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World J Gastroenterol. Oct 7, 2021; 27(37): 6231-6247
Published online Oct 7, 2021. doi: 10.3748/wjg.v27.i37.6231
Therapeutic drug monitoring in inflammatory bowel disease: The dawn of reactive monitoring
Farah Albader, Petra Anna Golovics, Lorant Gonczi, Talat Bessissow, Waqqas Afif, Peter Laszlo Lakatos
Farah Albader, Department of Internal Medicine, McGill University, Montreal H3G1A4, Quebec, Canada
Petra Anna Golovics, Division of Gastroenterology, Hungarian Defence Forces, Medical Centre, Budapest H-1062, Hungary
Petra Anna Golovics, Waqqas Afif, Peter Laszlo Lakatos, Division of Gastroenterology, McGill University, Montreal H3G 1A4, Quebec, Canada
Lorant Gonczi, First Department of Medicine, Semmelweis University, Budapest H-1083, Hungary
Talat Bessissow, Division of Gastroenterology, McGill University Health Centre, Montreal H3G 1A4, Quebec, Canada
Author contributions: All authors contributed equally to this paper with regards to the conception and structure of the paper in addition to the literature review, drafting and revision with unanimous approval of the final version.
Conflict-of-interest statement: Authors declare no conflict of interest.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Peter Laszlo Lakatos, MD, PhD, Professor, Staff Physician, Division of Gastroenterology, McGill University, 1650 Cedar Avenue, Montreal H3G 1A4, Quebec, Canada. kislakpet99@gmail.com
Received: March 19, 2021
Peer-review started: March 19, 2021
First decision: May 1, 2021
Revised: May 8, 2021
Accepted: August 31, 2021
Article in press: August 31, 2021
Published online: October 7, 2021
Processing time: 193 Days and 14.5 Hours
Abstract

Inflammatory bowel disease (IBD) is a chronic condition that significantly affects the quality of life of its patients. Biologic drugs have been the mainstay treatment in the management of IBD patients but despite their significant contribution, there remains a proportion of patients that do not respond or lose response to treatment. Therapeutic drug monitoring (TDM) involves measuring levels of serum drug concentrations and anti-drug antibodies. TDM of biologic drugs initially emerged to understand treatment failure in other immune mediated inflammatory diseases. This was then introduced in IBD to rationalize primary non-response or secondary loss of response, given that low serum drug concentrations or the formation of anti-drug antibodies are variably associated with treatment failure. The aim of this narrative review is to provide an overview regarding the current use of TDM in clinical practice and to present the evidence available regarding its use in both proactive and reactive clinical settings in preventing and managing treatment failure. This review also presents the existing evidence regarding the association of various clinical outcomes with specific thresholds of drug concentrations, in everyday practice. A narrative review of published articles and conference abstracts regarding the use of TDM in IBD management, through an electronic search using PubMed and ScienceDirect. TDM has proven to be superior and more cost effective in guiding management of patients with treatment failure compared to empiric dose escalation or change in treatment. Despite a trend towards an association between clinical outcomes and drug concentrations, proactive TDM based strategies have not been shown to achieve clear benefit in long-term outcomes. In the clinical setting, TDM has proven to be useful in managing IBD patients, and its use in the reactive setting, as an additional tool to help manage patients with treatment failure, is being promoted as newer guidelines and consensus groups implement TDM as part of the management plan.

Keywords: Therapeutic drug monitoring; Inflammatory bowel disease; Biologic therapies; Loss of response; Reactive; Proactive

Core Tip: In this review, we discuss the existing studies that looked at both proactive and reactive therapeutic drug monitoring (TDM) and concluded that in current practice, reactive TDM has been shown to be useful. When used as an adjunct to clinical assessment and biomarkers in patients with treatment failure, TDM has proven to be a valuable tool for subsequent management.