Considerations of critical quality attributes in the analytical comparability assessment of biosimilar products

Based on experience in clinical trial approvals and marketing authorizations for biosimilar products in Korea, we suggest principles for the analytical comparability assessment of biosimilar products with respect to regulatory considerations. The composition and manufacturing processes of biosimilar products can differ from those of the reference product depending on the information available for the reference product and the time of product development; however, the analytical characteristics of biosimilar products should be highly similar to those of the reference product. Although manufacturing an identical product in terms of the quality profile is nearly impossible due to the high molecular weight and complex structure of biological products, the developer of the biosimilar product should attempt to establish a quality level as similar to that of the reference product as possible. When comparing the similarity of quality attributes, the criticality of the quality attributes and the characteristics of orthogonal quality attributes need to be considered carefully. Based on the results from the analytical comparability assessment, the comparability results of non-clinical and clinical studies should be evaluated before claiming biosimilarity to the reference product. In this review, we focus on quality attribute evaluation based on our regulatory experience.