Loss of Response to Anti-TNFs: Definition, Epidemiology, and Management

Improved high-performance liquid chromatography tandem mass spectrometry method for quantification of infliximab in pediatric plasma and its application in therapeutic drug monitoring

RATIONALE

The application of infliximab (IFX) to immune-mediated disease is limited by the significant individual variability and associated clinical nonresponse, emphasizing the importance of therapeutic drug monitoring (TDM). Because of the cross-reactivity, limited linear range, and high costs, the clinical application of the previous reported methods was limited. Here, an improved high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method was developed to address the issues.

METHODS

This study developed an improved bioanalytical HPLC-MS/MS method coupling nanosurface and molecular-orientation limited proteolysis technology. The commercially available compound P14R was selected as the internal standard. This method was developed with fewer volume of reagents and was thoroughly validated. The validated method was applied to TDM in pediatric inflammatory bowel disease (IBD).

RESULTS

Chromatography was performed using a Shim-pack GISS-HP C18 metal-free column (3 μm, 2.1 × 100 mm) with a gradient elution of 0.1% formic acid in water and acetonitrile at 0.4 mL/min. Detection and quantitation were performed using electrospray ionization (ESI) and multiple reaction monitoring in the positive ion mode. The method was validated to demonstrate its selectivity, linearity, accuracy, precision, recovery, matrix effect, and stability. The method exhibited a linear dynamic range of 0.3-100 μg/mL, with intra- and inter-day precision and relative errors below 15%. The recovery and matrix effect were measured as 87.28%-89.72% and 41.98%-67.17%, respectively, which were effectively compensated by the internal standard. A total of 32 samples collected from 24 pediatric patients with IBD were analyzed using the validated method, and only 46.9% achieved the reported targeted trough level.

CONCLUSION

This study developed an improved HPLC-MS/MS method for the quantitative determination of IFX concentration in human plasma. The accurate, reliable, and cost-effective method was validated and utilized in the analysis of clinical samples. The results confirmed the importance of TDM on IFX and the clinical application prospects of the improved method.

4-Octyl itaconate alleviates dextran sulfate sodium-induced ulcerative colitis in mice via activating the KEAP1-NRF2 pathway

Ulcerative colitis (UC) is a chronic idiopathic inflammatory bowel disease with a relapsing-remitting course. Although its etiology remains unknown, excessive oxidative stress in colon is a major intermediate factor that can promote the progression of UC. In the present study, we investigated the effect and the underlying mechanisms of 4-Octyl itaconate (OI) on dextran sulfate sodium (DSS)-induced UC in mice. Our work identified that OI alleviated the colitis by reducing the oxidative stress and the apoptosis in colon tissue, then increasing the tight junction proteins expression and in turn enhancing the intestinal barrier function, thereby creating less severe inflammatory responses. Moreover, our results demonstrated that OI reduced the Kelch-like ECH-associated protein 1 (KEAP1) expression and subsequent upregulated nuclear factor E2-related factor (NRF2) expression and its nuclear translocation which in turn induced the expression of glutathione S-transferase (GST) and NAD(P)H: quinone oxidoreductase 1 (NQO1). In addition, ML385, a NRF2 antagonist, can inhibit the protective effects of OI on UC, indicating that the role of OI in this colitis model could be dependent on the activation of KEAP1-NRF2 pathway. Notably, OI co-administration significantly enhanced the therapeutic effects of mesalazine or 1400W on UC. Collectively, itaconate may have a great potential for use in the treatment of IBD.

Fluorescence-Based Lateral Flow Immunoassay for Quantification of Infliximab: Analytical and Clinical Performance Evaluation

BACKGROUND

Therapeutic drug monitoring of infliximab (IFX) can improve treatment outcomes; however, the temporal gap between drug concentration monitoring and subsequent availability restricts its practical application. To address this issue, an automated monitoring method, AFIAS IFX, was developed to rapidly and accurately analyze IFX concentration in blood. The analytical and clinical performances of this method were assessed to establish its clinical utility.

METHODS

The analytical performance of AFIAS IFX was evaluated according to Clinical and Laboratory Standard Institute guidelines. For clinical validation, AFIAS IFX was compared with 3 established enzyme-linked immunosorbent assay kits (LISA TRACKER, RIDASCREEN, and ImmunoGuide) using 100 consecutive samples from 28 patients treated with IFX. Passing-Bablok regression and Bland-Altman analyses were performed to compare the methods.

RESULTS

The detection and quantification limits of AFIAS IFX were 0.12 and 0.20 mcg/mL, respectively. Furthermore, AFIAS IFX analyzed samples within 10 minutes for concentrations up to 50 mcg/mL, exhibiting reproducibility (coefficient of variation [CV] ≤7.8%) and accuracy (recovery 98%-101%) with serum, plasma, and whole blood samples. Clinically, it exhibited a good correlation with the 3 established enzyme-linked immunosorbent assay kits. For patients treated with Remicade (IFX), the Passing-Bablok regression slope was 1.001-1.259, with a mean difference of -1.48 to 0.28 mcg/mL. For patients treated with CT-P13, the Passing-Bablok regression slope was 0.974-1.254, with a mean difference of -2.44 to 0.15 mcg/mL.

CONCLUSIONS

AFIAS IFX, a novel fluorescence-based lateral flow assay, exhibited excellent performance in analyzing IFX trough levels and is a potentially powerful tool for therapeutic drug monitoring in clinical settings, with opportunities for further development.

Switching within versus out of class following first-line TNFi failure in ulcerative colitis: real-world outcomes from a German claims data analysis

Background

Biologic agents have demonstrated efficacy in treating ulcerative colitis (UC); however, treatment failure to tumor necrosis factor inhibitors (TNFi) is common in the real world. Data on preferential sequencing in clinical practice after failure remain limited.

Objectives

This study aimed to evaluate real-world outcomes of patients cycling to TNFis or switching to non-TNFi biologics following first-line failure with TNFis.

Design

Retrospective cohort study in Germany.

Methods

Adult patients with UC were identified using administrative claims data from 1 May 2014 to 30 June 2022 provided by a statutory sickness fund. Patients newly initiating first-line therapy with TNFis and then switching to another agent were identified. Patients were defined as within-class switched (WCS), if they cycled to another TNFi, or outside-class switchers (OCS), if they switched to a non-TNFi biologic [ustekinumab (UST) or vedolizumab (VDZ)] and followed from index (switch date) to death, insurance end, or study end on 30 June 2022. Inverse probability of treatment weighting (IPTW) was performed to adjust for differences in baseline characteristics between groups, and weighted Cox regression models were used to compare primary (time to discontinuation and second treatment switch) and secondary outcomes (corticosteroid-free drug survival).

Results

We identified 166 patients initiating TNFis and switching to a subsequent treatment (mean age: 42.9 years, 49.4% female). Following IPTW, there were 71 and 76 patients in the WCS and OCS groups, respectively. Compared to OCS, WCS were more likely to discontinue the new therapy [hazard ratio (HR), 1.82, 95% confidence interval (CI), 1.14-2.89, p = 0.012], and switch a second time (HR, 3.46, 95% CI, 1.89-6.36, p < 0.001). Moreover, WCS showed an increased likelihood of initiating prolonged corticosteroid therapy (HR, 1.42, 95% CI, 0.77-2.59, p = 0.260); however, the results were not significant.

Conclusion

Following first-line TNFi failure, this study suggests that real-world outcomes among patients with UC are less favorable when cycling to another TNFi, compared to switching to a non-TNFi such as UST or VDZ.

A Network-Based Framework to Discover Treatment-Response-Predicting Biomarkers for Complex Diseases

Precision medicine's potential to transform complex autoimmune disease treatment is often challenged by limited data availability and inadequate sample size when compared with the number of molecular features found in high-throughput multi-omics data sets. Addressing this issue, the novel framework PRoBeNet (Predictive Response Biomarkers using Network medicine) was developed. ProBeNet operates under the hypothesis that the therapeutic effect of a drug propagates through a protein-protein interaction network to reverse disease states. ProBeNet prioritizes biomarkers by considering the following: i) therapy-targeted proteins, ii) disease-specific molecular signatures, and iii) an underlying network of interactions among cellular components (the human interactome). With ProBeNet, biomarkers were discovered predicting patient responses to both an established autoimmune therapy (infliximab) and an investigational compound (a mitogen-activated protein kinase 3/1 inhibitor). The predictive power of ProBeNet biomarkers was validated with retrospective gene-expression data from patients with ulcerative colitis and rheumatoid arthritis and prospective data from patient-derived tissues from patients with ulcerative colitis and Crohn disease. Machine-learning models using ProBeNet biomarkers significantly outperformed models using either all genes or randomly selected genes, especially when data were limited (<20 samples). These results illustrate the value of ProBeNet for reducing features and for constructing robust machine-learning models when limited data are available. ProBeNet may be used to develop companion and complementary diagnostic assays for complex autoimmune disease therapies, which may help stratify suitable patient subgroups in clinical trials, approve new drugs, and improve patient outcomes.

The potential for medical therapies to address fistulizing Crohn's disease: a state-of-the-art review

INTRODUCTION

Crohn's disease (CD) is a chronic, relapsing immune mediated disease, which is one of the two major types of inflammatory bowel disease (IBD). Fistulizing CD poses a significant clinical challenge for physicians. Effective management of CD requires a multidisciplinary approach, involving a gastroenterologist and a GI surgeon while tailoring treatment to each patient's unique risk factors, clinical representations, and preferences.

AREAS COVERED

This comprehensive review explores the intricacies of fistulizing CD including its manifestations, types, impact on quality of life, management strategies, and novel therapies under investigation.

EXPERT OPINION

Antibiotics are often used as first-line therapy to treat symptoms. Biologics that selectively target TNF-α, such infliximab (IFX), have shown high efficacy in randomized controlled trials. However, more than 50% of patients lose response to IFX, prompting them to explore alternative strategies. Current options include adalimumab and certolizumab pegol combination therapies, as well as small-molecule drugs targeting Janus kinases such as Upadacitinib. Furthermore, a promising treatment for complex fistulas is mesenchymal stem cells such as Darvadstrocel (Alofisel), an allogeneic stem cell-based therapy. However, surgical interventions are necessary for complex cases or intra-abdominal complications. Setons and LIFT procedures are the most common surgical options.

HLA-DQA1*05 correlates with increased risk of anti-drug antibody development and reduced response to infliximab in Chinese patients with Crohn's disease

Background

The efficacy of anti-TNF therapy in Crohn's disease (CD), such as infliximab, is often compromised by the development of anti-drug antibodies (ADAs). The genetic variation HLA-DQA1*05 has been linked to the immunogenicity of biologics, influencing ADA formation. This study investigates the correlation between HLA-DQA1*05 and ADA formation in CD patients treated with infliximab in a Chinese Han population and assesses clinical outcomes.

Methods

In this retrospective cohort study, 345 infliximab-exposed CD patients were genotyped for HLADQ A1*05A > G (rs2097432). We evaluated the risk of ADA development, loss of infliximab response, adverse events, and treatment discontinuation among variant and wild-type allele individuals.

Results

A higher percentage of patients with ADAs formation was observed in HLA-DQA1*05 G variant carriers compared with HLA-DQA1*05 wild-type carriers (58.5% vs 42.9%, P = 0.004). HLA-DQA1*05 carriage significantly increased the risk of ADAs development (adjusted hazard ratio = 1.65, 95% CI 1.18-2.30, P = 0.003) and was associated with a greater likelihood of infliximab response loss (adjusted HR = 2.55, 95% CI 1.78-3.68, P < 0.0001) and treatment discontinuation (adjusted HR = 2.21, 95% CI 1.59-3.06, P < 0.0001). Interestingly, combined therapy with immunomodulators increased the risk of response loss in HLA-DQA1*05 variant carriers.

Conclusions

HLA-DQA1*05 significantly predicts ADAs formation and impacts treatment outcomes in infliximab-treated CD patients. Pre-treatment screening for this genetic factor could therefore be instrumental in personalizing anti-TNF therapy strategies for these patients.

Protective properties of Ophiopogonin D in DSS-induced colitis: insights into microbiota modulation

BACKGROUND

Ulcerative colitis (UC), a chronic inflammatory gastrointestinal disorder, is becoming increasingly prevalent worldwide. Ophiopogonin D, which is derived from Ophiopogon japonicus, exhibits anti-inflammatory and antioxidant properties, yet its therapeutic potential in UC remains unclear.

METHODS

In this study, we employed a mouse model of DSS-induced colitis to assess the impact of Ophiopogonin D on various parameters, including weight loss, bloody stools, and inflammation in the colon.

RESULTS

Ophiopogonin-D treatment significantly mitigated these DSS-induced effects, improved colon permeability, and modulated inflammatory markers like ZO-1, MUC-2, TNF-α, and IL-1β in mice compared with the control. Furthermore, compared to the DSS-treatment group, Ophiopogonin-D treatment improved the α- and β-diversity indices of the mouse intestinal microbiota, along with an increase in the abundance of genera such as Akkermansia (AKK) and a decrease in the abundance of genera such as Enterobacter. Notably, propionic acid, a metabolite of AKK, demonstrated significant improvement in the symptoms of DSS-induced colitis in mice compared to the control. Moreover, propionic-acid administration also resulted in alterations in the levels of inflammatory factors and calreticulin within the intestinal tissues.

CONCLUSION

Overall, Ophiopogonin D significantly affects intestinal microbiota composition, thereby improving symptoms of DSS-induced colitis in mice. These findings present promising therapeutic strategies and potential pharmaceutical candidates for the treatment of ulcerative colitis.

Switching from Dose-Intensified intravenous to SubCutaneoUS infliximab in Inflammatory Bowel Disease (DISCUS-IBD): protocol for a multicentre randomised controlled trial

INTRODUCTION

A substantial proportion of patients with inflammatory bowel disease (IBD) on intravenous infliximab require dose intensification. Accessing additional intravenous infliximab is labour-intensive and expensive, depending on insurance and pharmaceutical reimbursement. Observational data suggest that subcutaneous infliximab may offer a convenient and safe alternative to maintain disease remission in patients requiring dose-intensified infliximab. A prospective, controlled trial is required to confirm that subcutaneous infliximab is as effective as dose-intensified intravenous infliximab, to identify predictors of disease flare and to establish the role of subcutaneous infliximab therapeutic drug monitoring.

METHODS AND ANALYSIS

The DISCUS-IBD trial is an investigator-initiated, prospective, multicentre, randomised, open-label non-inferiority study comparing the rate of disease flares in participants randomised to continue dose-intensified intravenous infliximab to those switched to subcutaneous infliximab after 48 weeks. Participants are adult patients with IBD in sustained corticosteroid-free remission on any regimen of dose-intensified infliximab up to a maximum of 10 mg/kg 4-weekly intravenously. Participants allocated to intravenous infliximab will continue infliximab at the same dose-intensified regimen they were receiving at study enrolment. Subcutaneous infliximab dosing will be stratified by prior intravenous infliximab dosing. Clinical (Harvey-Bradshaw Index, partial Mayo score), biochemical (C reactive protein, faecal calprotectin), pharmacokinetic (drug-level±antidrug antibodies) and qualitative data are collected 12-weekly until study conclusion at week 48. 13 sites across Australia will participate in recruitment to reach a calculated sample size of 120 participants.

ETHICS AND DISSEMINATION

Multisite ethics approval was obtained from the Health District Human Research Ethics Committee (HREC) at The Alfred Hospital under a National Mutual Acceptance (NMA) agreement (HREC/90559/Alfred-2022; Local Reference: Project 618/22, version 1.6, 2 March 2023). Findings will be reported at national and international gastroenterology meetings and published in peer-reviewed journals. DISCUS-IBD was prospectively registered with the Australian and New Zealand Clinical Trials Registry (ANZCTR) prior to commencing recruitment.

TRIAL REGISTRATION NUMBER

ACTRN12622001458729.

G Protein-Coupled Estrogen Receptor-Mediated Anti-Inflammatory and Mucosal Healing Activity of a Trimethylpyridinol Analogue in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is characterized by abnormal immune responses, including elevated proinflammatory cytokines, such as tumor necrosis factor-α (TNFα) and interleukin-6 (IL-6) in the gastrointestinal (GI) tract. This study presents the synthesis and anti-inflammatory evaluation of 2,4,5-trimethylpyridin-3-ol analogues, which exhibit dual inhibition of TNFα- and IL-6-induced inflammation. Analysis using in silico methods, including 3D shape-based target identification, modeling, and docking, identified G protein-coupled estrogen receptor 1 (GPER) as the molecular target for the most effective analogue, 6-26, which exhibits remarkable efficacy in ameliorating inflammation and restoring colonic mucosal integrity. This was further validated by surface plasmon resonance (SPR) assay results, which showed direct binding to GPER, and by the results showing that GPER knockdown abolished the inhibitory effects of 6-26 on TNFα and IL-6 actions. Notably, 6-26 displayed no cytotoxicity, unlike G1 and G15, a well-known GPER agonist and an antagonist, respectively, which induced necroptosis independently of GPER. These findings suggest that the GPER-selective compound 6-26 holds promise as a therapeutic candidate for IBD.

Real-life effectiveness and safety of vedolizumab in moderate-to-severe ulcerative colitis: A single-center experience in Northern China

Vedolizumab (VDZ), a monoclonal antibody to α4β7 integrin, is available for patients with moderate-to-severe ulcerative colitis (UC). This study planned to assess the real-world effectiveness and safety of VDZ for UC patients in Northern China. We enrolled patients with moderate-to-severe UC who underwent VDZ induction therapy from March 2021 to November 2022 at the Affiliated Hospital of Qingdao University. The primary outcome was clinical remission at weeks 14 and 52 after the initial VDZ therapy. Overall adverse events and risk factors associated with loss of response (LOR) were also evaluated. Seventy-three UC patients receiving VDZ therapy were included in this study. The rates of clinical response, clinical remission, and steroid-free clinical remission were 69.9%, 39.7%, and 34.2% at week 14 and 90.5%, 66.7%, and 64.4% at week 52, respectively. The mucosal remission rates were 37.5% (18/48) at week 14 ± 8 and 27.3% (9/33) at week 52 ± 16, while only 2 and 3 patients achieved mucosal healing at weeks 14 ± 8 and 52 ± 16, respectively. Of the UC patients, 23.3% experienced adverse events associated with VDZ, most of which were mild and self-limiting. Until the last follow-up, 37 of 73 UC patients experienced LOR during the maintenance period. Patients with a higher ulcerative colitis endoscopic severity index (UCEIS), partial Mayo scores (PMS), or hemoglobin below 120 g/L at baseline were more likely to experience LOR after VDZ induction therapy. VDZ is an effective and safe agent for patients with moderate-to-severe UC in Northern China. A high baseline UCEIS, PMS, or hemoglobin < 120 g/L may be an independent risk factor for LOR during the maintenance period.

Precision medicine: Externally validated explainable AI support tool for predicting sustainability of infliximab and vedolizumab in ulcerative colitis

OBJECTIVE

Drug sustainability (DS), a surrogate marker for drug efficacy, is important, especially when aiming for precision medicine. However, it lacks reliable prediction methods.

AIMS

To develop and externally validate a web-based artificial intelligence(AI)-derived tool for predicting DS of infliximab and vedolizumab in patients with moderate-to-severe Ulcerative Colitis (UC).

METHODS

Data from three Israeli centers included infliximab or vedolizumab patients treated for >54 weeks. Sustainability meant no corticosteroids, hospitalizations or surgeries. Machine learning techniques predicted >54-week and overall DS using baseline clinical data.

RESULTS

The model was developed using data from 246 patients from Rabin Medical Center and externally validated on 67 patients from Rambam Health Care Campus and Sheba Medical Center. No significant difference in DS was observed across the datasets. Most patients were biologic-naïve and primarily treated with vedolizumab. The model performed well, with an area under the ROC curve of 0.86, and showed good accuracy (65.5 %-76.9 %) across the test sets.

CONCLUSIONS

The study introduces a novel, AI-based tool for predicting >54-week DS of infliximab and vedolizumab in moderate-to-severe UC, using baseline parameters. This can aid clinical decision-making in the framework of precision medicine, promising to optimize disease management while maintaining physician autonomy.

Vedolizumab, Adalimumab, and Methotrexate Combination Therapy in Crohn's Disease (EXPLORER)

BACKGROUND & AIMS

Although biologics have revolutionized the treatment of Crohn's disease (CD), an efficacy ceiling has been reached. Combining biologic therapies may improve remission rates.

METHODS

EXPLORER, a phase 4, single-arm, open-label study, evaluated triple combination therapy with vedolizumab (300 mg on day 1, weeks 2 and 6, and then every 8 weeks), adalimumab (160 mg on day 2, 80 mg at week 2, then 40 mg every 2 weeks), and methotrexate (15 mg weekly) in biologic-naïve patients with newly diagnosed, moderate- to high-risk CD. Endoscopic remission at week 26 (primary end point; Simple Endoscopic Score for CD ≤2), clinical remission at weeks 10 and 26 (secondary end point; Crohn's Disease Activity Index <150), and incidences of adverse events and serious adverse events were evaluated.

RESULTS

Among 55 enrolled patients, the mean CD duration was 0.4 years, the mean baseline Simple Endoscopic Score for CD was 12.6, and the mean baseline Crohn's Disease Activity Index was 265.5. At week 26, 19 patients (34.5%) were in endoscopic remission. At weeks 10 and 26, 34 (61.8%) and 30 patients (54.5%), respectively, were in clinical remission. Post hoc Bayesian analysis showed that the probabilities that triple combination therapy produced a higher endoscopic remission rate (33.5%; 95% credible interval, 22.4-45.7) than placebo (14%), vedolizumab monotherapy (27%), or adalimumab monotherapy (30%) were 99.9% or higher, 86.3%, and 71.4%, respectively. Six patients had serious adverse events.

CONCLUSIONS

Combination therapy resulted in endoscopic and clinical remission at week 26 in 34.5% and 54.5% of patients, respectively, with no safety signal related to the treatment regimen. This supports further evaluation of combination therapy in CD.

CLINICALTRIALS

gov number: NCT02764762.

Solute Transporter OCTN1/Slc22a4 Affects Disease Severity and Response to Infliximab in Experimental Colitis: Role of Gut Microbiota and Immune Modulation

BACKGROUND

Inflammatory bowel diseases are chronic disabling conditions with a complex and multifactorial etiology, still incompletely understood. OCTN1, an organic cation transporter, could have a role in modulating the inflammatory response, and some genetic polymorphisms of this molecule have been associated with increased risk of inflammatory bowel diseases. Until now, limited information exists on its potential in predicting/modulating patient's response to therapies. The aim of this study was to evaluate the role of OCTN1 in modifying gut microbiota and mucosal immunity in response to infliximab therapy in murine colitis.

METHODS

A dextran sodium sulphate model of colitis was used to assess the clinical efficacy of infliximab administered intravenously in ocnt1 gene knockout mice and their C57BL/6 controls. Stool, colon, and mesenteric lymph node samples were collected to evaluate differences in gut microbiota composition, histology, and T cell populations, respectively.

RESULTS

Octn1 -/- influences the microbiota profile and is associated with a worse dysbiosis in mice with colitis. Infliximab treatment attenuates colitis-associated dysbiosis, with an increase of bacterial richness and evenness in both strains. In comparison with wild type, octn1-/- mice have milder disease and a higher baseline percentage of Treg, Tmemory, Th2 and Th17 cells.

CONCLUSIONS

Our data support the murine model to study OCTN1 genetic contribution to inflammatory bowel diseases. This could be the first step towards the recognition of this membrane transporter as a biomarker in inflammatory conditions and a predictor of response to therapies.

Impact of a Patient Support Program on time to discontinuation of adalimumab in Australian adult patients with immune-mediated inflammatory diseases-an observational study

This observational study evaluated the impact of a sponsor company-provided Patient Support Program (PSP) on discontinuation of adalimumab in adult Australian patients eligible for Pharmaceutical Benefit Scheme (PBS)-reimbursed adalimumab for Rheumatoid Arthritis (RA), Ankylosing Spondylitis (AS), Psoriatic Arthritis (PsA), Crohn's Disease (CD), Ulcerative Colitis (UC), or Hidradenitis Suppurativa (HS). Patients initiating adalimumab between May 2018 and September 2019 were enrolled into two prospective cohorts based on their decision to opt for or decline the PSP (PSP or non-PSP cohorts). In addition, a historical, retrospective Non-PSP cohort was established from the Services Australia 10% PBS dataset by extracting data of patients initiating adalimumab prior to the introduction of adalimumab PSPs and based on adalimumab PBS listing dates (AS: April 2007 to March 2009; PsA/RA: January 2007 to December 2008; CD: January 2009 to December 2010; HS and UC indications not included). Follow-up for all cohorts was 12 months. The primary endpoint was the time to discontinuation, compared between the prospective PSP cohort and the prospective or retrospective Non-PSP cohort. Inverse probability of treatment weighting was used to balance the cohorts. A Cox proportional hazards model indicated no difference in time to discontinuation between the prospective PSP (n = 162) and non-PSP (n = 65) cohorts (HR [95% CI] = 1.256 [0.616-2.563], p = 0.5304). The 12-month adalimumab persistence rates (95% CI) were 78% (69%, 84%) and 82% (67%, 90%), respectively. In contrast, discontinuation was less likely in the prospective PSP (n = 151) compared with the retrospective non-PSP (n = 297) cohort (HR [95% CI] = 0.44 [0.28-0.68], p<0.001). The 12-month persistence rates (95% CI) were 81% (76%, 90%) and 61% (56%, 67%), respectively. Overall, this study suggests that optimal adalimumab persistence can be achieved with either a structured PSP or healthcare support from other sources, but this was not the case more than a decade ago.

Enterococcus-derived tyramine hijacks α2A-adrenergic receptor in intestinal stem cells to exacerbate colitis

Inflammatory bowel disease (IBD) is characterized by dysbiosis of the gut microbiota and dysfunction of intestinal stem cells (ISCs). However, the direct interactions between IBD microbial factors and ISCs are undescribed. Here, we identify α2A-adrenergic receptor (ADRA2A) as a highly expressed GPCR in ISCs. Through PRESTO-Tango screening, we demonstrate that tyramine, primarily produced by Enterococcus via tyrosine decarboxylase (tyrDC), serves as a microbial ligand for ADRA2A. Using an engineered tyrDC-deficient Enterococcus faecalis strain and intestinal epithelial cell-specific Adra2a knockout mice, we show that Enterococcus-derived tyramine suppresses ISC proliferation, thereby impairing epithelial regeneration and exacerbating DSS-induced colitis through ADRA2A. Importantly, blocking the axis with an ADRA2A antagonist, yohimbine, disrupts tyramine-mediated suppression on ISCs and alleviates colitis. Our findings highlight a microbial ligand-GPCR pair in ISCs, revealing a causal link between microbial regulation of ISCs and colitis exacerbation and yielding a targeted therapeutic approach to restore ISC function in colitis.

Risankizumab Induction Therapy Achieves Early Symptom Improvements That Are Associated With Future Clinical and Endoscopic Outcomes in Crohn's Disease: Post Hoc Analysis of the ADVANCE, MOTIVATE, and FORTIFY Phase 3 Studies

BACKGROUND AND AIMS

Crohn's disease [CD] symptoms are a main driver for impaired quality of life, and fast relief is important for patient care. Stool frequency [SF] and abdominal pain score [APS] are patient-reported outcomes [PROs] measuring symptom severity, which are supported as treatment targets by the STRIDE-II consensus. This post hoc analysis examined the efficacy of risankizumab [RZB], a humanised monoclonal antibody with high specificity for interleukin-23 p19, for providing early symptom relief, along with the prognostic value of early symptom relief for achieving future clinical and endoscopic endpoints.

METHODS

Individual and combined measures of SF and AP at Weeks 1, 2, and 3 were assessed in patients with moderate to severe CD who received 600 mg intravenous RZB or placebo [PBO] in the ADVANCE or MOTIVATE induction studies. Multivariate logistic regression was used to examine the predictiveness of early symptom improvement for clinical and endoscopic outcomes following RZB induction and maintenance.

RESULTS

Higher rates of SF/APS clinical remission and enhanced clinical response were observed as early as Week 1 with RZB vs PBO. A larger proportion of patients achieved clinical endpoints with RZB vs PBO, irrespective of prior bio-failure status. Early PRO improvement was associated with a greater likelihood of achieving clinical and endoscopic improvement following 12-week induction and 52-week maintenance RZB dosing.

CONCLUSIONS

After the first intravenous RZB induction dose, significantly greater rates of symptom improvement vs PBO were achieved. Improvements could be observed as early as Week 1 and were predictive of Weeks 12 and 52 clinical and endoscopic improvement.

Therapeutic sequencing in inflammatory bowel disease: Determining the optimal position of vedolizumab for long-term Crohn's disease control using real-world evidence

BACKGROUND

Several biologics are available for the treatment of moderate to severe Crohn's disease, but data to optimize their use are scarce. Vedolizumab (VDZ) is a gut-selective anti-lymphocyte trafficking monoclonal antibody that was approved in 2014 for the treatment of moderate to severe Crohn's disease. Based on real-world evidence, a model was developed to examine the effect of VDZ's position in the treatment sequence on clinical outcomes.

OBJECTIVE

The aim of this study was to develop a model using real-world data to investigate how the positioning of VDZ in a sequence of biologic therapies for CD affects clinical effectiveness outcomes of quality-adjusted life-years (QALYS), patient-reported disease activity, and surgery rates.

METHODS

A semi-Markov sequential model was developed to identify the optimal position of VDZ in a treatment sequence that included corticosteroids (CS), two biologics, and best supportive care (BSC). Using real-world data, three sequences were compared: VDZ as first (position), second, and last biologic (with anti-tumor necrosis factor alpha agents adalimumab (ADA) and infliximab (IFX) and the anti-interleukin-12 and -23 agent ustekinumab (UST) as alternative biologic treatments). Published real-world evidence informed model inputs. Vedolizumab sequences were compared and ranked based on QALYS, patient-reported outcomes from Crohn's disease activity index scores, or proportion of patients undergoing surgery by the 10-year time horizon for model simulation. Sensitivity analyses were used to evaluate the impact of model input uncertainty.

RESULTS

Vedolizumab as the first biologic was the optimal position for this treatment according to all criteria, including yielding the highest QALYs (5.09) versus VDZ in second (4.97) and third (4.96) biologic sequence positions in sequences containing CS, anti-TNFα (aggregated data), UST, and BSC; 1780/2000 (89%) probabilistic simulations. In sequences containing ADA, VDZ, and UST biologics, ADA and VDZ in the first-line biologic position yielded QALYs of 5.09 versus 5.07, respectively. Adalimumab as the first biologic was best for clinical remission.

CONCLUSIONS

This simulation model using real-world evidence indicates that positioning VDZ or ADA as the first biologic is likely to lead to improved long-term patient outcomes when compared to administering these treatments later or starting with IFX monotherapy.

Development and validation of a novel therapeutic drug monitoring-based nomogram for prediction of primary endoscopic response to anti-TNF therapy in active Crohn's disease

Background

Anti-tumor necrosis factor (TNF) monoclonal antibodies, especially infliximab (IFX) and adalimumab (ADA), are considered the first-line treatment for active Crohn's disease (CD). However, the predictive role of therapeutic drug monitoring (TDM) of serum anti-TNF in monitoring the treatment of inflammatory bowel disease (IBD) remains controversial.

Objectives

To explore the correlation between serum anti-TNF levels and early endoscopic response in active CD using a TDM-based nomogram.

Design

Cross-sectional study.

Methods

The simplified endoscopic activity score for CD (SES-CD), Crohn's disease activity index (CDAI), laboratory parameters, and the serum trough levels of IFX and ADA were assessed.

Results

The trough levels of IFX or ADA were significantly higher in patients with endoscopic response compared to non-responders in the development cohort (p < 0.001). The IFX and ADA levels showed a weak but significantly negative correlation with SES-CD (p < 0.001), CDAI (p < 0.001), and C-reactive protein (CRP) (p < 0.001) at week 14 post-IFX therapy in the development cohort. Furthermore, the receiver operating characteristic curve revealed that an optimal level of IFX (4.80 μg/mL) and ADA (8.80 μg/mL) exhibited the best performance in predicting endoscopic response. Concomitantly, we developed a novel nomogram prediction model based on the results of multivariate logistic regression analysis, which consisted of CRP, albumin (Alb), and anti-TNF trough levels at week 14. The nomogram showed significant discrimination and calibration for both IFX and ADA in the development cohort and performed well in the external validation cohort.

Conclusion

This study demonstrates a robust association between serum concentrations of IFX, ADA, Alb, and CRP and primary endoscopic response in active CD patients. Importantly, the TDM- and laboratory marker-based nomogram may be used to evaluate the primary endoscopic response to anti-TNF therapy, especially for optimizing treatment strategies and switching therapy in CD patients.

Dual engineered bacteria improve inflammatory bowel disease in mice

Currently, there are many different therapies available for inflammatory bowel disease (IBD), including engineered live bacterial therapeutics. However, most of these studies focus on producing a single therapeutic drug using individual bacteria, which may cause inefficacy. The use of dual drugs can enhance therapeutic effects. However, expressing multiple therapeutic drugs in one bacterial chassis increases the burden on the bacterium and hinders good secretion and expression. Therefore, a dual-bacterial, dual-drug expression system allows for the introduction of two probiotic chassis and enhances both therapeutic and probiotic effects. In this study, we constructed a dual bacterial system to simultaneously neutralize pro-inflammatory factors and enhance the anti-inflammatory pathway. These bacteria for therapy consist of Escherichia coli Nissle 1917 that expressed and secreted anti-TNF-α nanobody and IL-10, respectively. The oral administration of genetically engineered bacteria led to a decrease in inflammatory cell infiltration in colon and a reduction in the levels of pro-inflammatory cytokines. Additionally, the administration of engineered bacteria did not markedly aggravate gut fibrosis and had a moderating effect on intestinal microbes. This system proposes a dual-engineered bacterial drug combination treatment therapy for inflammatory bowel disease, which provides a new approach to intervene and treat IBD. KEY POINTS: • The paper discusses the effects of using dual engineered bacteria on IBD • Prospects of engineered bacteria in the clinical treatment of IBD.

Nanomedicine for T-Cell Mediated Immunotherapy

T-cell immunotherapy offers outstanding advantages in the treatment of various diseases, and with the selection of appropriate targets, efficient disease treatment can be achieved. T-cell immunotherapy has made great progress, but clinical results show that only a small proportion of patients can benefit from T-cell immunotherapy. The extensive mechanistic work outlines a blueprint for using T cells as a new option for immunotherapy, but also presents new challenges, including the balance between different fractions of T cells, the inherent T-cell suppression patterns in the disease microenvironment, the acquired loss of targets, and the decline of T-cell viability. The diversity, flexibility, and intelligence of nanomedicines give them great potential for enhancing T-cell immunotherapy. Here, how T-cell immunotherapy strategies can be adapted with different nanomaterials to enhance therapeutic efficacy is discussed. For two different pathological states, immunosuppression and immune activation, recent advances in nanomedicines for T-cell immunotherapy in diseases such as cancers, rheumatoid arthritis, systemic lupus erythematosus, ulcerative colitis, and diabetes are summarized. With a focus on T-cell immunotherapy, this review highlights the outstanding advantages of nanomedicines in disease treatment, and helps advance one's understanding of the use of nanotechnology to enhance T-cell immunotherapy.

Engaging natural antibody responses for the treatment of inflammatory bowel disease via phosphorylcholine-presenting nanofibres

Inflammatory bowel disease lacks a long-lasting and broadly effective therapy. Here, by taking advantage of the anti-infection and anti-inflammatory properties of natural antibodies against the small-molecule epitope phosphorylcholine (PC), we show in multiple mouse models of colitis that immunization of the animals with self-assembling supramolecular peptide nanofibres bearing PC epitopes induced sustained levels of anti-PC antibodies that were both protective and therapeutic. The strength and type of immune responses elicited by the nanofibres could be controlled through the relative valency of PC epitopes and exogenous T-cell epitopes on the nanofibres and via the addition of the adjuvant CpG. The nanomaterial-assisted induction of the production of therapeutic antibodies may represent a durable therapy for inflammatory bowel disease.

ENTERPRET: A Randomized Controlled Trial of Vedolizumab Dose Optimization in Patients With Ulcerative Colitis Who Have Early Nonresponse

BACKGROUND & AIMS

Patients with ulcerative colitis (UC) may experience nonresponse to biologics, possibly as a result of low drug exposure. This trial assessed the efficacy of dose optimization in patients with UC who have early nonresponse to vedolizumab and high drug clearance.

METHODS

ENTERPRET was a phase 4, open-label, randomized, controlled trial that included patients with moderate to severe UC who had high drug clearance at week 5 (serum concentration, <50 μg/mL) and nonresponse to standard vedolizumab treatment at week 6. At week 6, eligible patients were randomized 1:1 to receive standard dosing (300 mg every 8 weeks) or dose-optimized vedolizumab (600 mg at week 6, then 300 mg every 4 weeks; or 600 mg at week 6, then 600 mg every 4 weeks [based on week 5 serum concentration]). The primary end point was endoscopic improvement at week 30.

RESULTS

Of 278 enrolled patients, 132 (47.5%) had a clinical response at week 6. From week 6, 108 patients received standard (n = 53) or dose-optimized vedolizumab (n = 55); among patients with nonresponse at week 6, 86.5% had high drug clearance. At week 30, 10 patients (18.9%) who received standard vedolizumab had endoscopic improvement vs 8 patients (14.5%) who received dose-optimized vedolizumab. Five patients (9.4%) who received standard vedolizumab had clinical remission at week 30 vs 5 patients (9.1%) who received dose-optimized vedolizumab; clinical response was observed in 17 (32.1%) and 17 patients (30.9%), respectively. Safety event rates were similar among treatment groups.

CONCLUSIONS

In patients with early nonresponse and high drug clearance, vedolizumab dose optimization is probably not required. A proportion of patients benefited from continued treatment irrespective of the dose received.

CLINICALTRIALS

gov: NCT03029143.

"Getting the Dose Right"-Revisiting the Topic With Focus on Biologic Agents

Nearly two decades after the Peck and Cross article '"Getting the dose right: facts, a blueprint, and encouragements" was published, a review of dose recommendations for biologics shows that the success in getting the dose right appears to have improved given the relatively low incidence of drug withdrawals and dosing/label changes. However, the clinical experience with monoclonal antibodies (MAbs) following approval has been less than perfect. In inflammatory diseases, the disease burden changes with time and high treatment failure rates have been reported. In addition, the use of concomitant steroids and immunosuppressant drugs with MAbs is common. These concomitant agents have their own safety issues and many immunosuppressant agents are not well-tolerated although they have been shown to reduce the incidence of anti-drug antibodies (ADA). This same complexity is seen in MAbs used in oncology as well, although with these agents the doses appear to be higher than needed, which results in high treatment costs and incidence of adverse events. Given the complexity of MAb pharmacokinetics, which makes providing a detailed description of dose options difficult, product labeling should include the options for alternative dose strategies and potentially include the use of therapeutic drug monitoring with dose individualization which have been shown to improve clinical response and reduce the incidence of ADA. So, while the recommended dosing for biologics seems improved over the issues noted 17 years ago, we still have some work to do.

Add-on multiple submucosal injections of the RNA oligonucleotide GUT-1 to anti-TNF antibody treatment in patients with moderate-to-severe ulcerative colitis: an open-label, proof-of concept study

BACKGROUND

Carbohydrate sulfotransferase 15 (CHST15) is an enzyme biosynthesizing matrix glycosaminoglycan that modulates tissue remodeling. We evaluated the efficacy of add-on submucosal injections of GUT-1, the RNA oligonucleotide inhibitor of CHST15, to ongoing anti-tumor necrosis factor (TNF) antibody treatment in patients with moderate-to-severe ulcerative colitis (UC).

METHODS

This was an open-label study of 250 nM of GUT-1 by endoscopic submucosal injections at weeks 0, 2, 4 in five UC patients who lost response during maintenance treatment to anti-TNF antibodies. The primary endpoint was the rate of endoscopic improvement at week 6 and secondary endpoints included the rates of clinical remission by modified Mayo Score (mMS). Patients received follow-up observation with continuous maintenance treatment by the same anti-TNF antibody till the time of clinical recurrence or for overall 52 weeks.

RESULTS

At week 6, rates of endoscopic improvement and clinical remission were 80% (n = 4/5) and 60% (n = 3/5), respectively. The mean Endoscopy Subscore was reduced from 2.4 (95%CI: 1.7 to 3.1) at baseline, to 1.0 (95%CI: 0.1 to 1.9) at week 6. The mean mMS was reduced from 7.8 (95%CI: 6.2 to 9.4) to 1.3 (95%CI: 2.9 to 4.3). GUT-1 was well tolerated. Three patients did not show clinical recurrence for 52 weeks. All three corticosteroid-dependent patients showed no corticosteroid exposure for at least 24 weeks after achieving clinical remission. Multiple dosing was also well tolerated.

CONCLUSIONS

Add-on multiple injections of GUT-1 to ongoing anti-TNF antibody was able to induce rapid and durable clinical responses in UC patients who lost response to anti-TNF therapy.

TRIAL REGISTRATION

Clinical trial Registration Number (Japan): UMIN000020900.

Rheumatoid factor titers, but not Fc fragments, may be strongly associated with drug survival of anti-TNF agents in patients with rheumatoid arthritis

OBJECTIVE

To investigate the effects of both the Fc fragment in tumor necrosis factor (TNF) inhibitors and rheumatoid factor (RF) titers on treatment survival, disease activity, and laboratory parameters in patients with rheumatoid arthritis (RA).

METHODS

In this retrospective cohort study, patients with RA who had started any anti-TNF therapy between January 2017 and March 2020 and who had stayed on this treatment for at least six months were included. The data of the patients were compared separately according to continuation or discontinuation of treatment and the presence or absence of Fc portion in the structure of anti-TNFs. Patients who were taking certolizumab pegol (CZP) without the Fc fragment were placed in the "without Fc group" (wo/Fc), while patients who were taking other drugs (adalimumab, etanercept, golimumab, and infliximab) were placed in the "with Fc group" (w/Fc).

RESULTS

Among the 221 RA patients whose data were available, 52 patients met the inclusion criteria and were included in the study. There was a significant difference in the DAS28-CRP score between wo/Fc group and w/Fc group in the third month of treatment (p=0.012). However, this difference did not persist at the sixth month of treatment (p=0.384). According to the cox-regression results, RF titers were determined to have a significant impact on the drug survival of anti-TNF agents when adjustments were made for the effects of other candidate predictors (Hazard ratio: 1.007 (1.002-1.012), p=0.009).

CONCLUSION

Our results suggest that compared to the Fc fragment, RF titers were the more important risk factor in survival of anti-TNF drugs.

Cytokine Profile in Predicting the Effectiveness of Advanced Therapy for Ulcerative Colitis: A Narrative Review

Cytokine-targeted therapies have shown efficacy in treating patients with ulcerative colitis (UC), but responses to these advanced therapies can vary. This variability may be due to differences in cytokine profiles among patients with UC. While the etiology of UC is not fully understood, abnormalities of the cytokine profiles are deeply involved in its pathophysiology. Therefore, an approach focused on the cytokine profile of individual patients with UC is ideal. Recent studies have demonstrated that molecular analysis of cytokine profiles in UC can predict response to each advanced therapy. This narrative review summarizes the molecules involved in the efficacy of various advanced therapies for UC. Understanding these associations may be helpful in selecting optimal therapeutic agents.

Antibiotics influence the risk of anti-drug antibody formation during anti-TNF therapy in Chinese inflammatory bowel disease patients

Aims: The formation of anti-drug antibodies (ADAs) during anti-tumor necrosis factor (anti-TNF) therapy is reported to lead to reducing serum drug levels, which may bring about a loss of response to treatment. Previous research has suggested an association between specific antibiotic classes and ADA formation during anti-TNF therapy. However, there are few studies specifically examining this association in Chinese inflammatory bowel disease (IBD) patients. Therefore, our study aimed to evaluate the possible effect of antibiotic use on ADA formation to anti-TNF therapy in Chinese patients with IBD. Methods: A total of 166 patients with IBD, including 149 with Crohn's disease (CD) and 17 with ulcerative colitis (UC), were included in this retrospective analysis. These patients were initially treated with anti-TNF therapy (infliximab or adalimumab) after January 2018 and reviewed with available ADA levels before October 2023. After univariable analysis of all the variables, a multivariate Cox proportional hazards model was used to assess the association between antibiotic use and ADA development. Results: Among 166 IBD patients treated with infliximab (108/166, 65.1%) or adalimumab (58/166, 34.9%), 31 patients (18.7%) were measured as positive ADA levels. Cox proportional hazard model demonstrated an increased risk of ADA formation in IBD patients who used β-lactam-β-lactamase inhibitor combinations (BL-BLIs) (HR = 5.143, 95%CI 1.136-23.270, p = 0.033), or nitroimidazoles (HR = 4.635, 95%CI 1.641-13.089, p = 0.004) during 12 months before the ADA test. On the contrary, a reduced risk was noted in patients treated with fluoroquinolones (HR = 0.258, 95% CI 0.072-0.924, p = 0.037). Moreover, the median serum infliximab or adalimumab concentration in patients with positive ADA levels was significantly lower than that in patients with negative ADA levels (infliximab: 0.30 vs. 1.85 μg/mL, p < 0.0001; adalimumab: 0.45 vs. 7.55 μg/mL, p = 0.0121). Conclusion: ADA development is associated with various antibiotic classes. BL-BLIs and nitroimidazoles might increase the risk of ADA formation during anti-TNF therapy in Chinese IBD patients, while the treatment with fluoroquinolones could probably reduce such risk. There were certain limitations in the retrospective analysis of the study, therefore, the results are just for reference, and other studies are needed to further confirm our findings.

Complementary Therapeutic Effect of Fecal Microbiota Transplantation in Ulcerative Colitis after the Response to Anti-Tumor Necrosis Factor Alpha Agent Was Lost: A Case Report

In patients with ulcerative colitis (UC), the development of an antidrug antibody (ADA) to anti-tumor necrosis factor (TNF)α agent is a crucial problem which aggravates the clinical course of the disease, being cited as one of the most common causes for discontinuing anti-TNFα treatment. This is due to ADA eventually causing secondary LOR, leading to discontinuation of anti-TNFα treatment. Recently, research on the microbiome and relationship between worsening UC and dysbiosis has been conducted. Further, investigations on the association between the microbiome and secondary LOR are increasing. Here, we present the therapeutic effect of fecal microbiota transplantation (FMT) on a 42-year-old man with secondary LOR and high ADA levels. FMT has recently been used for the treatment of, and for overcoming, drug resistance through microbiome modification. Stool samples were collected from the patient before and 4 weeks after FMT. Symptoms, including hematochezia and Mayo endoscopy sub-scores, improved after FMT, while ADA levels decreased by one-third to less than half the value (29 ng/mL) compared to before FMT (79 ng/mL). Additionally, the trough level of infliximab became measurable, which reflects the improvement in the area under the concentration (AUC). Butyricicoccus, Faecalibacterium, Bifidobacterium, Ligilactobacillus, Alistipes, and Odoribacter, which regulate immune responses and alleviate inflammation, also increased after FMT. We report a case in which microbiome modification by FMT increased the AUC of anti-TNFα in a patient who developed secondary LOR during anti-TNFα treatment, thereby improving symptoms and mucosal inflammation.

Upadacitinib for the treatment of moderate-to-severe Crohn's disease

Despite an increasing number of therapies for Crohn's disease (CD), half of patients do not respond to initial treatment or lose response over time, highlighting the need for novel therapies. Inhibition of Janus kinases (JAKs) has emerged as an important therapeutic target for CD. Upadacitinib is an orally administered selective JAK1 inhibitor, which is effective for the induction and maintenance of remission in moderately-to-severely active CD, including in patients with prior failure of biological therapy. Nonselective JAK inhibition has been associated with thromboembolic disease, cardiovascular events and malignancy in patients older than 50 years with rheumatoid arthritis and pre-existing cardiovascular risk factors, which should be considered upon prescription. Upadacitinib is the first and currently only oral advanced therapy for CD.

The gut microbiota-aromatic hydrocarbon receptor (AhR) axis mediates the anticolitic effect of polyphenol-rich extracts from Sanghuangporus

Inflammatory bowel disease (IBD) is a significant global health concern. The gut microbiota plays an essential role in the onset and development of IBD. Sanghuangporus (SH), a traditional Chinese medicinal mushroom, has excellent anti-inflammatory effects and is effective at modulating the gut microbiota. Despite these attributes, the specific anticolitic effects of SH and the mechanisms through which the gut microbiota mediates its benefits remain unclear. Herein, we demonstrated that polyphenol-rich extract from SH effectively alleviated the pathological symptoms of dextran sodium sulfate (DSS)-induced colitis in mice by modulating the gut microbiota. Treatment with SH distinctly enriched Alistipes, especially Alistipes onderdonkii, and its metabolite 5-hydroxyindole-3-acetic acid (5HIAA). Oral gavage of live A. onderdonkii or 5HIAA potently mitigated DSS-induced colitis in mice. Moreover, both 5HIAA and SH significantly activated the aromatic hydrocarbon receptor (AhR), and the administration of an AhR antagonist abrogated their protective effects against colitis. These results underscore the potent efficacy of SH in diminishing DSS-induced colitis through the promotion of A. onderdonkii and 5HIAA, ultimately activating AhR signaling. This study unveils potential avenues for developing therapeutic strategies for colitis based on the interplay between SH and the gut microbiota.

Clinical consequences of infliximab immunogenicity and the effect of proactive therapeutic drug monitoring: exploratory analyses of the randomised, controlled NOR-DRUM trials

BACKGROUND

Antidrug antibodies to TNF inhibitors might affect clinical outcomes. Proactive therapeutic drug monitoring allows for early detection of antidrug antibodies and might reduce negative clinical consequences. We aimed to explore how antidrug antibodies to the TNF inhibitor infliximab influence treatment outcomes, and to assess the effect of proactive therapeutic drug monitoring.

METHODS

This was a predefined exploratory analysis of data from the randomised, controlled NOR-DRUM trials. The trials were conducted in rheumatology, gastroenterology, and dermatology departments at 21 Norwegian hospitals. Adult patients (aged 18-75 years) with immune-mediated inflammatory diseases were randomly assigned to proactive therapeutic drug monitoring or standard infliximab dosing in the NOR-DRUM A trial (30-week follow-up) and the NOR-DRUM B trial (52-week follow-up). Antidrug antibodies were assessed with a drug-sensitive assay before each infusion. The outcomes of remission (at week 30), disease worsening (during 52 weeks), infusion reactions, and infliximab discontinuation were assessed according to the presence of antidrug antibodies and use of therapeutic drug monitoring.

FINDINGS

Between March 1, 2017, and Dec 12, 2019, 616 patients were included in the NOR-DRUM trials, of whom 615 had at least one serum infliximab and antidrug antibody assessment and were included in the present analyses. Mean age was 45 years (IQR 32-56), 305 (50%) patients were women, and 310 (50%) patients were men. Antidrug antibodies were detected in 147 (24%) patients. Remission at week 30 occurred in 25 (35%) of 72 patients with antidrug antibodies and 180 (54%) of 335 without antidrug antibodies (risk ratio 0·62 [95% CI 0·45-0·86]; p=0·0037). In patients with antidrug antibodies compared with patients without antidrug antibodies, higher rates were found for: disease worsening over 52 weeks (0·76 per person-year vs 0· 35 per person-year, hazard ratio [HR] 2·02 [95% CI 1·33-3·07]; p=0·0009), infusion reactions (0·16 per person-year vs 0·03 per person-year, HR 17·02 [6·98-41·47]; p<0·0001), and infliximab discontinuation (1·00 per person-year vs 0·20 per person-year, HR 6·64 [4·84-9·11]; p<0·0001). These associations were more pronounced in patients with high concentrations of antidrug antibodies than in those with low concentrations of antidrug antibodies. Independent of antibody status, therapeutic drug monitoring was associated with a lower risk of disease worsening (HR 0·41 [0·29-0·59]; p=0·0001) or an infusion reaction (HR 0·30 [0·12-0·73]; p=0·0076), and was associated with an increase in the rate of infliximab discontinuation (HR 1·37 [1·02-1·83]; p=0·037).

INTERPRETATION

In patients where antidrug antibodies were detected, remission was less likely to be reached and sustained, and infusion reaction or discontinuation of infliximab was more likely. Timely detection of antidrug antibodies by proactive therapeutic drug monitoring facilitated treatment decisions that reduced the negative consequences, both regarding infliximab effectiveness and safety. This highlights the role of proactive therapeutic drug monitoring in optimising infliximab therapy.

FUNDING

Inter-regional KLINBEFORSK grants and South-Eastern Norway Regional Health Authority grants.

Effectiveness and Persistency of Ustekinumab Treatment for Ulcerative Colitis: A Phoenix retrospective Cohort Study

Background

Real-world data regarding ustekinumab (UST) for ulcerative colitis (UC) particularly in biologics-naïve patients is currently limited. This study aimed to elucidate the real-world effectiveness and safety of UST for UC.

Methods

Overall, 150 patients with UC treated with UST from March 2020 to January 2023 were enrolled across 7 referral hospitals. To assess the clinical efficacy and persistence of UST, retrospective analyses were conducted from weeks 8 to 56. Predictive factors concerning the response and persistence of UST were examined through univariate and multivariate analyses.

Results

Of the 150 patients, 125 received UST for remission induction, including 36% biologics-naïve. The response and remission rates were 72.8% and 56.0% at week 8 and 73.2% and 63.4% at week 56, respectively. Biologics-naïve patients represented higher response and remission rates at week 8 (84.4% and 73.3%) than those with biologics exposure (66.2% and 46.2%). Patients with prior antitumor necrosis factor (anti-TNF) and vedolizumab (VDZ) exposure had relatively lower response and remission rates (34.5% and 24.1%, respectively). The 1-year cumulative persistence rate was 84.0%. Multivariate analysis revealed that the chronic continuous type and prior anti-TNF and VDZ exposure were negative predictive factors for week 8 responsiveness. Clinical response at week 8 was a predictor of 1-year persistence. Adverse event incidence remained notably low at 6.4%.

Conclusions

This study highlights the safety and effectiveness of UST as an induction and maintenance therapy for UC. Chronic continuous type and previous anti-TNF and VDZ exposure negatively contributed to short-term effectiveness, whereas short-term effectiveness provided good persistency.

Comprehensive overview of novel chemical drugs for ulcerative colitis: focusing on phase 3 and beyond

INTRODUCTION

Despite the growing number of highly efficacious biologics and chemical drugs for ulcerative colitis (UC), steroid-free disease control is still difficult to achieve in subgroups of patients due to refractoriness, adverse events, primary or secondary failure. New treatments are therefore still required in order to optimize clinical management of patients with UC.

AREAS COVERED

The efficacy and safety of both currently available and newly developed small molecules have been summarized. The PubMed database and clinicaltrials.gov were considered in order to search for phase 2b and 3 trials on new chemical drugs for UC. The study drugs reviewed included Janus kinases (JAK) and sphingosine-1-phosphate receptor (S1Pr) inhibitors, α4 integrin antagonist, and micro-RNA-124 upregulators.

EXPERT OPINION

Rapidity of onset, low immunogenicity, and safety are the main characteristics of small molecules currently available or under evaluation for treatment patients with UC. Among the currently available chemical drugs, the selective JAK and the S1Pr inhibitors are characterized by a good safety profile combined with the ability to induce clinical remission in UC. A relatively low frequency of endoscopic improvement and healing currently appears associated with their use, being higher in UC patients treated with S1Pr inhibitor Etrasimod. Overall, additional new safe and effective drugs are still required in order to optimize disease control in a larger majority of UC patients.

Predictive biomarkers for anti-TNF alpha therapy in IBD patients

Inflammatory bowel disease (IBD) is a chronic gastrointestinal condition characterized by severe gut inflammation, commonly presenting as Crohn's disease, ulcerative colitis or categorized as IBD- unclassified. While various treatments have demonstrated efficacy in adult IBD patients, the advent of anti-TNF therapies has significantly revolutionized treatment outcomes and clinical management. These therapies have played a pivotal role in achieving clinical and endoscopic remission, promoting mucosal healing, averting disease progression, and diminishing the necessity for surgery. Nevertheless, not all patients exhibit positive responses to these therapies, and some may experience a loss of responsiveness over time. This review aims to present a comprehensive examination of predictive biomarkers for monitoring the therapeutic response to anti-TNF therapy in IBD patients. It will explore their limitations and clinical utilities, paving the way for a more personalized and effective therapeutic approach.

Upadacitinib Achieves Clinical and Endoscopic Outcomes in Crohn's Disease Regardless of Prior Biologic Exposure

BACKGROUND & AIMS

Upadacitinib, an oral Janus kinase inhibitor, achieved significantly higher rates of clinical remission and endoscopic response vs placebo during induction (U-EXCEL [NCT03345849], U-EXCEED [NCT03345836]) and maintenance (U-ENDURE [NCT03345823]) treatment in patients with moderate-to-severe Crohn's disease. Prior biologic failure is often associated with reduced responses to subsequent therapies. This post hoc analysis assessed upadacitinib efficacy by prior biologic failure status.

METHODS

Patients were randomized to placebo or upadacitinib 45 mg (UPA45) for 12 weeks (induction). UPA45 clinical responders were enrolled in U-ENDURE and rerandomized to placebo, upadacitinib 15 mg, or upadacitinib 30 mg (UPA30) for 52 weeks. Assessments were by prior biologic failure.

RESULTS

Of 1021 patients, 733 (71.8%) had prior biologic failure. Across outcomes and subgroups, upadacitinib-treated patients achieved higher rates vs placebo. During induction, upadacitinib had higher rates vs placebo for clinical remission based on stool frequency/abdominal pain score (without failure: 54.0% vs 28.3%; with failure: 42.2% vs 14.1%) and endoscopic response (without failure: 52.0% vs 16.2%; with failure: 35.7% vs 5.3%). In maintenance, the greatest treatment effect (upadacitinib vs placebo) was among patients with prior biologic failure treated with UPA30 (clinical remission without failure: 58.5% vs 32.7%; with failure: 42.5% vs 8.7%; endoscopic response without failure: 43.9% vs 17.9%; with failure: 38.9% vs 4.0%). Patients without vs with prior biologic failure had fewer adverse events.

CONCLUSIONS

Upadacitinib led to higher absolutes rates of clinical and endoscopic outcomes in patients without vs with prior biologic failure. Patients treated with upadacitinib achieved greater rates of clinical and endoscopic improvements vs placebo, regardless of prior biologic exposure.

CLINICALTRIALS

gov: NCT03345849, NCT03345836, NCT03345823.

New, Old, and Shared Antibody Specificities in Autoimmune Diseases

Autoantibodies represent a primary characteristic of many systemic autoimmune diseases [...].

Ustekinumab in the Treatment of Inflammatory Bowel Diseases: Evolving Paradigms

Inflammatory bowel diseases, comprising Crohn's disease (CD) and ulcerative colitis (UC), are chronic, relapsing, and remitting immune-mediated inflammatory diseases affecting the gastrointestinal tract. Ustekinumab (UST) is a monoclonal antibody that blocks the p40 subunit of the anti-interleukin (IL) 12/23. Pivotal trials (CERTIFI and UNITI-IM for CD, UNIFI for UC) established the efficacy of UST for the induction and maintenance of remission in both CD and UC, with the most favorable results in naïve patients to biologics. In recent years, a wealth of 'real-world' data has emerged supporting positive clinical, endoscopic, and histological outcomes in patients treated with UST, as well as reassuring safety data. More recently, the results of the first head-to-head trials of UST and tumor necrosis factor (TNF) antagonists were reported. Moreover, a number of studies exploring the role of UST in specific clinical settings, such as perianal CD, postoperative complications and recurrence, extraintestinal manifestations, chronic antibiotic-refractory pouchitis, and pregnancy, were reported. This review explores the results reported to date on UST, including those from pivotal trials, real-world data, and emerging studies regarding therapeutic drug monitoring and immunogenicity. The safety profile of UST was also reviewed.

Brain-Gut Axis: Invasive and Noninvasive Vagus Nerve Stimulation, Limitations, and Potential Therapeutic Approaches

Inflammatory bowel disease (IBD) is a chronic relapsing condition with no known etiology and is characterized by disrupted gut homeostasis, chronic inflammation, and ulcerative lesions. Although current treatments can reduce disease activity, IBD frequently recurs once treatments are discontinued, indicating that treatments are ineffective in providing long-term remission. The lack of responsiveness and reluctance of some affected persons to take medications because of potential adverse effects has enhanced the need for novel therapeutic approaches. The vagus nerve (VN) is likely important in the pathogenesis of IBD, considering the decreased activity of the parasympathetic nervous system, especially the VN, and the impaired interaction between the enteric nervous system and central nervous system in patients with IBD. Vagus nerve stimulation (VNS) has demonstrated anti-inflammatory effects in various inflammatory disorders, including IBD, by inhibiting the production of inflammatory cytokines by immune cells. It has been suggested that stimulating the vagus nerve to induce its anti-inflammatory effects may be a potential therapeutic approach for IBD. Noninvasive techniques for VNS have been developed. Considering the importance of VN function in the brain-gut axis, VNS is a promising treatment option for IBD. This review discusses the potential therapeutic advantages and drawbacks of VNS, particularly the use of noninvasive transcutaneous auricular vagus nerve stimulation.

Baseline Expression of Immune Gene Modules in Blood is Associated With Primary Response to Anti-TNF Therapy in Crohn's Disease Patients

BACKGROUND AND AIMS

Anti-tumour necrosis factor [anti-TNF] therapy is widely used for the treatment of inflammatory bowel disease, yet many patients are primary non-responders, failing to respond to induction therapy. We aimed to identify blood gene expression differences between primary responders and primary non-responders to anti-TNF monoclonal antibodies [infliximab and adalimumab], and to predict response status from blood gene expression and clinical data.

METHODS

The Personalised Anti-TNF Therapy in Crohn's Disease [PANTS] study is a UK-wide prospective observational cohort study of anti-TNF therapy outcome in anti-TNF-naive Crohn's disease patients [ClinicalTrials.gov identifier: NCT03088449]. Blood gene expression in 324 unique patients was measured by RNA-sequencing at baseline [week 0], and at weeks 14, 30, and 54 after treatment initiation [total sample size = 814].

RESULTS

After adjusting for clinical covariates and estimated blood cell composition, baseline expression of major histocompatibility complex, antigen presentation, myeloid cell enriched receptor, and other innate immune gene modules was significantly higher in anti-TNF responders vs non-responders. Expression changes from baseline to week 14 were generally of consistent direction but greater magnitude [i.e. amplified] in responders, but interferon-related genes were upregulated uniquely in non-responders. Expression differences between responders and non-responders observed at week 14 were maintained at weeks 30 and 54. Prediction of response status from baseline clinical data, cell composition, and module expression was poor.

CONCLUSIONS

Baseline gene module expression was associated with primary response to anti-TNF therapy in PANTS patients. However, these baseline expression differences did not predict response with sufficient sensitivity for clinical use.

Antibody Drug Clearance: An Underexplored Marker of Outcomes with Checkpoint Inhibitors

Immune-checkpoint inhibitor (ICI) therapy has dramatically changed the clinical landscape for several cancers, and ICI use continues to expand across many cancer types. Low baseline clearance (CL) and/or a large reduction of CL during treatment correlates with better clinical response and longer survival. Similar phenomena have also been reported with other monoclonal antibodies (mAb) in cancer and other diseases, highlighting a characteristic of mAb clinical pharmacology that is potentially shared among various mAbs and diseases. Though tempting to attribute poor outcomes to low drug exposure and arguably low target engagement due to high CL, such speculation is not supported by the relatively flat exposure-response relationship of most ICIs, where a higher dose or exposure is not likely to provide additional benefit. Instead, an elevated and/or increasing CL could be a surrogate marker of the inherent resistant phenotype that cannot be reversed by maximizing drug exposure. The mechanisms connecting ICI clearance, therapeutic efficacy, and resistance are unclear and likely to be multifactorial. Therefore, to explore the potential of ICI CL as an early marker for efficacy, this review highlights the similarities and differences of CL characteristics and CL-response relationships for all FDA-approved ICIs, and we compare and contrast these to selected non-ICI mAbs. We also discuss underlying mechanisms that potentially link mAb CL with efficacy and highlight existing knowledge gaps and future directions where more clinical and preclinical investigations are warranted to clearly understand the value of baseline and/or time-varying CL in predicting response to ICI-based therapeutics.

Expression of Circulating let-7e and miR-126 May Predict Clinical Remission in Patients With Crohn's Disease Treated With Anti-TNF-α Biologics

BACKGROUND

The identification of new biomarkers predictive of response to antitumor necrosis factor alpha (anti-TNF-α) monoclonal antibodies remains an unmet medical need in Crohn's disease (CD) because a high percentage of patients show no clinical improvement after treatment or can lose response over time. MicroRNAs (miRNAs) can regulate inflammatory and immunological responses and were found to play a role in CD.

METHODS

Baseline serum samples from 37 CD patients previously treated with infliximab or adalimumab, as per clinical practice, were obtained from the serum library at the Gastroenterology Unit of the University Hospital of Pisa, Italy. Patients were categorized as responders or nonresponders based on the following treatment outcomes: clinical remission at weeks 14 and 54 and endoscopic remission at week 54. The expression levels of a panel of selected miRNAs were analyzed by real-time polymerase chain reaction. Comparisons of miRNA expression between responders and nonresponders and statistical analyses were performed by MedCalc and GraphPad Prism software. Receiver operating characteristic curve analyses were calculated to evaluate the predictive performance of potential biomarkers.

RESULTS

Patients in clinical remission at week 14 had a lower let-7e expression, whereas those in clinical remission at week 54 had lower levels of circulating miR-126 than nonresponders. The receiver operating characteristic curve analysis identified optimal cutoff values with assay sensitivity and specificity of 92.9% and 61.1%, for let-7e, and 62.5% and 83.3%, for miR-126, respectively.

CONCLUSION

These results provide evidence that expression levels of circulating let-7e and miR-126 at baseline may predict clinical remission in CD patients treated with anti-TNF-α biologics.

Maintenance Risankizumab Sustains Induction Response in Patients with Crohn's Disease in a Randomized Phase 3 Trial

BACKGROUND AND AIMS

Durable clinical remission, endoscopic healing, and biomarker normalization are key treatment goals for Crohn's disease. The selective anti-interleukin-23 p19 inhibitor risankizumab has demonstrated efficacy and safety in moderately to severely active Crohn's disease. This post-hoc analysis of data from the pivotal risankizumab maintenance study assessed whether risankizumab maintenance therapy sustained the clinical and endoscopic outcomes achieved with risankizumab induction therapy.

METHODS

We evaluated 462 patients who achieved a clinical response to risankizumab intravenous induction treatment and were re-randomized to receive subcutaneous risankizumab 360 mg, subcutaneous risankizumab 180 mg, or placebo [withdrawal] every 8 weeks for 52 weeks in the randomized, controlled FORTIFY maintenance study. Maintenance of clinical, endoscopic, and biomarker endpoints at week 52 among patients who achieved these endpoints after 12 weeks of induction treatment was evaluated.

RESULTS

A significantly higher proportion of patients receiving maintenance treatment with risankizumab 360 or 180 mg compared with placebo [withdrawal] maintained Crohn's Disease Activity Index remission [68.6%, 70.8%, vs 56.3%; p < 0.05], stool frequency/abdominal pain remission [69.2%, 64.1%, vs 50.5%; p < 0.01], endoscopic response [70.2%, 68.2%, vs 38.4%; p < 0.001], endoscopic remission [74.4%, 45.5%, vs 23.9%; p < 0.05], and Simple Endoscopic Score for Crohn's Disease of 0-2 [65.5%, 36.7%, vs 21.9%]. Most patients [56.8-83.3%] who achieved normalized faecal calprotectin or C-reactive protein during induction sustained them with maintenance risankizumab.

CONCLUSIONS

Subcutaneous risankizumab maintenance therapy results in durable improvement in clinical and endoscopic outcomes over 1 year in patients with moderately to severely active Crohn's disease.

CLINICAL TRIAL REGISTRATION NUMBER

NCT03105102.

Predictive, preventive and personalised approach as a conceptual and technological innovation in primary and secondary care of inflammatory bowel disease benefiting affected individuals and populations

Inflammatory bowel disease (IBD) is a global health burden which carries lifelong morbidity affecting all age groups in populations with the disease-specific peak of the age groups ranging between 15 and 35 years, which are of great economic importance for the society. An accelerating incidence of IBD is reported for newly industrialised countries, whereas stabilising incidence but increasing prevalence is typical for countries with a Westernised lifestyle, such as the European area and the USA. Although the aetiology of IBD is largely unknown, the interplay between the genetic, environmental, immunological, and microbial components is decisive for the disease manifestation, course, severity and individual outcomes. Contextually, the creation of an individualised patient profile is crucial for the cost-effective disease management in primary and secondary care of IBD. The proposed pathomechanisms include intestinal pathoflora and dysbiosis, chronic inflammation and mitochondrial impairments, amongst others, which collectively may reveal individual molecular signatures defining IBD subtypes and leading to clinical phenotypes, patient stratification and cost-effective protection against health-to-disease transition and treatments tailored to individualised patient profiles-all the pillars of an advanced 3PM approach. The paradigm change from reactive medical services to predictive diagnostics, cost-effective targeted prevention and treatments tailored to individualised patient profiles in overall IBD management holds a promise to meet patient needs in primary and secondary care, to increase the life-quality of affected individuals and to improve health economy in the area of IBD management. This article analyses current achievements and provides the roadmap for future developments in the area in the context of 3P medicine benefiting society at large.

Clinical use of biologics for Crohn's disease in adults: lessons learned from real-world studies

INTRODUCTION

The therapeutic armamentarium for managing Crohn's disease (CD) has expanded significantly in recent decades. Several biologics with three different mechanisms of action [anti-tumor necrosis factor (TNF)-α, anti-integrin α4β7, and anti-IL 12/23] are currently available to manage CD.

AREA COVERED

This narrative review aims to summarize the most significant efficacy and safety data on the use of infliximab (IFX), adalimumab (ADA), vedolizumab (VDZ) and ustekinumab (UST) for the treatment of CD obtained from studies conducted in the real world (RW), compared to the results of randomized clinical trials (RCTs).

EXPERT OPINION

RW studies reported that biologic agents included in this analysis have higher remission rates and lower adverse event rates than findings from RCTs for treating patients with CD. All biological agents have proven effective and safe in RW studies, even when using biosimilars or switching to subcutaneous administration of the molecules for which they are available. Finally, anti-TNF-α agents, particularly IFX, have a higher rate of adverse events (AEs) than VDZ and UST. Therefore, patients at higher risk of AEs may benefit from other biologics than anti-TNF-α. However, further long-term RW studies are needed to confirm these findings.

Prediction of response to anti-TNFα using integrative computational approaches in Crohn's disease-Needle in a haystack or a promising biomarker?

In the January issue of Cell Reports Medicine, Gerassy-Vainberg et al.1 demonstrate the utility of integrative methods to reveal molecular mechanisms associated with anti-tumor necrosis factor-alpha therapy response in patients with inflammatory conditions.

Aryl Hydrocarbon Receptor Regulates Muc2 Production Independently of IL-22 during Colitis

We previously reported that an aryl hydrocarbon receptor (AhR) ligand, indole-3-carbinol (I3C), was effective at reducing colitis severity through immune cell-mediated interleukin-22 (IL-22) production. Intestinal epithelial cells (IECs) are also involved in regulating colitis, so we investigated their AhR-mediated mechanisms in the current report. A transcriptome analysis of IECs in wildtype (WT) mice revealed that during colitis, I3C regulated select mucin proteins, which could be attributed to goblet cell development. To address this, experiments under in vivo colitis (mice) or in vitro colon organoid conditions were undertaken to determine how select mucin proteins were altered in the absence or presence of AhR in IECs during I3C treatment. Comparing WT to IEC-specific AhR knockout mice (AhRΔIEC), the results showed that AhR expression was essential in IECs for I3C-mediated protection during colitis. AhR-deficiency also impaired mucin protein expression, particularly mucin 2 (Muc2), independently of IL-22. Collectively, this report highlights the important role of AhR in direct regulation of Muc2. These results provide justification for future studies aimed at determining how AhR might regulate select mucins through mechanisms such as direct transcription binding to enhance production.

Challenges for further successful development of tumor necrosis factor targeting therapies for uveitis

INTRODUCTION

Uveitis is a heterogeneous group of ocular conditions characterized by inflammation of the uveal tract and is one of the leading causes of vision impairment. In developed countries, noninfectious uveitis (NIU) represents most cases and is challenging to treat due to its severity, chronicity, and high recurrence rates. The advent of anti-tumor necrosis factor-α (anti-TNF-α) agents have dramatically improved outcomes and changed treatment paradigms in NIU.

AREAS COVERED

The index article summarizes the present experience of anti-TNF-α agents in NIU pharmacotherapy and highlights the barriers to further research and development of anti-TNF-α agents for uveitis. Common challenges faced in NIU clinical drugs trials, specific difficulties in anti-TNF-α drug development, and promising competitor drug candidates are discussed and evaluated.

EXPERT OPINION

Anti-TNF-α agents have revolutionized NIU pharmacotherapy and greatly improved outcomes with good safety profiles. The great success of systemic infliximab and adalimumab in NIU treatment has resulted in little impetus for further development of this class of medication. Attempts have been made to deliver anti-TNF-α agents intravitreally but that has not been successful thus far. With expiring patents, competition from biosimilars and newer, novel molecules, it may not be viable to continue pursuing anti-TNF-α drug development.

Therapeutic drug monitoring in inflammatory bowel disease: A practical approach

The global burden of inflammatory bowel diseases (IBD) is estimated at 4.9 million and the global prevalence exceeds 0.3%. Multiple newer therapeutic agents have broadened the options for the therapy of IBD in the last three decades. Thiopurines, however, have retained their place as maintenance therapy in IBD, especially in resource-constrained setting. But thiopurines have narrow therapeutic range, often needing discontinuation due to side effects or lack of efficacy. Biologic agents revolutionized the treatment of IBD, but the efficacy is lost in 50% of patient after one year. These outcomes are often due to inadequate drug concentrations that may lead to the development of antibodies as well as pharmacodynamic failure. Therapeutic drug monitoring (TDM) was proposed to reduce loss of response and to optimize the therapy in patients on thiopurine and biologic therapy. TDM is based on exposure-response relationship, suggesting a positive correlation between elevated serum anti-TNF concentrations and favorable therapeutic outcomes. TDM has multiple facets. This article discusses the benefits, evidence and limitations of TDM. The practical use of TDM in clinical practice is highlighted. Newer developments in the field and their relevance in practice are discussed.