Mean highest placebo-matched change from baseline in QTc was -3.0 [ 90 % confidence interval ( CI ) -5.4 , -0.6 ] ms. At supratherapeutic axitinib exposures achieved with potent cytochrome P450 3A4/5 inhibition by ketoconazole , the model predicted mean QTc change of 6.5 ( 90 % CI 4.4-8 .5 ) ms. The slope population mean estimate was -0.331 ( 95 % CI -0.860 , 0.198 ) msmL/g for ketoconazole alone and 0.0725 ( 0.0445-0 .1005 ) msmL/ng for axitinib in the presence of ketoconazole .