In the run-in phase, participants received trastuzumab intravenously every 3 weeks for 18 weeks (Cycles 1-6). They first received trastuzumab 8 mg/kg once (Cycle 1) followed by trastuzumab 6 mg/kg 5 times for 15 weeks (Cycles 2-6). Participants could also receive a maximum of 6 cycles of standard chemotherapy for early breast cancer (neo-adjuvant or adjuvant) in the run-in phase.
Following the run-in phase, participants were randomized to receive trastuzumab 600 mg subcutaneously every 3 weeks in the thigh and upper arm in a cross-over design for a total of 24 weeks (Cycles 7-14). They received trastuzumab either in the thigh first for 4 cycles (Cycles 7-10) followed by trastuzumab in the upper arm for 4 cycles (Cycles 11-14) or the upper arm first (Cycles 7-10) followed by the thigh (Cycles 11-14). For Cycles 15-18, participants could choose the injection site for trastuzumab 600 mg subcutaneously every 3 weeks.
