Viral Clearance

Ask the Expert: Predicting Viral Clearance During Downstream Development

Until recently, downstream process development (PD) teams have lacked methods for easy, effective, and economical estimation of a process’s viral clearance capability. David Cetlin (senior director of R&D at Cygnus Technologies) delivered an “Ask the Expert” presentation on 13 October 2020 describing how MockV kits containing noninfectious mock-virus particles (MVPs) could fill that gap. Cetlin’s Presentation Viral clearance studies tend to be outsourced to contract research organizations (CROs) because they require biosafety level (BSL)-2 and -3 facilities for working with…

How Much Harm Can a Single Droplet Do? Considerations for a Viral Inactivation Step

Viral clearance is a fundamental aspect of viral safety for biopharmaceutical products. Regulatory agencies around the world require biomanufacturers to segregate their operations appropriately to mitigate the risks of carryover contamination from previous process steps or product batches and of crossover contamination between product(s) made in the same facility. Guidelines are vague in defining “appropriate,” leaving biomanufacturers to interpret regulatory expectations and define their own virus reduction and segregation strategies. Given the differences among manufacturing processes and facilities housing such…

Streamlined Polishing and Viral Clearance Using a New Hybrid, Biomimetic, Single-Use Anion Exchanger

Flow-through anion-exchange (AEX) chromatography is used frequently in biopharmaceutical purification processes for reduction of net–negatively charged host-cell proteins (HCPs) and viruses as part of a validated viral clearance strategy (1, 2). AEX column chromatography is the technology most often used for electrostatic viral clearance, particularly in commercial-scale biopharmaceutical manufacturing, for which columns have a long-established history of reliable and well-understood performance (3). Still, validation of HCP and viral clearance by AEX columns in biopharmaceutical processes involves complexities that contribute significantly…

A Challenge in Viral Clearance Determination: Estimation of Fifty-Percent Tissue Culture Infective Dose (TCID50) for Low Virus Concentrations

Performing viral clearance studies is an important safety element of manufacturing all biopharmaceuticals expressed from mammalian cells (1). Typically, viral clearance is described as a log reduction value (LRV) and calculated as the log10 of the ratio of input to output virus load. Amounts of virus load are calculated from the volume and concentration of input and output fractions. Virus concentration is often calculated as 50% of tissue-culture infective dose (TCID50) using the Spearman–Kärber (SK) equation (2, 3). In this…

A Response Plan for Viral Contamination in Bioproduction Facilities

The biopharmaceutical industry uses living biological systems as a platform for manufacturing of protein-based drugs, vaccines, and other therapies derived from or consisting of different cell types. On one hand, living systems are inherently susceptible to viral infection and may harbor endogenous viruses, so the potential for such contamination cannot be eliminated. On the other hand, the industry has an excellent patient-safety record. Viral safety is achieved through three fundamental measures: prevention (e.g., by selection), removal (by clearance and/or reduction),…

Detection and Clearance of Viruses in the Biopharmaceutical Industry

Viral contamination is a common threat to all animal- and human-derived biopharmaceuticals. This type of contamination can affect any part of a bioproduction process, so biomanufacturers need to perform viral testing studies and incorporate viral clearance methods into their processes. Viral contaminants can come from cell lines (e.g., endogenous retroviruses) or from adventitious (e.g., mycoplasma) introduction during drug manufacturing. Virus testing of master cell banks (MCBs), working cell banks (WCBs), end-of-production cell banks, and bulk unprocessed harvest material is called…

Monoclonal Antibody Aggregate Polish and Viral Clearance Using Hydrophobic-Interaction Chromatography

Hydrophobic Interaction chromatography (HIC) is a powerful polishing tool for the downstream purification and manufacture of biotherapeutics. HIC offers orthogonal selectivity for the clearance of difficult process and product-related impurities such as aggregates, host cell proteins and endogenous and adventitious viruses.  In this study, a family of POROS HIC resins with novel ethyl and benzyl chemistries was used to successfully polish two clinical stage monoclonal antibodies harboring very high levels of product aggregation (>10%). In addition to aggregate removal, viral…

Modeling Virus Clearance: Use of a Noninfectious Surrogate of Mouse Minute Virus As a Tool for Evaluating an Anion-Exchange Chromatography Method

Viral safety is a critical focus during biopharmaceutical manufacturing (1–5). Although well-characterized mammalian cells such as the Chinese hamster ovary (CHO) line have been used for decades, both endogenous expression of retroviral-like particles and exogenous contamination events from viruses warrant continued vigilance (6, 7). International regulatory agencies require biomanufacturers to validate the “viral clearance” efficacy of their downstream manufacturing process steps before resulting products can be awarded clinical trial or commercial approval (8–10). Currently, viral clearance testing is based on…

The Complete e-Book of Biosafety Testing

Expect the expected. But plan for the unexpected. If your Biosafety Development takes a nose dive, Eurofins Lancaster Laboratories’ team of regulatory experts and experienced scientists will help you land safely on two feet. Download The Complete e-Book of Biosafety Testing to learn more about our expertise in biologics raw materials, cell bank preparation, adventitious virus testing, viral clearance studies, next-generation sequencing, genetic stability testing, and more. This e-Book contains the following chapters: Mitigating Risk and Reducing Regulatory Scrutiny of…

Inactivation of Enveloped Viruses: Seeking Alternatives to a Problematic Surfactant

Triton X-100 detergent makes an interesting case study in bioprocess sustainability strategy. Also known as octylphenol ethoxylate (OPE), this nonionic surfactant has many uses in biopharmaceutical research and development. Among other laboratory applications, it is used to lyse cells and DNA in research, to solubilize membrane proteins and decellularize animal-derived tissues, to reduce the surface tension of aqueous solutions during immunostaining, and to remove sodium dodecyl sulfate (SDS) from polyacrylamide gel electrophoresis (PAGE) gels for analysis. It also serves as…