Abstract
Establishing biosimilarity of a biosimilar drug to its originator presents unique challenges as compared with small-molecule generic drugs. In addition to assessing structural and chemical characteristics of the molecule, its efficacy and safety must also be compared with its originator through pre-clinical and clinical comparability studies. Therefore, it is critical to develop and validate PK bioanalytical assays, which can assess biosimilar and originator, as well as their anti-drug antibodies ‘similarly’ in biological matrices.