Current views on N-glycolylneuraminic acid in therapeutic recombinant proteins.

The incorporation of the non-human N-glycolylneuraminic acid (Neu5Gc) in therapeutic recombinant proteins raises clinical concerns due to its immunogenic potential and the high prevalence of pre-existing anti-Neu5Gc antibodies in humans. The scientific literature is ambiguous regarding the actual impact of Neu5Gc-containing biotherapeutics as no severe adverse clinical manifestations were unequivocally attributed to Neu5Gc for currently marketed biotherapeutics. This review discusses structural and functional considerations of Neu5Gc-containing glycans regarding the potential impact on drug clearance, their recognition by pre-existing antibodies, and recent hypotheses regarding the tolerance to low Neu5Gc levels.

The Formidable Challenge of Controlling High Mannose-Type N-Glycans in Therapeutic mAbs.

The clinical efficacy and safety of therapeutic monoclonal antibodies (mAbs) are significantly affected by their Fc-glycosylation profile. High mannose-type N-glycans (HM) affect efficacy (in terms of antibody-dependent cell cytotoxicity), pharmacokinetics, and stability. While in endogenous IgGs the HM levels are very low, they are significantly higher in marketed therapeutic mAbs.