Statement: The Change From Baseline in Mean Duration of the QTcF Interval for patients in the primary trial was at its highest on Day 1 of the third cycle, post T-DM1 intravenous (IV) infusion.
Primary_evidence: Outcome Measurement:    Change From Baseline in Mean Duration of the QTc Interval   The QT interval is a measure of time between the start of the Q wave and the end of the T wave in the heart's electrical cycle. The corrected QT interval was calculated using Fridericia's correction (QTcF) from electrocardiogram (ECG) data. Each participant had triplicate QTcF intervals measured at each timepoint and the average was calculated for each patient at each timepoint. For each timepoint, a participant's corresponding baseline QTcF interval was subtracted from the average QTcF intervals to create a baseline-adjusted average QTcF interval.   Time frame: Cycle 1 Day 1, pre-dose (Baseline); Cycle 1 Day 1, 15 and 60 minutes post-dose; Cycle 1 Day 8; and Cycle 3 Day 1, 15 minutes pre-dose and 15 and 60 minutes post-dose. Results 1:    Arm/Group Title: T-DM1   Arm/Group Description: Trastuzumab emtansine (T-DM1) was administered to participants by intravenous (IV) infusion on Day 1 of every 3 week cycle at a dose of 3.6 mg/kg.   Overall Number of Participants Analyzed: 51   Mean (Standard Deviation)   Unit of Measure: milliseconds  Cycle 1, Day 1, 15 minutes post-dose [N=44]: 1.2         (8.3)   Cycle 1, Day 1, 60 minutes post-dose [N=45]: -1.0         (6.3)   Cycle 1, Day 8 [N=43]: -4.0         (13.4)   Cycle 3, Day 1, 15 minutes pre-dose [N=35]: -0.1         (10.1)   Cycle 3, Day 1, 15 minutes post-dose [N=37]: 4.7         (9.6)   Cycle 3, Day 1, 60 minutes post-dose [N=37]: 4.7         (10.9)