title: Characterization of a complex glycoprotein whose variable metabolic clearance in humans is dependent on terminal N-acetylglucosamine content.
abstract: Glycoproteins can be cleared from circulation if they carry oligosaccharide structures that are recognized by specific receptors. High-mannose type and asialo complex oligosaccharides are cleared by the mannose and asialoglycoprotein receptors, respectively. This paper presents the protein and terminal saccharide characterization for nine batches of a glycoprotein developed for pharmaceutical use. Each of these batches was evaluated in human pharmacokinetic (PK) studies, and had similar terminal elimination half-lives, but the initial clearance of this glycoprotein varied between batches. The protein is lenercept, an immunoadhesin comprising the Fc domain of human IgG1 and two tumor necrosis factor (TNF) binding domains derived from the extracellular portion of the TNFR1(p55). Lenercept is manufactured in Chinese hamster ovary (CHO) cells and is extensively N-glycosylated but is devoid of high-mannose glycans. The pharmacokinetic variability between these lots only correlated with terminal N-acetylglucosamine and not with terminal galactose, sialic acid or any polypeptide related parameter. The data emphasize the need for appropriate analytical methods for the characterization of glycoproteins, especially those designed for long half-lives, and show that assessment of the content of all three terminal saccharides is sufficient to ensure consistency of their PK performance properties.
authors.affiliation: Genentech, Inc., Analytical Development Department, 1 DNA Way, San Francisco, CA, USA. keck@gene.com
authors.forename: Rodney
authors.initials: R
authors.lastname: Keck
authors.forename: Namita
authors.initials: N
authors.lastname: Nayak
authors.forename: Laura
authors.initials: L
authors.lastname: Lerner
authors.forename: Shanta
authors.initials: S
authors.lastname: Raju
authors.forename: Stacey
authors.initials: S
authors.lastname: Ma
authors.forename: Thomas
authors.initials: T
authors.lastname: Schreitmueller
authors.forename: Stephen
authors.initials: S
authors.lastname: Chamow
authors.forename: Kathy
authors.initials: K
authors.lastname: Moorhouse
authors.forename: Claire
authors.initials: C
authors.lastname: Kotts
authors.forename: Andrew
authors.initials: A
authors.lastname: Jones
mesh_terms: D000117:Acetylglucosamine / Q000737:chemistry / Q000378:metabolism*; D000595:Amino Acid Sequence; D006023:Glycoproteins / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D006901:Hydroxylysine / Q000737:chemistry / Q000378:metabolism; D007525:Isoelectric Focusing; D007536:Isomerism; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000378:metabolism
chemical_list: D006023:Glycoproteins; D010455:Peptides; D006901:Hydroxylysine; D000117:Acetylglucosamine