Characterization of bevacizumab by dynamic light scattering while maintaining its native structure.

Bevacizumab, is a humanized monoclonal antibody and patents on Avastin® (Bevacizumab, Roche) will expire in the US in 2019 and in Europe in 2022. Therefore, bevacizumab is a popular target for biosimilar developers. One of the most common problems in the formulation of antibody drugs is protein aggregation. Dynamic light scattering (DLS) is a well-established method for the determination of hydrodynamic dimensions, aggregates, and aggregation points of proteins. In contradistinction to other techniques that require diluted samples or specific conditions, proteins and aggregates can maintain their native structure during DLS measurements. In recent studies, bevacizumab was characterized by DLS using diluted samples. In this study, we aimed at investigating the hydrodynamic dimensions, aggregates, and aggregation onset of bevacizumab (Altuzan®, Turkey, Roche) by DLS, while maintaining its native structure. The intensity, volume, and number-based particle size distribution profiles of the test samples were evaluated and the aggregation onset of the formulation was successfully determined against increasing temperature. It is shown that the preservation of the native structure of commercial formulations in DLS measurements provides an opportunity to the characterization of commercial products and development of biosimilars.