Virus filter scalability: Demonstration of consistent viral clearance across laboratory and manufacturing scales.

Virus removal filtration processes in biopharmaceutical manufacturing are developed, optimized and validated for viral clearance using laboratory scale filters. Thus, the scalability of these filters is critical for accurately extrapolating filtration performance and reliably extending viral clearance to manufacturing scale. Virus removal filter manufacturers generally validate scalability of filtration performance based on various filtration parameters, and virus removal capability is extended to manufacturing scale filters using inert, size-appropriate particles such as gold nanoparticles to avoid the risks associated with using mammalian viruses in large feed volumes. In this study, we use bacteriophage PP7 as a parvovirus model to directly demonstrate viral clearance on Planova™ BioEX virus removal filters across all scales, including manufacturing scale. Filters with hollow fibers from three spinning series with filter sizes ranging from 0.0003 to 4.0 m2 were tested for virus removal, flux, and protein recovery performance using BSA spiked with PP7. Complete viral clearance was observed across all filter sizes with PP7 LRV of ≥4.7 or higher. Flux and protein recovery were also consistent. These results demonstrate the scalability of filtration performance and consistent virus removal at all sizes, supporting the use of laboratory scale filters to validate viral clearance at manufacturing scales.

Characterizing the impact of pressure on virus filtration processes and establishing design spaces to ensure effective parvovirus removal.

Virus filtration provides robust removal of potential viral contaminants and is a critical step during the manufacture of biotherapeutic products. However, recent studies have shown that small virus removal can be impacted by low operating pressure and depressurization. To better understand the impact of these conditions and to define robust virus filtration design spaces, we conducted multivariate analyses to evaluate parvovirus removal over wide ranges of operating pressure, solution pH, and conductivity for three mAb products on Planova™ BioEX and 20N filters. Pressure ranges from 0.69 to 3.43 bar (10.0-49.7 psi) for Planova BioEX filters and from 0.50 to 1.10 bar (7.3 to 16.0 psi) for Planova 20N filters were identified as ranges over which effective removal of parvovirus is achieved for different products over wide ranges of pH and conductivity. Viral clearance at operating pressure below the robust pressure range suggests that effective parvovirus removal can be achieved at low pressure but that Minute virus of mice (MVM) logarithmic reduction value (LRV) results may be impacted by product and solution conditions. These results establish robust design spaces for Planova BioEX and 20N filters where high parvovirus clearance can be expected for most antibody products and provide further understanding of viral clearance mechanisms. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:1294-1302, 2017.