Table 1. Parameters of Kinetic Interaction with VEGFR2^a.

compd	Kd (nmol/L)	kon (s–1 × M–1)	koff (s–1)	residence time (min)
lenvatinib	2.1 ± 0.1	4.8 × 105 ± 1.4 × 104	9.9 × 10–4 ± 9.0 × 10–5	17 ± 2
sorafenib	33 ± 2.6	7.9 × 103 ± 1.5 × 102	2.6 × 10–4 ± 2.5 × 10–5	64 ± 6
sunitinib	30 ± 1.7	>1.9 × 105	>57 × 10–4	<2.9

^aK_d = equilibrium dissociation constant, calculated by using the Cheng–Prusoff equation from IC₅₀-like values obtained from the percent displacement values at time point, at which system has reached equilibrium; k_on = association rate constant; displacement traces at each compound concentration were fitted according to a monoexponential equation to yield k_obs. Secondary plot of k_obs over compound concentration was linearly fitted to generate k_on; k_off = dissociation rate constant (= K_d × k_on); residence time = 1/k_off. From standard errors of IC₅₀ and k_on calculated in regression analysis for curve fitting, errors for K_d, k_off, and residence time were calculated by Gaussian error propagation.