The manufacturing of monoclonal antibody (mAb) products is complex and consists of cell culture and clarification followed by several downstream purification steps. The cost associated with downstream purification amounts to &gt;70% of total mAb manufacturing costs. Protein A capture is a type of ligand affinity chromatography and is the first downstream step after centrifugation and depth filtration, used to capture the mAb of interest from the clarified cell culture broth. However, it is particularly expensive due to high utilization of expensive Protein A resin.<br/>In continuous chromatography, costs are reduced as column sizes and resin utilization is optimized, leading to increased productivity and efficiency. One of the important issues in protein A chromatography is to make loading decisions. As mAb product titres vary widely in the perfusion reactors used for continuous mammalian cell culture, loading becomes a problem as protein concentration needs to be measured in real-time for optimal loading to maximize resin utilization with minimal column size. Standard methods for measuring mAb concentration such as UV absorbance do not work for cell culture broth as they contain thousands of host cell proteins and host cell DNA. Other tools such as high-performance liquid chromatography create delays in making loading decisions, with the shortest methods thus far developed being ~4 minutes long.<br/>In this work, we have developed a near infrared spectroscopy (NIRS) based system for accurate real-time quantification of mAb concentrations in clarified cell culture harvest prior to loading. Concentration analyses are carried out using a multivariate NIRS spectral library model every 15 seconds. These are conveyed to a control algorithm and action module which controls the flowrates to a BioSMB continuous chromatography system. The system was validated with continuous protein A runs and induced concentration perturbations in the range of 0.5-8 mg/mL mAb concentration. The technology developed can be employed at large scale manufacturing where immediate decisions are needed for continuous chromatography loading.

System for making real-time loading decisions for protein A chromatography in continuous manufacturing

2019 Spring National Meeting

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