Cell-culture media is critical to the production of biologic drugs, including cell and gene therapies. Initially, media makers focused on increasing yield and productivity for protein-based applications. Today, productivity is high enough that downstream processing has become the bottleneck. Media manufacturers have thus turned their attention to improving the consistency and quality of protein expression. For therapeutic cells and viruses, yield and productivity continues to be a critical area of focus in addition to downstream processing. Several leading producers spoke with Cynthia Challener, editor of the Pharmaceutical Sciences, Manufacturing & Marketplace Report, about their efforts with respect to media development. Participants included Melanie Brandl, head of global marketing for cell culture media and supplements at EMD Millipore; Gautam Choudhary, associate vice-president, Gibco Cell Culture Bioproduction with Life Technologies; Willem Folkerts, clinical technologies portfolio and global marketing head, and Alexis Bossie, head of media R&D , both with Lonza Bioscience; and Bruce Lehr, director of cell sciences and development with SAFC.
Optimization of performance
Pharmaceutical Sciences, Manufacturing and Marketplace Report: What are the major trends in the development of cell-culture media today?
Choudhary (Life Technologies): All suppliers are moving toward chemically defined formulations that are also made from animal-origin free (AOF) components. Additionally, there is a growing trend toward the development of optimized platforms for media trains and a continued drive toward greater process yields through higher producing titer systems.
Lehr (SAFC): The focus has switched to product quality and the determination of how different media characteristics affect product quality, such as glycosylation patterns. This issue is of particular importance for biosimilar manufacture, where a major requirement is the ability to demonstrate that the biosimilar matches the branded drug as much as possible. Other trends include a growing interest in flexible manufacturing processes and the use of disposable equipment and the emerging use of perfusion systems.
Brandl (EMD Millipore): Media and feed platforms are developed to ease fast optimization of each fed-batch process respecting different cell-clone requirements. The success of the platform is linked to the formulation, but is also strongly dependent on the quality and safety profiles of cell-culture raw materials. Improvements in the solubility of single components are targeted to increase concentration levels and media performance.
Bossie (Lonza): For protein media, which is well-established, the focus is on optimization for platform cell lines to give high yields and desired protein characteristics, such as aggregation, glycosylation, and folding. For stem-cell media, and particularly pluripotent or mesenchymal stem cells, the media needs to be designed so that the desired highly specialized cells proliferate but do not differentiate until they are supposed to. The industry is driving towards xeno-free formulations here as well. Primary cells also require highly specialized media that provides proliferation without loss of function.
Managing raw materials
Pharmaceutical Sciences, Manufacturing and Marketplace Report: What approaches are being adopted to address upstream manufacturing process/material issues?
Brandl (EMD Millipore): Raw materials have to undergo defined qualification processes to secure quality, origin, and consistency in their manufacturing, including evaluation of serial amplification assays to check impurity impacts, trace elements, and the effect that individual components have on product quality. Beyond standard vendor qualification, EMD Millipore applies its pharmaceutical ingredient qualification expertise to bring the raw-material topic to the next level.
Bossie (Lonza): Verification of raw materials is necessary to ensure that they are not only of the required grade, but also “fit-for-use,” meaning ensuring that the raw materials function as needed. Today, Lonza is doing a lot more testing, particularly related to building capabilities for cell characterization and determination of how media impacts cell performance. Some of the tests include evaluation of cell-surface markers and the production of cytokines, growth factors, and other cell products that are indicative of cell behavior.
Folkerts (Lonza): Pharmaceutical industry customers want the therapeutic cells manufactured in clinical trials to be the same as those produced on a commercial scale. Therefore, an understanding of the impact of culture media is very important for obtaining better consistency from batch to batch.
Choudhary (Life Technologies): At Life Technologies, we have a robust vendor- management program. Individual components are scored for risk and processes have been put in place to mitigate any concerns. Additionally, analytical tools are employed to verify the composition of components.
Lehr (SAFC): Raw materials have become critical to media manufacturing and development. Pharmaceutical companies want more transparency, so they can follow the complete supply chain. In response to this growing need, SAFC has developed novel biological assays and evaluation technologies to ensure that all raw materials are appropriate for cell-culture applications. We are also collaborating closely with our customers and suppliers and working to develop methods for identifying all of the chemicals in formulated media, which can consist of up to 70 components.
Pharmaceutical Sciences, Manufacturing and Marketplace Report: What advances in cell- culture media can be expected in the near future? What about long term?
Lehr (SAFC): Pharmaceutical companies are looking for improved efficiency with respect to the formulation of chemically defined media for fed-batch operations. They are looking for good base media that can be used throughout production with their platform cell lines and use tweaks to feeds to optimize each different cell line. With the increased use of perfusion, there is also a need for media that is formulated specifically for those processes
Bossie (Lonza): In cell therapy, there is a move away from adherent technologies to the use of suspension systems that are similar to the systems used for protein production. The use of suspension systems will enable easier scale-up and also reduce the cost of manufacturing. These systems will require different media, particularly given the fragile and sensitive nature of the cells.
Choudhary (Life Technologies): Base cell-culture media continue to be improved upon, but there will likely be a point reached when the incremental benefits are minimal. However, functional additives focused on product quality, titer, and product safety look to become the focus for the future.
Brandl (EMD Millipore): Efforts are being made to achieve complete elimination of undefined components and at the same time gain better knowledge about the individual components and how they impact product quality. We also expect to see novel ingredients that dissolve easier and have better uptake profiles as well as improvements in the ability to control cell metabolism (e.g., lactate control). Other approaches are to make media safer with respect to any type of adventitious agents such as viruses, which is economical on the upstream side of the process.
Collaborations and product developments
Pharmaceutical Sciences, Manufacturing and Marketplace Report: What activities has your company pursued recently with respect to cell-culture media?
Folkerts (Lonza): Most recently, Lonza formed a collaboration with Sartorius Stedim Biotech (SSB) in which SSB will assume global sales and marketing of media and buffers used in the manufacture of protein-based therapeutics and vaccines while Lonza will continue to carry out development and manufacturing of these products. The media will be packaged in ready-to-use, prefilled SSB sterile single-use bags. The ability to offer fully integrated single-use solutions for the entire cell-culture process provides a real benefit to customers.
Bossie (Lonza): Lonza has also been awarded two separate contracts by the National Institutes of Health Center for Regenerative Medicine to produce induced pluripotent stem cells (iPSCs) for research purposes and clinical grade under current good manufacturing practices.
Brandl (EMD Millipore): EMD Millipore recently launched a new CHO media product as part of our platform development effort that offers a complete solution for cell-culture batch, fed-batch, and perfusion processes. Produced as a top quality dry powder in our cGMP-compliant manufacturing facility, it has shown equivalent or superior cell growth and production compared to several other commercially available media and demonstrated impressive purity and consistency, which is an important consideration in optimizing bioprocess control, especially in the rapidly emerging biosimilars production market.
Choudhary (Life Technologies): Life Technologies has developed and launched a pH-neutral, highly-concentrated additive designed to keep specific productivity high late in culture. This additive is also designed to have minimal impact on product quality. We also continue to expand our media format by adding highly-concentrated additives that not only enhance titer but are also easy to use.
Lehr (SAFC): SAFC’s Zinc Finger technology allows for genetic manipulations so that certain genes that control glycosylation (related to molecule antigenicity) can be knocked out and cell lines improved. We are also developing targeted integration as an improvement over random integration. It can speed up the process and enables control of gene placement for more controlled expression, which leads to both performance and regulatory benefits.
To meet our customers’ expectations for more efficient media development, we have adopted high-throughput systems for the rapid screening of hundreds of combinations of media products and feeds. The use of multivariate analysis and a design of experiment approach are also making it possible to identify key components and their impacts on media performance and protein quality.