A Case Study
To demonstrate the feasibility of using single-use technology at various steps throughout the biomanufacturing process, we
cite below a case study on the usage of disposable bioreactors.
The Challenge
A biotechnology company developing monoclonal antibody-based therapies, approached us to produce preclinical material for
toxicology studies and cGMP material for Phase 1 studies. The client company had a well-developed process that was ready for
technology transfer. The company had completed cell line and media development and was successful in scaling up to small-scale
(5 L) bench-top bioreactors. However, they had no capability for large-scale production. The client wanted us to complete
technology transfer and generate toxicology materials within six months, followed by production of Phase 1 materials within
nine months.
The Solution
The amount of cGMP therapeutic material required for Phase 1 stipulated that we use a 2000-L stirred-tank bioreactor. We developed
a successful process flow starting with a vial of master cell bank cells and scaled them up in sequence in Wave 20-L, 50-L,
200-L and 1000-L bioreactors to inoculate our 2000-L stirred-tank bioreactor for production.
One of our challenges in the process was to scale up the high density and high antibody yielding CHO cells in the 1000-L Wave
bioreactor to generate inoculum for the 2000-L stirred-tank bioreactor. To sustain the maximum viability of the cells in this
large vessel, we achieved the optimal mixing speed by adjusting both the angle of rocking and the rock rate. Using this model,
we prepared the entire seed train using Wave disposable bioreactors and generated inoculum for the 2000-L production reactor.5 The scale-up was successful and the process yielded the desired product volume for the Phase 1 clinical study. By using
single-use technologies, we were able to eliminate time-and resource-consuming CIP procedures and streamline the entire manufacturing
process. We completed the optimized scale-up process within the required timeframe and budget.
The Roadblocks
One of the challenges of adopting single-use technology is that not all cell lines are compatible with disposable bioreactors.
We have observed that an antibody-producing NSO cell line did not grow in Wave bioreactors in the presence of chemically defined
serum-free growth media with cholesterol. NSO cells require that external cholesterol be added to the media as a supplement.
However, we found that the cells grew poorly and adhered to the surface of the bag. This phenomenon was presumably because
of the cholesterol, as the problem could be overcome by selecting NS0 cells that did not require cholesterol.5
The second challenge in implementing disposable technologies is that the biggest disposable bioreactor commercially available
in the market is only 1,000 L in size. If a process needs to be scaled up to a higher volume, then the process must be transferred
to a stainless-steel bioreactor (as cited in the above case study).
Adopting single-use technology poses a major challenge in downstream processing and it needs to be developed further. Ion-exchange
filters do not have the same capacity as ion exchange resins, and are therefore of limited value in product-binding steps.
This is a significant limitation for scaling up ion exchange or affinity filters for large-scale chromatography steps. Although
single-use technology has come a long way, it has to satisfy the needs of downstream processing before a completely disposable
biomanufacturing process can be developed.
Acknowledgements
We would like to thank Michiel E. Ultee, PhD, senior director of process sciences, for his critical review of the manuscript.
Imara Charles, PhD, is a senior scientist and Yamuna Dasarathy, PhD, is a senior manager, marketing, both at Laureate Pharma, Princeton, NJ, 609.919.3393, yamuna.dasarathy@laureatepharma.com
Janet Lee was an upstream processing specialist at the time of submission and has since left the company.
References
1. Schultz TJ. Validation of an emerging trend in vaccine manufacturing: disposable technology, filters, containers, and connectors.
Disposable technologies for biopharmaceuticals. Institute of Validation Technology; 2007 Feb 27–Mar 21; Alexandria, VA.
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