Process development and optimization of fed-batch production processes for therapeutic proteins by CHO cells
© Clincke et al.; licensee BioMed Central Ltd. 2013
Published: 4 December 2013
In the biopharmaceutical industry, process development and optimization is key to produce high quality recombinant proteins at high yields. As technologies mature, pressure on cost and timelines becomes greater for delivering scalable and robust processes. Overall, process development should be viewed as a continuum from the early stages up to process validation. Here we outline a lean approach on upstream development during the initial phases to optimize yields while maintaining the desired product quality profiles. Early-stage process development was designed to lead to the establishment of a baseline process and to systematically include experiments with input parameters that have a high impact on performance and quality. At this stage, potential for pre-harvest titer and yield increases as well as product quality challenges were identified. Feed adjustments and systematic experiments with top, high, and medium impact parameters have then been performed to develop a robust and scalable process. This approach was applied to two early stage upstream processes.
Materials and methods
2L and 80L stirred tank bioreactors were run for 14 days in a fed-batch mode in a chemically defined medium. Feed was added daily from day 3 onwards. If required, antifoam C was added to the bioreactor by manual injections. DO, pH, and temperature were controlled at setpoint. DO was controlled using a multi-stage aeration cascade via a ring sparger. Viable cell concentration, cell viability, and average cell diameter were measured using a ViCell cell counter. The glucose, lactate, glutamine and ammonia concentrations were measured with a BioProfile Analyzer 400. On the day of harvest, the clarification was performed by centrifugation plus depth filtration. Monoclonal Antibody (MAb) concentration of the supernatant samples was quantified using Protein A high performance liquid chromatography.
Comparison of MAb titers (normalized) obtained for both cell lines at 2L scale and 80L scale
Cell line 1, Process 1
Cell line 2, Process 2
A similar process development approach was applied to both projects where identical high impact parameters were identified. Although process optimized for cell line 1 was not the best for cell line 2, we were able to use it as a starting point and were able to optimize within the tight timelines. For both projects, high titers were achieved following our lean approach on process development. The final process 1 optimized for a cell line 1 led to a 36% increase in monoclonal antibody titer. The final process 2 optimized for a cell line 2 led to a 43% increase in monoclonal antibody fragment titer. Comparable titers and product quality attributes were observed at 2L scale and 80L scale. Hence the adopted feeding strategy proved to be robust and scalable.
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.