Authors' response: Importance of defining loss of response before therapeutic drug monitoring

This study is hitherto the only published RCT of personalised antitumour necrosis factor-alpha (anti-TNFα) therapy where measurements of serum trough levels of drug and anti-drug antibodies (Abs) have been used to prospectively guide interventions according to proposed underlying immune-pharmacological basis for treatment failure. The study builds on our original hypothesis, which operates with IFX treatment failure caused by (1) drug immunogenicity with blockade of drug-mediated TNF-neutralisation by anti-IFX Abs and/or anti-IFX Ab-mediated increased drug clearance; (2) non-immune-mediated pharmacokinetic issues with low circulating IFX trough levels without anti-IFX Abs; or (3) in case of high circulating TNF-neutralising capacity pharmacodynamic issues with loss of...

Source: Gut - July 9, 2015 Category: Gastroenterology Authors: Steenholdt, C., Ainsworth, M. A. Tags: PostScript Source Type: research