Correlation Between Anti-TNF Serum Levels and Endoscopic Inflammation in Inflammatory Bowel Disease Patients

Maintenance-phase serum anti-TNF levels are not associated with mucosal healing in pediatric Crohn's disease

OBJECTIVES

Mucosal healing (MH) is a key therapeutic target in Crohn's disease (CD) and is associated with improved outcomes. While adult studies indicate a positive correlation between serum anti-tumor necrosis factor (TNF) levels and MH, data in pediatric patients is limited. We aimed to define the association of serum anti-TNF levels with MH in pediatric patients with CD during maintenance therapy.

METHODS

Retrospective data (2014-2023) was collected from pediatric CD patients treated with infliximab or adalimumab who performed an ileocolonoscopy at least 26 weeks after initiating therapy. Serum anti-TNF levels around endoscopic time were compared with endoscopic findings. MH was defined as complete absence of inflammatory or ulcerative lesions across all segments of the gastrointestinal tract. Univariable and multivariable logistic regression analysis was conducted to identify factors associated with MH.

RESULTS

Data were obtained from 107 patients (41 infliximab and 66 adalimumab), with a median age at diagnosis of 12.6 (9.9-14.0) years. Median time until ileocolonoscopy following anti-TNF initiation was 89.0 (56.3-152.3) weeks. MH was identified in 31 (29.0%) patients. Anti-TNF serum levels were comparable in the MH and non-MH groups (9.5 [4.9-13.9] vs. 9.3 [6.4-15.7] µg/mL; p = 0.73), without differences in patients treated with infliximab or adalimumab. In multivariable analysis, diagnosis weight Z-score (odds ratio [OR] = 2.860, 95% confidence interval [CI] = 1.005-8.138; p = 0.049), along with C-reactive protein (OR = 0.037, 95% CI = 0.002-0.687; p = 0.027) and fecal calprotectin (OR = 0.995, 95% CI = 0.990-1.000; p = 0.037) at time of ileocolonoscopy were significantly associated with MH.

CONCLUSIONS

In our cohort, anti-TNF levels during maintenance were not associated with MH in pediatric CD.

The Influence of Subclinical Active Inflammation on IFX Pharmacokinetic Modeling and Disease Progression Assessment: Findings from a Prospective Real-World Study in Inflammatory Bowel Disease Patients

BACKGROUND AND AIMS

Effective management of inflammatory bowel disease (IBD) relies on a comprehensive understanding of infliximab (IFX) pharmacokinetics (PK). This study's primary goal was to develop a robust PK model, identifying key covariates influencing IFX clearance (CL), while concurrently evaluating the risk of disease progression during the maintenance phase of IBD treatment.

METHODS

The multicenter, prospective, real-world DIRECT study was conducted in several care centers, which included 369 IBD patients in the maintenance phase of IFX therapy. A two-compartment population PK model was used to determine IFX CL and covariates. Logistic and Cox regressions were applied to elucidate the associations between disease progression and covariates embedded in the PK model.

RESULTS

The PK model included the contributions of weight, albumin, antidrug antibody (ADA), and fecal calprotectin (FC). On average, higher ADA, FC concentration and weight, and lower albumin concentration resulted in higher IFX CL. In the multivariate regression analyses, FC levels influenced the odds of disease progression in the majority of its definitions, when adjusted for several confounding factors. Additionally, alongside FC, both IFX and CL demonstrated a significant impact on the temporal aspect of disease progression.

CONCLUSION

In this 2-year real-world study, readily available clinical covariates, notably FC, significantly impacted IFX availability in IBD patients. We demonstrated that subclinical active inflammation, as mirrored by FC or CRP, substantially influenced IFX clearance. Importantly, FC emerged as a pivotal determinant, not only of IFX pharmacokinetics but also of disease progression. These findings underscore the need to integrate FC into forthcoming IFX pharmacokinetic models, amplifying its clinical significance.

Infliximab serum concentrations and disease activity in perianal fistulizing Crohn's disease: a cross-sectional study

INTRODUCTION

Several studies associate the presence of higher serum concentrations of infliximab (IFX) with fistula healing in perianal Crohn's disease (CD). This study aimed to evaluate serum IFX concentrations in patients with perianal fistulizing CD (PFCD) in the presence or absence of general, clinical, and radiological activities.

METHODS

This was a cross-sectional study in patients with PFCD during maintenance treatment with IFX from two centers. Serum IFX concentrations were measured before their next infusion and anal fistulas were evaluated by clinical examination and magnetic resonance imaging (MRI), whenever possible, performed 90 days before or after serum collection. According to clinical scores, radiological activity, and disease markers, patients were classified as in remission or active disease. Mean serum IFX concentrations were compared between the groups.

RESULTS

Thirty-eight patients with PFCD were included. Demographic characteristics were similar in patients with remission or active disease. The overall mean serum IFX concentration of the entire sample (n = 38) was 5.21 ± 4.75 μg/mL (median 3.63; IQR 1.44-8.82). Serum IFX levels were 6.25 ± 5.34 μg/mL (median 3.62; IQR 1.95-11.03) in the 23 (60.5%) patients in remission and 3.63 ± 3.24 μg/mL (median 3.63; IQR 1.32-6.43; p = 0.226) in the 15 (39 .5%) who presented active disease. When evaluating general, clinical, and radiological activity of PFCD, and deep remission in isolation, no statistical difference between the groups was observed (p = 0.226, p = 0.418, p = 0.126, and p = 0.232, respectively). The 13 (34.2%) patients with an optimized dose of IFX had significantly higher serum concentrations than the remaining 25 (65.8%) with a standard dose: 8.33 ± 4.41 μg/mL (median 8.36; IQR 3.82-11.20) vs. 3.59 ± 4.13 μg/mL (median 1.97; IQR 1.18-3.85) -p = 0.002. Patients in remission and with an optimized IFX dose had significantly higher serum IFX concentrations than those with a standard dose (p = 0.006), whereas no significant difference was observed among those with active disease (p = 0.083).

CONCLUSION

There were no differences in IFX serum concentrations in patients with clinical or radiological active PFCD as compared with those in remission. Patients with an optimized IFX dose had significantly higher serum concentrations than those with a standard dose. Patients in remission and with an optimized IFX dose had significantly higher serum concentrations than those with a standard dose.

Challenges in IBD Research 2024: Precision Medicine

Precision medicine is part of 5 focus areas of the Challenges in IBD Research 2024 research document, which also includes preclinical human IBD mechanisms, environmental triggers, novel technologies, and pragmatic clinical research. Building on Challenges in IBD Research 2019, the current Challenges aims to provide a comprehensive overview of current gaps in inflammatory bowel diseases (IBDs) research and deliver actionable approaches to address them with a focus on how these gaps can lead to advancements in interception, remission, and restoration for these diseases. The document is the result of multidisciplinary input from scientists, clinicians, patients, and funders, and represents a valuable resource for patient-centric research prioritization. In particular, the precision medicine section is focused on the main research gaps in elucidating how to bring the best care to the individual patient in IBD. Research gaps were identified in biomarker discovery and validation for predicting disease progression and choosing the most appropriate treatment for each patient. Other gaps were identified in making the best use of existing patient biosamples and clinical data, developing new technologies to analyze large datasets, and overcoming regulatory and payer hurdles to enable clinical use of biomarkers. To address these gaps, the Workgroup suggests focusing on thoroughly validating existing candidate biomarkers, using best-in-class data generation and analysis tools, and establishing cross-disciplinary teams to tackle regulatory hurdles as early as possible. Altogether, the precision medicine group recognizes the importance of bringing basic scientific biomarker discovery and translating it into the clinic to help improve the lives of IBD patients.

Precision medicine in inflammatory bowel disease

Inflammatory bowel disease (IBD) is an incurable disease characterized by remission-relapse cycles throughout its course. Both Crohn's disease (CD) and ulcerative colitis (UC), the two main forms of IBD, exhibit tendency to develop complications and substantial heterogeneity in terms of frequency and severity of relapse, thus posing great challenges to the clinical management for IBD. Current treatment strategies are effective in different ways in induction and maintenance therapies for IBD. Recent advances in studies of genetics, pharmacogenetics, proteomics and microbiome provide a strong driving force for identifying molecular markers of prognosis and treatment response, which should help clinicians manage IBD patients more effectively, and then, improve clinical outcomes and reduce treatment costs of patients. In this review, we summarize and discuss precision medicine in IBD, focusing on predictive markers of disease course and treatment response, and monitoring indices during therapeutic drug monitoring.

Precision medicine in inflammatory bowel disease: Individualizing the use of biologics and small molecule therapies

The advent of biologics and small molecules in inflammatory bowel disease (IBD) has marked a significant turning point in the prognosis of IBD, decreasing the rates of corticosteroid dependence, hospitalizations and improving overall quality of life. The introduction of biosimilars has also increased affordability and enhanced access to these otherwise costly targeted therapies. Biologics do not yet represent a complete panacea: A subset of patients do not respond to first-line anti-tumor necrosis factor (TNF)-alpha agents or may subsequently demonstrate a secondary loss of response. Patients who fail to respond to anti-TNF agents typically have a poorer response rate to second-line biologics. It is uncertain which patient would benefit from a different sequencing of biologics or even a combination of biologic agents. The introduction of newer classes of biologics and small molecules may provide alternative therapeutic targets for patients with refractory disease. This review examines the therapeutic ceiling in current treatment strategies of IBD and the potential paradigm shifts in the future.

Precision medicine in inflammatory bowel disease: Individualizing the use of biologics and small molecule therapies

The advent of biologics and small molecules in inflammatory bowel disease (IBD) has marked a significant turning point in the prognosis of IBD, decreasing the rates of corticosteroid dependence, hospitalizations and improving overall quality of life. The introduction of biosimilars has also increased affordability and enhanced access to these otherwise costly targeted therapies. Biologics do not yet represent a complete panacea: A subset of patients do not respond to first-line anti-tumor necrosis factor (TNF)-alpha agents or may subsequently demonstrate a secondary loss of response. Patients who fail to respond to anti-TNF agents typically have a poorer response rate to second-line biologics. It is uncertain which patient would benefit from a different sequencing of biologics or even a combination of biologic agents. The introduction of newer classes of biologics and small molecules may provide alternative therapeutic targets for patients with refractory disease. This review examines the therapeutic ceiling in current treatment strategies of IBD and the potential paradigm shifts in the future.

A critical review of adalimumab for the treatment of moderate-to-severe active ulcerative colitis in children

INTRODUCTION

Anti-tumor necrosis factor (TNF) antibodies play a major role in treating inflammatory bowel disease (IBD), both in adult and pediatric patients. While there is a large number of studies on efficacy and safety of infliximab in treating children and adolescents with ulcerative colitis (UC), data on adalimumab (ADA) are scarce.

AREAS COVERED

Here, we review published case reports, cohort and real-time data, as well as the first randomized trial, ENVISION I, using ADA for treating pediatric UC. Available evidence confirms good efficacy in inducing and maintaining remission in children and adolescents with UC, with even higher response rates compared to adult UC. ENVISION I showed that in UC patients responding to ADA induction therapy, almost half of the patients remained in remission after 52 weeks of therapy on high-dosing ADA (weekly administration). As already well experienced with other biologics, dosing schemes are different between pediatric and adult patients, with children often requiring higher dosing.

EXPERT OPINION

Further data are required to better understand how to optimize ADA therapy. The present and still-growing evidence places subcutaneous (sc.) anti-TNF-medication as alternative first-line therapy also for pediatric UC. This is also reflected by the preference for sc. medication of adolescent patients allowing less frequent and autonomous drug administration.

Infliximab trough level combined with inflammatory biomarkers predict long-term endoscopic outcomes in Crohn’s disease under infliximab therapy

BACKGROUND

Infliximab trough level (ITL) severely affects therapeutic outcomes of Crohn’s disease (CD) patients under infliximab (IFX). Recently, frontier research has focused on identifying ITL based on different therapeutic targets. Although previous studies have elaborated clinical value of ITL monitoring on short-term outcomes in CD patients during therapy, studies contraposing the predictive value of ITL on long-term endoscopic outcomes in CD patients are still scarce domestically and overseas.

AIM

To explore the predictive value of ITL in combination with inflammatory biomarkers on long-term endoscopic outcomes in CD with clinical remission during IFX maintenance therapy.

METHODS

CD patients with endoscopic remission under long-term IFX maintenance therapy in the First Affiliated Hospital of Zhejiang Chinese Medicine University from January 2012 to December 2020 were collected. ITL and inflammatory biomarkers were continuously monitored during the therapy. The Step I study was conducted from weeks 14 to 54 of IFX treatment. The Step II study was conducted from weeks 54 to 108 of IFX treatment. Endoscopic outcomes were defined as endoscopic activity (Crohn’s disease endoscopic index of severity score > 2 points or Rutgeerts score > i1) and endoscopic remission (Crohn’s disease endoscopic index of severity score ≤ 2 points or Rutgeerts ≤ i1). Endoscopic relapse free survival was defined as endoscopic remission at the beginning of the study stage and maintaining endoscopic remission during the study stage.

RESULTS

At week 14, low ITL [odds ratio (OR) = 0.666, 95% confidence interval (CI): 0.514-0.862, P < 0.01] and high fecal calprotectin (FCP) level (OR = 1.002, 95%CI: 1.001-1.004, P < 0.01) increased the risk of endoscopic activity at week 54. At week 54, low ITL (OR = 0.466, 95%CI: 0.247-0.877, P < 0.01) and high C-reactive protein (CRP) level (OR = 1.590, 95%CI: 1.007-2.510, P < 0.01) increased the risk of endoscopic activity at week 108. At week 14, ITL ≤ 5.60 μg/mL [area under the curve (AUC) = 0.83, 95%CI: 0.73-0.90, P < 0.001] and FCP > 238 μg/g (AUC = 0.82, 95%CI: 0.72-0.89, P < 0.001) moderately predicted endoscopic activity at week 54. ITL ≤ 5.60 μg/mL in combination with FCP > 238 μg/g indicated 82.0% possibility of endoscopic activity. At week 54, ITL ≤ 2.10 μg/mL (AUC = 0.85, 95%CI: 0.72-0.93, P < 0.001) and CRP > 3.00 mg/L (AUC = 0.73, 95%CI: 0.60-0.84, P = 0.012) moderately predicted moderate endoscopic activity at week 108. ITL ≤ 2.10 μg/mL in combination with CRP > 3.00 mg/L indicated 100.0% possibility of endoscopic activity. From weeks 14 to 54 of IFX treatment, patients with ITL > 5.60 μg/mL had higher rate of endoscopic relapse free survival than those with ITL ≤ 5.60 μg/mL (95.83% vs 46.67%). From weeks 54 to 108 of IFX treatment, patients with ITL > 2.10 μg/mL had higher rate of endoscopic survival free relapsed rate than those with ITL ≤ 2.10 μg/mL (92.68% vs 30.77%).

CONCLUSION

Combination of ITL, CRP, and FCP contribute to long-term endoscopic prognosis monitoring. During IFX maintenance treatment, low ITL, high CRP level, and high FCP level were independent risk factors of CD patients with clinical remission in adverse endoscopy outcomes within 1-year follow-up.

Biomarkers for Optimization and Personalization of Anti-TNFs in Pediatric Inflammatory Bowel Disease

The use of biological drugs has improved outcomes in pediatric inflammatory bowel disease (IBD). Prediction of the response to biological drugs would be extremely useful in IBD, and even more so in children, who are still growing physically and psychologically. Specific clinical, biochemical, and genetic parameters are considered predictive of response to biological drugs, although few studies have been carried out in children with IBD. In this review, we present current evidence on biological treatments used in pediatric IBD and the available biomarkers of response. We examine demographics, clinical characteristics, biomarkers (genetic, genomic, and cellular), and microbiota.

Stopping Anti-TNF in CD Remitters: Cons

Crohn’s disease may cause a life-long disease burden in many aspects due to its progressive nature. A large proportion of refractory patients have been benefiting from scheduled maintenance anti-TNF treatment; therefore, strategy to stop anti-TNF agents in Crohn’s disease is not widely conducted. There have been observational studies demonstrating that approximately half of the patients relapse within a year after discontinuation. Several factors have been suggested as potential predictors for relapse; however, a consensus has not been reached so far. Although most relapse can be rescued by the re-treatment with the same anti-TNF agent, a proportion of patients may result in progressive bowel damage and the need for surgery. Therefore, an attempt to stop anti-TNF is not recommended without careful discussion, even if they are in long-term remission.

Predictive value of blood concentration of biologics on endoscopic inactivity in inflammatory bowel disease: A systematic review

BACKGROUND

Although blood concentration of biologics is an important composition of disease management in inflammatory bowel disease (IBD) patients, complexity and uncertainty of biological management encourage many disputes in predicting the outcome of IBD patients through blood concentration of biologics.

AIM

To verify the predictive value of blood concentration of biologics on endoscopic inactivity in IBD patients under different situations.

METHODS

We searched PubMed/MEDLINE, Embase, and Web of Science up to May 2020 and identified IBD patients as the research cohort as well as the correlations between blood concentration of biologics and endoscopic inactivity in IBD patients as the research direction.

RESULTS

A total of 23 articles with 30 clinical studies and 1939 IBD patients were included. The predictive cut-off value of blood concentration of infliximab on mucosal healing should be 2.7-10.6 μg/mL in IBD. Blood concentration of infliximab reaching 5.0-12.7 μg/mL or more increased the probability of fistula healing/closure in perianal fistulizing Crohn's disease. Blood concentration of adalimumab reaching 7.2-16.2 μg/mL or more could predict mucosal healing in IBD. The predictive cut-off value of blood concentration of adalimumab on fistula healing/closure should be 5.9-9.8 μg/mL in perianal fistulizing Crohn's disease. Blood concentration of vedolizumab surpassing 25.0 μg/mL indicated mucosal healing in ulcerative colitis patients under maintenance therapy and the predictive cut-off value of blood concentration on mucosal healing or endoscopic remission under induction therapy in IBD could be 8.0-28.9 μg/mL.

CONCLUSION

Blood concentration of biologics should not be utilized to predict endoscopic inactivity of IBD independently due to discrepancies in clinical studies, whereas conducting therapeutic drug monitoring intensively contributes to precise therapy.

Advances in the optimization of therapeutic drug monitoring using serum, tissue and faecal anti-tumour necrosis factor concentration in patients with inflammatory bowel disease treated with TNF-α antagonists

INTRODUCTION

The relationship between clinical outcomes and serum anti-TNF levels is controversial. The aim of this study was to perform simultaneous analyses of serum, mucosal, and fecal anti-TNF-α levels.

METHODS

Consecutive IBD patients who received maintenance anti-TNF-α therapy were enrolled. The number of TNF-α positive cells in the mucosa was detected using immunofluorescent labeling on biopsy samples. Serum, mucosal and fecal anti-TNF-α, serum anti-drug antibody, and fecal calprotectin levels were determined using ELISA. Each patient underwent body composition analysis as well.

RESULTS

Data of 50 patients were analyzed. The number TNF-α positive cells was significantly higher in the inflamed part of the colon than in the un-inflamed part of the colon. Tissue and fecal drug levels did not show any association with serum drug levels; moreover, serum anti-TNF concentration did not correlate with endoscopic activity. Mucosal anti-TNF levels were higher only in IFX-treated patients in remission and IFX-treated patients with detectable fecal anti-TNF had lower tissue drug levels. Presence of the drug in the feces was significantly different according to disease activity.

CONCLUSION

Fecal drug concentration is suggested to be a better predictor of endoscopic activity and loss of response, and fecal drug monitoring may improve the estimation accuracy of tissue drug levels.

Impact of infliximab therapeutic drug level monitoring on outcomes of patients with inflammatory bowel disease: A real-world experience from a Middle Eastern cohort

BACKGROUND AND STUDY AIM

Therapeutic drug monitoring (TDM) through measurement of infliximab (IFX) trough levels and antibodies to infliximab (ATI) is performed to guide IFX intensification strategies and improve its efficacy. We conducted this study to explore the relationship between clinical and endoscopic/radiological remission and IFX and ATI levels in patients with inflammatory bowel disease (IBD) treated with IFX and to evaluate the appropriateness of treatment decision post TDM.

PATIENTS AND METHODS

This was a cross-sectional study of a cohort of adult patients with IBD. Serum IFX trough concentrations and ATI were measured.

RESULTS

A total of 129 patients [104] with ulcerative colitis (UC) and 25 with Crohn's disease (CD)] were included in this study, of whom 61.2% were men. The mean disease duration was 6.7 years, and 72% of patients with UC had extensive colitis. The mean serum IFX trough level was 4.1 µg/mL; the IFX trough levels were subtherapeutic in 75 patients (58%), therapeutic in 37 patients (29%), and supratherapeutic in 17 patients (13%). Positivity to ATI was found in 16 patients (12.4%). Only 43 patients (33.3%) underwent an appropriate change in therapy after TDM, patients with penetrating CD disease had low IFX levels and higher C-reactive protein levels at 12 months before TDM.

CONCLUSIONS

Patients with IBD with therapeutic IFX levels tend to have increased endoscopic/radiological remission rates. However, an appropriate change in management based on TDM was absent in the majority of patients, potentially reflecting the need to have a dashboard to support and guide clinicians in decision-making.

How to Optimize Treatment With Ustekinumab in Inflammatory Bowel Disease: Lessons Learned From Clinical Trials and Real-World Data

Ustekinumab is a fully human IgG1 monoclonal antibody that has been approved for the treatment of moderate to severe Crohn's disease, and more recently moderate to severe ulcerative colitis. It binds with high affinity to the p40 subunit of human interleukin-12 and 23. This mechanism of action prevents the bioactivity of both interleukins, thus precluding their interaction with the cell surface receptor protein. The pivotal clinical trials (UNITI-1, UNITI-2 and IM-UNITI) demonstrated its clinical efficacy and safety, in naïve patients and also in those previously exposed to immunosuppressants and/or biologics. There is now an extensive experience with its use worldwide, corroborating its favorable profile even in patients with refractory disease. However, the number of medical treatment options available in inflammatory bowel disease are still limited. Hence, we should prioritize the treatments that have a greater probability of response in an individual patient. Our aim was to review and summarize all the available literature regarding the potential predictors of response to ustekinumab that can increase the success rate with this therapy in clinical practice.

The Association Between Genetic Variants, Pharmacokinetics, and Infliximab Efficacy in Pediatric Patients With Crohn's Disease in China

Background: Infliximab is an effective therapy for Crohn's disease (CD). Early non-invasive predictors of disease remission allow for modification of treatments. The aim of this study was to investigate the associations between genetic variants, pharmacokinetics, and infliximab efficacy in pediatric patients with CD. Methods: This retrospective observational study included CD patients under infliximab therapy between August 2015 and December 2020. Information on demographics, laboratory tests, medication data, and disease activity index was collected. The trough levels of infliximab (TLI) and antibodies to infliximab (ATI) were measured at week 14, and reactive drug monitoring was performed during follow-up. Ten single-nucleotide polymorphisms involved in the NF-κB-mediated inflammatory response, pharmacokinetics, and therapeutic response to infliximab were genotyped. Results: A total of 62 pediatric CD patients were enrolled. The clinical remission (CR) rate was 69.4 and 63.2% at week 14 and week 30, respectively. TLI at week 14 was significantly independently associated with CR at week 14 and mucosal healing (MH) at week 30 (p = 0.007 and p = 0.025, respectively). The optimal TLI threshold level capable of distinguishing between the CR and non-CR groups was 2.62 μg/ml (p < 0.001, area under the curve = 0.79, sensitivity = 69.2%, specificity = 78.9%), while that capable of distinguishing between the MH and non-MH groups was 3.34 μg/ml (p < 0.001, area under the curve = 0.85, sensitivity = 78.6%, specificity = 79.4%). Rs3397 in TNFRSF1B was associated with time to ATI production in CD patients (p < 0.001). Conclusions: Higher TLI contributed to achieving MH. Genotyping rs3397 in TNFRSF1B may identify patients who are prone to generating immunogenicity to drugs.

Optimizing biologic therapy in IBD: how essential is therapeutic drug monitoring?

Proposed treatment targets for the management of inflammatory bowel disease (IBD) have moved beyond symptomatic improvement towards more objective end points, such as healing of the intestinal mucosa. This treat-to-target approach has been associated with improved disease outcomes such as diminished bowel damage, surgery and hospitalizations. Many patients with IBD require biologic therapy to achieve and maintain clinical and endoscopic remission, and antitumour necrosis factor antibodies remain the first-line biologic therapy in most areas of the world. Unfortunately, up to one-third of patients receiving this treatment are primary non-responders, and some patients that show an initial response can also lose response over time. Therapeutic drug monitoring (TDM) has been suggested as a useful tool to manage patients on antitumour necrosis factor treatment, including monitoring for dose escalation, de-escalation or to switch treatment. In this Perspective, we aim to summarize evidence and guidelines related to TDM in IBD management and also discuss potential strategies to optimize biologic treatment where TDM is not available.

Optimization of biologics to reduce treatment failure in inflammatory bowel diseases

Moderate to severe inflammatory bowel disease patients can fail to respond to conventional therapy and/or to biologic treatment. In the era of TNFα antagonists and other non-anti-TNF biologic drugs, it is important to review the literature on biologic treatment failure, which could be defined as primary non-response, secondary loss of response and intolerance. Therapeutic drug monitoring (TDM), that is, drug trough level and antidrug antibodies, should enable to determine the mechanisms of treatment failure and to optimize drug efficacy. There is a consensus on reactive TDM at the time of loss of response. Proactive TDM could be of interest during induction and/or maintenance, but randomized controlled trials are required.

The shining DIAMOND for evidence-based treatment strategies for Crohn's disease

Anti-tumor necrosis factor (TNF)-α antibodies are effective therapeutic agents to treat inflammatory bowel disease (IBD). In the biologic era, the development of immunogenicity has been a critical issue for secondary loss of response. The superiority of anti-TNF therapy in combination with immunomodulators (IMs) is well-established for infliximab (IFX) but less evident for adalimumab (ADA). To clarify the contribution of thiopurines to ADA-treated patients with Crohn's disease (CD), the deep remission of immunomodulator and adalimumab combination therapy for Crohn's disease (DIAMOND) studies provided the first randomized comparison of efficacy between ADA monotherapy and ADA with thiopurine. The results of the DIAMOND and DIAMOND2 studies revealed the appropriate ADA therapeutic strategy for immunosuppressant-naïve patients with active CD based on therapeutic drug monitoring, endoscopic findings and clinical issues regarding the use of thiopurines.

Combination therapy in inflammatory bowel disease patients: do we need to maximize the dose of azathioprine?

BACKGROUND

The use of combination therapy of anti-TNFα and thiopurines in inflammatory bowel disease (IBD) is associated with greater efficacy and lower immunogenicity. However, the dose of thiopurine in this setting remains to be elucidated.

AIM

To compare the trough levels, anti-TNFα antibodies and the inflammatory biomarkers between three groups in combotherapy: group 1 (dose of azathioprine <1 mg/kg); group 2 (dose of azathioprine ≥1 and <2 mg/kg), and group 3 (dose of azathioprine ≥2 mg/kg).

METHODS

A retrospective study was performed, selecting all patients with established diagnosis of IBD who were on combined maintenance treatment.

RESULTS

We included 99 patients, 52.5% female with median age 33 (17-61) years. Eighty patients (80.8%) were diagnosed with Crohn's disease and 19 (19.2%) with ulcerative colitis. Seventy-one (71.8%) patients were on infliximab (IFX) and 28 (28.3%) were on adalimumab (ADA). In patients treated with IFX, there were no differences in trough levels (p=.976) or formation of antibodies anti-IFX (p=.478) between groups. Moreover, there were no differences in inflammatory biomarkers: CRP (p=.385) and fecal calprotectin (p=.576) among the three groups. Regarding patients treated with ADA, there were no differences in trough levels of ADA (p=.249), formation of antibodies anti-ADA (p=.706) or in inflammatory biomarkers: CRP (p=.738) and fecal calprotectin (p=.269) among the three groups.

CONCLUSION

In our cohort, there were no differences between anti-TNFα trough levels, formation of anti-TNFα antibodies or inflammatory biomarkers among patients in combotherapy with azathioprine, irrespective of its dosage. In conclusion, our study suggests that maintaining therapeutic levels of anti-TNFα drugs without antibodies formation is feasible with lower doses of azathioprine, minimizing its side effects.

Proactive Monitoring of Adalimumab Trough Concentration Associated With Increased Clinical Remission in Children With Crohn's Disease Compared With Reactive Monitoring

BACKGROUND & AIMS

Proactive monitoring of drug trough concentrations and antibodies against drugs might help determine whether patients are likely to respond to treatment and increase efficacy. We investigated whether proactive drug monitoring is associated with higher rates of clinical remission in pediatric patients with Crohn's disease (CD).

METHODS

We performed a nonblinded, randomized controlled trial of 78 children with CD (6-18 years old; 29% female; mean age, 14.3 ± 2.6 years) who had not received prior treatment with a biologic agent but had responded to adalimumab induction therapy, under scheduled monitoring of clinical and biologic measures (based on clinical factors and levels of C-reactive protein and fecal calprotectin), at pediatric gastroenterology units in Israel from July 2015 through December 2018. The patients were randomly assigned to groups that received proactive monitoring (trough concentrations measured at weeks 4 and 8 and then every 8 weeks until week 72, n = 38) or reactive monitoring (physicians were informed of trough concentrations after loss of response, n = 40). In both groups, doses and intervals of adalimumab were adjusted to achieve trough concentrations of 5 μg/mL. The primary endpoint was sustained corticosteroid-free clinical remission at all visits (week 8 through week 72).

RESULTS

The primary endpoint was achieved by 31 children (82%) in the proactive group and 19 children (48%) in the reactive group (P = .002). Sixteen patients in the proactive monitoring group (42%) achieved a composite outcome of sustained corticosteroid-free remission, C-reactive protein ≤0.5 mg/dL, and level of fecal calprotectin ≤150 μg/g compared with 5 patients in the reactive monitoring group (12%) (P = .003). By week 72 of treatment, 33 patients in the proactive monitoring group had received adalimumab intensification (87%) compared with 24 patients in the reactive monitoring group (60%) (P = .001).

CONCLUSIONS

In a randomized controlled trial of pediatric patients with CD, we found that proactive monitoring of adalimumab trough concentrations and adjustment of doses and intervals resulted in significantly higher rates corticosteroid-free clinical remission than reactive monitoring (measuring trough concentration after loss of response). Clinicaltrials.gov no.: NCT02256462.

Real-world short-term effectiveness of ustekinumab in 305 patients with Crohn's disease: results from the ENEIDA registry

BACKGROUND

There are limited data of ustekinumab administered according to the doses recommended in the UNITI studies.

AIM

To assess the real-world, short-term effectiveness of ustekinumab in refractory Crohn's disease (CD) METHODS: Multicentre study of CD patients starting ustekinumab after June 2017 at the recommend dose (260, 390 or 520 mg based on weight ~6 mg/kg IV week 0 and 90 mg subcutaneously week 8). Values for Harvey-Bradshaw Index (HBI), C-reactive protein (CRP) and faecal calprotectin (FC) were recorded at baseline and at weeks 8 and 14. Demographic and clinical data, previous treatments, AEs and hospitalisations were documented. Possible predictors of clinical remission were examined.

RESULTS

Three hundred and five patients were analysed (≥2 previous anti-TNFα therapies 64% and vedolizumab 29%). At baseline, 217 (72%) had an HBI >4 points. Of these, 101 (47%) and 126 (58%) achieved clinical remission at weeks 8 and 14, respectively. FC levels returned to normal (<250 µg/g) in 46% and 54% of the patients at weeks 8 and 14 respectively. CRP returned to normal (<3 mg/L) in the 35% and 41% of the patients at week 8 and 14 respectively. AEs were recorded in 38, and 40 patients were hospitalised. Intolerance to the most recent anti-TNF agent and fewer previous anti-TNF agents were associated with clinical remission at week 14. Endoscopic severity was associated with poor response.

CONCLUSION

This is the first study to show the real-world effectiveness and safety of ustekinumab administered according to the recommended induction regimen in a cohort of highly refractory CD patients.

Therapeutic drug monitoring in inflammatory bowel disease: for every patient and every drug?

PURPOSE OF REVIEW

The current review provides an updated overview on the role of therapeutic drug monitoring (TDM) of biological therapies in inflammatory bowel disease (IBD). We examine the data behind TDM for the antitumor necrosis factor agents, vedolizumab and ustekinumab, in patients with IBD. In addition, we discuss reactive vs. proactive TDM.

RECENT FINDINGS

There is a positive correlation between biologic drug concentrations and favorable therapeutic outcomes in IBD, although the majority of data refer to antitumor necrosis factor therapy. Reactive TDM has rationalized the management of patients with IBD with loss of response to biological therapy. Moreover, reactive TDM of infliximab has been proven to be more cost-effective when compared with empiric dose optimization. Preliminary data suggest that proactive TDM of infliximab and adalimumab applied in patients with clinical response/remission is associated with better therapeutic outcomes compared with standard of care (empiric treatment and/or reactive TDM).

SUMMARY

For all biologics in IBD, there is a positive correlation between drug concentrations and favorable therapeutic outcomes. Reactive TDM is the new standard of care for optimizing biologic therapies in IBD, whereas recent data suggest an important role of proactive TDM for optimizing antitumor necrosis factor therapy in IBD.