Host cell protein removal from biopharmaceutical preparations: Towards the implementation of quality by design

Abstract

Downstream processing of protein products of mammalian cell culture currently accounts for the largest fraction of the total production cost. A major challenge is the removal of host cell proteins, which are cell-derived impurities. Host cell proteins are potentially immunogenic and can compromise product integrity during processing and hold-up steps. There is an increasing body of evidence that the type of host cell proteins present in recombinant protein preparations is a function of cell culture conditions and handling of the harvest cell culture fluid. This, in turn, can affect the performance of downstream purification steps as certain species are difficult to remove and may require bespoke process solutions. Herein, we review recent research on the interplay between upstream process conditions, host cell protein composition and their downstream removal in antibody production processes, identifying opportunities for increasing process understanding and control. We further highlight advances in analytical and computational techniques that can enable the application of quality by design.

Targeted capture of Chinese hamster ovary host cell proteins: Peptide ligand binding by proteomic analysis

“…Calculated p ‐values for ANOVA comparisons of each peptide resin compared to both benchmark resins (Capto Q and Capto Adhere) are provided. Species identified by shotgun proteomics in this study identified as “problematic” based on prior art (Aboulaich et al, ; Bailey‐Kellogg et al, ; Chiu et al, ; Fischer et al, ; Gagnon et al, ; Goey et al, ; Jawa et al, ; Levy et al, ; Mechetner et al, ; Zhang et al, ). * p < .05.…”

“…The application of proteomics‐based approaches at different stages of mAb production has revealed new challenges related to the removal of the host cell protein (HCP) impurities secreted by the mAb‐expressing cells. In a recent review of HCP removal strategies, Goey, Al huthali, and Kontoravdi () presented a thorough survey of HCPs that pose a significant risk to patient's health, and highlighted the challenges that mAb manufacturers face in ensuring rigorous HCP clearance. The authors recommend that upstream process conditions be controlled to minimize downstream bottlenecks and challenges, including high product titers as well as high HCP levels that accompany them.…”

“…This study focuses on problematic HCPs in three primary categories based on risk factors described above: (a) HCPs co‐eluting with mAbs in the capture step, herein referred to as Group I (Aboulaich et al, ; Gagnon et al, ; Levy et al, ; Mechetner et al, ; Zhang et al, ), including IgG‐associated and Protein A‐binding HCPs, (b) HCPs that cause product degradation, or Group II (Aboulaich et al, ; Bee et al, ; Chiu et al, ; Goey et al, ; Zhang et al, ), and (c) HCPs with high immunogenicity risk, or Group III (Bailey‐Kellogg et al, ; Fischer et al, ; Goey et al, ; Jawa et al, ). In typical mAb platform processes, the large majority of HCPs are removed at the product capture step with Protein A‐based adsorbents; thus, the design of the subsequent intermediate and final polishing steps is highly dependent on their ability to remove the species that co‐elute with IgG from Protein A.…”

“…Group II HCPs, or mAb‐degrading HCPs, comprise enzymatically active species that induce product degradation. This study focuses on species that are known to cleave or alter the mAb product directly, including cathepsins, metalloproteinases, serine protease HTRA1, and sialidases (Aboulaich et al, ; Bee et al, ; Goey et al, ; Zhang et al, ). In addition, this group includes species that cause degradation due to conformational changes in the mAb, such as protein disulfide isomerase, 78 kDa glucose‐regulated protein (also known as binding immunoglobulin protein or BiP), and heat shock protein (Goey et al, ).…”

“…This study focuses on species that are known to cleave or alter the mAb product directly, including cathepsins, metalloproteinases, serine protease HTRA1, and sialidases (Aboulaich et al, ; Bee et al, ; Goey et al, ; Zhang et al, ). In addition, this group includes species that cause degradation due to conformational changes in the mAb, such as protein disulfide isomerase, 78 kDa glucose‐regulated protein (also known as binding immunoglobulin protein or BiP), and heat shock protein (Goey et al, ). This subset also includes species that are thought to cause product degradation indirectly; lipoprotein lipase, for example, is thought to degrade polysorbate excipients in final formulations, resulting in reduced shelf life of the drug product (Chiu et al, ).…”