Infliximab Trough Levels Are Not Predictive of Relapse in Patients with IBD in Endoscopic Remission: A Multicenter Cohort Study

Abstract

Background-Therapeutic drug monitoring (TDM) is important in optimizing use of biologics in inflammatory bowel diseases (IBD). However, the role of proactive TDM during remission remains uncertain.Methods-This retrospective study included patients receiving infliximab (IFX) therapy at Massachusetts General Hospital (MGH) or Erasmus University Medical Center (EMC). All eligible patients had completed induction phase of IFX and were in clinical and endoscopic remission. Our primary outcome was clinical relapse within 2 years after baseline. Multivariable regression models examined the association between infliximab trough levels during remission and relapse, need for IBD-related surgery or hospitalization.Results-Our study cohort included 110 patients with IBD (72 CD, 38 UC) on IFX maintenance therapy. In total 12 patients (10.9%) experienced relapse of disease over 2 years. The mean IFX trough level at baseline was 8.0 μg/mL (±8.6) and did not differ between the institutions. 49.1% of patients had levels < 5μg/mL and 2.7% had antibodies to infliximab at baseline. There was no difference in the mean IFX trough levels between patients who relapsed (7.5 μg/mL ± 3.7 μg/mL) over 24 months compared to those who did not (8.1 μg/mL ± 7.9 μg/mL, p=0.815). On multivariable logistic regression analysis, IFX trough levels at baseline were not associated with relapse of disease over 24 months (OR 1.01, 95%CI 0.93 -1.09, p=0.856).Terms of use and reuse: academic research for non-commercial purposes, see here for full terms. https://www.springer.com/aam terms-v1

Advantages of Proactive Therapeutic Drug Monitoring in a Prospective Cohort of Children With Inflammatory Bowel Disease Treated With Anti‐Tumour Necrosis Factor

“…A comprehensive literature review and expert consensus statement recently added further clarity on the benefits of reactive and proactive TDM of biologic treatments, particularly anti-TNF (15). The topic still remains, however, largely debated (17).…”

Therapeutic Drug Monitoring of Non-Anti-Tumor Necrosis Factor Biologics

“…1 In contrast, even for anti-TNF therapy, there is less robust data on whether proactive TDM during quiescence beneficially impacts maintenance of sustained remission with recent studies demonstrating mixed results. 2 For the non-anti-TNF agents, the utility of TDM is less well-proven; there may be several reasons for this. First, the concept of fecal loss during active inflammation resulting in subtherapeutic trough concentration is less well proven for the non-TNF biologic agents.…”

Highs and Lows of Proactive Therapeutic Drug Monitoring in Crohn’s Patients

“…Moreover, and of concern, it is not possible to predict which patients will respond to which biologic therapies. Borren et al [5] reported stable infliximab concentrations over time in their patient population, albeit data were only available for a limited percentage of their patient population. The stability was posited to be due to less fecal loss of drug in quiescent disease.…”

“…The need to optimize a level when someone is in remission, however, remains unclear. The study by Borren et al [5] suggests that this level is likely to remain stable and does not predict the risk of flaring. In fact, their study showed no difference in trough levels in those who relapsed versus those who did not (7.5 μg/mL ± 3.7 μg/mL vs. 8.1 μg/mL ± 7.9 μg/mL, p = 0.815) even though levels were typically above the target 5 μg/mL [5].…”

“…The study by Borren et al published in this issue of Digestive Diseases and Sciences [5] sought to help address some of these questions by studying the effects of TDM in patients with quiescent IBD receiving infliximab maintenance therapy. Patients were confirmed to be in clinical and endoscopic remission.…”