We enrolled women with HER2-positive early breast cancer and randomly assigned them to receive oral lapatinib ( 1500 mg ) , intravenous trastuzumab ( 4 mg/kg loading dose followed by 2 mg/kg ) , or lapatinib ( 1000 mg ) plus trastuzumab ( same dose as for single agent ) in combination for 6 weeks , followed by an additional 12 weeks of the assigned anti-HER2 therapy in combination with weekly paclitaxel ( 80 mg/m ( 2 ) ) .