Anion exchange chromatography provides a robust, predictable process to ensure viral safety of biotechnology products

Abstract

The mammalian cell-lines used to produce biopharmaceutical products are known to produce endogenous retrovirus-like particles and have the potential to foster adventitious viruses as well. To ensure product safety and regulatory compliance, recovery processes must be capable of removing or inactivating any viral impurities or contaminants which may be present. Anion exchange chromatography (AEX) is a common process in the recovery of monoclonal antibody products and has been shown to be effective for viral removal. To further characterize the robustness of viral clearance by AEX with respect to process variations, we have investigated the ability of an AEX process to remove three model viruses using various combinations of mAb products, feedstock conductivities and compositions, equilibration buffers, and pooling criteria. Our data indicate that AEX provides complete or near-complete removal of all three model viruses over a wide range of process conditions, including those typically used in manufacturing processes. Furthermore, this process provides effective viral clearance for different mAb products, using a variety of feedstocks, equilibration buffers, and different pooling criteria. Viral clearance is observed to decrease when feedstocks with sufficiently high conductivities are used, and the limit at which the decrease occurs is dependent on the salt composition of the feedstock. These data illustrate the robust nature of the AEX recovery process for removal of viruses, and they indicate that proper design of AEX processes can ensure viral safety of mAb products.

Understanding the mechanism of virus removal by Q sepharose fast flow chromatography during the purification of CHO‐cell derived biotherapeutics

“…For instance, the mechanism indicates that parameters which are important for electrostatic forces, such as salt concentration, pH, and competing ionic impurities, could have significant impacts on viral clearance. In fact, conductivity and pH have previously been shown to be important for this process (Curtis et al, 2003;Strauss et al, 2009). Conversely, our inability to observe any non-electrostatic interactions contributing to viral clearance suggests that viral clearance is less likely to be affected by residual hydrophobic impurities such as lipids or non-ionic detergents.…”

“…Although most of these do not describe much characterization of the processes used, a few have demonstrated that salt concentration (or conductivity), salt composition, and pH are important factors for viral clearance (Curtis et al, 2003;Strauss et al, 2009). These correlations are consistent with those expected for electrostatic interactions, and they indicate that such interactions are necessary for a high level of viral clearance.…”

“…While developing these tools, an understanding of the mechanism by which the operation functions allows focus to be placed on those parameters which are most important for the process to achieve its intended outcome. QSFF has been shown to provide robust removal of viral contaminants over wide ranges of parameter and feedstock variations (Curtis et al, 2003;Strauss et al, 2009). However, the process of viral clearance provides unique challenges which protein and virus chromatography techniques have not addressed.…”

“…In addition to the virus purification literature, there are also published reports describing viral clearance using QSFF resin (Curtis et al, 2003;Norling et al, 2005;Shi et al, 1999bShi et al, , 2004Strauss et al, 2009;Valera et al, 2003). Although most of these do not describe much characterization of the processes used, a few have demonstrated that salt concentration (or conductivity), salt composition, and pH are important factors for viral clearance (Curtis et al, 2003;Strauss et al, 2009).…”

“…One important function of the AEX step is its ability to remove putative viral contaminants and impurities. Virus reduction studies investigating AEX conditions have shown the step to be highly effective at removing both enveloped and non-enveloped viruses, consistently achieving log 10 reduction values (LRVs) greater than 4 (Curtis et al, 2003;Norling et al, 2005;Shi et al, 1999bShi et al, , 2004Strauss et al, 2009;Tayot et al, 1987;Valera et al, 2003;Zolton and Padvelskis, 1984). In order to ensure that this unit operation maintains its ability to remove viruses while allowing for further development of the step, it is important to gain an understanding of the mechanisms by which AEX processes remove viruses from mAb feedstocks.…”