TABLE 3.

Binding of anti-Her2 IgG1 containing the combinatorial beneficial Fc variants to human and murine FcγRs by competition AlphaLISA® assay and Biacore analysis

The amino acid substitutions in Fc chain A and Fc chain B, which contain the heterodimerization mutations K392D + K409D and E356K + D399K, respectively, are shown under the Sequence Variations column. The effect of concentrations at 50% inhibition (EC₅₀, nm) of anti-Her2 IgG1 containing the designated Fc variants to the interaction of wild type IgG1 and human FcγRIIIA (Val-158) or FcγRIIIA (Phe-158) are indicated under the AlphaLISA® Assay column. Measurements of k_on (1/ms), k_off (1/s), and K_D (nm) of anti-Her2 IgG1 containing the designated Fc variants are summarized under the Biacore Analysis column. a, homodimeric IgG1; b, ND, not determined. M01 is an anti-Her2 wild type IgG1; M02 (or 2X) is an anti-Her2 IgG1 containing S239D + I332E in both Fc chains; M03 (or 3X) is an anti-Her2 IgG1 containing S239D + I332E + A330L in both Fc chains; M04 is an anti-Her2 IgG1 containing only charge pair residues for Fc heterodimerization.