As of early 2022, the coronavirus disease 2019 (COVID-19) pandemic remains a substantial global health concern. Different treatments for COVID-19, such as anti-COVID-19 neutralizing monoclonal antibodies (mAbs), have been developed under tight timelines. Not only mAb product and clinical development but also chemistry, manufacturing, and controls (CMC) process development at pandemic speed are required to address this highly unmet patient need. CMC development consists of early- and late-stage process development to ensure sufficient mAb manufacturing yield and consistent product quality for patient safety and efficacy. Here, we report a case study of late-stage cell culture process development at pandemic speed for mAb1 and mAb2 production as a combination therapy for a highly unmet patient treatment. We completed late-stage cell culture process characterization (PC) within approximately 4 months from the cell culture process definition to the initiation of the manufacturing process performance qualification (PPQ) campaign for mAb1 and mAb2, in comparison to a standard one-year PC timeline. Different strategies were presented in detail at different PC steps, i.e., pre-PC risk assessment, scale-down model development and qualification, formal PC experiments, and in-process control strategy development for a successful PPQ campaign that did not sacrifice quality. The strategies we present may be applied to accelerate late-stage process development for other biologics to reduce timelines.

BACKGROUND The stability of amino acids (AAs) in a highly concentrated cell culture medium is affected by medium preparation and storage conditions. Variability in the concentration of medium components (including AAs) can influence cell culture performance and product quality attributes. RESULTS In this report, the impact of preparation pH, preparation temperature, and storage temperature was evaluated on the stability of 16 AAs in a highly concentrated cell culture feed medium. Optimizing the medium pH enabled an increase in the initial feed medium concentration by 30% plus 3.9 g L−1 tyrosine with no observed precipitation after 28 days. Up to 6.0 g L−1 tyrosine can be supplemented in the medium at ~pH 10 without precipitation. Moreover, preparing the medium at 40–50 °C prevented precipitation during storage at 4–8 °C. A slight negative impact on AA stability during this high‐temperature preparation was observed, but this impact was negligible relative to the AA degradation observed during extended storage of media prepared at 37 °C. The optimal preparation pH and temperature allowed the concentrated medium to be stored at 4–8 °C with minimal AA degradation and without precipitation. These discoveries were further supported by principal component analysis of AA profile similarity before and after storage at different pH and temperature conditions. CONCLUSION This study describes the medium preparation parameters to improve AA stability and mitigate precipitation issues. The optimization strategy will facilitate the development of robust cell culture production processes. © 2022 Society of Chemical Industry (SCI).