title: The effect of protein A cycle number on the performance and lifetime of an anion exchange polishing step.
abstract: Most mAb platform purification processes consist of an affinity capture step followed by one or two polishing steps. An understanding of the performance linkages between the unit operations can lead to robust manufacturing processes. In this study, a weak-partitioning anion-exchange chromatography polishing step used in a mAb purification process was characterized through high-throughput screening (HTS) experiments, small-scale experiments including a cycling study performed on qualified scale-down models, and large-scale manufacturing runs. When material from a Protein A column that had been cycled <10× was loaded on the AEX resin, early breakthrough of impurities and premature loss of capacity was observed. As the cycle number on the Protein A resin increased, the capacity of the subsequent AEX step increased. Different control strategies were considered for preventing impurity breakthrough and improving AEX resin lifetimes. Depth filtration of the Protein A peak pool significantly improved the AEX resin capacity, robustness, and lifetime. Further, the turbidity of the Protein A pool has the potential for use as an in-process control parameter for monitoring the performance of the AEX step.
authors.affiliation: Pfizer Biopharmaceuticals, 1 Burtt Road, Andover, MA 01810, USA.
authors.forename: Timothy
authors.initials: T
authors.lastname: Iskra
authors.forename: Glen R
authors.initials: GR
authors.lastname: Bolton
authors.forename: Jonathan L
authors.initials: JL
authors.lastname: Coffman
authors.forename: Ranga
authors.initials: R
authors.lastname: Godavarti
mesh_terms: D000837:Anion Exchange Resins; D002852:Chromatography, Ion Exchange; D002853:Chromatography, Liquid; D057166:High-Throughput Screening Assays; D010449:Peptide Mapping; D021241:Spectrometry, Mass, Electrospray Ionization; D017550:Spectroscopy, Fourier Transform Infrared; D013205:Staphylococcal Protein A / Q000737:chemistry*; D053719:Tandem Mass Spectrometry
chemical_list: D000837:Anion Exchange Resins; D013205:Staphylococcal Protein A