Table 4.
Virus properties and virus reduction factors achieved in the rFIXFc virus clearance validation studies
| Virus reduction factor* | |||||||
|---|---|---|---|---|---|---|---|
| Virus name | Virus type | Virus size (nm) | Affinity chromatography (log10) | Intermediate chromatography (log10) | Pseudo affinity chromatography (log10) | Planova 15N viral filtration (log10) | Overall reduction factor (log10)†,‡ |
| Xenotropic murine leukaemia virus | Retrovirus (enveloped RNA virus) | 80–130 | 4.4 | 2.2 | 3.5 | >5.9§ | >16.0§ |
| Suid herpes virus 1 | Enveloped DNA virus | 120–200 | 3.7 | 1.0 | 5.3 | >5.1§ | >14.1§ |
| Reovirus type 3 | Non-enveloped RNA virus | 60–80 | 3.3 | 0.4 | 6.1 | >6.6§ | >16.0§ |
| Mouse minute virus | Non-enveloped DNA virus | 18–22 | 2.9 | 1.2 | 3.3 | 4.5 | 11.9 |
rFIXFc, recombinant factor IX Fc fusion protein.
Numerical values shown in the table represent the reduction factor for the respective rFIXFc manufacturing process steps and viruses.
Total reduction factor (log10) is the sum of the lowest reduction factor value (log10) from duplicate determinations for each of the process steps. For the chromatography steps, the reportable value is the lowest value obtained between new and aged (cycled) chromatography resin virus clearance studies.
Reduction factor = log10 (viral load of input/viral load of output).
A ‘>’ indicates virus levels were below levels of quantitation for the respective steps.