Alpha-gal (Gal-alpha(1-3)-Gal) is a disaccharide fragment found on the glycans of some glycoprotein therapeutics produced in mammalian expression systems – particularly those from mouse-derived cell lines.

Galα1-3Gal is a non-human epitope that has caused adverse clinical reactions (including IgE-mediated anaphylaxis) in patients. It could also lead to diminished clinical efficacy due to increased serum clearance.Gal-alpha(1-3)-Gal is a high priority

Glycosylation Critical Quality Attribute (GCQA) and developers of biologic drugs should effectively optimise, measure and control the glycosylation of their products to limit Galα1-3Gal levels throughout the product life cycle.