Imatinib is a targeted therapy used in the treatment of chronic myeloid leukemia (CML) and gastrointestinal stromal tumors (GIST). It has significantly changed the management of these conditions.

It belongs to a class of drugs known as tyrosine kinase inhibitors (TKIs).

Imatinib works by blocking specific abnormal proteins, such as BCR-ABL and KIT, which are involved in signaling pathways that drive cancer cell growth. By inhibiting these signals, imatinib may slow or stop the proliferation of cancer cells.

Because it is more targeted than traditional chemotherapy, it may have a different side effect profile, although effects on normal cells can still occur.