Ensuring Cell Line Stability for Protein Therapeutics

Cell line development (CLD) plays a pivotal role in the production of biotherapeutic molecules. The primary goal during CLD is to generate and identify the most stable cell lines capable of robust production of high-quality therapeutic molecules. To achieve this, screening for both product quality and productivity is essential. Identifying and optimizing stable high-yield cell lines early contributes to accelerating the entire drug development process and the success of the pipeline.

In addition to classical biologic drugs such as monoclonal antibodies (mAbs), new therapeutic modalities are being developed at a rapid pace. These include bi-, tri-, and multi-specific antibodies, antibody-drug conjugates (ADCs), and fusion proteins such as bispecific T-cell engagers (BiTEs) and peptide-Fc proteins or peptibodies (1,2). The increasing complexity and diversity of these new modalities require innovative analytical approaches that integrate technologies such as capillary electrophoresis (CE) and mass spectrometry (MS). Integrated CE–MS technologies provide the necessary sensitivity, accuracy, and precision to monitor key product quality attributes (PQAs), detect data inconsistencies, and thus characterize, screen, and select optimal cell line clones early in the CLD process.

Managing data inconsistencies in CLD

Given the vast number of potential clones entering the development pipeline, methods to rapidly prioritize candidates are crucial. These methods must be able to quickly and precisely assess the critical quality attributes (CQAs) of the protein products to narrow down the best candidates. Chemical post-translational modifications (PTMs), such as glycosylation, deamidation, and oxidation, are considered CQAs as they often result in charge variants that affect the product’s stability, efficacy, potency, and safety. As such, PTMs must be characterized and controlled throughout the drug development pipeline.

Traditional methods such as enzyme-linked immunosorbent assays (ELISAs) have limitations in sensitivity, specificity, and coverage, which can delay the identification of inconsistencies. Identifying and mitigating data inconsistencies early in the development process is paramount during CLD to ensure the stability and efficacy of the final biotherapeutic product. The integration of CE- and MS-based technologies offers a robust solution that can significantly enhance the detection of data inconsistencies, facilitating the development of stable cell lines for bioproduction.

CE provides rapid assays that can assess key factors affecting final product stability, such as charge and glycan profiles, while MS offers precise information about key factors affecting product quality, such as molecular modifications and their localization and protein structure.

Ensuring product stability

During the manufacturing of mAbs and other complex therapeutics, heterogeneity can arise from enzymatic cleavage and PTMs. Ensuring stability and consistency in therapeutic protein production necessitates meticulous monitoring and control of PTMs and genetic mutations. Moreover, the early detection and characterization of these PTMs during CLD can prevent costly and time-consuming issues later in the production process.

The final therapeutic product can be affected by changes induced by various cell processing and growth conditions, which, therefore, must be comprehensively understood. Alterations in titer, cell culture media, and other process conditions can induce PTMs that affect the stability and activity of the final protein product. Therefore, gathering comprehensive information about key quality attributes, including PTMs, is crucial to understanding the stability of proteins produced by cell lines.

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References

1. SCIEX. Improving the mAb Characterization Process. Whitepaper. Feb. 8, 2024.
2. Zhang, Z.; McCloskey, R. Untangling the Identity of Charge Variants in Antibody-Drug Conjugates. PharmacyTimes.com, Jan. 31, 2024.

About the authors

Roxana McCloskey is senior global marketing manager, Protein Therapeutics, and Zoe Zhang is manager, Biopharma Applications; both at SCIEX.

Article details

BioPharm International®
eBook: Emerging Therapies
September 2024
Pages: 8–15

Citation

When referring to this article, please cite it as McCloskey, R; Zhang, Z. Ensuring Cell Line Stability for Protein Therapeutics. BioPharm International Emerging Therapies eBook, September 2024.