TABLE 4.
Homodimeric IgG1 variants do not improve the binding to FcγRIIIA as effectively as the asymmetrically engineered heterodimeric IgG1 variant
Homodimeric and heterodimeric anti-Her2 IgG1 variants were made and compared with a competition AlphaLISA® assay. The variant alias, protein type, sequence variations in each Fc chain, and EC50 values for binding to FcγRIIIA V158 and FcγRIIIA F158 are summarized.
| Variants | Type | Sequence variation |
huFcγRIIIa Val-158, EC50 (nm) | huFcγRIIIa Phe-158, EC50 (nm) | |
|---|---|---|---|---|---|
| Chain A | Chain B | ||||
| Anti-Her2 IgG1 (M01) | Homodimer | WT | WT | 817.8 | 333 |
| Anti-Her2 IgG1 (M02) | Homodimer | S239D + I332E | S239D + I332E | 17.59 | 11.94 |
| Anti-Her2 IgG1 (M03) | Homodimer | S239D + I332E + A330L | S239D + I332E + A330L | 14.95 | 6.742 |
| Anti-Her2 IgG1 (M04) | Heterodimer | K392D + K409D | E356K + D399K | 653.9 | 186.5 |
| Anti-Her2 IgG1 (W144) | Heterodimer | K392D + K409D + A330F + K334V | E356K + D399K + L234Y + K290Y + Y296W | 6.77 | 4.44 |
| Anti-Her2 IgG1 (W199) | Homodimer | A330F + K334V | A330F + K334V | 115.3 | 48.54 |
| Anti-Her2 IgG1 (W211) | Homodimer | L234Y + K290Y + Y296W | L234Y + K290Y + Y296W | 40.7 | 36.92 |
| Anti-Her2 IgG1 (W202) | Homodimer | A330F + K334V + L234Y + K290Y + Y296W | A330F + K 334V + L234Y + K290Y + Y296W | 77.23 | 50.55 |
| anti-Her2 IgG1 (W188) | Heterodimer | K392D + K409D + S239D + A330F + K334V | E356K + D399K + L234Y + K290Y + Y296W | 5.38 | 3.26 |
| Anti-Her2 IgG1 (W203) | Homodimer | S239D + A330F + K334V | S239D + A330F + K334V | 16.35 | 9.08 |
| Anti-Her2 IgG1 (W211) | Homodimer | L234Y + K290Y + Y296W | L234Y + K290Y + Y296W | 40.7 | 36.92 |
| Anti-Her2 IgG1 (W204) | Homodimer | S239D + A330F + K334V + L234Y + K290Y + Y296W | S239D + A330F + K334V + L234Y + K290Y + Y296W | 11.03 | 5.9 |