Comparison of Radial and Axial Flow Chromatography for Monoclonal Antibody Downstream Processing at Bench and Pilot Scales

Axial Flow Chromatography (AFC) is widely used for the purification of therapeutic Monoclonal Antibodies (MAbs). However, AFC columns can generate high pressure drops across the resin bed, preventing operation of the column at high flow rates especially at pilot or manufacturing-scales. Radial Flow Chromatography (RFC) was developed to provide lower pressure drops during chromatographic separations. In these studies, small and pilot-scale columns were used to evaluate purification of a MAb using both AFC and RFC technologies. A bench-scale, wedge RFC column (250 mL) was compared to a bench-scale AFC column at various linear velocities with resulting Residence Times (RT) using Protein A resin for the recovery of a monoclonal antibody. The bench RFC column was successfully operated at 4.5 min RT for equilibration and loading steps and 2 min RT for washing, elution and cleaning steps without compromising yield. The RFC column had approximately 50% lower pressure drop than the AFC column at similar flow rates. The process was then scaled-up to 5 L using a pilot-scale RFC column. The 5-L RFC column was operated at 4.5 min RT for equilibration and loading and 2 min. RT for washing, elution and cleaning with no loss of yield. However, pressure drop across the 5 L RFC column was higher than expected, but antibody recovery yields were similar for both column types. Subsequent investigations revealed a potential design issue with the RFC column. Overall, RFC has great potential to be used for pilot or manufacturing scale without high pressure drop concerns, which will certainly improve processing efficiency.