ÄKTA avant 25 system controlled by UNICORN™ 6 software was used to develop a two-step chromatography process for purification of a monoclonal antibody (MAb). MabSelect SuRe™, a protein A-based chromatography medium (resin) was used for the initial capture step while the multimodal anion exchanger Capto™ adhere was used for reduction of impurities in a second, polishing step. An experimental design was applied to the polishing step to screen loading conditions. Sample pH, conductivity, and load were varied. Using 1 ml prepacked HiTrap™ columns, the design was run in less than 24 h and a reduced design was performed to establish the robustness of the process conditions. Using the Design of Experiments (DoE) functionality incorporated in UNICORN 6 together with HiScreen™ prepacked columns, optimization of the overall process was achieved in approximately one week. Despite the challenging nature of the feed studied, high yield and purity of the target MAb was achieved.
Time and flexibility are essential in process development of purification processes for biopharmaceutical compounds. ÄKTA avant 25 is a chromatography system designed for fully automated process development using rigid chromatography media. Productivity is enhanced by the Design of Experiments (DoE) software functionality incorporated in UNICORN 6. DoE (Fig 1) facilitates easy and fast process development, is a powerful tool for optimizing chromatography conditions, and increases throughput in the process development lab.
In the purification of monoclonal antibodies (MAb), protein A is the chromatography medium of choice for capture, due to its high selectivity giving excellent purity and ease of use at large and small scale. Therefore, protein A-based media are the basis for the platform approach to MAb purification.
Subsequent downstream processing can be performed according to a variety of chromatography techniques and combinations of techniques (especially ion exchange and hydrophobic interaction chromatography). A novel approach to MAb purification involves a two-step process (Fig 2) whereby a multimodal chromatography medium, capable of both anion exchange as well as other types of interaction, enables the selective removal of antibody dimers and aggregates (D/A), and removal of host cell protein (HCP), DNA, and viruses at the same time (1, 2). In order to take full advantage of the beneficial properties of a multimodal chromatography medium, a thorough purification process optimization is required.