Glycosylation and Immunogenicity in Recombinant Proteins Acting on the FVIII/VWF–ADAMTS13 Axis

Recombinant protein therapeutics used in thrombosis and hemostasis exhibit diverse immunogenic and pharmacokinetic behaviors, much of which can be attributed to host cell-dependent glycosylation. Glycan structures influence clearance, receptor recognition, antigen processing, and immune tolerance in protein specific ways. Factor VIII (FVIII), which also functions as a regulator that promotes ADAMTS13‑mediated cleavage of von Willebrand factor (VWF), represents a paradigm in which differences in glycan processing among host cell lines contribute to inhibitor formation by modulating antigen uptake and presentation. In contrast, VWF demonstrates a distinct model in which terminal sialylation and antennary branching primarily regulate clearance rather than immunogenicity; CHO derived recombinant VWF, enriched in α2 3 sialylation, shows reduced ASGPR mediated hepatic uptake and prolonged half life. ADAMTS13 presents a third, clinically unique case. Its multidomain architecture and dependence on N glycans for folding and epitope shielding may render it structurally vulnerable, and the absence of α2 6 sialylation in CHO derived rADAMTS13 may impair CD22 mediated B cell tolerance, potentially predisposing patients with congenital thrombotic thrombocytopenic purpura to alloantibody formation. Recent clinical observations underscore the need for long term immunogenicity monitoring. Collectively, these examples highlight glycosylation as a protein specific regulatory system that shapes both immunogenicity and pharmacokinetics. Future development of recombinant therapeutics targeting the VWF–ADAMTS13 axis will require optimized host cell selection, advanced glycoengineering, non immunogenic half life extension technologies, and integrated immunogenicity prediction models. Understanding and controlling glycosylation will be central to designing safer and more effective recombinant protein therapies in thrombosis and hemostasis.