid cells as well as BCR-ABL positive leukemia lines derived from CML patients in blast crisis.

Indications

Imatinib mesylate is a kinase inhibitor indicated for the treatment of: • Newly diagnosed adult and pediatric patients with Philadelphia chromosome positive chronic myeloid leukemia (Ph+ CML) in chronic phase • Patients with Philadelphia chromosome positive chronic myeloid leukemia (Ph+ CML) in blast crisis (BC), accelerated phase (AP), or in chronic phase (CP) after failure of interferon-alpha therapy • Adult patients with relapsed or refractory Philadelphia chromosome positive acute lymphoblastic leukemia (Ph+ ALL) • Pediatric patients with newly diagnosed Philadelphia chromosome positive acute lymphoblastic leukemia (Ph+ ALL) in combination with chemotherapy • Adult patients with myelodysplastic/myeloproliferative diseases (MDS/MPD) associated with platelet-derived growth factor receptor (PDGFR) gene re-arrangements.

Dosage and administration (summary)

Adults with Ph+ CML CP : 400 mg/day Adults with Ph+ CML AP or BC : 600 mg/day Pediatrics with Ph+ CML CP : 340 mg/m 2 /day Adults with Ph+ ALL : 600 mg/day Pediatrics with Ph+ ALL 340 mg/m 2 /day Adults with MDS/MPD : 400 mg/day Adults with ASM : 100 mg/day or 400 mg/day Adults with HES/CEL : 100 mg/day or 400 mg/day Adults with DFSP : 800 mg/day Adults with metastatic and/or unresectable GIST : 400 mg/day Adjuvant treatment of adults with GIST : 400 mg/day Patients with mild to moderate hepatic impairment : 400 mg/day Patients with severe hepatic impairment : 300 mg/day All doses of imatinib mesylate tablets should be taken with a meal and a large glass of water.

Contraindications

None. None .

Warnings and precautions

• Edema and severe fluid retention have occurred. Weigh patients regularly and manage unexpected rapid weight gain by drug interruption and diuretics. ( 5.1 , 6.1 ) • Cytopenias, particularly anemia, neutropenia, and thrombocytopenia, have occurred. Manage with dose reduction, dose interruption, or discontinuation of treatment. Perform complete blood counts weekly for the first month, biweekly for the second month, and periodically thereafter. • Severe congestive heart failure and left ventricular dysfunction have been reported, particularly in patients with comorbidities and risk factors.

Pregnancy

Pregnancy Risk Summary Imatinib mesylate tablets can cause fetal harm when administered to a pregnant woman based on human and animal data. There are no clinical studies regarding use of imatinib mesylate tablets in pregnant women.

Storage and supply

Each imatinib mesylate film-coated tablet contains 100 mg or 400 mg of imatinib free base. 100 mg Tablets Brownish orange, slightly biconvex, round film-coated tablets with functional scoring, engraved "IMA" over score "100" on one side, "APO" on the other side Bottles of 30 tablets………………………...…………NDC 60505-2900-3 Bottles of 90 tablets……………………………………

Source: Imatinib Mesylate (Imatinib Mesylate) — US FDA prescribing information, 2026-09-08, DailyMed. Summarised and shortened; the full label governs. Iranian registration, indications and labelling may differ.