Updates in therapeutic drug monitoring in inflammatory bowel disease

Reactive Immunomodulator Addition to Infliximab Monotherapy Restores Clinical Response in Inflammatory Bowel Disease: A Meta-Analysis

BACKGROUND AND AIMS

Patients with inflammatory bowel disease (IBD) receiving infliximab (IFX) commonly experience immunogenic loss of response (LOR) by formation of anti-drug antibodies (ADAs). An immunomodulator (IMM) used in combination with initial IFX induction is known to reduce ADA development and improve clinical outcomes. We aimed to assess the impact of reactively adding an IMM to patients on IFX monotherapy.

METHODS

We conducted a retrospective cohort study and systematic review with meta-analysis of patients with IBD demonstrating immunologic LOR, with or without clinical LOR, that had an IMM (azathioprine, 6-mercaptopurine, or methotrexate) reactively added (reactive combination therapy; rCT) to combat elevated ADAs and raise IFX level. Data were extracted for pooled effect size estimation using random-effects models, and ADA and IFX trough levels were compared pre- and post-IMM initiation.

RESULTS

We identified 6 patients who received rCT due to rising ADA titers and low IFX levels. Median ADA titer decreased from 506 ng/mL (interquartile range (IQR) [416-750]) to 76.5 ng/mL (IQR [25.8-232]), an 85% decrease (p = 0.031). Median IFX trough increased from 0.4 µg/mL (IQR [0.4-0.48]) to 8.25 µg/mL (IQR [3.7-9.6]), a 20.6-fold increase (p = 0.038). Meta-analysis pooled effect size of 7 studies with 89 patients showed an 87% ADA titer reduction [95% confidence interval (CI) = 72-94%], 6.7-fold increased IFX trough (95% CI = 2.4-18.7), and 76% clinical remission rescue rate (95% CI = 59-93%).

CONCLUSIONS

These results suggest rCT is a valid rescue strategy in patients with immunogenic LOR to IFX to reduce ADA titers, restore therapeutic IFX levels, and recapture clinical remission of IBD.

Recent Advances in the Optimization of Anti-TNF Treatment in Patients with Inflammatory Bowel Disease

Despite the evolution in inflammatory bowel disease (IBD) management during the last 20 years owing to the advent of new advanced therapies, anti-TNF agents still remain the cornerstone of therapy for both Crohn's disease and ulcerative colitis. However, this does not only secure favorable outcomes for patients considering the progressive disease character and the high likelihood of primary or secondary loss of response. Therefore, trying to reach a better treatment approach and maximize the benefits anti-TNF agents offer, optimization strategies should be examined. It has been indicated that optimizing treatment with anti-TNF enhances drug efficacy and has been associated with improved disease outcomes and a complication-free disease course. From this perspective, we aim to provide an overview of currently available data and recent advances in the practices of anti-TNF treatment optimization. Special focus has been given to the role of therapeutic drug monitoring (TDM), as well as the utility of combining anti-TNF with an immunomodulator and the treat-to-target approach.

Impact of Obesity on the Course of Management of Inflammatory Bowel Disease—A Review

It is already well-known that visceral adipose tissue is inseparably related to the pathogenesis, activity, and general outcome of inflammatory bowel disease (IBD). We are getting closer and closer to the molecular background of this loop, finding certain relationships between activated mesenteric tissue and inflammation within the lumen of the gastrointestinal tract. Recently, relatively new data have been uncovered, indicating a direct impact of body fat on the pattern of pharmacological treatment in the course of IBD. On the other hand, ileal and colonic types of Crohn’s disease and ulcerative colitis appear to be more diversified than it was thought in the past. However, the question arises whether at this stage we are able to translate this knowledge into the practical management of IBD patients or we are still exploring the scientific background of this pathology, having no specific tools to be used directly in patients. Our review explores IBD in the context of obesity and associated disorders, focusing on adipokines, creeping fat, and possible relationships between these disorders and the treatment of IBD patients.