Nilotinib is used to treat certain types of chronic myeloid leukemia (CML; a type of cancer of the white blood cells) who have recently found to have this condition in adults and children 1 year of age and older. It is also used to treat certain types of CML whose disease could not be treated successfully with imatinib (Gleevec) or adults who cannot take imatinib. Nilotinib is also used to treat certain types of CML in children 1 year of age or older whose disease could not be treated successfully with other tyrosine kinase inhibitor therapies. Nilotinib is in a class of medications called kinase inhibitors. It works by blocking the action of the abnormal protein that signals cancer cells to multiply. This helps to stop or slow the spread of cancer cells.