Characterization of Biosimilar Monoclonal Antibodies and Their Reference Products Approved in Japan to Reveal the Quality Characteristics in Post-approval Phase

BACKGROUND: Promoting the use of biosimilars is a global issue from the perspective of reducing medical costs. In Japan, the replacement of original biopharmaceuticals with biosimilars has not progressed as expected. To promote the use of biosimilar monoclonal antibodies, it is necessary to increase the public's understanding of biosimilars by evaluating and confirming the quality of biosimilar products. However, there are limited data to compare among multiple biosimilars and/or the reference, and among their product lots. OBJECTIVE: In this study, we evaluated quality attributes of multiple lots of reference products and their biosimilars to determine the extent of distribution in quality attributes between products as well as the quality consistencies from lot to lot. METHODS: As the quality attributes, the glycosylation profile, charge heterogeneity, binding affinity for the antigen and Fcγ receptors, and high-molecular-weight species and subvisible particles were measured. RESULTS: The degree of similarity in quality attributes with a reference product was different for each biosimilar product. We confirmed the differences between reference and biosimilar product reported in previous articles or review reports, and that some quality attributes of biosimilars were out of the quality ranges of reference products. Although lot-to-lot variations and trends at some degrees were observed for some products, no clear drifts among lots were observed. CONCLUSION: Analyzing several lots of these products enabled us to capture a profile of quality characteristics for each product. Overall, the extent of variability of each quality attribute among reference products and biosimilars was revealed by this study for the first time.