Bosutinib is primarily used in the treatment of chronic myeloid leukemia (CML), a type of cancer that affects the blood and bone marrow. It works by inhibiting specific tyrosine kinases, which are enzymes that promote the growth of cancer cells. This targeted therapy helps to slow down or stop the progression of CML, particularly in patients who have developed resistance to other treatments. Bosutinib is often prescribed for patients in the chronic, accelerated, or blast phase of CML. It is taken orally, usually once daily, and is part of a broader strategy to manage and control the disease. Regular monitoring is required to assess its effectiveness and manage potential side effects.