Monoclonal antibody (mAb) manufacturing processes typically contain several steps that are evaluated for their ability to remove or inactivate viruses that may be present in the process material.
The availability of cleaner virus stocks for virus clearance studies has raised the question of what level of virus purity is best suited for virus clearance evaluations of various unit operations. One approach is to use minimally purified virus spikes for testing unit operations that come early in a drug manufacturing process and spikes of higher purity for testing of later steps.
An alternative technique would be to use highly purified stocks for all tests because less purified virus stocks have the potential to distort performance of any unit operation, thus making the scaled-down model less representative of the manufacturing process.
A study was conducted to investigate whether highly purified spikes are appropriate for use in evaluations of several different types of virus clearance operations.
Parvovirus and retrovirus stocks of two different purities were produced and used as virus spikes for low pH virus inactivation, anion exchange (AEX) flow-through chromatography, and virus filtration operations. The effects on virus reduction as well as unit operation performance were measured.
Results showed that the less purified virus spikes adversely affected the performance of the scaled-down models, but levels of virus reduction across the unit operations were not influenced by spike purity. This suggests that highly purified spikes are well suited for use in evaluation of various types of virus clearance operations.