Viral Clearance

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…

Viral Risk Mitigation: A Global Regulatory Perspective

The production of biologics will always have the risk of viral contamination. Manufacturers have developed a multitiered approach — tailored to individual processes — to prevent adventitious viruses from entering production processes, detect contamination in raw materials and process intermediates, and remove viruses in downstream purification. This article provides an overview of the global regulatory framework to ensure the viral safety of biologics. Past Contamination Events Past contamination events have resulted in corrective and preventative actions to reduce the risk…

Virus Segregation During Purification Processes: Calculation of Critical Potential Carryover of Viruses

Before a pharmaceutical product is introduced into humans, either in a clinical trial or as a marketed product, virus safety must be evaluated carefully. Virus safety normally is ensured using a three step complementary approach: selecting and testing cell lines and/or raw materials for the absence of viruses, testing the product at appropriate steps of production, and assessing the capacity of a production process to clear infectious viruses (1). The latter (also referred to as viral clearance) is the subject herein. Spiking studies are conducted to evaluate the capacity of a purification…

Advanced Viral Clearance Study Design: A Total Viral Challenge Approach to Virus Filtration

Biologics derived from mammalian organisms have been accepted for therapeutic use for almost a century (1). However, these pharmaceuticals have the potential for contamination with pathogenic adventitious agents such as viruses. With cell-line–derived recombinant proteins, the viral risks commonly include viruses in the Retroviridae and Parvoviridae families (2). As patient safety and manufacturing facility suitability became significant concerns in the 1980s and 1990s, several industry and regulatory bodies reached consensus on how to approach the unique challenges of viral safety…

Evaluating Adsorptive Filtration As a Unit Operation for Virus Removal

Most recombinant monoclonal antibodies (MAbs) are produced by mammalian cells. Because biopharmaceuticals derived from mammalian tissue culture carry the risk of adventitious virus contamination, regulatory agencies expect risk-mitigation strategies to include validation of purification unit operations for their ability to clear viruses (1). Guidelines from the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) describe how to prove viral clearance in downstream purification processes using an orthogonal approach (2). Viral log10 reduction values (LRVs) are…

Current Thinking in Viral Safety: Risk Management Protects Patients

BPI’s editor in chief S. Anne Montgomery recently caught up with long-time editorial advisor Hazel Aranha (purification technologies technology expert for Sartorius Stedim Biotech, North America). They discussed a number of topics related to viral safety. Montgomery: What is the current thinking regarding virus-safety assurance in biopharmaceutical manufacturing? How is the industry preventing viral contamination? Aranha: The “holy grail” of viral safety — absolute freedom from extraneous agents or residual pathogenicity — is a myth. That said, biopharmaceutical products have…

Viral Clearance in Antibody Purification Using Tentacle Ion Exchangers

Manufacturers strive toward cost-effective purification of target molecules and a high level of confidence that their biologics are safe and not compromised by the presence of endogenous retrovirus-like particles or adventitious viruses (1). Reliable reduction of viral particles throughout downstream purification processes must be ensured through different techniques such as chemical treatment, filtration, and chromatography. Common monoclonal antibody (MAb) purification schemes use both cation- and anion-exchange chromatography steps (CEX, AEX). Although CEX (to remove product- and process-related impurities) is not…

Virus-Filtration Process Development Optimization: The Key to a More Efficient and Cost-Effective Step

Size-exclusion–based parvovirus filtration is an important step toward drug product safety in biopharmaceutical production. However, once a virus filter is in place, and the required virus safety is ensured, less attention typically is paid to its optimization within the process. That might seem odd given that virus filtration can be one of the more expensive downstream processing steps ($/g protein processed). Most likely, the lack of attention can be attributed to aggressive timelines, limited process development resources, and the virus…

Identification and Quantification of Heat-Shock Protein 70: A Major Host-Cell Protein Contaminant from HEK Host Cells

Recombinant therapeutic proteins are commonly produced by cell lines such as Chinese hamster ovary (CHO), human embryonic kidney (HEK) 293, murine myeloma (NS0), and Escherichia coli bacterial cells. Host-cell proteins (HCPs) are indigenous proteins produced by those expression hosts and considered to be process-related impurities generated from the cell culture process (1). HCPs are potentially harmful and immunogenic to patients, and they can compromise the stability of protein drugs (2–4). For those reasons, HCPs must be consistently removed or reduced…

Fundamental Strategies for Viral Clearance Part 2: Technical Approaches

Viral safety is required for biologics manufactured to treat human diseases. Although significant improvements in ensuring viral safety have been made over the past few decades, “zero risk” of viral contamination is a myth. Viral contamination risk can be carefully managed by screening raw materials, testing process intermediates, and evaluating how effectively manufacturing processes remove and inactivate viruses. Viral clearance studies verify virus removal or inactivation by a manufacturing process. Although regulatory agencies have expectations for the designs of those…