ABSTRACT
Recently, biosimilar antibodies have become a mainstream component of the biopharmaceutical industry in China. The principle requirements for the development and evaluation of biosimilars are based on proving similarity in product quality (analytical similarity) between a proposed biosimilar candidate and the originator reference drug. However, because the quality of a reference drug often varies during the life cycle and not all reference drug samples are able to collected by a biosimilar sponsor, it has not been practical to accurately determine the critical quality attributes as well as an accurate control range through the characterization of the limited number of reference drug lots that are typically collected. Therefore, the development and evaluation of biosimilars has been challenging both for industry and regulatory agencies. In this article, The Chemistry, Manufacturing and Control (CMC) dossier of the rituximab originator company and the dossiers of 18 biosimilar companieswere retrospectively analyzed. Furthermore, the assessment criteria to determine quality similarity of rituximab biosimilar candidates have been proposed, which criteria have been used by reviewing the physicochemical and biological properties data obtained from 123 lots of the reference drug. Moreover, some case studies have been provided that illustrate the application of the proposed analytical similarity criteria in the practice of drug evaluation.