Lapatinib: A sword with two edges

Lapatinib is an oral dual tyrosine kinase inhibitor targeting EGFR1 and EGFR2 (HER2). Phase I trials have shown that lapatinib is well tolerated, with mild diarrhea and skin rush as common adverse effects, and low cardiotoxicity. Phase II and III trials provided evidences on clinical effectiveness in advanced or metastatic breast cancer and potential against brain metastases. Lapatinib is active in combination with trastuzumab and in trastuzumab-resistant patients, moreover it has synergistic action with capecitabine. Several clinical trials are in progress to explore the effectiveness of lapatinib in other combinations and against several tumor types.