Many TNFis contain an Fc region, which can potentially be affected by high RF levels.6-10 Because RF binds to Fc fragments, higher RF levels may be associated with greater drug clearance of Fc-containing TNFis, resulting in lower active drug concentrations.5,6,11,12
These images are not meant to compare efficacy or safety. The clinical relevance is unknown.
Fab’=fragment antigen-binding; Fc=fragment crystallizable; IgG=immunoglobulin G; PEG=polyethylene glycol; TNF=tumor necrosis factor; TNFi=tumor necrosis factor inhibitor.
Figure adapted from Porter C, et al. Certolizumab pegol does not bind the neonatal Fc receptor (FcRn): Consequences for FcRn-mediated in vitro transcytosis and ex vivo human placental transfer. J Reprod Immunol. 2016;116:7-12, with permission from Elsevier.