Effect of PALBACE^® on QTc Interval

No clinically relevant effects on the QTc interval were reported for PALBACE® at the recommended dose of 125 mg daily.¹​​​​​​​

*PALOMA-2 (PALBACE^® + letrozole vs. placebo + letrozole in ET-sensitive HR+/HER2- mBC) included a QTc evaluation sub-study as a definitive QT interval prolongation assessment for palbociclib.²
Time-matched triplicate ECGs were performed at 0, 2, 4, 6 and 8 hours at baseline (Day 0) and on Cycle 1 Day 14.² 
Additional ECGs were collected from all patients for safety monitoring.²
The QT interval was corrected for heart rate using Fridericia’s correction (QTcF), Bazett’s correction (QTcB) and  a study-specific correction factor (QTcS). No patients in the PALBACE^® + letrozole arm of the sub-study had a maximum post-baseline QTcS or QTcF value of ≥480 ms, or a maximum increase from clock time-matched baseline for QTcS or QTcF values of ≥60 ms.²
The upper bounds of the one-sided 95% CI for the mean change from time-matched baseline for QTcS, QTcF and QTcB at all time points and at steady-state C_max following repeated administration of 125 mg PALBACE^® were less than 10 ms.²
There was no evidence of clinically significant effects of PALBACE^® + letrozole on QTc, the PR interval or the QRS complex.²

CI, confidence interval; C_max, maximum concentration; ECG, electrocardiogram; ET, endocrine therapy; HR+/ HER2-, hormone receptor-positive/human epidermal growth factor receptor 2-negative; mBC, metastatic breast cancer; QTc, QT interval corrected for heart rate; QTcB, QT interval Bazett’s correction; QTcF, QT interval Fridericia’s correction; QTcS, QT interval study-specific correction factor.

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