Definition

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. GW572016 blocks EGFR and other proteins, which may help keep cancer cells from growing. It is a type of tyrosine kinase inhibitor. Also called lapatinib ditosylate and Tykerb.