Bracketed generic inactivation of rodent retroviruses by low pH treatment for monoclonal antibodies and recombinant proteins

Abstract

Viral safety is a predominant concern for monoclonal antibodies (mAbs) and other recombinant proteins (RPs) with pharmaceutical applications. Certain commercial purification modules, such as nanofiltration and low-pH inactivation, have been observed to reliably clear greater than 4 log(10) of large enveloped viruses, including endogenous retrovirus. The concept of "bracketed generic clearance" has been proposed for these steps if it could be prospectively demonstrated that viral log(10) reduction value (LRV) is not impacted by operating parameters that can vary, within a reasonable range, between commercial processes. In the case of low-pH inactivation, a common step in mAb purification processes employed after protein A affinity chromatography, these parameters would include pH, time and temperature of incubation, the content of salts, protein concentration, aggregates, impurities, model protein pI, and buffer composition. In this report, we define bracketed generic clearance conditions, using a prospectively defined bracket/matrix approach, where low-pH inactivation consistently achieves >or=4.6 log(10) clearance of xenotropic murine leukemia virus (X-MLV), a model for rodent endogenous retrovirus. The mechanism of retrovirus inactivation by low-pH treatment was also investigated.

Recovery and purification process development for monoclonal antibody production

“…Mammalian cells used in the manufacture of mAbs and other therapeutic recombinant proteins produce endogenous retroviruses and are occasionally infected with adventitious viruses during processing. 101 Due to safety requirements, mammalian cell-derived products may contain less than one virus particle per million doses. This typically translates to approximately 12-18 log 10 clearance of endogenous retroviruses and 6 log 10 clearance for adventitious viruses.…”

Antiviral effect of arginine against herpes simplex virus type 1

“…Arginine showed a synergistic effect on virus inactivation with low pH or increased temperature. Virus inactivation is a critical step for biopharmaceutical production (6), indicating the usefulness of arginine for virus clearance, although the mechanism of enhanced virus inactivation by arginine is unclear.…”

Discovery and Characterization of a Peptide Motif That Specifically Recognizes a Non-native Conformation of Human IgG Induced by Acidic pH Conditions

“…Acidic pH conditions are not only used for elution of IgG from the Protein A column, but are also used as a method for eradicating virus contamination (2,13). It has been reported that, when antibodies are exposed to acidic pH conditions, a conformer with properties that are different to normal IgG is generated (14).…”