lapatinib

Definition of lapatinib ditosylate
National Cancer Institute

lapatinib ditosylate

(luh-PA-tih-nib dy-TOH-sih-layt)
A drug used with capecitabine or letrozole to treat certain types of HER2-positive breast cancer that are advanced or have spread. It is also being studied in the treatment of other types of cancer. Lapatinib ditosylate blocks EGFR and other proteins, which may help keep cancer cells from growing. It is a type of tyrosine kinase inhibitor. Lapatinib is the active ingredient of lapatinib ditosylate. Also called GW572016 and Tykerb.

Source: NCI Dictionary of Cancer Terms