Mapping the mAb Aggregation Propensity Using Self-Interaction Chromatography as a Screening Tool

Abstract

The osmotic second virial coefficient ( B), which describes protein-protein molecular interactions in solution, was determined using self-interaction chromatography (SIC) for an IgG1-type mAb across a wide range of solution conditions. These data were compared with its time dependent aggregation behavior, as determined using size-exclusion chromatography (SEC), and its temperature dependent aggregation behavior using dynamic light scattering (DLS) over a four-week period (SEC) or overnight (DLS). DLS and SEC gave consistent data on aggregation behavior, which correlated well with experimental B trends across the wide pH (4-9) and NaCl concentration (0-1.0 M) ranges studied. The IgG aggregated at pH 4 for 0.5-1.0 M NaCl concentrations and for 0 M NaCl concentrations at pH 8. Best stability against aggregation was exhibited for the pH range from 5 to 8 at 0.8-1.0 M NaCl. SIC data were able to be classified within the one-day solution conditions for aggregation, which were not identified for 2-3 weeks in the accelerated SEC stability study. The ability of SIC to provide such data rapidly reflects the fundamentally thermodynamic nature of this parameter and of the aggregation process itself. Proteins with attractive protein-protein interactions and negative B coefficients in the range -3 to -6 clearly exhibit aggregation behavior, while B values in the range 0 to 2 showed good stability toward aggregation. SIC allows the rapid screening of solution conditions for which mAbs will exhibit stability to aggregation while requiring 90% less time and material compared with that required for a conventional SEC aggregation study.

Physicochemical Stability of Monoclonal Antibodies: A Review

“…70 If strongly negative, the osmotic second virial coefficient may reflect a higher probability for the protein to form multimers as negative values of this coefficient show the existence of net attractive forces between solute molecules present. 71,72 Likewise, zeta potential can be a good indicator of the surface charges that may lead to electrostatic and van der Waals interactions. 62 Temperature mAbs, like other therapeutic proteins, can be exposed to temperature variations during their processing, storage, and transportation.…”

Nucleation in Protein Aggregation in Biotherapeutic Development: A look into the Heart of the Event

“…This may also lead to native precipitation related to low solubility, without requiring the presence of conformational changes. Depending on the extent of protein unfolding required for aggregation, native protein-protein interactions may [38][39][40][41][42][43] or may not 33,41,42,[44][45][46] be a good predictor of aggregation, as discussed in ref. 33 .…”

Rapid Estimation of Size-Based Heterogeneity in Monoclonal Antibodies by Machine Learning-Enhanced Dynamic Light Scattering

“…The kD and the sedimentation interacting parameter (kS) are used to determine the virial coefficient (B2). The virial coefficients are indicators of protein–protein interaction (PPI) and/or antibody self-association, , which further has been used to assess the solution viscosities and colloidal stability of highly concentrated mAbs solutions. − Furthermore, kD has been found to be a key biophysical property for the mAbs, exhibiting statistically significant correlations with multiple biophysical attributes of antibody formulations such as apparent solubility, viscosity behavior, and electrostatic properties. , …”