Cell Line Development

Guidelines for Choosing the Right mAb Cell Line - Part 2

Developing a mAb? Have you considered these cell line development factors? Let EirGenix’s experience and wisdom guide you towards success!


Monoclonal antibodies (mAbs) are powerful tools for diagnosing and treating various diseases and have revolutionized the field of medicine and biotechnology. Constructing one begins with selecting the optimum cell line. In this article, we'll explore how EirGenix can optimize the process of selecting a monoclonal antibody cell line so that you develop a better and more cost-effective mAb.

As we stated in Part 1 of this series, choosing the right monoclonal antibody cell line matters. Different cell lines have distinct characteristics, and the choice of a cell line can significantly impact the binding affinity and specificity of your mAb. Some cell lines are known for their high antibody production rates, while others may be slower or less efficient. Also, different cell lines may have varying levels of acceptance by regulatory agencies.

A well-characterized, stable cell line can help maintain the consistency of your mAb production over time. You may ask, what is a “well-characterized, stable cell line?“ A well-characterized, stable cell line for a monoclonal antibody is a cell line that has been genetically engineered to produce a specific antibody with high yield, stability, and purity. A well-characterized cell line should also have a well-defined genetic background, a minimal risk of contamination, and a consistent performance in different culture conditions. Variability in cell line behavior can lead to inconsistencies in antibody quality.

The speed of development is also a critical consideration. EirGenix has a proven system to accelerate our timelines for Cell Line Development, as stated earlier, to achieve DNA to Research Cell Bank (RCB) in 12 weeks.

However, regardless of the cell line chosen, it is important to optimize the expression vector, the transfection and selection methods, the clone isolation and screening techniques, and the culture conditions to ensure the best quality and quantity of the antibody. We will discuss this further below.

 

Cell line system

At EirGenix, other than the commercially available cell line made from CHO cells, such as CHO-S which could come with royalty payments down the road (that could affect your commercial cost of goods), we offer our established expression platforms, EG CHO-K1 and EG CHO-GS. These are great alternatives with promising productivity and stability along with a royalty-free license.* Moreover, EG-established cell lines are Master Cell Bankable (MCB) (cGMP grade) with a fully characterized and comprehensive record of successful projects, providing you with trust and assurance in cell line development. Better yet, they offer a consistent productivity of 3-6 g/L for a standard mAbs platform which the average titer has been proven through many projects.

Culture Media

Ensuring the selection of appropriate growth media and maintaining consistent process conditions is pivotal for producing high-quality, high-yield therapeutic antibodies. Striking a balance among media, production processes, and optimal clones is crucial for reliable robust cell growth and scalable processes. In our approach, we combined commercial chemically defined cell culture media with proprietary feeding strategies within a standard CHO cell production process. We also adopted a multi-scale approach, utilizing both a traditional shaker flask method and the Ambr®15 mini bioreactor platform for screening media and culture conditions. This comprehensive strategy is designed to ensure optimal process performance, emphasizing both product titer and quality.

Vectors and signal peptide selection

The EirGenix cell line development platform also encompasses our proprietary expression vectors, specifically designed to enhance and stabilize gene expression for a wide range of molecules with various modalities. The proprietary expression vector not only improves gene expression efficiency but also features a proprietary signal peptide promoting more efficient cleavage and thus reducing peptide-related impurities. This platform is tailored to help you develop the optimal process for your molecules.

Single cell cloning and monoclonality

It is important in clone selection to use a single-cell printer and image system to guarantee monoclonality. Unlike at other CDMOs, EirGenix uses an automated workstation, in conjunction with the high-throughput titer detection system, to enhance the efficiency of the clone selection workflow. The single-cell cloning technology ensures high-confidence monoclonality and provides essential evidence for regulatory submissions. Eventually, the incorporation of automated technologies streamlines and accelerates the cell line development process, leading to enhanced efficiency and reduced unpredictability in your production process.

Cell line stability

As stated in part 1 of the article, Cell Line stability and regulatory acceptance are critical factors. At EirGenix, we have proven data that shows that over 75% of clones remain stable to the 60th generation. The stable expression of the target protein can guarantee the cell line's ability to sustain consistent productivity, which is critical for scaling up to large bioreactor volumes or implementing perfusion systems. This reliability ensures long-term, uninterrupted production capability. Failure to have that stability means an inferior clone and could present issues down the road! We have a wealth of experience gained from successfully submitting many projects to various regulatory agencies and thus we can ensure compliance with regulatory requirements.

Case Study: monoclonal antibody

At EirGenix, across more than twenty (20) projects aimed at developing a cell line for a standard monoclonal antibody using the EG CHO K1 and EG CHO GS platform, we have successfully established a stable clone with productivity ranging from 3g/L to 6g/L. Notably, over 75% of these clones remain stable up to the 60th generation. Furthermore, for further upstream process optimization such as the Design of Experiments (DOE) or perfusion processes (e.g., N-1 process), we have achieved a productivity improvement of over 1.5-fold. Additionally, these cell lines are highly amenable to scaling up in large-scale bioreactors. This case underscores our extensive experience in monoclonal antibody cell line development.

Case Study: bi-specific antibody (application)

In a case study to develop a cell line for a bi-specific antibody utilizing EirGenix CHO-K1 cell line, we achieved establishing a monoclonal clone with protein productivity of 2.9g/L. Remarkably, the cell line exhibited stability for at least 60 generations and maintained a consistent titer range of 2.9-3g/L. Productivity has further proven to exceed 4g/L following later upstream process optimization. This case highlights our success in optimizing cell line development and upstream processes, ensuring reliable bi-specific antibody production.

Conclusion

In cell line development, the key strategies include automated high-throughput screening, parallel processing, and streamlined workflows for accelerated timelines. Achieving high yield is possible through optimized expression vector and new host cell line generation. Furthermore, media screening enhances cell growth and productivity, and easily scalable cell lines are developed for large-scale production manufacturing.

Key things to consider are:

  1. Screen for High-Performing Clones - High-Throughput Screening: Implement automated and high-throughput systems that allow for the rapid screening of a large number of clones and various modalities.
  2. Accelerated the timeline in cell line development – Use Parallel Processing: Simultaneous experiments to accelerate the discovery of promising clones and process conditions. Use Streamlined Workflows: Optimize the development platform and eliminate bottlenecks to accelerate the development timeline.
  3. Achieve High Yield – Work on construction optimization: Optimizing the combination of different components of expression vectors to improve the expression of various modalities, overcome gene silencing, and increase the stability of transgene expression.
  4. Generate new CHO cell lines - Development of cell line by isolating it from the parental host or engineering to generate a new host with a robust and improved protein production phenotype.
  5. Screen the Media: Conduct commercial medium screening in cell line development to promote higher cell growth and productivity.
  6. Ensure Cell Line Stability - Optimizing the combination of different components of expression vectors to increase the stability of transgene expression.
  7. Ensure monoclonality - Single-Cell Cloning: Utilize single-cell cloning techniques and a powerful image system to ensure monoclonality.
  8. Use easily scalable Cell Lines - Develop cell lines that are specifically adapted to suspension culture conditions with chemically defined medium for seamless scale-up. Optimize bioprocess parameters to handle higher cell concentrations and ensure consistent performance in scale-up.

These solutions combine innovative technologies, optimized construction, host cell lines, and workflows to address the challenges encountered in CHO cell line development, ultimately enabling the production of high-quality biopharmaceuticals efficiently, cost effectively, and reliably.

Consider working with EirGenix!

Are you seeking a contract development and manufacturing partner that has it all – quality, reliability, flexibility, and reasonable pricing? At EirGenix, we offer all of this and top-notch customer service. Since 2012, EirGenix has offered mammalian and microbial biopharma development and production including cell line establishment, large-scale production process development, analytical method development, and cGMP quality system operations that are certified by the US FDA, Japan PMDA, Australian TGA, Taiwan FDA, and Europe EMA. You can virtually tour our site here. We would appreciate the opportunity to collaborate with you! Click on this link to contact our BD team.

 

* Royalty-free cell lines are offered as long as the development work and manufacturing are done at EirGenix. If not, a one-time transfer fee may be charged.

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