Lapatinib is well tolerated with clinical activity in heavily pretreated HER-2+, but not EGFR+/HER-2-, IBC. In this study, coexpression of pHER-2 and pHER-3 in tumors seems to predict for a favorable response to lapatinib. These findings warrant further investigation of lapatinib monotherapy or combination therapy in HER-2+ IBC.

Lapatinib monotherapy had modest clinical activity in HER2-positive metastatic breast cancer that progressed on prior trastuzumab regimens. No apparent clinical activity was observed in chemotherapy-refractory, HER2-negative disease.

No abstract

Most DEs in lapatinib-treated patients present early, are mild to moderate in severity, and infrequently require dose modification or treatment interruption. Lapatinib-associated DEs appear to differ clinically from those associated with EGFR TKIs in both frequency and severity.