Antibody fragments (Fab’s) represent important structure for creating new therapeutics. Compared to full antibodies, Fab’ fragments possess certain advantages, including higher mobility and tissue penetration, ability to bind antigen monovalently and lack of fragment crystallizable (Fc) region-mediated functions such as antibody-dependent cell mediated cytotoxicity (ADCC) or complement-dependent cytotoxicity (CDC). The main drawback for the use of Fab’s in clinical applications is associated with their short half-life in vivo, which is a consequence that no longer has the Fc region. To exert meaningful clinical effects, the half-life of Fab’s need to be extended, which has been achieved by postproduction chemical attachment of polyethylene glycol (PEG) chain to protein using PEGylation technology.

Advantages of PEGylation

PEGylation is an established tool to increase potency, half-life and solubility of biopharmaceuticals, which can be used for modifying biological compounds such as cytokines, antibody fragments, interleukins, hormones, oligonucleotides and some of proteins and peptides.

PEGylation can be effective in:
• Improving Bioavailability
• Prolonging Blood Circulation
• Maximizing Pharmacokinetics
• Reducing Immunogenicity
• Decreasing Frequency of Dosing