“Circular dichroism has been used/proposed in 96% of biosimilar applications involving mAbs and other biotherapeutics”
Regulatory consideration for characterization of HOS in biotechnology products, M. T. Gutierrez Lugo, Ph. D., OBP/CDER/FDA. 5th International Symposium on HOS of Protein Therapeutics 2016
Demonstrate similarity of your product to the innovator with confidence and find differences early on.
In this example, comparison between biosimilar and innovator confirmed statistical significance of minor differences seen in tertiary structure (data not shown), suggesting the need for further development.
Ensure your innovator is what you expect it to be.
In the same project, statistical analysis of near-UV CD data (n = 3, normalized for protein concentration by simultaneous absorbance measurements) suggested that tertiary structure of Fab fragments showed differences for innovator lots from different geographical regions.