Table 2.

Structural and functional comparison between a biosimilar drug and a reference drug (10)

Identical primary amino acid sequence (minor N- or C-terminal truncations may be allowed that do not affect safety or effectiveness)
Primary, tertiary, and quaternary structure
Post-translational modifications (glycosylation and phosphorylation)
Other potential variants (protein deamidation, oxidation, and aggregation)
Intentional chemical modifications (PEGylation)
Lot-to-lot variability
Functional assays: bioassays, biologic assays, binding assays, and enzyme kinetics