Viral Clearance

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…

Evaluating Adsorptive Filtration As a Unit Operation for Virus Removal

To date, the majority of recombinant monoclonal antibodies (MAbs) have been produced by mammalian cells. During such production processes, the potential risk of entrained viruses must be critically considered (1). Contamination can arise from animal cell lines or from adventitious viruses introduced during manufacturing. To ensure the viral safety of biotechnology products, companies can take four complementary approaches (2, 3): Using animal-component–free raw materials wherever possible Virus testing of master cell banks Virus testing of unprocessed harvest Performing downscale virus…

Fundamental Strategies for Viral Clearance – Part 1: Exploring the Regulatory Implications

Over the past several decades, biologics such as monoclonal antibodies (MAbs) and recombinant proteins have provided therapeutic benefits and efficacy for the treatment of human disease. Completion of the human genome project (launched in 1990) produced a draft of the genome in 2001. A full sequence was published on the 50th anniversary (2003) of the initial publication of Watson and Crick’s papers on the double-helical structure of DNA (1). That large volume of genetic information has been translated into usable…

IgM Purification with Hydroxyapatite

Hydroxyapatite (HA) has a long and successful history in the field of antibody purification, and it has worked well for immunoglobulin M (IgM) monoclonal antibodies (MAbs) (1,2,3,4,5,6,7,8). Applications range from initial capture to intermediate purification to final polishing. HA is best known for its superior ability to reduce antibody aggregates, but it also supports excellent reduction of DNA, viruses, and endotoxins. As IgM MAbs exhibit increasing potential in the fields of cancer and infectious disease and in stem-cell therapies, HA’s…

Impact of Process Interruption on Virus Retention of Small-Virus Filters

Manufacturers of biopharmaceuticals using mammalian cell culture must have processes in place to minimize the likelihood of virus contamination of their products. Regulatory agencies provide guidelines for testing strategies and best practices to assure raw-material safety and control of the manufacturing process. Safety assurance relies on an interdependent matrix of managed risks, including characterization and control of raw materials, extensive testing of process intermediates, and demonstration of the virus removal capabilities of purification unit operations Figure 1:  () A dedicated…

Virus Risk Mitigation for Raw Materials

Recombinant protein–based medicinal products and modern cell-based vaccines have a very strong safety history with respect to viral and microbial contamination. However, virus contamination incidents do occur occasionally in manufacturing processes, and they can consume many resources and be expensive to rectify. The root cause of contamination incidents in recent years is most likely the use of contaminated raw materials. These include bovine serum contaminated with reovirus, epizootic hemorrhagic disease virus, Cache valley virus or vesivirus 2117; porcine trypsin contaminated…

Development Strategies for Novel Vaccines for Infectious Diseases

In a vaccine development program, the probability of success at each transition decreases, even though the actual probability of moving from one phase to another can be 50–80% (Figure 1). Many compounds and vaccine candidates are screened out even before they get into preclinical studies. Developers can implement different approaches to reduce product failure risk before a program gets expensive, including Establishing a product development plan (PDP) Identifying and mitigating risk with gap analysis Learning from the mistakes of others…

Industry Adoption of Membrane Adsorbers

Membrane adsorbers (MAs) are the fastest-growing segment in single-use bioprocessing. But their future is not entirely certain. According to BioPlan Associates’ latest survey of biopharmaceutical manufacturing, the MA market has been growing at ~20% annually since 2006 (1). Paradoxically, however, the segment may not be a true “rising star.” Our study also shows that MAs remain among the least-often adopted devices among biomanufacturers. So the question of how and whether MA technology can revolutionize bioprocessing remains open. Market for Membrane…

Simpler and More Efficient Viral Vaccine Manufacturing

Human and veterinary vaccines are divided into five main categories: conjugate, toxoid, subunit, inactivated (killed), and live (attenuated) vaccines (1). The vast majority of currently licensed human and veterinary vaccines are inactivated or live (2, 3). They are produced mostly using adherent cells: primary cells such as chicken embryo fibroblasts (CEF), human diploid cells such as MRC-5, or continuous cell lines such as Vero and MDCK (4). The pioneering legacy inherited by vaccine manufacturing development has led to strategies for…