Table 2.

Variables and parameters of the mathematical models. Default or median values for the parameters are given across all calibration sets; a more detailed list for each of the calibrations of these values can be found in the supplementary materials.

Variables	Description	Units
T	Number of tumor cells	cells
A b	Number of bound trastuzumab antibodies	molecules
P i	Amount of internalized paclitaxel	pmol
A f	Number of free trastuzumab antibodies	molecules
P f	Amount of free paclitaxel	pmol
Parameters	Description	Units	Median/Default Value
k	Tumor cell growth rate (calibrated)	1/t	0.83
η A	Antiproliferative effect per amount of bound trastuzumab antibody (calibrated)	1/Ab	2.51
$t_A^{⁎}$	Delay for bound trastuzumab effect due to intracellular signaling (calibrated)	t	1.93
θ	Tumor cell carrying capacity (calibrated)	cells	0.67
δ P	Carrying capacity reduction amount per amount of internalized paclitaxel (calibrated)	cells/Pi	0.23 × 102
γ P	Rate of decay for initial paclitaxel toxicity (calibrated)	1/t	6.35
$t_P^{⁎}$	Time to paclitaxel toxic effect decrease (calibrated)	t	1.48
S	Drug synergy parameter (calibrated)	unitless	1
β A	Binding rate of trastuzumab antibody per available HER2 receptors (calibrated)	1/(receptors · t)	8.78
HER2 exp	Average HER2 expression per tumor cell (assigned)	Receptors/cell	1.94 × 106
α P	Paclitaxel internalization rate (calibrated)	1/(cell · t)	0.68