Glivec, also known as Imatinib Mesylate, is a targeted therapy medication used in the treatment of certain types of cancer. It is most commonly prescribed for chronic myeloid leukemia (CML) and gastrointestinal stromal tumors (GISTs), but it is also effective against other forms of cancer. Glivec works by inhibiting specific tyrosine kinase enzymes, which are involved in the growth and spread of cancer cells. By blocking these enzymes, Glivec helps to stop the proliferation of cancer cells and can lead to remission in many patients. It is typically administered orally and is known for its role in significantly improving the prognosis and quality of life for individuals diagnosed with these cancers.