Human Cell Line FVIII Replacement Therapy
FVIII replacement therapy is the standard of care for Hemophilia A – trusted and proven to be safe and effective over decades of use1. However, not all FVIII treatments are the same. There are differences in the way they are manufactured, purified, and importantly, in the host cell line that is used for expression of the rFVIII protein.
NUWIQ is the first and only rFVIII produced in a human cell line without chemical modification or protein fusion.2,3. In fact, no animal proteins are added during the production of NUWIQ.4
The Importance of Post-Translational Modifications (PTMs) in the Production of rFVIII 4
- PTMs are the biochemical modifications that are made to the rFVIII protein during or after its biosynthesis 4
- PTMs are species-specific; different protein expression systems (e.g. human or hamster cell lines) produce different PTMs for the same protein sequence
- Several different kinds of PTMs can occur within the cells, but for rFVIII protein expression, glycosylation and sulfation are the most vital for functionality and von Willebrand factor (VWF)-binding affinity4
Glycosylation Has Structural and Functional Impacts on rFVIII Protein 4
- Glycosylation is the covalent attachment of carbohydrate structures (glycans) to a protein
- It is achieved by the sequential action of many different enzymes (e.g. glycosyl transferases and glycosidases)
- Glycosylation affects several aspects of rFVIII protein structure and function:
- Level of protection from protease cleavage
- Protein stability (pH, temperature)
- Immunogenic properties
- Coverage of antigenic epitopes by glycans
NUWIQ Glycosylation is Comparable to Native Plasma-Derived FVIII4
- Human cells can accurately replicate human glycosylation without producing potentially antigenic epitopes
- Protein expression in animal cells results in glycosylation with non-human epitopes, which are potentially antigenic to humans
- NUWIQ contains only human glycan epitopes
Sulfation – Strengthening Protein-to-Protein Interactions
- Sulfation is a PTM that occurs on the exposed tyrosine residues of a protein
- There are six sulfated tyrosines in native, human FVIII, found in the a1, a2 and a3 domains
- Sulfation at all six sites is required for full FVIII activity
- Full sulfation at Tyrosine 1680 is vital for VWF-binding affinity and FVIII stability
NUWIQ Sulfation is Comparable to Native Plasma-Derived FVIII4
NUWIQ is fully sulfated at Tyrosine 1680 (Tyr168)
NUWIQ has been shown to have high VWF-binding affinity, and less than 1% unbound FVIII 2
- Cafuir LA, Christine L. Kempton CL. Ther Adv Hematol. 2017;8(10):303–313.
- Sandberg H, et al. Thromb Res.2012;130:808-817.
- Casademunt E, et al. Eur J Haematol. 2012;89:165-176.
- Kannicht C, et al. Thromb Res. 2013;131:78-88.