Table 3.

Potency of affinity matured anti- PD-1 antibodies in the inhibition of PD-1. The half-maximal response (EC₅₀) of selected anti- PD-1 antibodies in the interaction of PD-1 with PD-L1 in a cell co-culture reporter assay was determined by fitting the data depicted in Figure 7 by non-linear regression using the dose-response (stimulation) equation (four parameter) using Prism 7 software (GraphPad Software Inc). The R-squared (R²) values statistical measure of how close the data are to the fitted regression line. VH CDR3 sequences are shown in column 3.

VH	VL	VH	EC50 (nM)	R2
337_1_C08	WT	DRDYYDAG	25	0.982
K5E3	61	..E.K...	6.9	0.987
K5T8	9	....K..T	5	0.983
Nivolumab		NDDY	7.2	0.969