Downstream Processing

Capture of CH1-Containing Bispecific Antibodies: Evaluating an Alternative to Protein A

Bispecific antibodies (BsAbs) are designed to recognize and bind two different antigens, in many cases for the purpose of immune effector-cell activation to destroy cancer cells (1). Such BsAbs mediate cell killing by binding simultaneously to an antigen that is overexpressed on tumor cells and to the CD3 receptor, activating cytotoxic T lymphocytes (2). Using proprietary UniRat human heavy-chain technology combined with OmniFlic human fixed–light-chain antibody technology licensed from Ligand Pharmaceuticals, Teneobio has produced several bispecific antibodies, each targeting a…

Dynamic Binding Capacities of Protein A Resins for Antibody Capture: A Comparative Evaluation

The dynamic binding capacity (DBC) of a chromatography resin represents the total amount of target protein that the resin will bind under actual flow conditions before significant breakthrough of unbound protein occurs. This is a useful parameter for predicting what the process performance of a resin will be in actual use. DBC affects the overall amount of resin that can be packed in a given column for a process — and the number of batches that can be processed cost-effectively…

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…

Setting a Cornerstone for Platform Purification of Exosomes

Exosomes are a subject of rapidly growing therapeutic interest in the biopharmaceutical industry for two principal reasons. The first reason is that they are the primary communicators of instructions from source cells to target cells. Exosome surface features define their destination. They recognize complementary features on target cells, dock with them, and deliver their programmed instructions in the form of microRNA. The second reason is that exosomes are immunologically silent. As normal human cell products, and by contrast with gene…

Ask the Expert: Highly Sensitive Host-Cell Protein Analyses Using Novel Chromatography Technology

Geert Van Raemdonck (global field support expert at PharmaFluidics) and Koen Sandra (scientific director of the Research Institution for Chromatography, RIC) teamed up for a 10 October 2019 “Ask the Expert” webinar to introduce micro Pillar Array Column (μPAC™) technology for liquid chromatography–mass spectrometry (LC–MS) for host-cell protein (HCP) detection. Van Raemdonck explained that μPAC technology approaches chromatography differently than does packed-bed technology. Microfluidic channels with arrays of free-standing pillars are etched lithographically into a silicon wafer. The resulting permeability…

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…

Adenovirus Downstream Process Intensification: Implementation of a Membrane Adsorber

Historically, companies developing vaccines have used attenuated pathogens, inactivated infectious agents, or antigenic constituents purified from pathogenic sources. In the past 20 years, technological advances such as recombination and viral vectors, have enabled development of vaccines against diseases with previously no available treatments (1). Viral vectors have become one of the most rapidly evolving and promising fields in vaccinology and regenerative medicine. In addition to preventing infectious disease, they have a broad range of potential applications, including treatment of hereditary…

Addressing Regulatory Requirements for Filter Integrity Testing

Filter integrity is a fundamental element of sterility assurance during production of biopharmaceutical and vaccine products. Integrity test results are a key foundation for drug lot release, so any external element that could affect their reliability must be viewed as a critical issue. But when should a filter integrity test be performed? This article highlights the Sartocheck 5 Plus filter integrity tester as a means to address regulatory requirements. Please fill out the form below to read the full article…

Rapid Mammalian Cell Harvest Without Centrifugation for Antibody Purification: Using a Novel System for Cell Culture Media Clarification

Monoclonal antibody (MAb) expression systems typically use signal peptides to ensure secretion of antibodies into cell culture media. Although that reduces the complexity of purification and prevents the need for cell disruption, it does require using expensive and time-consuming techniques to separate cells from antibody-containing cell culture fluids. In this study, we describe our tests of the novel Sartoclear Dynamics Lab V system (Sartorius S Lab Instruments GmbH and Co. KG) for rapid clarification of cell culture media without requiring…

Rapid Implementation of Novel Affinity Purification: Manufacture of Commercial-Scale Next-Generation Antibody Therapies

The rapid and cost-effective production of conventional monoclonal antibodies (MAbs) for clinical trials and commercial supply has contributed toward their wide adoption. Production processes have become more efficient because common purification processes are being used across structurally similar MAbs during key steps of process development and manufacturing. Such successful platform approaches can remove unwanted impurities and are stable across processing conditions, irrespective of the MAb being purified. In addition, they are readily available at the required volume to support large-scale…