Pharmacokinetic Parameters for Factor IX Falloff Studies 1 to 4
| Animal . | Falloff . | |||
|---|---|---|---|---|
| 1 (T = 0) . | 2 (T = 80 days) . | 3 (T = 162 days) . | 4 (T = 388 days) . | |
| Half-life (hours) | ||||
| 84269 | 7.0 (0.97) | 5.5 (0.99) | 7.1 (0.88) | 9.1 (0.77) |
| RQ1234 | 4.7 (1.00) | 5.4 (0.98) | 8.1 (0.94) | 5.7 (0.90) |
| RQ1305 | 8.9 (0.77) | 6.8 (0.97) | 8.5 (0.48) | 11.1 (0.89) |
| Peak Recovery (% of predicted level) | ||||
| 84269 | 166 | 161 | 146 | 100 |
| RQ1234 | 181 | 118 | 96 | 83 |
| RQ1305 | 111 | 120 | 95 | 111 |
| Animal . | Falloff . | |||
|---|---|---|---|---|
| 1 (T = 0) . | 2 (T = 80 days) . | 3 (T = 162 days) . | 4 (T = 388 days) . | |
| Half-life (hours) | ||||
| 84269 | 7.0 (0.97) | 5.5 (0.99) | 7.1 (0.88) | 9.1 (0.77) |
| RQ1234 | 4.7 (1.00) | 5.4 (0.98) | 8.1 (0.94) | 5.7 (0.90) |
| RQ1305 | 8.9 (0.77) | 6.8 (0.97) | 8.5 (0.48) | 11.1 (0.89) |
| Peak Recovery (% of predicted level) | ||||
| 84269 | 166 | 161 | 146 | 100 |
| RQ1234 | 181 | 118 | 96 | 83 |
| RQ1305 | 111 | 120 | 95 | 111 |
Half-life determinations for each falloff study were calculated from the slope of the fitted equation describing the logarithm of factor IX as a function of time over the interval including time points at 1, 2, 4, and 8 hours. Values listed are the half-life in hours with the coefficient of variance for the fitted curve in parentheses for each value. The peak recovery is the mean of duplicate determinations of the highest factor IX level divided by the theoretical value predicted on the basis of a 25 unit per kg dose (1.25 μg/mL, assuming 5 μg/mL as 100% normal factor IX level).