Keywords: Product quality, mAbs, mammalian cell culture, CHO cells, protein aggregation
Monoclonal antibodies (mAbs) are successful biotherapeutics in the treatment of various diseases . During manufacturing of mAbs higher molecular weight (HMW) aggregates can be formed during upstream (USP) and downstream (DSP) processing, which negatively influence product yields, reduce the therapeutic efficacy of the mAbs and trigger immunogenic responses upon administration[2, 3]. Reducing the level of aggregates during USP could improve the production of biopharmaceuticals and reduce the burden on expensive DSP removal of the HMW species. However, the lack of analytical tools to detect mAb aggregates in USP restricts understanding the origin of the aggregates and identifying cell culture conditions influencing product quality to reduce the level of mAb aggregates. We present a high-throughput compatible method which allows quantification of mAb aggregate formation directly in cell culture samples of Chinese hamster ovary (CHO) cells replacing falsifying, laborious and time-consuming chromatographic methods. Using this new methodology, we have screened for different culture conditions effecting mAb aggregate formation in a non-producing and a mAb producing CHO cell line. Finally, we have identified important process parameters to influencing protein aggregation in mammalian cell culture. Hence, our work demonstrates that the formation of mAb aggregates can be assessed directly in mammalian cell culture and product quality can be controlled by the selection of certain cell culture process parameters.