Cell Line Development

Enhanced Galactosylation of Monoclonal Antibodies: Using Medium Supplements and Precursors of UDP-Galactose, Part 2

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In Part 1 of this report, we described our development of a high-throughput assay for analyzing monoclonal antibody (MAb) glycans and how we used it to evaluate the effects of medium supplements on galactosylation of MAbs produced by two different cell lines (1). This month, we examine galactosylation of a MAb produced by a third cell line. A discussion follows on the benefits of this high-throughput assay before we highlight the similarities and differences in galactosylation among the three MAbs…

March 23, 2018

Therapeutic IgG-Like Bispecific Antibodies: Modular Versatility and Manufacturing Challenges, Part 2

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Monoclonal antibodies (MAbs) are bivalent and monospecific, with two antigen-binding arms that both recognize the same epitope. Bispecific and multispecific antibodies, collectively referred to herein as bispecific antibodies (bsAbs), can have two or more antigen-binding sites, which are capable of recognizing and binding two or more unique epitopes. Based on their structure, bsAbs can be divided into two broad subgroups: IgG-like bsAbs and non–IgG-like bsAbs. We have chosen to focus on the former in this review. Part one provides a…

February 16, 2018

eBook: Addressing Quality in Cell-Line Development — Direct Analysis of Bioreactor Harvest for Clone Selection and Process Optimization

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Using Direct Analysis of Bioreactor Harvest for Clone Selection and Process Optimization Therapeutic monoclonal antibodies (MAbs) mostly are manufactured using bioengineered mammalian cells cultured in a bioreactor for two to three weeks. High temperatures and an altered redox environment may compromise the quality of MAbs produced (e.g., fragmentation, truncation), as can the presence of proteases, reductases, and other chemicals released from dead cells. Thus, it would be valuable to establish analytical methods that can help cell culture groups monitor immunoglobulin…

February 15, 2018

An Approach to Generating Better Biosimilars: Considerations in Controlling Glycosylation Variability in Protein Therapeutics

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The global market for biotherapeutics has expanded extensively over the past decade and is projected to account for more than a quarter of the pharmaceutical market by 2020, with sales exceeding US$290 billion (1). Continued expansion of the biosimilar marketplace has led to many commercial opportunities and technical challenges. The biological systems used to manufacture such drug products are inherently variable — a feature that has important consequences for the reproducibility, safety, and efficacy of the resulting products. Therefore, a…

February 14, 2018

Antibody–Drug Conjugates: Fast-Track Development from Gene to Product

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In the fight against cancer, antibody–drug conjugates (ADCs) represent an increasingly important therapeutic approach. These biopharmaceuticals are designed to maximize the therapeutic index of cytotoxic small-molecule drugs through their selective delivery to tumor cells while leaving normal, healthy cells untouched. Structurally, an ADC is a monoclonal antibody (MAb) conjugated by a chemical linker to a potent cytotoxic drug. Conceptually, the MAb serves as the delivery component, targeting a specific tumor antigen that ideally is not expressed (or is expressed at…

November 16, 2017

Conditional/Inducible Gene-Expression Mouse Models Using Advanced Gene Editing

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Transgenic mouse models have been an essential part of biomedical research for many decades. They have provided valuable insights in developmental biology, gene regulation, and our understanding of the genetic basis of human disease. And they play a critical role in drug discovery and development. Traditional methods to generate these mouse models entailed a milieu of disadvantages: e.g., low efficiency, high incidence of undesirable recombination outcomes, randomly and multiply inserted genes of interest, ectopic expression, gene silencing, and insertional mutations…

March 20, 2017

Using Glycosidases to Remove, Trim, or Modify Glycans on Therapeutic Proteins

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One of the most common posttranslational modifications of eukaryotic proteins is glycosylation. Glycosylation of proteins can affect many biological activities. For therapeutic glycoproteins, it can modify biological activity, targeting, trafficking, serum half life, clearance, and recognition by receptors (1, 2). For such reasons, biomanufacturers must monitor and characterize the glycosylation patterns of their recombinant therapeutic proteins (3, 4). Therapeutic proteins have two main types of glycosylation: N-linked glycans and O-linked glycans (5). Attachment of an N-glycan starts in the endoplasmic…

February 4, 2016

Heading for a CHO Revolution: The Need for Cell Line Engineering to Improve Manufacturing Cell Lines

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The first recombinant protein licensed for use by the United States Food and Drug Administration (US FDA) was human insulin in 1982 (1). That approval was followed in 1987 by the development of tissue plasminogen activator (tPA), the first complex glycosylated protein generated in mammalian cells to be licensed for therapeutic use. Since then, this area of biology has rapidly expanded in clinics: The FDA approved an average of 15 new biological entities every year between 2006 and 2011 (2).…

January 13, 2016

Special Report: Turning Discoveries into Products — Developability Assessments and Highly Efficient Process Design

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High costs and long timelines for biopharmaceutical development are cause for reflecting on how best to allocate resources from the earliest discovery stage through critical go–no-go junctures. With inputs ranging from science, engineering, and economics, the coined term developability becomes the synthesis of answers to such questions as How well does the target represent a disease state? Does manipulating that state bring about improvement? Does the molecule behave as expected in living systems? What can be done about the emergence of independent safety, toxicology, and/or immunogenicity warning signs? Can the molecule…

October 15, 2015

Comparison of Concentration Measurement Technologies in Bioprocess Solutions

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Biopharmaceutical manufacturing involves complex process steps. Exacting production conditions are typically required to maximize the yield, purity, and quality of biological products. In recent years, process analytical technology (PAT) has been increasingly used to monitor key process and performance parameters in real time. That has enabled better control of production conditions. An important parameter required to achieve consistent results in many bioprocessing steps is solute concentration in process fluids. The Critical Need for Concentration Measurement Many biopharmaceutical manufacturing process steps require measuring…

October 15, 2015