TABLE 1.
Anti-ClfA MAbs: correlation between affinity and in vitro activity
| Antibody and ClfA variant | Affinitya |
Fibrinogen bindingb (IC50 [μM]) | ||
|---|---|---|---|---|
| Kon (M−1 s−1) | Koff (s−1) | Kd | ||
| SAR114 | ||||
| ClfA001 | 2.41E+06 | 6.01E−06 | 2.493 pM | 16.09 |
| ClfA002 | 2.13E+06 | 9.53E−05 | 44.77 pM | 6.004 |
| ClfA004 | 5.62E+06 | 6.46E−06 | 1.15 pM | 13.61 |
| 11H10 | ||||
| ClfA001 | 1.09E+06 | 6.80E−03 | 6.22 nM | 24.59 |
| ClfA002 | ND | 997.5 | ||
| ClfA004 | 8.45E+05 | 6.39E−03 | 7.55 nM | 23.94 |
a
Affinity constants (Kd) of SAR114 and 11H10 to the main ClfA variants were determined as the ratio between dissociation (Koff) and association (Kon) rate constants, as measured by Biacore. The affinity of 11H10 to ClfA002 could not be determined (ND).
b
In vitro activity of both anti-ClfA MAbs was measured in the fibrinogen binding inhibition assay for the main three ClfA variants and is expressed as IC50.