Continuous Preparative SEC for Purification of "Difficult-to-Manufacture" Proteins--A Feasibility Study

The advent of new antibody formats, such as multispecific antibodies or Fc-fusion proteins, imposes new challenges on downstream processing. Classical Protein A or ion exchange chromatography may not be capable of delivering adequate product quality if impurities display similar physicochemical properties compared to the target product. Size exclusion chromatography (SEC) with the possibility to purify according to the molecule size suffers from low productivity and is, thus, rarely used in commercial antibody purification. In this feasibility study, the principle suitability of continuous SEC using simulated moving bed chromatography to separate bovine serum albumin (BSA) and myoglobin, as model proteins, is shown. The applicability of this approach for separation of high molecular weight species (HMWs) from a multispecific antibody is then further evaluated. Compared to batch SEC, productivity is increased by a factor of 2.2 while maintaining higher product quality and yield. Additionally, BSA and myoglobin are separated with a productivity increase of factor 3.3-3.4, showing the feasibility of considering continuous SEC as an emerging viable option for "difficult-to-manufacture" proteins, especially for purification of a specific molecule in larger quantities.