Expression Platforms

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

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…

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

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…

A Stirred, Single-Use, Small-Scale Process Development System: Evaluation for Microbial Cultivation

Mammalian and microbial protein production platforms have been used for over 30 years to produce a number of successful biologic drugs, including monoclonal antibodies (MAbs), recombinant proteins, and therapeutic enzymes (1). Most biologics are produced by mammalian cell lines, with Chinese hamster ovary (CHO) cells being the most widely used. However, microbial cells also are used to express recombinant therapeutic proteins, and almost 30% of currently approved biologics are produced by Escherichia coli bacteria (2). With worldwide biologics sales >56…

Comparing Culture Methods in Monoclonal Antibody Production: Batch, Fed-Batch, and Perfusion

Recombinant protein manufacturing with Chinese hamster ovary (CHO) cells represents over 70% of the entire biopharmaceutical industry (1). In fact, human monoclonal antibodies (hMAbs) produced by CHO cells have played a major role in both the diagnostic and therapeutic markets for decades. One of the first human–mouse chimeric MAbs to obtain FDA approval was Roche’s rituximab treatment for non-Hodgkin’s lymphoma, chronic lymphocytic leukemia, and rheumatoid arthritis. Since that approval in 1997, scores of chimeric, humanized, and human MAbs have gained…

HCP Antigens and Antibodies from Different CHO Cell Lines

Cell lines derived from Chinese hamster ovary (CHO) cells are widely used in therapeutic protein production because they can perform human-compatible posttranslational modifications, they are easy to use for manufacturing, and they do not propagate most human pathogenic viruses (1, 2). Expressed therapeutic proteins are secreted into CHO culture supernatant along with impurities originating from the host cells themselves. Such host cell proteins (HCPs) are important contaminants for monitoring because they directly affect drug quality, safety, and efficacy. HCPs are…

Simplification of Fed-Batch Processes with a Single-Feed Strategy

Chinese hamster ovary (CHO) cells commonly are used to produce recombinant proteins such as monoclonal antibodies (MAbs) for research, diagnostic, and therapeutic purposes. Culture processes typically rely on a fed-batch approach in which a basal medium enables initial cell growth. Concentrated feeds are used to prevent nutrient depletion, thereby extending culture duration and improving cell growth, viability, and protein titer. A neutral pH feed is desirable because culture pH should remain stable after feedings. The extremely low solubility of l-tyrosine…

Rapid Development of High-Quality, Robust Mammalian Cell Culture Manufacturing Processes

With increasing industry emphasis on providing both rapid and robust processes, companies are reaping the benefits of new tools for risk management and process analytical controls. As a current example of these approaches, Fujifilm Diosynth scientists have accelerated the development process from gene to finish by shortening the timeline, incorporating quality by design (QbD) principles, and designing the process to be as robust as possible. When the Apollo mammalian expression cell line was introduced three years ago, the time from…

Fucosylation of a Therapeutic Antibody: Effects on Antibody-Dependent, Cell-Mediated Cytotoxicity (ADCC) Potency and Efficacy

Product quality attributes are critical for the functionality and manufacturability of therapeutic antibodies. They can be significantly influenced by a number of production process parameters, such as cell culture media. The composition of growth and feed media can influence antibody glycosylation, including the concentration of ammonia, glutamine, glucose, and metal ions (1, 2). Thus, it is critical during media development and optimization to monitor and consider a culture medium’s impact on glycosylation. For therapeutic antibodies whose mechanism of action includes…

A Single-Use Process for Production of Recombinant Human Follicle-Stimulating Hormone

Follicle-stimulating hormone (FSH) is a heterodimeric glycoprotein consisting of noncovalently linked α and β subunits. It stimulates the growth of immature follicles in ovaries and primary spermatocytes in testes and thus plays an important role in human reproduction (1). Human menopausal gonadotropin for infertility treatment was first introduced into clinical practice in 1950 (2, 3). Subsequently, treatments with urinary FSH have been replaced by recombinant human FSH (rh-FSH), which has been shown to provide several advantages such as absence of…

Development, Qualification, and Application of a Bioreactor Scale-Down Process: Modeling Large-Scale Microcarrier Perfusion Cell Culture

Qualified scale-down models of large-scale cell culture processes are essential to conducting studies for applications such as investigating manufacturing deviations, enhancing process understanding, and improving process robustness. For example, scale-down models can be used for raw material investigations as well as evaluation and qualification of new good manufacturing practice (GMP) cell banks for manufacturing implementation. Process characterization studies are performed also with qualified scale-down models to improve process consistency (1, 2). Often it is impractical to conduct investigational studies at…