Stress Factors in mAb Drug Substance Production Processes: Critical Assessment of Impact on Product Quality and Control Strategy

Abstract

The success of biotherapeutic development heavily relies on establishing robust production platforms. During the manufacturing process, the protein is exposed to multiple stress conditions that can result in physical and chemical modifications. The modified proteins may raise safety and quality concerns depending on the nature of the modification. Therefore, the protein modifications potentially resulting from various process steps need to be characterized and controlled. This commentary brings together expertise and knowledge from biopharmaceutical scientists and discusses the various manufacturing process steps that could adversely impact the quality of drug substance (DS). The major process steps discussed here are commonly used in mAb production using mammalian cells. These include production cell culture, harvest, antibody capture by protein A, virus inactivation, polishing by ion-exchange chromatography, virus filtration, ultrafiltration-diafiltration, compounding followed by release testing, transportation and storage of final DS. Several of these process steps are relevant to protein DS production in general. The authors attempt to critically assess the level of risk in each of the DS processing steps, discuss strategies to control or mitigate protein modification in these steps, and recommend mitigation approaches including guidance on development studies that mimic the stress induced by the unit operations.

Strategies for high‐concentration drug substance manufacturing to facilitate subcutaneous administration: A review

“…Freeze-thaw scale-down models have been developed and demonstrated across range of mAb concentrations up to 200 g/L (Puri, Morar-Mitrica, Crotts, & Nesta, 2015). Factors to consider during development of the freezing and storage process include denaturation of protein at the ice-water interface (Strambini & Gabellieri, 1996), the cold denaturation phenomenon (Privalov, 1990), cryoconcentration (Strambini & Gonnelli, 2007), excipient behavior (Hauptmann et al, 2018), and pH shifts (Das et al, 2019).…”

“…At cryogenic temperatures, the brittleness of polymers used in drug substance packaging should be taken into consideration. Disposable plastic bags are susceptible to breakage (Das et al, 2019). This makes container integrity more important because the loss of the contents of a given volume will have larger financial impact due to the greater amount of product mass lost.…”

“…mAb drug substance is often stored in a frozen state, which provides several benefits. The frozen state lowers molecular alterations of protein associated with mobile water, such as hydrolysis (Das et al, 2019). It also decreases the risk of microbial growth, and minimizes interfacial adsorption and foaming during transportation, potentially increasing the protein stability (Das et al, 2019).…”

“…Despite these advantages, the freeze–thaw process can pose a risk to the product quality (Das et al, 2019; Laptos & Omersel, 2018). The frozen storage temperature should be selected well below the glass transition temperature to avoid continuous cycling of the protein through frozen and nonfrozen states (Das et al, 2019). Freeze–thaw scale‐down models have been developed and demonstrated across range of mAb concentrations up to 200 g/L (Puri, Morar‐Mitrica, Crotts, & Nesta, 2015).…”

“…The frozen state lowers molecular alterations of protein associated with mobile water, such as hydrolysis (Das et al, 2019). It also decreases the risk of microbial growth, and minimizes interfacial adsorption and foaming during transportation, potentially increasing the protein stability (Das et al, 2019). Despite these advantages, the freeze–thaw process can pose a risk to the product quality (Das et al, 2019; Laptos & Omersel, 2018).…”