(231b) Pre-Formulation Tool to Rapidly Predict the Stability of Monoclonal Antibodies

Pre-formulation
tool to rapidly predict the stability of monoclonal antibodies

S. Hedberg*, J.Y.Y Heng*,
D.R. Williams* and J. Liddell**

ABSTRACT

Protein-protein
molecular interactions are known to be involved in protein solution aggregation
behaviour and are a common issue for the manufacturing of therapeutic proteins
such as mAbs. Much effort has been employed to gain a
better understanding of aggregation. However, the mechanisms leading to protein
aggregation are still not fully understood. The osmotic second virial coefficient (B₂₂) is a fundamental
physiochemical property that describes protein-protein interactions 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), which has demonstrated recent promise as a tool for the better
understanding of phase behaviour of proteins. Another technique,
cross-interaction chromatography (CIC), has shown to be an even more
high-throughput technique than its predecessor with possibly the same
capabilities.

The
first part of this paper is a scale-down SIC study of therapeutic mAbs from laboratory scale macro-columns to micro-scale
columns, which enables the use of micrograms or milligrams of mAb for B₂₂ determinationsin order
to obtain a complete formulation screen.

The
second part of this work presents an extensive formulation study of a mAbs system, varying pH and salt, as well as the presence
of different stabilisers and different external factors known to induce
aggregation. The B₂₂ and B₂₃ values determined from the
formulation study are then correlated with aggregation kinetics obtained from
size-exclusion chromatography and dynamic light scattering. It was shown that
over all test conditions good correlations could especially be found between B₂₂
and aggregation rate.

The
third part of the study includes investigation of conformational changes of the
monoclonal antibodies. The B₂₂ data previously obtained were
directly correlated with the conformational changes observed in the mAb to create a predictive tool that can detect any early
conformational changes.

In
summary this work intends to gain a better understanding of the fundamental
mechanisms of aggregation and to develop a more predictive capability by
studying the chromatogram output resulting from the self- and
cross-interactions between the same or different proteins.

REFERENCES

Hedberg, S. H. M., Heng, J. Y. Y., Williams, D. R. & Liddell, J. M.
(2016). Micro Scale Self-Interaction Chromatography of Proteins: A Mab Case-Study. Journal of Chromatography A, 1434,
57-63.

Quigley, A. & Williams, D. R. (2015). The Second Virial
Coefficient as a Predictor of Protein Aggregation Propensity: A
Self-Interaction Chromatography Study. European Journal of Pharmaceutics and
Biopharmaceutics, 96, 282-290.