Increasing Infliximab Dose Based on Symptoms, Biomarkers, and Serum Drug Concentrations Does Not Increase Clinical, Endoscopic, and Corticosteroid-Free Remission in Patients With Active Luminal Crohn's Disease

Therapeutic drug monitoring in inflammatory bowel disease: recent developments

INTRODUCTION

Therapeutic Drug Monitoring (TDM) has an important role in the management of inflammatory bowel disease (IBD) patients on infliximab (IFX) or adalimumab and is recommended in IBD patients presenting a loss of response under anti TNF agent. But, TDM was not recommended for others biotherapies.

AREAS COVERED

Analyzing all publications about TDM and biologics in IBD patients, we reported the major results for each biotherapy.

EXPERT OPINION

Emerging data suggest that TDM will probably be similarly useful forIFX SC. In contrast, there is no demonstrated clinical benefit to the use of TDM with golimumab. For vedolizumab results for the use of both reactive and proactive TDM are discordant. For ustekinumab, data supports the existence of an exposure response relationship, albeit of a lesser magnitude than with anti-TNF agents. Finally, recent data from small case series suggests that TDM could be valuable in optimizing anti-IL23 agents, particularly risankizumab, but this requires further clarification. Consistent with the new concept of 'proactive' strategy, recent data support the utility of dashboard-driven model informed precision dosing (MIDP) of anti-TNF agents, in particular infliximab. Dashboards are software systems using Bayesian population pharmacokinetic modelling to individualize recommendations for target drug levels.

Enteric-coated cerium dioxide nanoparticles for effective inflammatory bowel disease treatment by regulating the redox balance and gut microbiome

Reactive oxygen species (ROS) play crucial roles in the pathogenesis of inflammatory bowel disease (IBD) by disrupting the mucosal barrier and subsequently leading to the dysregulation of the gut microbiome. Therefore, ROS scavengers present a promising and comprehensive strategy for the effective IBD treatment. In the current work, we explored the therapeutic potential of cerium dioxide (CeO2) nano-enzyme, which is well-known for their potent antioxidant properties and capability to mimic natural antioxidant enzymes in the regulation of oxidative stress. We developed a novel enteric-coated nanomedicine (CeO2@S100) aiming at improving the oral delivery efficacy of CeO2 in the complex gastrointestinal environment. CeO2@S100 is composed of a CeO2 nanoparticle core and a protective polyacrylic acid resin shell (Eudragit S100), ensuring targeted delivery of the core specifically at inflamed intestinal sites due to the negative surface charge. In vivo experiments revealed CeO2@S100 significantly alleviates the IBD by balancing oxidative stress and regulating gut microbiota in a dextran sulfate sodium-induced mouse colitis model. The uncomplicated synthesis of CeO2@S100 highlights its promise for clinical use, presenting an effective and safe approach to managing IBD.

Crohn's Patient Serum Proteomics Reveals Response Signature for Infliximab but not Vedolizumab

BACKGROUND

Crohn's disease is a chronic inflammatory bowel disease that affects the gastrointestinal tract. Common biologic families used to treat Crohn's are tumor necrosis factor (TNF)-α blockers (infliximab and adalimumab) and immune cell adhesion blockers (vedolizumab). Given their differing mechanisms of action, the ability to monitor response and predict treatment efficacy via easy-to-obtain blood draws remains an unmet need.

METHODS

To investigate these gaps in knowledge, we leveraged 2 prospective cohorts (LOVE-CD, TAILORIX) and profiled their serum using high-dimensional isobaric-labeled proteomics before treatment and 6 weeks after treatment initiation with either vedolizumab or infliximab.

RESULTS

The proportion of patients endoscopically responding to treatment was comparable among infliximab and vedolizumab cohorts; however, the impact of vedolizumab on patient sera was negligible. In contrast, infliximab treatment induced a robust response including increased blood-gas regulatory response proteins, and concomitant decreases in inflammation-related proteins. Further analysis comparing infliximab responders and nonresponders revealed a lingering innate immune enrichments in nonresponders and a unique protease regulation signature related to clotting cascades in responders. Lastly, using samples prior to infliximab treatment, we highlight serum protein biomarkers that potentially predict a positive response to infliximab treatment.

CONCLUSIONS

These results will positively impact the determination of appropriate patient treatment and inform the selection of clinical trial outcome metrics.

How comparative studies can inform treatment decisions for Crohn's disease

INTRODUCTION

As new therapies for the treatment of Crohn's disease (CD) are approved, there is an increasing need for evidence that clarifies their positioning and sequencing.

AREAS COVERED

Comparative effectiveness research (CER) aims to inform physicians' decisions when they choose which intervention (drug or treatment strategy) to administer to their patients. Pragmatic head-to-head trials represent the best tools for CER, but only a few have been published in the IBD field. Network meta-analyses can point toward the superiority of one drug over another, but they do not reflect everyday clinical practice. Finally, real-world evidence complements that coming from head-to-head trials and network meta-analyses, assessing the real-life effectiveness of therapeutic interventions.

EXPERT OPINION

There is insufficient evidence to create a definitive therapeutic algorithm for CD, but some general considerations can be made. Anti-TNF-α agents seemingly represent the most 'sustainable' first-line choice, considering benefit-harm ratio and costs; vedolizumab, ustekinumab, and risankizumab may be considered as first-line choice when safety issues become prominent. In the event of pharmacodynamic failure, out-of-class swap is to be preferred - possibly with anti-IL23p19 as the best option, with unclear data regarding upadacitinib positioning; a second anti-TNF-α could be considered, as a second choice, after pharmacokinetic failure.

"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.

Model-informed precision dosing: State of the art and future perspectives

Model-informed precision dosing (MIPD) stands as a significant development in personalized medicine to tailor drug dosing to individual patient characteristics. MIPD moves beyond traditional therapeutic drug monitoring (TDM) by integrating mathematical predictions of dosing, and considering patient-specific factors (patient characteristics, drug measurements) as well as different sources of variability. For this purpose, rigorous model qualification is required for the application of MIPD in patients. This review delves into new methods in model selection and validation, also highlighting the role of machine learning in improving MIPD, the utilization of biosensors for real-time monitoring, as well as the potential of models integrating biomarkers for efficacy or toxicity for precision dosing. The clinical evidence of TDM and MIPD is discussed for various medical fields including infection medicine, oncology, transplant medicine, and inflammatory bowel diseases, thereby underscoring the role of pharmacokinetics/pharmacodynamics and specific biomarkers. Further research, particularly randomized clinical trials, is warranted to corroborate the value of MIPD in enhancing patient outcomes and advancing personalized medicine.

Evaluating the Efficacy of Infliximab in Inflammatory Bowel Disease: A Systematic Review of the Literature

The introduction of steroid therapy in 1955 markedly decreased the mortality rate of severe ulcerative colitis (UC) from 24% in the placebo group to 7%, and it is currently less than 1% in specialist centers. Despite this advancement, the response of severe UC to steroids has stagnated over the past 50 years, with a high rate of colectomy persisting for severe to moderately severe cases. Infliximab (IFX) (Remicade, Centocor Inc., Malvern, PA, United States), an intravenously administered chimeric monoclonal immunoglobulin G1 antibody targeting tumor necrosis factor-alpha (TNF-α), has shown efficacy in numerous randomized controlled trials for treating moderate to severe and fistulizing Crohn's disease, particularly in patients unresponsive to conventional therapies. This led to its approval by the US Food and Drug Administration in 1998 for treating active and fistulizing Crohn's disease. Most clinical research on IFX has focused on Crohn's disease, which is characterized as a Th1-type condition driven by pro-inflammatory cytokines like TNF-α. Conversely, UC has traditionally been viewed as a Th2-type condition where TNF-α plays a lesser role. However, recent studies indicate that TNF-α might also contribute to the pathogenesis of UC. These findings highlight the necessity for larger randomized controlled trials to further investigate the benefits of therapies like IFX, with the ultimate goal of improving treatment outcomes and quality of life for patients with inflammatory bowel disease.

Infliximab serum concentrations in luminal Crohn's disease and its relationship with disease activity: A multicentric cross-sectional study

OBJECTIVES

In Latin America, experience with monitoring serum Infliximab (IFX) concentrations is scarce. Our study aimed to compare IFX serum concentrations between patients with active disease or in remission.

PATIENTS AND METHODS

A cross-sectional study was performed in patients with luminal Crohn's disease (CD) during maintenance treatment with IFX. Patients were classified as in remission or disease activity according to clinical scores and endoscopic, radiological, and laboratory markers. A comparison of IFX trough levels between the two groups was performed.

RESULTS

80 CD patients were included [41 (51%) in remission and 39 (49%) with active disease]. In the analysis of general disease activity, the median serum levels of IFX in patients with remission and with active CD were 5.63 [0.03-14.40] vs. 3.84 [0.03-14.40] (p=0.287). Furthermore, there was no difference in serum IFX concentrations in endoscopic, radiological, and laboratory activities. Only in the clinical evaluation there was a significant difference in the median serum IFX levels between patients in remission and disease activity, 5.63 [0.03-14.40] vs. 2.14 [0.32-10.54] (p=0.042).

CONCLUSIONS

IFX serum concentrations during maintenance treatment were similar in patients with luminal CD in remission and general, endoscopic, radiological, and laboratory disease activity. Patients with clinically active disease had lower IFX concentrations than patients in remission.

Personalised therapy in inflammatory bowel disease

Inflammatory bowel diseases (IBD), with ulcerative colitis and Crohn's disease being their most common presentations, comprise a spectrum of diverse disease phenotypes, exhibiting variable behaviors ranging from an indolent course to aggressive phenotypes that impact quality of life of these patients. The last two decades have been marked by the development of new medications (biological therapy and novel small molecules) with diverse mechanisms of action, which have revolutionized the management of IBD, thereby enhancing the quality of life for these patients. This landscape of multiple therapeutic options underscores the need to define which medication will benefit each patient the most and at what speed it should be started. The objective of this review is to present personalized approaches for patients with IBD, thus contributing to therapeutic management.

Best Practice for Therapeutic Drug Monitoring of Infliximab: Position Statement from the International Association of Therapeutic Drug Monitoring and Clinical Toxicology

BACKGROUND

Infliximab, an anti-tumor necrosis factor monoclonal antibody, has revolutionized the pharmacological management of immune-mediated inflammatory diseases (IMIDs). This position statement critically reviews and examines existing data on therapeutic drug monitoring (TDM) of infliximab in patients with IMIDs. It provides a practical guide on implementing TDM in current clinical practices and outlines priority areas for future research.

METHODS

The endorsing TDM of Biologics and Pharmacometrics Committees of the International Association of TDM and Clinical Toxicology collaborated to create this position statement.

RESULTS

Accumulating data support the evidence for TDM of infliximab in the treatment of inflammatory bowel diseases, with limited investigation in other IMIDs. A universal approach to TDM may not fully realize the benefits of improving therapeutic outcomes. Patients at risk for increased infliximab clearance, particularly with a proactive strategy, stand to gain the most from TDM. Personalized exposure targets based on therapeutic goals, patient phenotype, and infliximab administration route are recommended. Rapid assays and home sampling strategies offer flexibility for point-of-care TDM. Ongoing studies on model-informed precision dosing in inflammatory bowel disease will help assess the additional value of precision dosing software tools. Patient education and empowerment, and electronic health record-integrated TDM solutions will facilitate routine TDM implementation. Although optimization of therapeutic effectiveness is a primary focus, the cost-reducing potential of TDM also merits consideration.

CONCLUSIONS

Successful implementation of TDM for infliximab necessitates interdisciplinary collaboration among clinicians, hospital pharmacists, and (quantitative) clinical pharmacologists to ensure an efficient research trajectory.

Mechanisms and management of loss of response to anti-TNF therapy for patients with Crohn's disease: 3-year data from the prospective, multicentre PANTS cohort study

BACKGROUND

We sought to report the effectiveness of infliximab and adalimumab over the first 3 years of treatment and to define the factors that predict anti-TNF treatment failure and the strategies that prevent or mitigate loss of response.

METHODS

Personalised Anti-TNF therapy in Crohn's disease (PANTS) is a UK-wide, multicentre, prospective observational cohort study reporting the rates of effectiveness of infliximab and adalimumab in anti-TNF-naive patients with active luminal Crohn's disease aged 6 years and older. At the end of the first year, sites were invited to enrol participants still receiving study drug into the 2-year PANTS-extension study. We estimated rates of remission across the whole cohort at the end of years 1, 2, and 3 of the study using a modified survival technique with permutation testing. Multivariable regression and survival analyses were used to identify factors associated with loss of response in patients who had initially responded to anti-TNF therapy and with immunogenicity. Loss of response was defined in patients who initially responded to anti-TNF therapy at the end of induction and who subsequently developed symptomatic activity that warranted an escalation of steroid, immunomodulatory, or anti-TNF therapy, resectional surgery, or exit from study due to treatment failure. This study was registered with ClinicalTrials.gov, NCT03088449, and is now complete.

FINDINGS

Between March 19, 2014, and Sept 21, 2017, 389 (41%) of 955 patients treated with infliximab and 209 (32%) of 655 treated with adalimumab in the PANTS study entered the PANTS-extension study (median age 32·5 years [IQR 22·1-46·8], 307 [51%] of 598 were female, and 291 [49%] were male). The estimated proportion of patients in remission at the end of years 1, 2, and 3 were, for infliximab 40·2% (95% CI 36·7-43·7), 34·4% (29·9-39·0), and 34·7% (29·8-39·5), and for adalimumab 35·9% (95% CI 31·2-40·5), 32·9% (26·8-39·2), and 28·9% (21·9-36·3), respectively. Optimal drug concentrations at week 14 to predict remission at any later timepoints were 6·1-10·0 mg/L for infliximab and 10·1-12·0 mg/L for adalimumab. After excluding patients who had primary non-response, the estimated proportions of patients who had loss of response by years 1, 2, and 3 were, for infliximab 34·4% (95% CI 30·4-38·2), 54·5% (49·4-59·0), and 60·0% (54·1-65·2), and for adalimumab 32·1% (26·7-37·1), 47·2% (40·2-53·4), and 68·4% (50·9-79·7), respectively. In multivariable analysis, loss of response at year 2 and 3 for patients treated with infliximab and adalimumab was predicted by low anti-TNF drug concentrations at week 14 (infliximab: hazard ratio [HR] for each ten-fold increase in drug concentration 0·45 [95% CI 0·30-0·67], adalimumab: 0·39 [0·22-0·70]). For patients treated with infliximab, loss of response was also associated with female sex (vs male sex; HR 1·47 [95% CI 1·11-1·95]), obesity (vs not obese 1·62 [1·08-2·42]), baseline white cell count (1·06 [1·02-1·11) per 1 × 109 increase in cells per L), and thiopurine dose quartile. Among patients treated with adalimumab, carriage of the HLA-DQA1*05 risk variant was associated with loss of response (HR 1·95 [95% CI 1·17-3·25]). By the end of year 3, the estimated proportion of patients who developed anti-drug antibodies associated with undetectable drug concentrations was 44·0% (95% CI 38·1-49·4) among patients treated with infliximab and 20·3% (13·8-26·2) among those treated with adalimumab. The development of anti-drug antibodies associated with undetectable drug concentrations was significantly associated with treatment without concomitant immunomodulator use for both groups (HR for immunomodulator use: infliximab 0·40 [95% CI 0·31-0·52], adalimumab 0·42 [95% CI 0·24-0·75]), and with carriage of HLA-DQA1*05 risk variant for infliximab (HR for carriage of risk variant: infliximab 1·46 [1·13-1·88]) but not for adalimumab (HR 1·60 [0·92-2·77]). Concomitant use of an immunomodulator before or on the day of starting infliximab was associated with increased time without the development of anti-drug antibodies associated with undetectable drug concentrations compared with use of infliximab alone (HR 2·87 [95% CI 2·20-3·74]) or introduction of an immunomodulator after anti-TNF initiation (1·70 [1·11-2·59]). In years 2 and 3, 16 (4%) of 389 patients treated with infliximab and 11 (5%) of 209 treated with adalimumab had adverse events leading to treatment withdrawal. Nine (2%) patients treated with infliximab and two (1%) of those treated with adalimumab had serious infections in years 2 and 3.

INTERPRETATION

Only around a third of patients with active luminal Crohn's disease treated with an anti-TNF drug were in remission at the end of 3 years of treatment. Low drug concentrations at the end of the induction period predict loss of response by year 3 of treatment, suggesting higher drug concentrations during the first year of treatment, particularly during induction, might lead to better long-term outcomes. Anti-drug antibodies associated with undetectable drug concentrations of infliximab, but not adalimumab, can be predicted by carriage of HLA-DQA1*05 and mitigated by concomitant immunomodulator use for both drugs.

FUNDING

Guts UK, Crohn's and Colitis UK, Cure Crohn's Colitis, AbbVie, Merck Sharp and Dohme, Napp Pharmaceuticals, Pfizer, and Celltrion Healthcare.

Forecasted infliximab concentrations during induction predict time to remission and sustained disease control of inflammatory bowel disease

BACKGROUND

Infliximab (IFX) exposure is established as a predictive factor of pharmacokinetic (PK) origin in inflammatory bowel disease (IBD), and expert consensus is to achieve adequate exposure during induction to achieve and sustain remission.

METHODS

We retrospectively evaluated the performance of a Bayesian PK tool in IBD patients starting IFX. Trough IFX serum levels collected immediately before the third (at week 6) and fourth (at week 14) infusions were evaluated from 307 IBD patients (median age=17 years, 50 % females, 83 % with Crohn's disease). Forecasted IFX concentration at the fourth infusion were estimated using serum IFX, antibodies to IFX, albumin and weight determined immediately before the third infusion using population PK calculator with Bayesian prior. The outcome variable was a clinical & biochemical remission status achieved (CRP levels below 3 mg/L in presence of clinical remission). Statistics consisted of Kaplan Meier analysis with calculation of Hazard ratio (HR), and logistic regression.

RESULTS

IFX concentration above 15 µg/mL immediately before the third infusion associated with shorter time to clinical & biochemical remission than concentration below 15 µg/mL without reaching significance (163±14 days vs 200±16 days, respectively; p=0.052). However, using PK parameters at the third infusion, forecasted IFX concentrations above 10 µg/mL immediately before the fourth infusion were significantly associated with a higher rate (HR=1.6 95 %CI: 1.1 to 2.1 p<0.01) and shorter time to remission (148±18 days vs 200±13 days p<0.01). In the presence of IFX concentration above 15 µg/mL at the third infusion, there was a significant 2.5-fold higher likelihood of sustained clinical & biochemical remission status during maintenance as compared to IFX concentrations below 15 µg/mL (p<0.01). Forecasted IFX level above 10 µg/mL at fourth infusion associated with significantly 3.9-fold higher likelihood of clinical & biochemical remission as compared to forecasted IFX concentrations below 10 µg/mL (p<0.01).

CONCLUSIONS

These data further support that optimized IFX concentrations during induction are associated with enhanced disease control in IBD.

Therapeutic drug monitoring in inflammatory bowel diseases. Position statement of the Spanish Working Group on Crohn's Disease and Ulcerative Colitis

The treatment of inflammatory bowel disease has undergone a significant transformation following the introduction of biologic drugs. Thanks to these drugs, treatment goals have evolved from clinical response and remission to more ambitious objectives, such as endoscopic or radiologic remission. However, even though biologics are highly effective, a significant percentage of patients will not achieve an initial response or may lose it over time. We know that there is a direct relationship between the trough concentrations of the biologic and its therapeutic efficacy, with more demanding therapeutic goals requiring higher drug levels, and inadequate exposure being common. Therapeutic drug monitoring of biologic medications, along with pharmacokinetic models, provides us with the possibility of offering a personalized approach to treatment for patients with IBD. Over the past few years, relevant information has accumulated regarding its utility during or after induction, as well as in the maintenance of biologic treatment, in reactive or proactive strategies, and prior to withdrawal or treatment de-escalation. The aim of this document is to establish recommendations regarding the utility of therapeutic drug monitoring of biologics in patients with inflammatory bowel disease, in different clinical practice scenarios, and to identify areas where its utility is evident, promising, or controversial.

One-Year Clinical Outcomes of Subcutaneous Infliximab Maintenance Therapy Compared With Intravenous Infliximab Maintenance Therapy in Patients With Inflammatory Bowel Disease: A Prospective Cohort Study

BACKGROUND

Although the pharmacokinetic profile of subcutaneous (SC) infliximab (IFX) is superior to conventional intravenous (IV) IFX, long-term efficacy and safety of SC IFX in patients with inflammatory bowel disease (IBD) have not been reported yet. This study aimed to evaluate long-term clinical outcomes of IBD patients treated with SC IFX compared with those of IBD patients treated with IV IFX during maintenance therapy.

METHODS

This prospective cohort study enrolled 61 IBD patients in clinical remission who received scheduled IFX maintenance therapy. Of them, 38 patients were switched to SC IFX, while 23 patients continued IV IFX with dose optimization. Enrolled patients were followed up for 1 year. The primary outcome was durable remission defined as clinical remission (Crohn's disease, Harvey-Bradshaw index <5; ulcerative colitis, partial Mayo score <2) and biochemical remission (C-reactive protein <0.5 mg/dL) with IFX trough level ≥3 µg/mL throughout the follow-up period.

RESULTS

One-year clinical remission, 1-year biochemical remission, and mucosal healing did not differ between the IV and SC IFX groups (n = 20 of 23 vs 33 of 38; P = 1.000; n = 22 of 23 vs 34 of 38; P = .641; and n = 10 of 18 vs 17 of 25; P = .414, respectively). During follow-up, the number of patients with IFX trough level <3 μg/mL was significantly lower in the SC IFX group (n = 0 of 38, 0%) than in the IV IFX group (n = 10 of 23, 43%) (P < .001). The SC IFX group showed higher 1-year durable remission than the IV IFX group (n = 31 of 38, 82% vs n = 11 of 23, 48%; P = .013). The incidence of IFX-related adverse events did not differ significantly between both groups (26% vs 39%; P = .446).

CONCLUSION

The SC IFX switch induced a higher 1-year durable remission rate than continuing IV IFX in patients with IBD during scheduled maintenance therapy, showing similar safety.

Simulated cost-effectiveness of a novel precision-guided dosing strategy in adult patients with Crohn's disease initiating infliximab maintenance therapy

BACKGROUND

Patients with Crohn's disease (CD) who lose response to biologics experience reduced quality of life (QoL) and costly hospitalizations. Precision-guided dosing (PGD) provides a comprehensive pharmacokinetic (PK) profile that allows for biologic dosing to be personalized. We analyzed the cost-effectiveness of infliximab (IFX) PGD relative to two other dose intensification strategies (DIS).

METHODS

We developed a hybrid (Markov and decision tree) model of patients with CD who had a clinical response to IFX induction. The analysis had a US payer perspective, a base case time horizon of 5 years, and a 4-week cycle length. There were three IFX dosing comparators: PGD; dose intensification based on symptoms, inflammatory markers, and trough IFX concentration (DIS1); and dose intensification based on symptoms alone (DIS2). Patients that failed IFX initiated ustekinumab, followed by vedolizumab, and conventional therapy. Transition probabilities for IFX were estimated from real-world clinical PK data and interventional clinical trial patient-level data. All other transition probabilities were derived from published randomized clinical trials and cost-effectiveness analyses. Utility values were sourced from previous health technology assessments. Direct costs included biologic acquisition and infusion, surgeries and procedures, conventional therapy, and lab testing. The primary outcomes were incremental cost-effectiveness ratios (ICERs). The robustness of results was assessed via one-way sensitivity, scenario, and probabilistic sensitivity analyses (PSA).

RESULTS

PGD was the cost-effective IFX dosing strategy with an ICER of 122,932 $ per quality-adjusted life year (QALY) relative to DIS1 and dominating DIS2. PGD had the lowest percentage (1.1%) of patients requiring a new biologic through 5 years (8.9% and 74.4% for DIS1 and DIS2, respectively). One-way sensitivity analysis demonstrated that the cost-effectiveness of PGD was most sensitive to the time between IFX doses. PSA demonstrated that joint parameter uncertainty had moderate impact on some results.

CONCLUSIONS

PGD provides clinical and QoL benefits by maintaining remission and avoiding IFX failure; it is the most cost-effective under conservative assumptions.

Precise infliximab exposure and pharmacodynamic control to achieve deep remission in paediatric Crohn's disease (REMODEL-CD): study protocol for a multicentre, open-label, pragmatic clinical trial in the USA

INTRODUCTION

The only biologic therapy currently approved to treat moderate to severe Crohn's disease in children (<18 years old) are those that antagonise tumour necrosis factor-alpha (anti-TNF). Therefore, it is critically important to develop novel strategies that maximise treatment effectiveness in this population. There is growing evidence that rates of sustained corticosteroid-free clinical remission, endoscopic healing and drug durability considerably improve when patients receive early anti-TNF dose optimisations guided by reactive or proactive therapeutic drug monitoring and pharmacodynamic monitoring. In response, our team has developed a personalised and scalable infliximab dosing intervention that starts with dose selection and continues throughout maintenance to optimise drug exposure. We hypothesise that a precision dosing strategy starting from induction and targeting dose-specific pharmacokinetic and pharmacodynamic endpoints throughout therapy will significantly improve outcomes compared with a conventional dosing strategy.

METHODS AND ANALYSIS

Conduct a clinical trial to assess rates of deep remission between Crohn's disease patients receiving infliximab with precision dosing (n=90) versus conventional care (n=90). Patients (age 6-22 years) will be recruited from 10 medical centres in the USA. Each centre has been selected to provide either precision dosing or conventional care dosing. Precision dosing includes the use of a clinical decision support tool (RoadMAB) from the start of infliximab to achieve specific (personalised) trough concentrations and specific pharmacodynamic targets (at doses 3, 4 and 6). Conventional care includes the use of a modified infliximab starting dose (5 or 7.5 mg/kg based on the pretreatment serum albumin) with a goal to achieve maintenance trough concentrations of 5-10 µg/mL. The primary endpoint is year 1 deep remission defined as a combination of clinical remission (paediatric Crohn's disease activity index<10 (child) or a Crohn's disease activity index<150 (adults)), off prednisone>8 weeks and endoscopic remission (simple endoscopic severity-Crohn's disease≤2).

ETHICS AND DISSEMINATION

). The study protocol has been approved by the Cincinnati Children's Hospital Medical Centre Institutional Review Board. Study results will be disseminated in peer-reviewed journals and presented at scientific meetings.

TRIAL REGISTRATION NUMBER

NCT05660746.

CT-based pancreatic radiomics predicts secondary loss of response to infliximab in biologically naïve patients with Crohn's disease

OBJECTIVES

Predicting secondary loss of response (SLR) to infliximab (IFX) is paramount for tailoring personalized management regimens. Concurrent pancreatic manifestations in patients with Crohn's disease (CD) may correlate with SLR to anti-tumor necrosis factor treatment. This work aimed to evaluate the potential of pancreatic radiomics to predict SLR to IFX in biologic-naive individuals with CD.

METHODS

Three models were developed by logistic regression analyses to identify high-risk subgroup prone to SLR. The area under the curve (AUC), calibration curve, decision curve analysis (DCA), and integrated discrimination improvement (IDI) were applied for the verification of model performance. A quantitative nomogram was proposed based on the optimal prediction model, and its reliability was substantiated by 10-fold cross-validation.

RESULTS

In total, 184 CD patients were enrolled in the period January 2016 to February 2022. The clinical model incorporated age of onset, disease duration, disease location, and disease behavior, whereas the radiomics model consisted of five texture features. These clinical parameters and the radiomics score calculated by selected texture features were applied to build the combined model. Compared to other two models, combined model achieved favorable, significantly improved discrimination power (AUCcombined vs clinical 0.851 vs 0.694, p = 0.02; AUCcombined vs radiomics 0.851 vs 0.740, p = 0.04) and superior clinical usefulness, which was further converted into reliable nomogram with an accuracy of 0.860 and AUC of 0.872.

CONCLUSIONS

The first proposed pancreatic-related nomogram represents a credible, noninvasive predictive instrument to assist clinicians in accurately identifying SLR and non-SLR in CD patients.

CRITICAL RELEVANCE STATEMENT

This study first built a visual nomogram incorporating pancreatic texture features and clinical factors, which could facilitate clinicians to make personalized treatment decisions and optimize cost-effectiveness ratio for patients with CD.

KEY POINTS

• The first proposed pancreatic-related model predicts secondary loss of response for infliximab in Crohn's disease. • The model achieved satisfactory predictive accuracy, calibration ability, and clinical value. • The model-based nomogram has the potential to identify long-term failure in advance and tailor personalized management regimens.

Efficacy and safety of proactive drug monitoring in inflammatory bowel disease treated with anti-TNF agents: A systematic review and meta-analysis

BACKGROUND AND AIMS

A systematic review and a meta-analysis of the literature was conducted to assess efficacy and safety of proactive therapeutic drug monitoring (TDM) versus conventional management during maintenance treatment with anti-tumour necrosis factor (anti-TNFα) in patients with inflammatory bowel disease (IBD).

METHODS

A search was conducted up to January 2022 (MEDLINE, EMBASE, and the Cochrane Library). The primary outcome was the ability to maintain clinical remission at 12 months. The certainty of evidence was determined using the GRADE approach.

RESULTS

Nine studies were identified: one systematic review, six randomised clinical trials, and two cohort studies. No superior efficacy of proactive TDM [relative risk 1.16; 95% confidence interval (CI): 0.98-1.37, n=528; I2=55%] was shown. Proactive TDM could improve the durability of anti-TNFα treatment [odds ratio (OR) 0.12; 95%CI: 0.05-0.27; n=390; I2=45%), prevent acute infusion reactions (OR 0.21; 95%CI: 0.05-0.82; n=390; I2=0%), decrease adverse events (OR 0.38; 95%CI: 0.15-0.98; n=390; I2=14%), and reduce the probability of surgery, at lower economical expenditure.

CONCLUSIONS

The analysed evidence did not confirm the superiority of proactive TDM of anti-TNFα treatment over conventional management in patients with IBD, so proactive TDM should not currently be recommended.

The impact of proactive versus reactive drug monitoring of infliximab on treatment outcomes in patients with crohn's disease

BACKGROUND

Therapeutic drug monitoring (TDM) plays a crucial role in the management of Crohn's disease (CD) patients receiving infliximab (IFX). While reactive TDM has been more commonly utilized previously, recent research suggests that proactive TDM may offer greater benefits for patients.

OBJECTIVE

To compare treatment outcomes among patients receiving different monitoring modalities of IFX.

METHODS

This was a retrospective cohort study that enrolled 142 CD patients who initiated IFX therapy at the First Affiliated Hospital of Nanjing Medical University from January 2014 to June 2021. The patients were divided into a reactive (n = 43) and proactive (n = 99) group. The outcome measures included sustained clinical response and remission rates, biological remission rates, endoscopic response and remission rates achieved in both groups at weeks 30 and 54. The incidence of adverse events (AEs), changes in IFX trough concentrations (TCs) and treatment adjustments within 54 weeks were also evaluated.

RESULTS

Kaplan-Meier analysis demonstrated that the proactive group exhibited significantly higher cumulative probabilities of sustained clinical response, sustained clinical remission, and endoscopic response by Week 54. Compared to the reactive group, patients in the proactive group achieved significantly reduced rates of AEs-related hospitalization and surgery. After adjusting treatment strategies, the median concentration and the proportion of patients achieved an effective therapeutic concentration (TC > 3 μg/mL) at Week 54 was both significantly higher in the proactive group.

CONCLUSIONS

Proactive TDM of IFX plays a more crucial role in timely adjustment of treatment strategies and maintenance of effective concentrations, thereby contributing to the outcomes for CD patients.

Attitudes, perceptions and barriers in implementing therapeutic drug monitoring for anti-TNFs in inflammatory bowel disease: a survey from the Middle East

Background

A growing body of evidence underscores the beneficial impact of therapeutic drug monitoring (TDM) on the efficacy and cost-effectiveness of anti-tumour necrosis factor (TNF) therapy in patients with inflammatory bowel disease (IBD).

Objectives

We surveyed clinician attitudes, perceptions and barriers related to TDM in IBD in the Middle East.

Design

A 15-question survey was distributed through national gastroenterological societies in five Middle Eastern countries (UAE, Saudi Arabia, Kuwait, Lebanon and Egypt).

Methods

Data on clinician characteristics, demographics, utilization patterns and obstacles related to the adoption of TDM with anti-TNFs were gathered. Logistic regression analysis was used to predict factors influencing the utilization of TDM.

Results

Among 211 respondents (82% male), 82% were consultants, 8% were physicians with an interest in gastroenterology (GI), and 6% were GI trainees. Of these, 152 met inclusion criteria, treating >5 IBD patients per month and ⩾1 with an anti-TNF per month. TDM was used in clinical practice by 78% (95% CI: 71-85) of respondents. TDM was utilized following the loss of response (LOR) in 93%, for primary non-response (PNR) in 40% and before restarting anti-TNF therapy after a drug holiday in 33% of respondents, while 34% used TDM proactively. No specific factors were associated with the use of TDM. Barriers to TDM use included cost (85%), time lag to results (71%) and lack of insurance reimbursement (65%). Overall knowledge of TDM (70%), interpretation and actioning of results (76%) or awareness of clinical guidelines (57%) were not perceived as barriers. If barriers were removed, 95% would use TDM more frequently; 93% for LOR, 60% for PNR, 50% when restarting after a drug holiday, and 54% would use TDM proactively.

Conclusion

Most gastroenterologists use TDM for LOR, with cost, time lag and insurance reimbursement being significant barriers. Addressing these barriers would increase the judicious use of reactive and proactive TDM to optimize anti-TNF therapy in IBD.

Infliximab for maintenance of medically-induced remission in Crohn's disease

BACKGROUND

Infliximab is a monoclonal antibody that binds and neutralises tumour necrosis factor-alpha (TNF-α) which is present in high levels in the blood serum, mucosa and stool of patients with Crohn's disease.

OBJECTIVES

To determine the efficacy and safety of infliximab for maintaining remission in patients with Crohn's disease.

SEARCH METHODS

On 31 August, 2021 and 23 June, 2023, we searched CENTRAL, Embase, MEDLINE, ClinicalTrials.gov, and WHO ICTRP.

SELECTION CRITERIA

Randomised controlled trials (RCTs) in which infliximab was compared to placebo or another active comparator for maintenance, remission, or response in patients with Crohn's disease.

DATA COLLECTION AND ANALYSIS

Pairs of review authors independently selected studies and conducted data extraction and risk of bias assessment. We expressed outcomes as risk ratios and mean differences with 95% confidence intervals. We assessed the certainty of the evidence using GRADE. Our primary outcome was clinical relapse. Secondary outcomes were loss of clinical response, endoscopic relapse, and withdrawal due to serious and adverse events.

MAIN RESULTS

Nine RCTs with 1257 participants were included. They were conducted between 1999 and 2022; seven RCTs included biologically-naive patients, and the remaining two included a mix of naive/not naive patients. Three studies included patients in clinical remission, five included patients with a mix of activity scores, and one study included biologic responders with active disease at baseline. All studies allowed some form of concomitant medication during their duration. One study exclusively included patients with fistulating disease. The age of the participants ranged from 18 to 69 years old. All but one single-centre RCT were multicentre RCTs. Four studies were funded by pharmaceutical companies, two had a mix of commercial and public funding, and two had public funding. Infliximab is probably superior to placebo in preventing clinical relapse in patients who have mixed levels of clinical disease activity at baseline, and are not naive to biologics (56% vs 75%, RR 0.73, 95% CI 0.63 to 0.84, NNTB = 5, moderate-certainty evidence). We cannot draw any conclusions on loss of clinical response (RR 0.59, 95% CI 0.37 to 0.96), withdrawals due to adverse events (RR 0.66, 95% CI 0.37 to 1.19), or serious adverse events (RR 0.60, 95% CI 0.36 to 1.00) because the evidence is very low certainty. Infliximab combined with purine analogues is probably superior to purine analogues for clinical relapse (12% vs 59%, RR 0.20, 95% CI 0.10 to 0.42, NNTB = 2, moderate-certainty evidence), for patients in remission, and who are not naive to biologics. We cannot draw any conclusions on withdrawals due to adverse events (RR 0.47, 95% CI 0.15 to 1.49), and serious adverse events (RR 1.19, 95% CI 0.54 to 2.64) because the evidence is very low certainty. We cannot draw any conclusions about the effects of infliximab on serious adverse events compared to purine analogues (RR 0.79, 95% CI 0.37 to 1.68) for a population in remission at baseline because the evidence is very low certainty. There was no evidence available for the outcomes of clinical relapse, loss of clinical response, and withdrawal due to adverse events. Infliximab may be equivalent to biosimilar for clinical relapse (47% vs 40% RR 1.18, 95% CI 0.82 to 1.69), and it may be slightly less effective in averting loss of clinical response (49% vs 32%, RR 1.50, 95% CI 1.01 to 2.23, low-certainty evidence), for a population with mixed/low disease activity at baseline. Infliximab may be less effective than biosimilar in averting withdrawals due to adverse events (27% vs 0%, RR 20.73, 95% CI 2.86 to 150.33, low-certainty evidence). Infliximab may be equivalent to biosimilar for serious adverse events (10% vs 10%, RR 0.99, 95% CI 0.39 to 2.50, low-certainty evidence). We cannot draw any conclusions on the effects of subcutaneous biosimilar compared with intravenous biosimilar on clinical relapse (RR 1.01, 95% CI 0.65 to 1.57), loss of clinical response (RR 0.94, 95% CI 0.70 to 1.25), and withdrawals due to adverse events (RR 0.77, 95% CI 0.30 to 1.97) for an active disease population with clinical response at baseline because the evidence is of very low certainty. We cannot draw any conclusions on the effects of infliximab compared to adalimumab on loss of clinical response (RR 0.68, 95% CI 0.29 to 1.59), withdrawals due to adverse events (RR 0.10, 95% CI 0.01 to 0.72), serious adverse events (RR 0.09, 95% CI 0.01 to 1.54) for an active disease population with clinical response at baseline because the evidence is of very low certainty. There was no evidence available for the outcome of clinical relapse.

AUTHORS' CONCLUSIONS

Infliximab is probably more effective in preventing clinical relapse than placebo (moderate-certainty evidence). Infliximab in combination with purine analogues is probably more effective in preventing clinical and endoscopic relapse than purine analogues alone (moderate-certainty evidence). No conclusions can be drawn regarding prevention of loss of clinical response, occurrence of withdrawals due to adverse events, or total adverse events due to very low-certainty evidence for both of these comparisons. There may be little or no difference in prevention of clinical relapse, withdrawal due to adverse events or total adverse events between infliximab and a biosimilar (low-certainty evidence). Infliximab may lead to more loss of clinical response than a biosimilar (low-certainty evidence). We were unable to draw meaningful conclusions about other comparisons and outcomes related to missing data or very low-certainty evidence due to serious concerns about imprecision and risk of bias. Further research should focus on comparisons with other active therapies for maintaining remission, as well as ensuring adequate power calculations and reporting of methods.

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.

Therapeutic Drug Monitoring for Biologic and Small-Molecule Therapies for Inflammatory Bowel Disease

Background: Inflammatory bowel disease (IBD), encompassing ulcerative colitis and Crohn's disease, necessitates long-term medical therapy to manage symptoms and prevent complications. Therapeutic drug monitoring (TDM) has emerged as a strategy to optimize treatment efficacy, particularly with anti-tumour necrosis factor (anti-TNF) alpha drugs. This review explores the role of TDM for non-anti-TNF advanced therapies in IBD, focusing on vedolizumab, ustekinumab, tofacitinib, upadacitinib, risankizumab and ozanimod. Methods: The literature search, conducted through OVID (Medline) and PubMed, delves into proactive versus reactive TDM, timing of monitoring and methods for measuring drug levels and anti-drug antibodies. Results: While ustekinumab and vedolizumab exhibit exposure-response relationships, consensus on target levels and the role of TDM adjustments remains elusive. Limited data on risankizumab suggest a dose-dependent response, while for small molecule therapies (janus kinase inhibitors and ozanimod), the absence of real-world data and commercially available TDM tools pose challenges. Conclusion: At present, with the available data, there is a limited role for TDM in non-anti-TNF biologic and small-molecule therapies. This review underscores the need for further research to delineate the utility of TDM in guiding treatment decisions for these agents.

Controversies in the management of anti-TNF therapy in patients with Crohn's disease: a Delphi consensus

BACKGROUND

Despite research, there are still controversial areas in the management of Crohn's disease (CD).

OBJECTIVE

To establish practical recommendations on using anti-tumour necrosis factor (TNF) drugs in patients with moderate-to-severe CD.

METHODS

Clinical controversies in the management of CD using anti-TNF therapies were identified. A comprehensive literature review was performed, and a national survey was launched to examine current clinical practices when using anti-TNF therapies. Their results were discussed by expert gastroenterologists within a nominal group meeting, and a set of statements was proposed and tested in a Delphi process.

RESULTS

Qualitative study. The survey and Delphi process were sent to 244 CD-treating physicians (response rate: 58%). A total of 14 statements were generated. All but two achieved agreement. These statements cover: (1) use of first-line non-anti-TNF biological therapy; (2) role of HLA-DQA1*05 in daily practice; (3) attitudes in primary non-response and loss of response to anti-TNF therapy due to immunogenicity; (4) use of ustekinumab or vedolizumab if a change in action mechanism is warranted; (5) anti-TNF drug level monitoring; (6) combined therapy with an immunomodulator.

CONCLUSION

This document sought to pull together the best evidence, experts' opinions, and treating physicians' attitudes when using anti-TNF therapies in patients with CD.

Performance of a New Rapid Point-of-Care Test for Infliximab Levels in Patients with Inflammatory Bowel Disease: A Comparison to ELISA

BACKGROUND

Therapeutic drug monitoring of infliximab levels in patients with inflammatory bowel disease (IBD) optimizes patients' treatment. The reference technique is based on enzyme-linked immunosorbent assay (ELISA) although point of care (POC) assays are being developed.

AIMS

To assess the performance of a new rapid immunochromatographic POC assay (Promonitor Quick IFX) compared with ELISA technique to measure infliximab levels in patients with IBD.

METHODS

A prospective, observational, unicentric study was performed on capillary blood samples from patients with IBD before infliximab infusion (trough levels). Infliximab levels and anti-infliximab antibodies were measured using the ELISA technique (Promonitor IFX) and the POC assay. Correlation between both techniques was assessed by Pearson's coefficient. Quantitative differences were evaluated by Bland-Altman analysis. Samples were stratified according to infliximab therapeutic ranges (< 3 μg/mL, 3-8 μg/mL, and > 8 μg/mL).

RESULTS

A total of 135 experimental samples were assessed. Infliximab levels showed a high correlation between POC and ELISA tests (r = 0.84, P < 0.001). The mean difference between tests was 1.46 μg/mL (P < 0.001), being minimal for concentrations < 8 μg/mL. POC and ELISA assays showed an overall concordance of 87.4%. Most samples were in the same therapeutic range, which lead to equivalent therapeutic decisions. POC and ELISA assays detected the presence of anti-infliximab antibodies in 2.2% and 3.7% of the samples, respectively.

CONCLUSIONS

POC assay results in blood samples from patients with IBD were comparable to those obtained with the reference ELISA technique. The POC assay could be considered for routine testing based on its ease of use and rapidity.

Correlation between trough levels of infliximab and postoperative endoscopic recurrence in Crohn's disease patients submitted to ileocolonic resections

OBJECTIVES

The aim of this study was to evaluate serum levels of Infliximab (IFX) in patients with Crohn's disease (CD) who underwent an ileocolonic resection and to correlate them with the presence or absence of endoscopic disease recurrence.

METHODS

An observational and cross-sectional study was carried out in patients from 2 treatment centers in Curitiba-PR, with CD, who underwent ileocaecal resection and used IFX after surgery. Drug serum levels were measured, and colonoscopy was performed 30 days before or after collection. Patients were then divided into two groups: with or without endoscopic recurrence (defined as a Rutgeerts score greater than or equal to 2), and mean serum IFX levels were identified and compared. The primary objective was the correlation between recurrence and the median levels of IFX, performed comparatively between groups.

RESULTS

Of the 21 patients included in the study, 14 had no endoscopic recurrence and 7 had it. There was no difference between groups in terms of baseline patient characteristics, mono or combo therapy treatment, serum albumin, and the time elapsed between collection of serum levels and diagnosis, surgery, and beginning of therapy. Patients with endoscopic recurrence used more biologics previously ( P  = 0.027). There was no difference between the median values of serum IFX levels between the groups: (4.71 [0.03-14.4]) in patients without recurrence versus (2.18 [0.88-14]) in those with recurrence ( P  = 0.601).

CONCLUSION

Low serum IFX levels were not correlated with postoperative endoscopic recurrence. Studies with a larger number of patients are needed to better test the proposed hypothesis.

Small molecule agents in clinical management of inflammatory bowel disease: Current status and future prospects

Inflammatory bowel disease (IBD), encompassing ulcerative colitis (UC) and Crohn's disease (CD), is a chronic non-specific inflammatory disorder affecting the intestines. It is characterized by a protracted course with frequent relapses, potentially resulting in disability, heightened surgical risk, diminished patient quality of life, and increased familial and societal economic burden. Current understanding posits that genetic, immune, and environmental factors, as well as the intestinal microbiota, collectively contribute to the pathogenesis and progression of these diseases. Notably, the prevalence of IBD in China has exhibited a gradual rise in recent years. The inadequate effectiveness and adverse effects of conventional medications, including 5-aminosalicylic acid (5-ASA), corticosteroids, and immunosuppressants, have hindered the effective management of certain patients with IBD. In the realm of biological agents, anti-tumor necrosis factor (TNF) antagonists have emerged as the pioneering targeted therapy, extensively employed for an extended period. However, extensive data analysis spanning several decades reveals a notable proportion of primary and secondary loss of response to these agents. Hence, the ongoing introduction of novel targeted therapy medications, including small molecule agents, has presented a new avenue for individuals who have experienced inadequate response to conventional treatment and anti-TNF therapy. Nevertheless, additional investigation and research are required to determine the optimal role of small molecule agents as initial treatment options. This article provides a comprehensive overview of the efficacy and safety of small molecular agents in recent clinical trials for the treatment of IBD, and explores the treatment decision-making process to identify optimal subsequent treatment drugs and guide the selection of appropriate first-line targeted therapy drugs.

Precision Dosing of Anti-TNF Therapy in Pediatric Inflammatory Bowel Disease

PURPOSE OF THE REVIEW

This review focuses on recent advancements in anti-TNF therapeutic drug monitoring (TDM), pharmacogenetics and personalized drug selection for children with inflammatory bowel disease (IBD).

RECENT FINDINGS

Several real-world studies and one clinical trial in children have demonstrated that proactive TDM, targeting higher exposure concentrations (> 5 µg/mL), can improve disease remission rates and enhance durability of the anti-TNF biologics. Recent data from both adult and pediatric IBD patients have revealed an association between a genetic polymorphism (HLA-DQA1*05) and the development of auto-drug antibodies. The impact of this association on clinical outcomes, considering more routine use proactive TDM and dose optimization in children, is still under investigation. Additionally, recent studies have identified potential inflammatory signatures and biomarkers that may serve as companion diagnostics for anti-TNF biologics. The effective management of anti-TNF therapies in children with IBD requires evidence-based precision dosing strategies, including routine TDM and proactive pharmacodynamic assessments.

A Systematic Review on Long-Term Efficacy Outcome Measures in Crohn's Disease Patients

BACKGROUND

The traditional long-term treatment goal of Crohn's disease [CD] is maintenance of corticosteroid-free clinical remission. Additional treatment targets, such as biochemical, endoscopic and patient-reported remission, are advocated. The relapsing-remitting nature of CD provides a challenge to the timing of target assessment. Cross-sectional assessment at predetermined moments disregards the health state in between measurements. In this systematic review, we provide an overview of outcomes used to assess long-term efficacy in clinical trials in CD.

METHODS

A systematic search of the PubMed and EMBASE databases was performed to identify clinical trials in luminal CD reporting on maintenance treatment [strategies] since 1995. Two independent reviewers selected eligible articles for full text retrieval, and assessed if long-term corticosteroid-free clinical, biochemical, endoscopic or patient-reported efficacy outcomes were used.

RESULTS

The search resulted in 2452 hits and 82 articles were included. Clinical activity was used in 80 studies [98%] as the long-term efficacy outcome, and in 21 [26%] of these concomitant corticosteroid use was taken into account. C-reactive protein was used in 32 studies [41%], faecal calprotectin in 15 studies [18%], endoscopic activity in 34 studies [41%] and patient-reported outcome in 32 studies [39%]. In seven studies, clinical, biochemical, endoscopic activity and the patient's perspective were measured. In most studies cross-sectional measures or multiple measurements over time were used.

CONCLUSION

In none of the published clinical trials in CD was sustained remission on all treatment targets reported. Cross-sectional outcomes at predetermined times were widely applied, leading to lack of information regarding sustained corticosteroid-free remission for this relapsing-remitting chronic disease.

A Review of Therapeutic Drug Monitoring in Patients with Inflammatory Bowel Disease Receiving Combination Therapy

Background: Inflammatory Bowel Disease (IBD) impacts millions worldwide, presenting a major challenge to healthcare providers and patients. The advent of biologic therapies has enhanced the prognosis, but many patients exhibit primary or secondary non-response, underscoring the need for rigorous monitoring and therapy optimization to improve outcomes. Objective: This narrative review seeks to understand the role of therapeutic drug monitoring (TDM) in optimizing treatment for IBD patients, especially for those on combination therapies of biologics and immunomodulators. Methods: A comprehensive synthesis of the current literature was undertaken, focusing on the application, benefits, limitations, and future directions of TDM in patients receiving a combination of biologic therapies and immunomodulators. Results: While biological therapies have improved outcomes, rigorous monitoring and therapy optimization are needed. TDM has emerged as a pivotal strategy, enhancing outcomes cost-effectively while reducing adverse events. While most data pertain to monotherapies, TDM's applicability also extends to combination therapy. Conclusion: TDM plays a crucial role in the treatment optimization of IBD patients on combination therapies. Further research is needed to fully understand its potential and limitations in the broader context of IBD management.

Correlation between Treatment Outcomes and Serum Vitamin D Levels As Well As Infliximab Trough Concentration among Chinese Patients with Crohn's Disease

Background

The relationship between vitamin D (vit-D) levels and the effectiveness of infliximab (IFX) in patients with Crohn's disease (CD) remains controversial.

Objective

To evaluate the interaction between vit-D levels and the response to IFX therapy in patients with CD.

Methods

This was a retrospective cohort study. Serum vit-D and IFX trough concentrations (TC) were measured in 84 patients, and statistical analyses were performed.

Results

The total vit-D deficiency rate at enrollment, at week 14 and week 38, was 64.3%, 41.67%, and 37.5%, respectively (P < 0.001). CD activity index (CDAI) (120, range, 93-142.75) and simplified endoscopic activity score for CD (SES-CD) (2, range, 0-4) at week 14 were lower than that of enrollment (CDAI, 136.5, range, 101.25-196; SES-CD 13, range, 5-23) (P < 0.001). The biochemical remission (BR), clinical remission (CR), endoscopic remission (ER), and response (ERe) rates of week 38 were 76.1%, 88.5%, 22.4%, and 67.2%, respectively. vit-D levels at enrollment were positively correlated with CDAI at week 38 (P = 0.024). IFX serum TC was related to BR (P = 0.036), CR (P = 0.032) at week 14, and ERe (P = 0.009) at week 38.

Conclusion

Among Chinese patients with CD, vit-D levels prior to IFX therapy are related to CDAI scores, and IFX serum TC is associated with BR, CR, and ERe.

Influence of HLADQA1*05 Genotype in Adults With Inflammatory Bowel Disease and Anti-TNF Treatment With Proactive Therapeutic Drug Monitoring: A Retrospective Cohort Study

BACKGROUND

Carriers of the human leucocyte antigen variant HLADQA1*05 (rs2097432) are at risk of developing antibodies against infliximab and adalimumab with reduced tumor necrosis factor (TNF) antagonist persistence. The impact of proactive therapeutic drug monitoring (PTDM) on this association has been barely assessed.

METHODS

We conducted a retrospective single-center cohort study including patients with inflammatory bowel disease starting anti-TNF therapy between January 2017 and March 2021. Proactive therapeutic drug monitoring was defined as periodic drug level measurement (≥2 determinations during the first year of treatment and ≥1/annual determination during the following years), regardless of clinical condition, followed by dose optimization. Variables associated with treatment persistence were assessed with multivariable Cox regression analysis.

RESULTS

A total of 112 patients were included, 52 (46.4%) HLA-DQA1*05 carriers, with a median follow-up of 73.9 (interquartile range, 35.4-133.1) weeks. Combination therapy with thiopurines was more frequent among HLA-DQA1*05 noncarriers (28 [46.7%] vs 12 [23.1%]; P = .01). Clinical remission rates at week 14 (77.9% vs 73.9%; P = .69) and 56 (73.2% vs 68.4%; P = .64) were similar between HLA-DQA1*05 noncarriers and carriers. Drug persistence was higher among HLA-DQA1*05 carriers (hazard ratio [HR], 0.32; 95% confidence interval, 0.14-0.71; P = .01). Multivariable Cox regression analysis identified systemic steroids at anti-TNF initiation (HR, 4; 95% confidence interval, 1.7-9.7) as a risk factor and HLA-DQA1*05 carriers (HR, 0.31; 95% confidence interval, 0.12-0.81) as a protective factor of treatment cessation.

CONCLUSION

In adult patients with PTDM, a positive HLA-DQA1*05 genotype does not associate a higher risk of treatment cessation nor worse clinical outcomes.

The Combination of Predictive Factors of Pharmacokinetic Origin Associates with Enhanced Disease Control during Treatment of Pediatric Crohn's Disease with Infliximab

Infliximab (IFX) concentrations are a predictive factor (PF) of pharmacokinetic (PK) origin in the treatment of Crohn's disease (CD). We evaluated Clearance, another PF of PK origin, either alone or in combination with concentrations. They were evaluated from two cohorts, the first designed to receive standard dosing (n = 37), and the second designed to proactively target therapeutic IFX concentrations (n = 108). Concentrations were measured using homogeneous mobility shift assay. Clearance was estimated using the nonlinear mixed effects methods with Bayesian priors. C-reactive protein-based clinical remission (<3 mg/L in the absence of symptoms) was used for the disease control outcome measure. Longitudinal changes in disease control due to factors including time, IFX concentration, and Clearance were analyzed using repeated event analysis. Change in objective function value (∆OFV) was calculated to compare concentration and Clearance. The results indicated that lower baseline Clearance and proactive dosing associated with enhanced disease control during induction (p < 0.01). Higher IFX concentrations and lower Clearance measured at the second, third, and fourth infusion yielded improved disease control during maintenance (p < 0.032). During maintenance, the association with disease control was better with Clearance than with concentrations (∆OFV = -19.2; p < 0.001), and the combination of both further minimized OFV (p < 0.001) with markedly improved clinical yield in the presence of both PF of PK origin. We conclude that the combination of IFX concentration and Clearance are better predictors of therapeutic outcome compared with either one alone.

Benefits and Challenges of Treat-to-Target in Inflammatory Bowel Disease

There is notable disparity between symptomatology and disease activity in a significant proportion of patients with inflammatory bowel disease (IBD), and escalation of treatment based on symptoms alone can fail to significantly alter the course of disease. The STRIDE-II position statement, published in 2021 by the Selecting Therapeutic Targets in Inflammatory Bowel Disease (STRIDE) initiative of the International Organisation for the Study of IBD (IOIBD) provides the most current recommendations for a treat-to-target (T2T) approach in IBD. Despite the benefits offered by a T2T approach in IBD, there are numerous drawbacks and current limitations to its widespread implementation in real-world clinical practice. Owing to the lack of a standardised definition of MH, outcome data are heterogeneous and limit the comparability of existing data. Further, studies investigating the likelihood of achieving MH with a T2T approach are limited and largely retrospective. Evidence of the real-world feasibility of tight monitoring is currently minimal and demonstrates sub-optimal adherence among patients. Further, the few studies on the acceptability and uptake of a T2T approach in real-world practice demonstrate the need for increased acceptability on both patients' and clinicians' behalf. Real-world applicability is further limited by the need for repeated endoscopic assessments of MH as well as a lack of guidance on how to incorporate the various treatment targets into therapeutic decision-making. We aim to review the benefits and challenges of the T2T approach and to discuss potential solutions to further patient care.

The Role of Therapeutic Drug Monitoring in Children

The use of biologic therapies has changed the treatment landscape for children with inflammatory bowel disease. While the novel biologics have improved clinical outcomes, there remains a significant gap in achieving endoscopic remission, prolonged steroid-free remission, and drug durability. Contributing to this gap is the paucity of real-world pharmacokinetic studies in children and a failure to dose optimize therapy during induction. Emerging data from a pediatric clinical trial and several observational studies have shown that the combination of proactive therapeutic drug monitoring and achievement of early therapeutic concentrations is effective in achieving improved outcomes. The next steps will be to leverage these past studies to develop more innovative clinical trials to properly assess the safety and effectiveness of proactive therapeutic drug monitoring in children.

Simultaneous quantification and structural characterization of monoclonal antibodies after administration using capillary zone electrophoresis-tandem mass spectrometry

Monoclonal antibodies (mAbs) are demonstrating major success in various therapeutic areas such as oncology and the treatment of immune disorders. Over the past two decades, novel analytical methodologies allowed to address the challenges of mAbs characterization in the context of their production. However, after administration only their quantification is performed and insights regarding their structural evolution remain limited. For instance, clinical practice has recently highlighted significant inter-patient differences in mAb clearance and unexpected clinical responses, without providing alternative interpretations. Here, we report the development of a novel analytical strategy based on capillary zone electrophoresis coupled to tandem mass spectrometry (CE-MS/MS) for the simultaneous absolute quantification and structural characterization of infliximab (IFX) in human serum. CE-MS/MS quantification was validated over the range 0.4-25 µg·mL^-1 corresponding to the IFX therapeutic window and achieved a LOQ of 0.22 µg·mL^-1 (1.5 nM) while demonstrating outstanding specificity compared to the ELISA assay. CE-MS/MS allowed structural characterization and estimation of the relative abundance of the six major N-glycosylations expressed by IFX. In addition, the results allowed characterization and determination of the level of modification of post-translational modifications (PTMs) hotspots including deamidation of 4 asparagine and isomerization of 2 aspartate. Concerning N-glycosylation and PTMs, a new normalization strategy was developed to measure the variation of modification levels that occur strictly during the residence time of IFX in the patient's system, overcoming artefactual modifications induced by sample treatment and/or storage. The CE-MS/MS methodology was applied to the analysis of samples from patients with Crohn's disease. The data identified a gradual deamidation of a particular asparagine residue located in the complementary determining region that correlated with IFX residence time, while the evolution of IFX concentration showed significant variability among patients.

Mucosal healing assessment in Crohn's disease with normalized iodine concentration from dual-energy CT enterography: comparison with endoscopy

OBJECTIVES

Mucosal healing (MH) is an important goal in the treatment of patients with Crohn's disease (CD). Noninvasive assessment of MH with normalized iodine concentration (NIC) is unknown.

METHODS

In this retrospective study, 94 patients with diagnosed CD underwent endoscopy and dual-energy CT enterography (DECTE) at the post-infliximab treatment review. Two radiologists reviewed DECTE images by consensus for assessing diseased bowel segments of the colon or terminal ileum, and the NIC was measured. Patients were divided into transmural healing (TH), MH and non-MH groups. The diagnostic performance of the MH and non-MH groups with clinical factors and NIC was assessed utilizing receiver operating characteristic (ROC) curve analysis.

RESULTS

Of the 94 patients included in our study, 8 patients achieved TH, 34 patients achieved MH, and 52 patients did not achieve MH at the post-IFX treatment review. The area under the ROC curve (AUC), sensitivity, specificity, and accuracy values were 0.929 (95% confidence interval [CI] 0.883-0.967), 0.853, 0.827, and 0.837, respectively, for differentiating MHs from non-MHs, and the optimal NIC threshold was 0.448. The AUC of the combined model for distinguishing MHs from non-MHs in CD patients, which was based on the NIC and calprotectin, was 0.964 (95% CI 0.935-0.987).

CONCLUSIONS

The normalized iodine concentration measurement in DECTE has good performance in assessment MH in patients with CD. Iodine concentration from DECTE can be used as a radiologic marker for MH.

Personalizing therapy selection in inflammatory bowel disease

INTRODUCTION

Inflammatory bowel disease (IBD) is a complex disease, caused by aberrant immune responses to environmental stimuli where genetic, metabolomic, and environmental variables interact to cause mucosal inflammation. This review sheds light on the different drug and patient related factors that affect personalization of biologics in IBD treatment.

AREAS COVERED

We utilized the online research database PubMed to carry out literature search pertaining to therapies in IBD. We incorporated a combination of primary literature as well as review articles and meta-analyses in writing this clinical review. In this paper, we discuss the mechanisms of action for different biologics, the genotype and phenotype of patients, and pharmacokinetics/pharmacodynamics of drugs, as factors that influence response rates. We also touch upon the role of artificial intelligence in treatment personalization.

EXPERT OPINION

The future of IBD therapeutics is one of precision medicine, based on the identification of aberrant signaling pathways unique to individual patients as well as exploring the exposome, diet, viruses, and epithelial cell dysfunction as part of disease pathogenesis. We need global cooperation for pragmatic study designs as well as equitable access to machine learning/artificial intelligence technology to reach the unfulfilled potential of IBD care.

Relationship Between Serum Ustekinumab Trough Concentration and Clinical and Biochemical Disease Activity: A Real-World Study in Adult Patients with Crohn's Disease

BACKGROUND AND OBJECTIVES

The role of therapeutic drug monitoring for ustekinumab in the treatment of Crohn's disease has not been defined. This study aimed to explore the relationship of serum ustekinumab trough concentration (UTC) with clinical and biochemical disease outcomes in a real-world setting.

METHODS

We performed a retrospective analysis of Crohn's disease patients treated at a single tertiary centre. Ustekinumab was given as a single intravenous induction dose, followed by maintenance subcutaneous injections every 4 to 8 weeks. Rates of clinical remission (Harvey-Bradshaw Index ≤ 4), biochemical remission (C-reactive protein < 5 mg/l and faecal calprotectin < 150 μg/g) and complete remission were assessed at baseline and at the time of UTC testing during maintenance therapy. The association between baseline variables and UTC was tested using linear regression. We also performed an external validation analysis of UTC cut-offs established in four previously published studies.

RESULTS

This study included 43 patients. Compared to 8-weekly dosing, a 2.49- and 2.65-fold increase in UTC was associated with 6-weekly and 4-weekly dosing respectively. However, there was no significant difference in clinical, biochemical or complete remission among the dosing groups. An external validation of previously published optimal UTC cut-offs found low predictive value for our patient population.

CONCLUSIONS

In this study, dosing interval was the only determinant significantly associated with a higher UTC for patients on maintenance ustekinumab therapy. While a higher UTC may be achieved with dose escalation, it was not associated with improved rates of clinical or biochemical response in our cohort.

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.

The cost of inflammatory bowel disease in high-income settings: a Lancet Gastroenterology & Hepatology Commission

The cost of caring for patients with inflammatory bowel disease (IBD) continues to increase worldwide. The cause is not only a steady increase in the prevalence of Crohn's disease and ulcerative colitis in both developed and newly industrialised countries, but also the chronic nature of the diseases, the need for long-term, often expensive treatments, the use of more intensive disease monitoring strategies, and the effect of the diseases on economic productivity. This Commission draws together a wide range of expertise to discuss the current costs of IBD care, the drivers of increasing costs, and how to deliver affordable care for IBD in the future. The key conclusions are that (1) increases in health-care costs must be evaluated against improved disease management and reductions in indirect costs, and (2) that overarching systems for data interoperability, registries, and big data approaches must be established for continuous assessment of effectiveness, costs, and the cost-effectiveness of care. International collaborations should be sought out to evaluate novel models of care (eg, value-based health care, including integrated health care, and participatory health-care models), as well as to improve the education and training of clinicians, patients, and policy makers.

Perspectives of Therapeutic Drug Monitoring of Biological Agents in Non-Infectious Uveitis Treatment: A Review

Biological drugs, especially those targeting anti-tumour necrosis factor α (TNFα) molecule, have revolutionized the treatment of patients with non-infectious uveitis (NIU), a sight-threatening condition characterized by ocular inflammation that can lead to severe vision threatening and blindness. Adalimumab (ADA) and infliximab (IFX), the most widely used anti-TNFα drugs, have led to greater clinical benefits, but a significant fraction of patients with NIU do not respond to these drugs. The therapeutic outcome is closely related to systemic drug levels, which are influenced by several factors such as immunogenicity, concomitant treatment with immunomodulators, and genetic factors. Therapeutic drug monitoring (TDM) of drug and anti-drug antibody (ADAbs) levels is emerging as a resource to optimise biologic therapy by personalising treatment to bring and maintain drug concentration within the therapeutic range, especially in those patients where a clinical response is less than expected. Furthermore, some studies have described different genetic polymorphisms that may act as predictors of response to treatment with anti-TNFα agents in immune-mediated diseases and could be useful in personalising biologic treatment selection. This review is a compilation of the published evidence in NIU and in other immune-mediated diseases that support the usefulness of TDM and pharmacogenetics as a tool to guide clinicians’ treatment decisions leading to better clinical outcomes. In addition, findings from preclinical and clinical studies, assessing the safety and efficacy of intravitreal administration of anti-TNFα agents in NIU are discussed.

Defining the Failure of Medical Therapy for Inflammatory Bowel Disease in the Era of Advanced Therapies: A Systematic Review

BACKGROUND

The expansion of advanced therapies for inflammatory bowel disease created a lag between the development of these new therapies and their incorporation and use in daily practice. At present, no clear definitions for treatment optimization, treatment failure or criteria to abandon therapy are available. We aimed to centralize criteria for a nonresponse to all available molecules and to summarize guideline principles for treatment optimization.

METHODS

We conducted a systematic review of studies that reported criteria for the treatment response to all advanced therapies (infliximab, adalimumab, golimumab, ustekinumab, vedolizumab and tofacitinib) in patients with inflammatory bowel disease.

RESULTS

Across trials, criteria for a response of both patients with ulcerative colitis and Crohn's disease are heterogenous. Investigators use different definitions for clinical and endoscopic remission, and endoscopic response and outcomes are assessed at variable time points. Current society guidelines provide heterogenous recommendations on treatment optimization. Most available data on loss of response concern anti-TNF molecules, and newer therapies are not included in the guidelines.

CONCLUSION

The lack of clear definitions and formal recommendations provide the premise for empirical treatment strategies and premature abandonment of therapies.

Treatment escalation and de-escalation decisions in Crohn's disease: Delphi consensus recommendations from Japan, 2021

BACKGROUND

We aimed to develop criteria for treatment intensification in patients with (1) luminal Crohn's disease (CD), (2) CD with perianal disease and/or fistula, (3) CD with small bowel stenosis, (4) in the postoperative setting, and (5) for discontinuing or reducing the dose of treatment in patients with CD.

METHODS

PubMed and Embase were searched for studies published since 1998 which may be relevant to the five defined topics. Results were assessed for relevant studies, with preference given to data from randomized, controlled studies. For each question, a core panel of 12 gastroenterologists defined the treatment target and developed statements, based on the literature, current guidelines, and relevant additional studies. The evidence supporting each statement was graded using the Oxford Centre for Evidence-Based Medicine: Levels of Evidence (March 2009). A modified Delphi process was used to refine statements and gain agreement from 54 Japanese specialists at in-person and online meetings conducted between October 2020 and April 2021.

RESULTS

Seventeen statements were developed for treatment intensification in luminal CD (targeting endoscopic remission), six statements for treatment intensification in perianal/fistulizing CD (targeting healing of perianal lesions and complete closure of the fistula), six statements for treatment intensification in CD with small bowel stenosis (targeting resolution of obstructive symptoms), seven statements for treatment intensification after surgery (targeting endoscopic remission), and five statements for discontinuing or reducing the dose of treatment in patients with CD.

CONCLUSIONS

These statements provide guidance on how and when to intensify or de-intensify treatment for a broad spectrum of patients with CD.

Azathioprine Withdrawal Is Cost-Effective in Patients with Crohn's Disease in Remission on Infliximab and Azathioprine

BACKGROUND

In Crohn's disease, combination therapy with infliximab and azathioprine is more effective than either drug alone but is associated with a higher risk of therapy-related complications. Though therapy de-escalation can reduce risks and save costs, it is associated with a risk of Crohn's disease relapse.

AIMS

We aimed to study the cost-effectiveness of de-escalation strategies in Crohn's disease patients in remission on infliximab and azathioprine.

METHODS

We constructed a decision tree with Markov models for continuation of infliximab and azathioprine, discontinuation of azathioprine followed by its re-introduction in case of relapse, discontinuation of azathioprine followed by infliximab dose intensification without azathioprine reintroduction in case of relapse and discontinuation of infliximab. Third-party payers' perspective with a willingness-to-pay threshold of $100,000/quality-adjusted life years was used. Markov cycle length was 3 months, and the study period was 5 years. A 35-year-old patient with Crohn's disease in clinical remission on azathioprine 150 mg daily and infliximab 5 mg/kg every 8 weeks was used for base-case analysis.

RESULTS

Azathioprine withdrawal followed by its reintroduction upon relapse was the dominant strategy as it was the most effective and least expensive approach on base-case analysis. It was also cost-effective in 99.3% of Monte Carlo trial simulations. AZA withdrawal without IFX dose intensification upon relapse was the least effective and the most expensive strategy.

CONCLUSION

Azathioprine withdrawal is the most effective and least costly de-escalation strategy in CD patients in remission on combination therapy if AZA re-introduction is performed upon CD relapse.

Precision medicine and drug optimization in adult inflammatory bowel disease patients

Inflammatory bowel diseases (IBD) encompass two main entities including ulcerative colitis and Crohn's disease. Although having a common global pathophysiological mechanism, IBD patients are characterized by a significant interindividual heterogeneity and may differ by their disease type, disease locations, disease behaviours, disease manifestations, disease course as well as treatment needs. Indeed, although the therapeutic armamentarium for these diseases has expanded rapidly in recent years, a proportion of patients remains with a suboptimal response to medical treatment due to primary non-response, secondary loss of response or intolerance to currently available drugs. Identifying, prior to treatment initiation, which patients are likely to respond to a specific drug would improve the disease management, avoid unnecessary side effects and reduce the healthcare expenses. Precision medicine classifies individuals into subpopulations according to clinical and molecular characteristics with the objective to tailor preventative and therapeutic interventions to the characteristics of each patient. Interventions would thus be performed only on those who will benefit, sparing side effects and expense for those who will not. This review aims to summarize clinical factors, biomarkers (genetic, transcriptomic, proteomic, metabolic, radiomic or from the microbiota) and tools that could predict disease progression to guide towards a step-up or top-down strategy. Predictive factors of response or non-response to treatment will then be reviewed, followed by a discussion about the optimal dose of drug required for patients. The time at which these treatments should be administered (or rather can be stopped in case of a deep remission or in the aftermath of a surgery) will also be addressed. IBD remain biologically complex, with multifactorial etiopathology, clinical heterogeneity as well as temporal and therapeutic variabilities, which makes precision medicine especially challenging in this area. Although applied for many years in oncology, it remains an unmet medical need in IBD.