Comprehensive Characterization of N ‐Glycosylation in Darbepoetin Alfa

EPO analogues are representative glycoprotein drugs composed of heterogeneous, multiple antennary N ‐glycans. NESP® and Aranesp® are hyperglycosylated EPO, marketed under the same international nonproprietary name as darbepoetin alfa. The multiple antennary N ‐glycans are a key factor that increases the half‐life of the drug in the body, which is closely related to efficacy. Thus, control of N ‐glycosylation is important in providing patients with consistent efficacy. This paper reports on the comprehensive characterization of N ‐glycosylation of darbepoetin alfa products. The results of N ‐glycan analysis of NESP® and Aranesp® showed difference in the ratio of N ‐glycans containing N ‐acetyllactosamine and O ‐acetylated sialic acid. Although there were some differences, the overall N ‐glycan structures and profiles were comparable. In particular, darbepoetin alfa products accounted for the largest proportion of tetra‐sialo N ‐glycans, greater than 75%. This study increases understanding of N ‐glycan profiles and structural information of darbepoetin alfa.