Levin 400mg Tablets Levin 400 contains Imatinib, a small-molecule protein tyrosine kinase inhibitor that selectively inhibits the BCR-ABL tyrosine kinase, the constitutive abnormal tyrosine kinase created by the Philadelphia chromosome abnormality. It also inhibits the receptor tyrosine kinases for platelet-derived growth factor (PDGFR) and stem cell factor (SCF)/c-KIT. By binding to the ATP-binding site of these enzymes, Imatinib blocks downstream signaling pathways, suppressing proliferation and inducing apoptosis in BCR-ABL positive leukemic cells as well as Kit-positive gastrointestinal stromal tumor (GIST) cells. Levin 400 is indicated for the treatment of newly diagnosed Philadelphia chromosome-positive chronic myeloid leukemia (Ph+ CML), Ph+ acute lymphoblastic leukemia (Ph+ ALL), myelodysplastic/myeloproliferative diseases, and c-KIT positive unresectable and/or metastatic gastrointestinal stromal tumors (GIST).