Industrial bioprocessing perspectives on managing therapeutic protein charge variant profiles

Abstract

Controlling the charge profile of therapeutic protein is a critical challenge in the current quality-by-design (QbD) paradigm, throughout all phases of biologics process development (PD): cell line development, upstream cell culture, recovery process, downstream purification, and analytical characterization. Charge variant profiles may influence efficacy and/or lead to unintended side-effects. Thus, maintaining a consistent charge profile is of tremendous importance, and increasingly, researchers have focused efforts toward developing strategies to mitigate variability during cell culture and to improve separation and detection of charge variants. Current understanding of factors affecting charge variant formation during manufacturing remains inadequate, and sometimes, even substantial commitment of resources may still not fully achieve the desired or consistent profiles. As such, this review attempts to provide a comprehensive resource for the biologics community by summarizing the impact of charge variants and CQA management, analytical methods for charge variant detection, as well as strategies in downstream and upstream PD for controlling charge variant profiles.

Antibody Structure and Function: The Basis for Engineering Therapeutics

“…Upstream consideration of developability metrics should reduce the frequency of failures in later downstream development stages. Optimization of stability in the early stages of discovery can reduce complications in upstream and downstream process optimization as well as increase the potential for successful drug product formulations [218,219]. Nonetheless, downstream processing can minimize some levels of oxidation via the presence of free radical scavengers, elimination of redox metal ions, addition of chelation agents, protection from light, decrease in storage temperature, and reduction of exposure to oxygen.…”

“…Human IgG is produced with C-terminal Lysines that are cleaved off in circulation. There can be changes in charge variation C terminal lysine loss can enhance complement activation [257] Glycation Reducing sugar reaction with Lysines Charge variants [218]; Structural heterogeneity [258] Biological activity on Fab and Fc *…”

Recent Developments in Bioprocessing of Recombinant Proteins: Expression Hosts and Process Development

“…Cultivations in standard 96-well-microtiter plates represent the optimal system for miniaturization (Duetz, 2007;Baumann and Hubbuch, 2017). MTPs were successfully used for recombinant protein process development (Long et al, 2014;Chung et al, 2018;Fink et al, 2019;Keil et al, 2019).…”

Elemental metal variance in cell culture raw materials for process risk profiling

“…Raw material variability in cell culture media has been shown to cause an abundance of problems which can affect a wide range of cell culture characteristics including cell growth, product quality, and drug efficacy. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] There are multiple sources for raw material nonuniformity including material misformulation, impurities and contaminants, and chemical degradation. 5 The most common impurities are trace elements from numerous raw material sources.…”