Table 1.

Binding kinetics and TF-1 proliferation IC₅₀ values for wild-type anti-GMCSFR antibody 28G5 and affinity matured antibody variant 574D04

Assay parameter	Wild type	574D04
kon, M−1 s−1	2.45 × 105	1.21 × 106
koff, s−1	1.75 × 10−2	1.70 × 10−4
Kd, nM	71.4	0.14
Kd wild-type/Kd variant	–	514
TF-1 IC50, nM	43	0.005
TF-1 IC50 wild-type/TF-1 IC50 variant	–	8600
pH 7.4 Kd, nM	–	0.145
pH 5.7 Kd, nM	–	13.4
pH 5.7 Kd/pH 7.4 Kd	–	92

k_on = association rate constant; k_off = dissociation rate constant; K_d = equilibrium dissociation constant; IC₅₀ = half maximal inhibitory concentration.