Process Development Tool to Rapidly Predict the Stability of Biopharmaceuticals

Process Development Tool to Rapidly Predict the Stability of Biopharmaceuticals

S. Hedberg, Y. Hutabarat, J. Heng, J. Haigh, D. Williams                

ABSTRACT

Protein aggregation is a critical problem for the safety of biopharmaceuticals as they are linked to adverse immunologically related responses in patients. Much effort has been made to gain a better understanding of aggregation, however, the mechanisms leading to protein aggregation are still not fully understood. Protein-protein molecular interactions in solution are known to be involved in protein solution aggregation behaviour and are a common issue for the manufacturing of biopharmaceuticals such as monoclonal antibodies, mAbs.  

Therefore, a major industrial and academic challenge is the development of fast and reliable methods, either theoretically or experimentally driven, which allow formulation scientists to identify optimal biopharmaceutical species and solution conditions which deliver stable solution products, thus avoiding aggregation. The osmotic second virial coefficient (B₂₂) is a fundamental physiochemical property that describes the thermodynamics of the protein-protein interactions in solution, which can be a useful tool for predicting the aggregation propensity of proteins.

One way of predicting aggregation propensity is self-interaction chromatography (SIC) that can be used for determining the osmotic second virial coefficient (B₂₂). This technique has recently demonstrated to be a tool that can successfully predict phase behaviour of proteins. However, due to the need to immobilise every protein in order to make B₂₂ measurements makes this technique less ideal for use in process development. Another technique, cross-interaction chromatography (CIC), has shown to be an even more high-throughput technique than its predecessor with similar capabilities. In CIC only one protein needs to be immobilised in order to screen a range of other proteins.

In a case study a number of different monoclonal antibodies from both IgG1 and IgG4 subclasses, and a polyclonal antibody were immobilised and screened on each of the columns for a wide range of process development conditions. The aim was to see if the osmotic second virial cross coefficient (B₂₃) between two proteins can be used to predict B₂₂.

The results of the case study were very successful and proved to be a good prediction of the B₂₂ value for all the proteins in all conditions. This will enable a rapid process development tool with only mg quantities of biopharmaceutical species that can be injected on a generic column e.g. a polyclonal IgG column.

Previously, the accuracy of the B₂₂ values of several of the mAbs has been directly validated by the use of traditional gel filtration chromatography methods and dynamic light scattering, to investigate the size and quantity of aggregates over time. This has shown that the determined B₂₂ held powerful information about the long term stability of biopharmaceuticals.

In summary, this work has developed a rapid and high-throughput tool, which manages to estimate the B₂₂ values for different biopharmaceutical products using minimal amounts of protein. This will help scientists in the biopharmaceutical industry finding suitable conditions for process development as well as picking drug candidates with high long term stability.