Therapeutic drug monitoring is predictive of loss of response after de-escalation of infliximab therapy in patients with inflammatory bowel disease in clinical remission

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.

De-escalation of Biologic Treatment in Inflammatory Bowel Disease: A Comprehensive Review

INTRODUCTION

Biologic therapy is an effective treatment for inflammatory bowel disease [IBD]. However due to cost and safety concerns, dose de-escalation strategies after achieving remission have been suggested.

AIM

To critically review available data on dose de-escalation of biologics [or other advanced therapies] in IBD. We will focus on studies evaluating de-escalation to standard dosing in patients initially optimised, and also on studies assessing de-escalation from standard dosing.

METHODS

A systematic bibliographic search was performed.

RESULTS

The mean frequency of de-escalation after previous dose intensification [12 studies, 1,474 patients] was 34%. The corresponding frequency of de-escalation from standard dosing [five studies, 3,842 patients] was 4.2%. The relapse rate of IBD following anti-tumour necrosis factor [TNF] de-escalation to standard dosing in patients initially dose-escalated [10 studies, 301 patients] was 30%. The corresponding relapse rate following anti-TNF de-escalation from standard dosing [nine studies, 494 patients] was 38%. The risk of relapse was lower for patients in clinical, biologic, and endoscopic/radiological remission at the time of de-escalation. A role of anti-TNF therapeutic drug monitoring in the decision to dose de-escalate has been demonstrated. In patients relapsing after de-escalation, re-escalation is generally effective. De-escalation is not consistently associated with a better safety profile. The cost-effectiveness of the de-escalation strategy remains uncertain. Finally, there is not enough evidence to recommend dose de-escalation of biologics different from anti-TNFs or small molecules.

CONCLUSIONS

Any consideration for de-escalation of biologic therapy in IBD must be tailored, taking into account the risks and consequences of a flare and patients' preferences.

Observational Study to Compare Biological Drug Concentration Quantification Techniques and Immunogenicity in Patients with Immune-Mediated Diseases

Measuring biological drugs' trough concentrations and the concentrations of anti-drug antibodies is a valuable practice for treatment optimization. ELISA techniques are the gold standard for biological drug concentration quantification, but new techniques such as chemiluminescence immunoassays present some advantages. The aim of this unicentric prospective observational study is to compare the infliximab, adalimumab, vedolizumab and ustekinumab trough levels and anti-adalimumab and anti-infliximab antibodies concentrations obtained when using a chemiluminescent instrument (i-TRACK®, Theradiag, Croissy-Beaubourg, France) and an ELISA instrument (TRITURUS®, Griffols, Barcelona, Spain). Linear regression, Pearson or Spearman tests, Bland-Altman plots and the Cohen kappa test were applied for every sample. The correlation was excellent for both assays in the measurement of all drug concentrations. In general, values were lower when measured using i-TRACK than when using TRITURUS, especially when the values were high. Both techniques proved valuable in clinical practice for monitoring adalimumab and infliximab drug concentration. However, the results were modest for ustekinumab and vedolizumab, so caution is recommended and further research is needed. The limited number of anti-drug antibody-positive samples precluded a comparison between the techniques.

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.

Comparative Evaluation of Four Commercially Available Immunoassays for Therapeutic Drug Monitoring of Infliximab and Adalimumab

Therapeutic drug monitoring (TDM) of anti-TNF-α is an important tool in clinical practice for inflammatory diseases. In this study, we have evaluated the performance of several assays for drug and antidrug antibodies (ADA) measurement in the serum. 50 sera from patients treated with infliximab (IFX) and 49 sera from patients treated with adalimumab (ADAL) were monitored with four immunoassays. We have compared Promonitor, i-Track10^®, and ez-track1 assays to our gold standard Lisa Tracker^® ELISA using Cohen's kappa, Passing-Bablok, and Bland-Altman analysis. The qualitative analysis evaluated by Cohen's kappa values found for IFX measurements an "almost perfect" concordance for Promonitor, "moderate" for i-Track10^® and "substantial" for ez-Track1. For ADAL, kappa values were "moderate" for all tested methods. For anti-IFX, kappa values were "almost perfect" for Promonitor, "fair" for i-Track10^®, and "substantial" for ez-Track1. For anti-ADAL, kappa values were "almost perfect" for all three assays. For quantitative analysis of drug measurements, Pearson's r values were all above 0.9 and Lin's concordance coefficients of all immunoassays were around 0.80. Performances of the four evaluated immunoassays were acceptable for TDM based on our laboratory experience. Nevertheless, concordance between the four methods for IFX measurement was not perfect and we recommend the use of the same assay for the follow-up of a given patient. The performances of the four immunoassays evaluated were similar and are acceptable for TDM based on our laboratory experience.

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 EVALUATION OF INFLIXIMAB TROUGH LEVEL FAVORS MAINTENANCE THERAPY OF PATIENTS WITH INFLAMMATORY BOWEL DISEASE

BACKGROUND

Crohn's disease (CD) and ulcerative colitis (UC) are chronic diseases that result from the deregulation of the mucosal immune system of the gastrointestinal tract. The use of biological therapies, including infliximab (IFX), is one of the strategies to treat both CD and UC. The IFX treatment is monitored by complementary tests, namely: fecal calprotectin (FC); C-reactive protein (CRP); and endoscopic and cross-sectional imaging. Besides, serum IFX evaluation and antibody detection are also used.

OBJECTIVE

To evaluate trough levels (TL) and antibodies in a population with inflammatory bowel (IBD) disease undergoing treatment with IFX, and the factors that might impact the treatment effectiveness.

METHODS

Retrospective, cross-sectional study with patients with IBD that were assessed for TL and antibody (ATI) levels in a southern Brazilian hospital, from June 2014 to July 2016.

RESULTS

The study assessed 55 patients (52.7% female) submitted to serum IFX and antibody evaluations (95 blood samples, 55 first test; 30 second test, and 10 as third testing. Forty-five (47.3%) cases were diagnosed with CD (81.8%), and ten with UC (18.2%). Serum levels were adequate in 30 samples (31.57%), subtherapeutic in 41 (43.15%), and supratherapeutic in 24 (25.26%). IFX dosages were optimized for 40 patients (42.10%), maintained for 31 (32.63%), and discontinued for 7 (7.60%). The intervals between infusions were shortened in 17.85% of the cases. In 55 tests (55.79%), the therapeutic approach was exclusively defined according to IFX and/or serum antibody levels. The assessment of patients one year later indicated that: the approach was maintained with IFX for thirty-eight patients (69.09%); the class of biological agent was changed for eight (14.54%); changes using the same class of biological agent occurred for two patients (3.63%); the medication was discontinued and not replaced for three patients (5.45%), and four patients (7.27%) were lost to follow-up.

CONCLUSION

There were no differences in TL between groups with or without immunosuppressants, serum albumin (ALB), erythrocyte sedimentation rate (ESR), FC, CRP, and endoscopic and imaging examinations. Current therapeutic approach could be maintained for almost 70% of patients. Thus, serum and antibody levels are a useful tool in the follow-up of patients undergoing maintenance therapy and after treatment induction in patients with inflammatory bowel disease.

Multi-utility of therapeutic drug monitoring in inflammatory bowel diseases

Inflammatory bowel disease (IBD) treatment targets have progressed over time from clinical response to clinical and endoscopic remission. Several data have shown a positive correlation between serum biologic drug concentrations and favorable therapeutic outcomes. Therapeutic drug monitoring (TDM) has evolved as an important approach for optimizing the use of immunobiologics, especially antitumor necrosis factor therapy, in patients with IBD. The use of TDM is supported by medical societies and IBD experts in different contexts; however, challenges remain due to knowledge gaps that limit the widespread use of it. The aim of this review is to assess the role of TDM in IBD, focusing on the implementation of this strategy in different scenarios and demonstrating the multi-utility aspects of this approach in clinical practice.

Therapeutic Drug Monitoring of Biologics in Crohn's Disease

Reactive therapeutic drug monitoring (TDM) is considered the standard of care for optimizing biologics in inflammatory bowel disease (IBD) including Crohn's disease (CD). Preliminary data show that proactive TDM is associated with positive outcomes in IBD and can be also used to efficiently guide therapeutic decisions in specific clinical scenarios. Higher biological drug concentrations are associated with favorable therapeutic outcomes in specific IBD populations or phenotypes including pediatric CD, perianal fistulizing CD, small bowel CD, and following an ileocolonic resection for CD. Future perspectives of TDM include the use of rapid testing, pharmacogenomics, and pharmacokinetic dashboards toward individualized therapy.

The Future of Precision Medicine to Predict Outcomes and Control Tissue Remodeling in Inflammatory Bowel Disease

Inflammatory bowel disease is characterized by significant interindividual heterogeneity. With a wider selection of pharmacologic and nonpharmacologic interventions available and in advanced developmental stages, a priority for the coming decade is to determine accurate methods of predicting treatment response and disease course. Precision medicine strategies will allow tailoring of preventative and therapeutic decisions to individual patient needs. In this review, we consider the future of precision medicine in inflammatory bowel disease. We discuss the critical need to extend from research focused on short-term symptomatic response to integrative multi-omic systems biology strategies to identify and validate biomarkers that underpin precision approaches. Crucially, the international community has collective responsibility to provide well-phenotyped and -curated longitudinal datasets for scientific discovery and validation. Research must also study broader aspects of the immune response, including components of the extracellular matrix, to better understand biological pathways initiating and perpetuating tissue fibrosis and longer-term disease complications.

Delaying an infliximab infusion by more than 3 days is associated with a significant reduction in trough levels but not with clinical worsening

BACKGROUND

Higher infliximab trough levels (TLs) correlate with better clinical, inflammatory, and endoscopic outcomes among inflammatory bowel disease (IBD) patients. Although standard scheduled infliximab therapy regimen consists of infusions at pre-defined time-points (weeks 0, 2, 6, and every 8 weeks), short-period deviations from therapeutic schedule are common in 'real life', but the pharmacokinetic impact of these deviations has not been explored. In this study, we aim to determine whether short-period deviations from infusion schedule affect infliximab-TL.

METHODS

A retrospective analysis of all IBD patients receiving infliximab maintenance therapy every 8 weeks was conducted in a tertiary medical center. Patients with anti-drug antibodies, deliberate interval shortening and <3 sequential maintenance sera available were excluded. Associations between time since last infusion and TL were studied. Statistical analysis was performed using generalized estimating equations.

RESULTS

Out of over 10,000 sera, 2088 sera of 302 maintenance period stable infliximab-therapy-patients met inclusion criteria (median TL 4.1 μg/mL, interquartile range (IQR) 2.3-6.5 μg/mL). A delay beyond 3 days in infusion schedule (n > 59 days since last infusion) was found to significantly affect TL (mean difference in TL 0.9 μg/mL, 95% confidence interval (CI): 0.03-1.9 μg/mL, p < 0.04). Furthermore, among patients with delayed infusions, 80% had TL below 5 μg/mL, in comparison to 55% of patients who were not late (odds ratio (OR): 2.81, CI: 2.02-3.92, p < 0.0001).

CONCLUSION

Real-life delays of ⩽3 days from infusion protocol can probably be allowed. Delays >3 days culminate in measurable decrease of TL, although effect on clinical outcome is unclear. This needs to be taken into account when interpreting drug-level test results.

SUMMARY

A total of 2088 sera of 302 maintenance period inflammatory bowel disease (IBD) patients treated with infliximab were analyzed, to assess effect of small deviations from infusion schedule on TLs. A significant decline in patients' trough level (TL) was noted as early as 3 days after scheduled infusion.

Optimizing biologic therapy in inflammatory bowel disease: a Delphi consensus in the United Arab Emirates

BACKGROUND

Inflammatory bowel diseases (IBD) are chronic, relapsing-remitting inflammatory conditions with a substantial negative impact on health-related quality of life and work productivity. Treatment of IBD has been revolutionized by the advent of biologic therapies, initially with anti-TNF agents and more recently with multiple alternatives targets, and yet more under development.

OBJECTIVES

Approximatively one third of patients do not respond to biologic therapy and more importantly a significant proportion experiences partial response or loss of response during treatment. The latter are common clinical situations and paradoxically are not addressed in the commercial drug labels and available guidelines. There is therefore a clinical need for physicians to understand when and how eventually to optimize the biologic therapy.

DESIGN

This consensus using a Delphi methodology was promoted and supported by the Emirates Society of Gastroenterology and Hepatology to close this gap.

DATA SOURCES AND METHODS

Following an extensive systematic review of over 60,000 studies, 81 studies with dose escalation and five addressing drug monitoring were selected and in addition five systematic reviews and three guidelines.

RESULTS AND CONCLUSION

after three rounds of voting 18 statements were selected with agreement ranging from of 80% to 100.

A Comprehensive Literature Review and Expert Consensus Statement on Therapeutic Drug Monitoring of Biologics in Inflammatory Bowel Disease

Therapeutic drug monitoring (TDM) of biologics is a rapidly evolving field. We aimed to provide a consensus statement regarding the clinical utility of TDM for biologics in inflammatory bowel disease (IBD). A modified Delphi method was applied to develop consensus statements. A comprehensive literature review was performed regarding TDM of biologic therapies in IBD, and 45 statements were subsequently formulated on the potential application of TDM in IBD. The statements, along with literature, were then presented to a panel of 10 gastroenterologists with expertise in IBD and TDM who anonymously rated them on a scale of 1-10 (1 = strongly disagree and 10 = strongly agree). An expert consensus development meeting was held virtually to review, discuss, refine, and reformulate statements that did not meet criteria for agreement or that were ambiguous. During the meeting, additional statements were proposed. Panelists then confidentially revoted, and statements rated ≥7 by 80% or more of the participants were accepted. During the virtual meeting, 8 statements were reworded, 7 new statements were proposed, and 19 statements were rerated. Consensus was finally reached in 48/49 statements. The panel agreed that reactive TDM should be used for all biologics for both primary nonresponse and secondary loss of response. It was recommended that treatment discontinuation should not be considered for infliximab or adalimumab until a drug concentration of at least 10-15 μg/mL was achieved. Consensus was also achieved regarding the utility of proactive TDM for anti-tumor necrosis factor therapy. It was recommended to perform proactive TDM after induction and at least once during maintenance. Consensus was achieved in most cases regarding the utility of TDM of biologics in IBD, specifically for reactive and proactive TDM of anti-tumor necrosis factors.

Cumulative Exposure to Infliximab, But Not Trough Concentrations, Correlates With Rate of Infection

BACKGROUND & AIMS

Infliximab increases the risk of infection in patients with inflammatory bowel diseases (IBD), but there is controversy over the relationship between drug concentration and infections. We aimed to assess factors associated with infection in infliximab-treated patients, including pharmacokinetic features.

METHODS

We collected data from 209 patients with IBD (102 men; mean age, 39 y; 159 with Crohn's disease; 54 received combination therapy) who received an infliximab maintenance regimen from November 2016 through April 2017 in France. Data were collected from each infusion visit (total of 640 infusions). Infliximab exposure was estimated based on the area under the curve (AUC) of drug concentration in pharmacokinetic models; individual exposures over the 6-month period were estimated based on the sum of the AUC (ΣAUC).

RESULTS

The mean infliximab trough level was 5.46 mg/L, and the mean ΣAUC was 3938 ± 1427 mg.d/L. A total of 215 infections were collected from the 640 infusion visits; 123 patients (59%) had at least 1 infection. Factors independently associated with infection after multivariate analysis were smoking (odds ratio [OR], 2.05; P = .046), IBD flare (OR, 2.71; P = .006), and a high ΣAUC of infliximab (above 3234 mg x d/L) (OR, 2.02; P = .02). The ΣAUC was higher in patients with an occurrence of infection (P = .04) and correlated with the number of infections (P = .04). Trough concentration of infliximab alone was not associated with infection.

CONCLUSIONS

Almost two-thirds of patients treated with infliximab developed an infection; risk was individually correlated with cumulative increase in drug exposure, but not infliximab trough level.

Effectiveness of Dose De-escalation of Biologic Therapy in Inflammatory Bowel Disease: A Systematic Review

INTRODUCTION

De-escalation of biologic therapy is a commonly encountered clinical scenario. Although biologic discontinuation has been associated with high rates of relapse, the effectiveness of dose de-escalation is unclear. This review was performed to determine the effectiveness of dose de-escalation of biologic therapy in inflammatory bowel disease.

METHODS

We searched EMBASE, MEDLINE, and the Cochrane Central Register of Controlled Trials from inception to October 2019. Randomized controlled trials and observational studies involving dose de-escalation of biologic therapy in adults with inflammatory bowel disease in remission were included. Studies involving biologic discontinuation only and those lacking outcomes after dose de-escalation were excluded. Risk of bias was assessed using the Newcastle-Ottawa Scale.

RESULTS

We identified 1,537 unique citations with 20 eligible studies after full-text review. A total of 995 patients were included from 18 observational studies (4 prospective and 14 retrospective), 1 nonrandomized controlled trial, and 1 subgroup analysis of a randomized controlled trial. Seven studies included patients with Crohn's disease, 1 included patients with ulcerative colitis, and 12 included both. Overall, clinical relapse occurred in 0%-54% of patients who dose de-escalated biologic therapy (17 studies). The 1-year rate of clinical relapse ranged from 7% to 50% (6 studies). Eighteen studies were considered at high risk of bias, mostly because of the lack of a control group.

DISCUSSION

Dose de-escalation seems to be associated with high rates of clinical relapse; however, the quality of the evidence was very low. Additional controlled prospective studies are needed to clarify the effectiveness of biologic de-escalation and identify predictors of success.

Combined Biologic and Immunomodulatory Therapy is Superior to Monotherapy for Decreasing the Risk of Inflammatory Bowel Disease-Related Complications

BACKGROUND AND AIMS

The combination of infliximab and azathioprine is more efficacious than either therapy alone for Crohn's disease [CD] and ulcerative colitis [UC]. However, it is uncertain whether these benefits extend to real-world clinical practice and to other combinations of biologics and immunomodulators.

METHODS

We collected health administrative data from four Canadian provinces representing 78 413 patients with inflammatory bowel disease [IBD] of whom 11 244 were prescribed anti-tumour necrosis factor [anti-TNF] agents. The outcome of interest was the first occurrence of treatment failure: an unplanned IBD-related hospitalization, IBD-related resective surgery, new/recurrent corticosteroid use or anti-TNF switch. Multivariable Cox proportional hazards modelling was used to assess the association between the outcome of interest and receiving combination therapy vs anti-TNF monotherapy. Multivariable regression models were used to assess the impact of choice of immunomodulator or biologic on reaching the composite outcome, and random effects generic inverse variance meta-analysis of deterministically linked data was used to pool the results from the four provinces to obtain aggregate estimates of effect.

RESULTS

In comparison with anti-TNF monotherapy, combination therapy was associated with a significant decrease in treatment ineffectiveness for both CD and UC (CD: adjusted hazard ratio [aHR] 0.77, 95% confidence interval [CI] 0.66-0.90; UC: aHR 0.72, 95% CI 0.62-0.84). Combination therapy was equally effective for adalimumab and infliximab in CD. In UC azathioprine was superior to methotrexate as the immunomodulatory agent (aHR = 1.52 [95% CI 1.02-2.28]) but not CD (aHR = 1.22 [95% CI 0.96-1.54]).

CONCLUSION

In an analysis of a database of real-world patients with IBD, combination therapy decreased the likelihood of treatment failure in both CD and UC.

Relapse rate following withdrawal of anti-TNF therapy in patients with inflammatory bowel disease: A real-life cohort from northern India

BACKGROUND

The decision to withdraw anti-tumor necrosis factor (anti-TNF) therapy in patients with inflammatory bowel disease (IBD) remains controversial, especially in the developing world, where its long-term use is restrained by side effects and prohibitive cost. Present study evaluated the relapse rate and its predictors following anti-TNF withdrawal in a cohort of IBD patients from northern India.

METHODS

Patients with IBD who received anti-TNF therapy (induction and beyond), and were under follow-up at All India Institute of Medical Sciences, New Delhi, from January 2005 to July 2018 were included. Demographic features, disease characteristics, duration, response to anti-TNF therapy, and relapse rate after its withdrawal were analyzed.

RESULTS

Among 4600 patients with IBD under follow-up, 90 (1.9%) received anti-TNF therapy, of whom 11 were excluded (8-complete records unavailable; 3-received only single dose). Of 79 patients (mean age-40.1 ± 14.2 years; 53.2% males; 31 [39.2%] ulcerative colitis, 47 [59.5%] Crohn's disease; median follow-up-24 [12-39] months), 9 (11.4%) were primary non-responders, 19 (24.1%) had secondary loss of response, and 51 (64.5%) maintained clinical response on anti-TNF. Anti-TNF was withdrawn in 45 (57%) patients (major causes: financial burden-16.5%; tubercular reactivation-12.7%), of whom 33 were in clinical remission. Over a median follow-up of 26 (7.5-45) months, 15 patients (45.5%) relapsed. Most of them responded to antibiotics, steroids, or anti-TNF agents; only 3 required surgery. On Kaplan-Meier analysis, long disease duration prior to therapy was a significant predictor of relapse (hazard ratio [HR] = 1.33, p = 0.034).

CONCLUSION

Almost 50% patients with IBD in clinical remission relapse within a year of anti-TNF withdrawal. However, most of these patients have a favorable disease course and respond to medical therapy.

TDM of Anti-TNF Agents: The Importance of Being Active!

Therapeutic drug monitoring (TDM) for anti-TNFα agents hass gained an increased momentum; although it is surely recommended in case of loss of response, its usefulness during maintenance therapy is still debated. Fernandes et al have added useful information in this regard.

Appropriate Therapeutic Drug Monitoring of Biologic Agents for Patients With Inflammatory Bowel Diseases

BACKGROUND & AIMS

Therapeutic drug monitoring (TDM) is widely available for biologic therapies in patients with inflammatory bowel disease (IBD). We reviewed current data and provided expert opinion regarding the clinical utility of TDM for biologic therapies in IBD.

METHODS

We used a modified Delphi method to establish consensus. A comprehensive literature review was performed regarding the use of TDM of biologic therapy in IBD and presented to international IBD specialists. Subsequently, 28 statements on the application of TDM in clinical practice were rated on a scale of 1 to 10 (1 = strongly disagree and 10 = strongly agree) by each of the panellists. Statements were accepted if 80% or more of the participants agreed with a score ≥7. The remaining statements were discussed and revised based on the available evidence followed by a second round of voting.

RESULTS

The panel agreed on 24 (86%) statements. For anti-tumor necrosis factor (anti-TNF) therapies, proactive TDM was found to be appropriate after induction and at least once during maintenance therapy, but this was not the case for the other biologics. Reactive TDM was appropriate for all agents both for primary non-response and secondary loss of response. The panellists also agreed on several statements regarding TDM and appropriate drug and anti-drug antibody (ADA) concentration thresholds for biologics in specific clinical scenarios.

CONCLUSION

Consensus was achieved towards the utility of TDM of biologics in IBD, particularly anti-TNF therapies. More data are needed especially on non-anti-TNF biologics to further define optimal drug concentration and ADA thresholds as these can vary depending on the therapeutic outcomes assessed.

Controversies in Inflammatory Bowel Disease: Exploring Clinical Dilemmas Using Cochrane Reviews

A symposium organized by the Cochrane IBD Group and presented at the 2017 Digestive Disease Week annual meeting reviewed the recent literature on several controversial topics in inflammatory bowel disease (IBD) management including the efficacy of oral aminosalicylates for induction and maintenance of Crohn's disease (CD), the feasibility of drug withdrawal in patients with quiescent CD, and strategies for detecting colon cancer in patients with IBD. This article summarizes the data presented at that session.

Predictors of relapse following infliximab de-escalation in patients with inflammatory bowel disease: the value of a strategy based on therapeutic drug monitoring

BACKGROUND

There are limited data concerning infliximab drug monitoring during de-escalation of the treatment of inflammatory bowel disease (IBD).

AIM

To define the rate and the predictors of relapse following infliximab de-escalation in IBD patients in remission.

METHODS

All IBD patients at a single referral centre in clinical and biological remission and in whom the dose of infliximab had been de-escalated were included. Patients in remission with a high trough level of infliximab (>7 mg/L) were considered to be trough level-based de-escalation patients. The data were retrieved from a prospective IBD database. Actuarial analysis was performed for statistical purposes.

RESULTS

A total of 146 de-escalations were performed in 96 patients (Crohn's disease/ulcerative colitis: 68%/32%); 54 (37%) were based on clinical remission only, and 92 (63%) were based on clinical remission associated with a trough level above 7 mg/L. The cumulative probabilities of relapse following infliximab de-escalation were 16% and 47% at 1 and 2 years, respectively. Ulcerative colitis was associated with an increased risk of relapse (HR = 3.2, P = 0.005). Conversely, combination therapy at infliximab initiation (HR = 0.39, P = 0.0110) and trough level-based de-escalation were associated with decreased risk of relapse (HR = 0.45, P = 0.024). Trough levels before and after de-escalation were well correlated; a decrease by half was observed following a 2-week interval increase or a half-dose decrease.

CONCLUSION

The use of trough levels to assess the feasibility of dose de-escalation seems to be a prerequisite for decreasing the risk of relapse.

Comparison of Point-of-Care and Classical Immunoassays for the Monitoring Infliximab and Antibodies Against Infliximab in IBD

OBJECTIVE

The primary objective is to assess whether the POC assays to measure infliximab residual trough level in the serum of IBD patients were non-inferior to the ELISA techniques available on the market, and to determine which of them was the most robust. The second is to compare three different ELISA kits for monitoring anti-infliximab antibodies (ATI).

METHODS

The assays were carried out on patients' sera using four ELISA kits from four different suppliers (three with a monoclonal antibody and one polyclonal) and two rapid techniques provided by BÜHLMANN (Quantum Blue^®) and R-Biopharm (Ridaquick) for monitoring infliximab levels. ATI were measured by three ELISA sets (Grifols, Theradiag, and R-Biopharm) which have different positivity limits and different units.

RESULTS

We measured infliximab residual level and ATI in the serum of 90 IBD patients (85 treated with infliximab and five with adalimumab). All of the infliximab assays were very well correlated when analyzed with Spearman nonparametric correlation (0.93 ≤ r ≤ 0.99), and the two POC assays were also excellently correlated (r = 0.98). The ATI monitoring kits revealed a correlation ranging from 0.73 to 0.96 when comparing positive and negative patients. When normalizing the quantitative values between the different ELISA tests (expressed arbitrarily by using multiples of the positivity limits defined by each supplier), the Spearman r coefficient ranged from 0.81 to 0.93.

CONCLUSION

The available evidence allows us to conclude that all of the infliximab monitoring assays correlate well and may be used for IFX monitoring; albeit variations in measured IFX concentration among different assays remain present, these assays could be interchangeable. The ATI monitoring techniques are all capable of detecting ATI-positive patients, but because of the difference in the positivity limits and the measurement units, it is better to follow a patient rate with one definite kit.

Therapeutic drug monitoring of tumour necrosis factor inhibitors in the management of chronic inflammatory diseases

Tumour necrosis factor inhibitor therapy has drastically changed the management of chronic inflammatory diseases. Some important drawbacks that can cause loss of response during treatment with these drugs are related to their large individual variability, the disease burden and the formation of antidrug antibodies that increase its clearance. Therapeutic drug monitoring of these drugs is not yet recommended by all scientific societies, and if so, only in patients with inflammatory symptoms. Proactive therapeutic drug monitoring represents a new strategy with many potential clinical benefits, including the prevention of immunogenicity, a reduction in the need for rescue therapy and greater durability of tumour necrosis factor inhibitor treatment. The review is based on a systematic search of the literature for controlled trials, systematic reviews, experimental studies, guideline papers and cohort studies addressing the best practice in tumour necrosis factor inhibitor therapeutic drug monitoring. Although there is ample evidence supporting the use of therapeutic drug monitoring in clinical practice to achieve better outcomes, some challenges have been detected. Many studies are focused on finding solutions for the lack of standardization of analytical methods to measure tumour necrosis factor inhibitor and antidrug antibodies concentrations. Other challenges are development of effective cost-saving proactive algorithms to identify optimal drug concentrations and the research on the role of antidrug antibodies, especially in the management and prevention of loss of response. Therapeutic drug monitoring of tumour necrosis factor inhibitor offers a rational approach to the optimization of the treatment of chronic inflammatory disease. Although prospective controlled trials yield little conclusive evidence of its benefits, there is growing acceptance of its value in clinical practice.

Withdrawal of immunosuppressant or biologic therapy for patients with quiescent Crohn's disease

BACKGROUND

Crohn's disease (CD) is a chronic, relapsing and remitting disease of the gastrointestinal tract that can cause significant morbidity and disability. Current treatment guidelines recommend early intervention with immunosuppressant or biological therapy in high-risk patients with a severe disease phenotype at presentation. The feasibility of therapeutic de-escalation once remission is achieved is a commonly encountered question in clinical practice, driven by patient and clinician concerns regarding safety, adverse events, cost and national regulations. Withdrawal of immunosuppressant and biologic drugs in patients with quiescent CD may limit adverse events and reduce healthcare costs. Alternatively, stopping these drug therapies may result in negative outcomes such as disease relapse, drug desensitization, bowel damage and need for surgery.

OBJECTIVES

To assess the feasibility and safety of discontinuing immunosuppressant or biologic drugs, administered alone or in combination, in patients with quiescent CD.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase and the Cochrane IBD Group Specialized Register from inception to 19 December 2017. We also searched the reference lists of potentially relevant manuscripts and conference proceedings to identify additional studies.

SELECTION CRITERIA

Randomized controlled trials (RCTs) and prospective cohort studies that followed patients for a minimum duration of six months after drug discontinuation were considered for inclusion. The patient population of interest was adults (> 18 years) with CD (as defined by conventional clinical, endoscopic or histologic criteria) who had achieved remission while receiving immunosuppressant or biologic drugs administered alone or in combination. Patients then discontinued the drug regimen following a period of maintenance therapy of at least six months. The comparison was usual care (i.e. continuation of the drug regimen).

DATA COLLECTION AND ANALYSIS

The primary outcome measure was the proportion of patients who relapsed following discontinuation of immunosuppressant or biologic drugs, administered alone or in combination. Secondary outcomes included: the proportion of patients who responded to the reintroduction of immunosuppressant or biologic drugs, given as monotherapy or combination therapy; the proportion of patients who required surgery following relapse; the proportion of patients who required hospitalization for CD following relapse; the proportion of patients who developed new CD-related complications (e.g. fistula, abscesses, strictures) following relapse; the proportion of patients with elevated biomarkers of inflammation (CRP, fecal calprotectin) in those who stop and those who continue therapy; the proportion of patients with anti-drug antibodies and low serum trough drug levels; time to relapse; and the proportion of patients with adverse events, serious adverse events and withdrawal due to adverse events. For dichotomous outcomes, we calculated the risk ratio (RR) and 95% confidence interval (95% CI). Data were analyzed on an intention-to-treat basis where patients with missing outcome data were assumed to have relapsed. The overall quality of the evidence supporting the primary and secondary outcomes was assessed using the GRADE criteria.

MAIN RESULTS

A total of six RCTs (326 patients) evaluating therapeutic discontinuation in patients with quiescent CD were eligible for inclusion. In four RCTs azathioprine monotherapy was discontinued, and in two RCTs azathioprine was discontinued from a combination therapy regimen consisting of azathioprine with infliximab. No studies of biologic monotherapy withdrawal were eligible for inclusion. The majority of studies received unclear or low risk of bias ratings, with the exception of three open-label RCTs, which were rated as high risk of bias for blinding. Four RCTs (215 participants) compared discontinuation to continuation of azathioprine monotherapy, while two studies (125 participants) compared discontinuation of azathioprine from a combination regimen to continuation of combination therapy. Continuation of azathioprine monotherapy was shown to be superior to withdrawal for risk of clinical relapse. Thirty-two per cent (36/111) of azathioprine withdrawal participants relapsed compared to 14% (14/104) of participants who continued with azathioprine therapy (RR 0.42, 95% CI 0.24 to 0.72, GRADE low quality evidence). However, it is uncertain if there are any between-group differences in new CD-related complications (RR 0.34, 95% CI 0.06 to 2.08, GRADE low quality evidence), adverse events (RR 0.88, 95% CI 0.67 to 1.17, GRADE low quality evidence), serious adverse events (RR 3.29, 95% CI 0.35 to 30.80, GRADE low quality evidence) or withdrawal due to adverse events (RR 2.59, 95% CI 0.35 to 19.04, GRADE low quality evidence). Common adverse events included infections, mild leukopenia, abdominal symptoms, arthralgias, headache and elevated liver enzymes. No differences between azathioprine withdrawal from combination therapy versus continuation of combination therapy were observed for clinical relapse. Among patients who continued combination therapy with azathioprine and infliximab, 48% (27/56) had a clinical relapse compared to 49% (27/55) of patients discontinued azathioprine but remained on infliximab (RR 1.02, 95% CI 0.68 to 1.52, P = 0.32; GRADE low quality evidence). The effects on adverse events (RR 1.11, 95% CI 0.44 to 2.81, GRADE low quality of evidence) or serious adverse events are uncertain (RR 1.00, 95% CI 0.21 to 4.66; GRADE very low quality of evidence). Common adverse events in the combination therapy studies included infections, liver test elevations, arthralgias and infusion reactions.

AUTHORS' CONCLUSIONS

The effects of withdrawal of immunosuppressant therapy in people with quiescent Crohn's disease are uncertain. Low quality evidence suggests that continuing azathioprine monotherapy may be superior to withdrawal for avoiding clinical relapse, while very low quality evidence suggests that there may be no difference in clinical relapse rates between discontinuing azathioprine from a combination therapy regimen, compared to continuing combination therapy. It is unclear whether withdrawal of azathioprine, initially administered alone or in combination, impacts on the development of CD-related complications, adverse events, serious adverse events or withdrawal due to adverse events. Further high-quality research is needed in this area, particularly double-blind RCTs in which biologic therapy or an immunosuppressant other than azathioprine is withdrawn.

Early intervention in Crohn's disease: towards disease modification trials

Crohn's disease (CD) is a chronic progressive destructive inflammatory bowel disease. As in rheumatoid arthritis, there is increasing evidence that early treatment initiation with disease-modifying agents, such as biological drugs, may lead to complete disease control, prevention of disease progression thus protecting against irreversible damage and restoration of normal quality of life. Data from randomised clinical trials with immunosuppressants and biologics suggest that treating patients with a disease duration of <2 years and an absence of complications may significantly reduce the risk for complications and increase time in remission in patients with CD. Moreover, rapid disease control may effectively prevent disease progression and allow dose reduction or even withdrawal of treatment, reducing the risk of long-term adverse events and healthcare costs. However, prospective disease modification trials are needed to confirm these initial results. Here we review the literature regarding early intervention in adult patients with CD and propose criteria for future disease modification trials.

The Evolving Evidence for Therapeutic Drug Monitoring of Monoclonal Antibodies in Inflammatory Bowel Disease

PURPOSE OF REVIEW

Biological medications are effective in inflammatory bowel disease (IBD) but adverse events, cost, and loss of response make their use challenging. Therapeutic drug monitoring (TDM) allows clinicians to more safely, effectively, and efficiently use medications. The purpose of this article is to review and summarize the most recent literature pertaining to TDM in IBD.

RECENT FINDINGS

Measurement of biological drug trough levels predicts ongoing patient response and can be used to titrate the medication to be more effective and efficient. Antibodies against the medications predict loss of response and adverse events. Using both parameters can predict response to subsequent biologicals. Newer biologicals show similar characteristics to those more commonly used. Management protocols using drug and antibody levels optimize medication use and may be cost-effective. Recent evidence suggests benefit to TDM of biologicals in IBD.

Reactivation of Intestinal Inflammation Is Suppressed by Catestatin in a Murine Model of Colitis via M1 Macrophages and Not the Gut Microbiota

While there is growing awareness of a relationship between chromogranin-A (CHGA) and susceptibility to inflammatory conditions, the role of human catestatin [(hCTS); CHGA_352–67] in the natural history of established inflammatory bowel disease is not known. Recently, using two different experimental models, we demonstrated that hCTS-treated mice develop less severe acute colitis. We have also shown the implication of the macrophages in this effect. The aims of this study were to determine (1) whether hCTS treatment could attenuate the reactivation of inflammation in adult mice with previously established chronic colitis; (2) whether this effect is mediated through macrophages or the gut microbiota. Quiescent colitis was induced in 7–8-week-old C57BL6 mice using four cycles (2–4%) of dextran sulfate sodium. hCTS (1.5 mg/kg/day) treatment or vehicle started 2 days before the last induction of colitis and continuing for 7 days. At sacrifice, macro- and microscopic scores were determined. Colonic pro-inflammatory cytokines [interleukin (IL)-6, IL-1β, and TNF- α], anti-inflammatory cytokines (IL-10, TGF- β), classically activated (M1) (iNOS, Mcp1), and alternatively activated (M2) (Ym1, Arg1) macrophages markers were studied using ELISA and/or RT-qPCR. In vitro, peritoneal macrophages isolated from naïve mice and treated with hCTS (10⁻⁵ M, 12 h) were exposed to either lipopolysaccharide (100 ng/ml, 12 h) to polarize M1 macrophages or to IL-4/IL-13 (20 ng/ml) to polarize M2 macrophages. M1/M2 macrophage markers along with cytokine gene expression were determined using RT-qPCR. Feces and mucosa-associated microbiota (MAM) samples were collected, and the V4 region of 16 s rRNA was sequenced. Micro- and macroscopic scores, colonic IL-6, IL-1β, TNF- α, and M1 macrophages markers were significantly decreased in the hCTS-treated group. Treatment did not have any effect on colonic IL-10, TGF-β, and M2 markers nor modified the bacterial richness, diversity, or the major phyla in colitic fecal and MAM samples. In vitro, pro-inflammatory cytokines levels, as well as their gene expression, were significantly reduced in hCTS-treated M1 macrophages. hCTS treatment did not affect M2 macrophage markers. These findings suggest that hCTS treatment attenuates the severity of inflammatory relapse through the modulation of the M1 macrophages and the release of pro-inflammatory cytokines.

Dose escalation of biologics in Crohn's disease: critical review of observational studies

BACKGROUND

Biologics used to treat Crohn's disease (CD) may lose their effect over time, requiring dose escalation. Little information is available on this topic.

AIM

To summarize rates of dose escalation, duration, de-escalation in observational studies of CD in adults treated with adalimumab, infliximab, and vedolizumab in Europe.

METHODS

Two independent investigators searched Medline and Embase for observational studies published in 1998-2015 and proceedings from four major scientific meetings. Rates were summarized descriptively.

RESULTS

In total, 58 articles from 12 European countries were analyzed (49 full articles, nine abstracts), providing 65 reports with 7,850 patients; 35 reported on 3,830 patients with adalimumab (ADA), and 30 on 4,020 patients with infliximab (IFX). Overall, 29.9% ± 3.5% of patients required dose escalation; 32.8% ± 6.2% with ADA and 25.2% ± 2.4% with IFX (p = .35 between drugs). Rates increased according to line of treatment: 19% for first line, 37% second, and 41% third. The median time to loss of response was 12 months, and the weighted average was 15.1 ± 5.9 months. Median time to escalation was 6.7 months; 6.7 months for ADA and 7.5 for IFX (p = .86). Short-term response rates to escalation were 63% for ADA and 45% for IFX (p = .08). There were no papers available for vedolizumab.

CONCLUSIONS

A substantial proportion of patients receiving ADA or IFX for Crohn's disease require dose escalation after a short period of time.

Understanding the complications of anti-tumor necrosis factor therapy in East Asian patients with inflammatory bowel disease

Remarkable advances have been made in the treatment of inflammatory bowel disease since the introduction of anti-tumor necrosis factor-α agents, especially for patients who are refractory to or cannot tolerate conventional therapies. Currently, infliximab, adalimumab, and golimumab are available in the East Asian medical market, and these agents have been shown to be effective for inducing and maintaining long-term remission of inflammatory bowel disease. Despite their clinical benefits, anti-tumor necrosis factor therapy can also lead to increased vulnerability to infections, development of autoimmune diseases and malignancy, and decreased immunogenicity of vaccinations. Because infectious diseases, such as tuberculosis, hepatitis, and influenza, remain major health problems in East Asia, more cautious use of biologics is needed. To further improve treatment efficacy and safety, close monitoring of inflammation, regular surveillance for malignancy, and regularly scheduled vaccinations are needed. Treatment strategies for biologics should be customized to meet the needs of different patients.

Clinical impact of immunomonitoring in the treatment of inflammatory bowel disease

Despite improvement in outcomes, loss of response (LOR) to tumor necrosis factor-alpha (TNFα) therapies is a big concern in the management of inflammatory bowel disease. LOR is associated with flares of disease, increased hospitalisation rates, need for surgical interventions, and decline in quality of life. LOR may be multifactorial, but immunogenicity makes a significant contribution. Traditionally doses of anti-TNFα have been adjusted based on clinical response, using a standard approach. Immunomonitoring involves the measurement of anti-TNFα trough and antibody levels. It takes into account the underlying pharmacokinetics of anti-TNFα therapies. Expanding on this a treat to target approach may be used, where doses are intensified, or tailored to the individual based on the measurement of anti-TNFα trough and antibody levels. This review looks at the history, evolution, and clinical impact that immunomonitoring is having in the treatment of inflammatory bowel disease. It will focus on the role of immunomonitoring in helping to achieve long lasting deep remission and mucosal healing. It will explore the different options in terms of best measuring trough and antibody levels, explore possible advantages of immunomonitoring, and discuss its role in best optimising response, at induction, during the maintenance phase of treatment, as well as a role in withdrawing or switching therapy.

Therapeutic drug monitoring of anti-tumour necrosis factor-α agents in inflammatory bowel disease

INTRODUCTION

Anti-TNFα therapy has revolutionised treatment of inflammatory bowel disease, however primary non-response and secondary loss of response are a significant problem. Therapeutic drug monitoring (TDM) has recently emerged as a means of optimising use of anti-TNFα agents. Areas covered: TDM of anti-TNFα agents can guide clinical decisions during treatment failure events, prevent treatment failure events, and potentially result in significant healthcare cost saving. TDM for anti-TNFα agent involves measurement of drug levels and anti-drug antibodies, and can be performed reactively or proactively. Reactive TDM reserves testing for treatment failure events, while proactive TDM also consists of periodic TDM for patients responding to anti-TNFα therapy to allow treatment optimisation. Generation of anti-drug antibodies is recognised as one important mechanism of treatment failure and adverse events. Expert opinion: Evidence strongly supports TDM at time of treatment failure, while studies employing proactive TDM have demonstrated conflicting results. TDM can also help better select patients likely to remain in clinical remission on anti-TNFα treatment interruption. Currently TDM is used to optimise anti-TNFα treatment, but it is not used by most clinicians to prevent adverse reactions to anti-TNFα agents.