Table 4.
In vivo protection against tetanus toxin challenge in 3 studies.
| VHH/VHH combination | VHH in 1st dilutiona (nM) | Lowest VHH concentration giving 100% protection (nM) | Potency (IU/mg) |
|---|---|---|---|
| Study 1 | |||
| T2G13 | 1000 | >1000 | <1.04 |
| T3L | 1000 | >1000 | <1.04 |
| T6G13 | 1000 | 1000 | 1.04 |
| T15G13 | 1000 | 500 | 1.21 |
| T16G13 | 1000 | >1000 | <1.04 |
| T6T16A12 | 100 | ≤3.1 | >93 |
| Study 2 | |||
| T6G13 + T16G13 | 125 | ≤3.91b | NDc |
| T2G13 + T3L + T6G13 + T16G13 | 125 | ≤3.91 | ND |
| T6G13 + T15G13 | 125 | ≤3.91 | ND |
| T2G13 + T3L + T6G13 + T15G13 | 125 | ≤3.91 | ND |
| T15G13 + T16G13 | 125 | >125 | ND |
| T15G13 + T6T16A12 | 68.75 | ≤2.15 | ND |
| T6T16A12 | 6.25 | ≤0.2 | >1478 |
| Study 3d | |||
| T6T16A12 | 0.2 | 0.2e | 1510 |
| T6G13 + T16G13 | 0.4 | > 0.4 | ND |
| T15G13 + T6T16A12 | 0.4 | 0.4 | ND |
a
For VHH mixtures the total VHH concentration is given; i.e. the individual VHHs are present at equivalent (molar) amounts.
b
Full protection at all dilutions.
c
ND, not determined since it contains mixture of VHHs.
d
Fourfold dilution steps; in other two studies a twofold dilution step was used.
e
50% protection at top dilution only.