Viral Clearance

Biosimilars, Oxidative Damage, and Unwanted Immunogenicity

Concerns about the economic viability of biosimilars center on their high development cost relative to small-molecule generics, along with (and partly because of) the difficulty in demonstrating bioequivalence for these complex molecules. Immunogenicity is a particular area of increasing vigilance at both the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) (1, 2). Unwanted immunogenicity is an underlying cause of multiple deleterious effects for all protein-based therapeutics — including loss of efficacy, altered pharmacokinetics, and reduced…

“Transformation By Infection”

Every bioprocess begins with an expression system, and every expression system begins with DNA transfection. Derived from transformation and infection, the word paradoxically has come to be applied mainly to nonviral methods of genetically engineering cells; viral-vector–mediated DNA transfer is often called transduction. There are chemical, particulate, physical/mechanical, and viral means of getting new genetic material into a cell, and that DNA may take a number of different forms. Even the cloning method (pictured right) using a microscopic needle to…

Artifacts of Virus Filter Validation

Virus filters are used in biomanufacturing to ensure the safety of biopharmaceutical drug products. As part of filter implementation, manufacturers are required to validate that the filtration process can indeed remove virus. Validations are typically performed at contract testing organizations (CTOs) that are “equipped for virological work and performed by staff with virological expertise in conjunction with production personnel involved in designing and preparing a scaled-down version of the purification process” (1). Virus removal capability of a filtration process is…

Implementing Disposable Sampling Devices for Fully Autoclaved Equipment

Sampling is used extensively to monitor both behavior and quality throughout biopharmaceutical processesing (1, 2). Methods must deliver representative samples and — more important — not compromise the integrity of a given unit operation or the process of which it is part. When microorganisms, animal cells, viruses, or nonfilterable materials are involved, sampling methods must not introduce contamination (see the “Regulatory Requirements” box). For successful sampling, three methods have been used routinely over the years: steam-in-place (SIP) valves; aseptic tube…

Performance of a Salt-Tolerant Membrane Adsorber in Flow-Through Mode

Monoclonal antibodies (MAbs) have become the most prevalent therapeutics in the biopharmaceutical industry. Their downstream purification typically involves protein A chromatography as a capture step followed by one or two additional chromatographic polishing steps. Additional unit operations dedicated specifically for viral clearance (e.g., viral inactivation and filtration) are added to ensure product safety. According to a survey of Amgen processes, after processing through a protein A column, only trace amounts of impurities such as Chinese hamster ovary cell protein (CHOP)…

Rapid Detection of Pandemics

A Coronavirus — like severe acute respiratory syndrome (SARS) — is back in the headlines. On returning from a trip to Saudi Arabia in summer 2012, a Qatari national was struck down by a mystery respiratory illness. Because of inadequate diagnostic capabilities, the patient was transferred from Qatar to London for intensive-care treatment and diagnosis. The UK Health Protection Agency (HPA) confirmed infection with the same Coronavirus strain discovered by a Dutch team following the death of a Saudi national…

Retention of Highly Penetrative A. laidlawii Mycoplasma Cells

    Mycoplasma are infamous for contaminating cell culture lines at rates as high as 80% (1,2,3,4,5). For biopharmaceutical processes, the inadvertent use of contaminated culture medium or medium components can lead to contamination of an aseptic process-validation media fill or cell culture medium for a bioreactor (6,7,8,9,10,11). Thoroughly testing medium components before use is generally impractical because of the large volume of material in use. Frequently, culture media cannot be autoclaved (because of the presence of heat-sensitive components or…

Current Issues in Assuring Virological Safety of Biopharmaceuticals

The weakest link in the chain is also the strongest. It can break the chain.— Stanislaw Jerzy Lec, Polish writer, poet and satirist (1906–1966) Biologicals ushered in a new era for treating debilitating and life-threatening illnesses. According to a Pharmaceutical Research and Manufacturers of America (PhRMA) 2011 report, more than 900 biotech medicines and vaccines are in development that are targeting more than 100 diseases (1). Market researchers expect annual sales of biologics (now at about US$100 billion) to grow…