Improved Long-term Outcomes of Patients With Inflammatory Bowel Disease Receiving Proactive Compared With Reactive Monitoring of Serum Concentrations of Infliximab

Proactive Therapeutic Drug Monitoring of Ustekinumab Is Associated With Increased Drug Persistence in Patients With Inflammatory Bowel Disease

BACKGROUND

There are limited data on the role of proactive therapeutic drug monitoring (TDM) of ustekinumab (UST) in patients with inflammatory bowel disease (IBD). This study investigated the efficacy and safety of proactive TDM in IBD patients treated with subcutaneous (sc) UST.

METHODS

This was a retrospective single-center cohort study. Consecutive patients with IBD who received maintenance subcutaneous (sc) UST therapy and underwent TDM from January 2017 to February 2023 were eligible for inclusion. Patients were followed through May 2024 or until drug discontinuation or an IBD-related surgery. Patients underwent either at least one proactive TDM or reactive TDM only. Survival analysis was performed to evaluate drug persistence, defined as no need for drug discontinuation due to loss of response, serious adverse event (SAE) or an IBD-related surgery, and IBD-related hospitalizations.

RESULTS

The study population consisted of 83 patients (proactive TDM, n = 46) of whom 67 (81%) had Crohn's disease. Patients who had at least one proactive TDM had higher drug persistence (Log-rank P < .001) and less IBD-related hospitalization (Log-rank P = .012) compared to patients undergoing only reactive TDM. In multivariable COX proportional hazard regression analysis, at least one proactive TDM was associated with increased drug persistence (hazard ratio [HR]: 5; 95% confidence interval [95% CI], 2-10; P < .001) and decreased IBD-related hospitalization (HR: 0.24; 95% CI, 0.07-0.83; P = .024). There was no SAE reported.

CONCLUSIONS

This retrospective study showed that proactive TDM is associated with increased drug persistence and decreased IBD-related hospitalization in IBD patients treated with sc UST.

Is therapeutic drug monitoring a dancing partner for TNF-α inhibitors in real-world practice? Answers from an updated systematic review and meta-analysis

INTRODUCTION

This systematic review aimed to determine the effect of therapeutic drug monitoring (TDM) for tumor necrosis factor-α inhibitors (TNF-αI) in immune-mediated inflammatory diseases (IMIDs) based on real-world evidence, as results from published meta-analyses based on randomized controlled trials (RCTs) may not fully capture the nuances of clinical practice due to strict criteria.

METHODS

We searched PubMed, Embase, and the Cochrane Library up to 1 August 2023. Cohort studies comparing TDM (proactive and reactive) with empirical management were included. Primary outcome was effectiveness [for IBDs: clinical remission; for rheumatic diseases: clinical remission or low disease activity], with certainty of evidence appraised using the GRADE approach. Secondary outcomes included treatment failure, serious adverse events (SAEs), IMIDs-related surgeries or hospitalizations, and anti-drug antibodies (ADAs) development risk.

RESULTS

Twenty-four cohort studies were included and almost all were on infliximab. For IBDs, compared with empirical management, proactive TDM significantly improved clinical remission (RR = 1.15, 95% CI = 1.04-1.28), reduced IBDs-related surgeries (RR = 0.46, 95% CI = 0.26-0.81), hospitalizations (RR = 0.60, 95% CI = 0.43-0.83), SAEs (RR = 0.23, 95% CI = 0.07-0.76), and ADAs development risk (RR = 0.34, 95% CI = 0.19-0.60). Reactive TDM significantly lowered hospitalization rates and might be cost-effective. Proactive TDM outperformed reactive TDM in secondary outcomes. For rheumatic diseases, benefits of TDM were inconclusive due to limited evidence.

CONCLUSIONS

Real-world evidence supports proactive TDM of TNF-αI (particularly infliximab) in IBDs to improve effectiveness, safety, and immunogenicity. However, benefits of TDM for different TNF-αI in other IMIDs remain uncertain.

PROTOCOL REGISTRATION

www.crd.york.ac.uk/ PROSPERO identifier is CRD42022370846.

Different infliximab induction dosing regimens do not affect remission rates up to 1 year in children with Crohn's disease

OBJECTIVES

Multiple studies in patients with Crohn's disease (CD) treated with anti-tumor necrosis factor alpha agents have shown that proactive therapeutic drug monitoring (TDM) during the maintenance phase leads to improved outcomes. We aimed to assess whether accelerated (IFX) administration during induction resulted in improved outcomes.

METHODS

This retrospective study included CD patients aged 5-17.9 years that were treated with IFX. We compared outcomes of patients treated during induction with 5-8 mg/kg dosing at Weeks 0, 2, 6, and 14 (Group 1), versus accelerated dosing (≥8 mg/kg and/or >4 infusions until Week 14, Group 2) of IFX. Primary outcome was steroid-free clinical remission by Week 52.

RESULTS

Sixty-eight patients were included, of whom seven discontinued IFX before Week 14, due to infusion reactions, immunogenic failure, or primary nonresponse. Comparison of Group 1 (n = 25) and Group 2 (n = 36) showed similar clinical characteristics, as well as inflammatory markers, at IFX initiation. Despite receiving significantly more IFX, and reaching a higher trough level by Week 14 (10.3 ± 1.2 vs. 3.3 ± 0.7, p < 0.001), the median Pediatric Crohn's disease Activity Index (PCDAI) was slightly higher in Group 2 versus Group 1 (14 [5-20] vs. 5 [0-15], p = 0.02). However, at Weeks 26 and 52 the PCDAI and inflammatory markers were comparable between the groups. Moreover, about 70% in both groups achieved the desirable trough IFX levels by Week 52.

CONCLUSION

Accelerated IFX dosing during induction did not result in improved outcomes up to 12 months follow-up. Prospective studies are required to determine the exact timing in which proactive TDM should be applied.

Ischemic heart disease mortality in individuals with inflammatory bowel disease: A nationwide analysis of disparities in the United States

INTRODUCTION

Inflammatory bowel disease (IBD) is linked to immune-mediated pathogenesis and a pro-inflammatory state, leading to accelerated atherosclerosis. This earlier onset of clinical cardiovascular disease poses significant morbidity and mortality. We sought to identify IHD mortality trends in individuals with IBD in the United States (US).

METHODS

Mortality due to ischemic heart diseases (IHD) as the underlying cause of death with the IBD as a contributor of death were queried from death certificates using the CDC database from 1999 to 2020. Yearly crude mortality rates (CMR) were estimated by dividing the death count by the respective population size, reported per 100,000 persons. Mortality rates were adjusted for age using the Direct method and compared by demographic subpopulations. Log-linear regression models were utilized to assess temporal variation (annual percentage change [APC]) in mortality.

RESULTS

Age-adjusted mortality rates (AAMR) decreased from 0.11 in 1999 to 0.07 in 2020, primarily between 1999 and 2018 (APC -4.41, p < 0.001). AAMR was higher among male (AAMR 0.08) and White (AAMR 0.08) populations compared to female populations (AAMR 0.06) and Black (AAMR 0.04) populations, respectively. No significant differences were seen when comparing mortality between urban (AAMR 0.07) and rural (AAMR 0.08) regions. Southern US regions (AAMR 0.06) had the lowest mortality rates when compared to the other US census regions: Northeastern (AAMR 0.08), Midwestern (AAMR 0.08), and Western (AAMR 0.08).

CONCLUSION

Disparities in IHD mortality exist among individuals with IBD in the US based on demographic factors, with an overall decline in mortality during the 22-year period. Further investigation is warranted to confirm these findings and evaluate for contributors to the observed disparities.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Proactive Therapeutic Drug Monitoring Is Associated With Increased Drug Persistence in Patients With Inflammatory Bowel Disease Treated With Intravenous Vedolizumab

BACKGROUND

There are limited data regarding therapeutic drug monitoring (TDM) of non-anti-tumor necrosis factor therapy in inflammatory bowel disease (IBD). This study aimed to evaluate the efficacy of proactive TDM in IBD patients treated with intravenous (iv) vedolizumab (VDZ).

METHODS

This single-center retrospective cohort study included consecutive IBD patients treated with maintenance iv VDZ therapy undergoing TDM from November 2016 to March 2023. Patients were followed through June 2023 and were divided in to 2 groups: those who had at least 1 proactive TDM vs those who underwent only reactive TDM. A survival analysis was performed to evaluate drug persistence, defined as no need for drug discontinuation due to loss of response, serious adverse event, or an IBD-related surgery.

RESULTS

The study population consisted of 94 patients (proactive TDM, n = 72) with IBD (ulcerative colitis, n = 53). Patients undergoing at least 1 proactive TDM compared with patients having only reactive TDM demonstrated a higher cumulative probability of drug persistence (Log-rank P < .001). In multivariable Cox proportional hazard regression analysis, at least 1 proactive TDM was the only factor associated with drug persistence (hazard ratio, 14.3; 95% confidence interval [CI], 3.8-50; P < .001). A ROC analysis identified a VDZ concentration of 12.5 µg/mL as the optimal drug concentration threshold associated with drug persistence (area under the ROC curve: 0.691; 95% CI, 0.517-0.865; P = .049).

CONCLUSION

In this single-center retrospective study reflecting real-life clinical practice, proactive TDM was associated with increased drug persistence in patients with IBD treated with iv VDZ.

Vedolizumab in the treatment of Crohn's disease: A promising therapeutic approach

Crohn's disease (CD) is a chronic and debilitating inflammatory bowel disease that affects millions of individuals worldwide. Despite the availability of various treatment options, a significant number of patients do not achieve remission or experience adverse effects with conventional therapies. Vedolizumab, a novel therapeutic agent, has emerged as a promising approach in the management of CD. Despite improvements in treatment choices, there is still a demand for medicines that are efficient and well-tolerated. Vedolizumab, a monoclonal antibody targeting α4β7 integrin, has emerged as a promising therapeutic approach for the treatment of CD. The review aims to provide a summary of vedolizumab, current treatment options, impact of vedolizumab on the patient's quality of life, mechanism of action, clinical effectiveness, safety and efficacy of vedolizumab, potential side effects or risks associated with vedolizumab therapy, and potential predictors. Furthermore, we investigate limitations and challenges associated with vedolizumab and possible future developments and medical implications. This review provides a comprehensive examination of the present data supporting vedolizumab as a possible treatment option for CD, highlighting its benefits and outlining prospective directions for future study and clinical practice improvement.

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.

Medical management of pediatric inflammatory bowel disease

Management of inflammatory bowel disease, both Crohn's disease (CD) and ulcerative colitis (UC), has seen a seismic shift over the past decade. Over the past five years, there has been the introduction of many new therapies with differing mechanisms of action and a goal of achieving mucosal healing, as well as clinical and biochemical remission (1,2). In addition, management is aimed at restoring normal growth and normalizing quality of life. The ultimate goal is to individualize medical management and determine the right drug for the right patient by identifying which inflammatory pathway is predominant and avoiding unwarranted lack of efficacy or side effects through biomarkers and risk prognostication. Patient's age, location of disease, behavior (inflammatory vs. penetrating/structuring), severity and growth delay all play into deciding on the best treatment approach. Ultimately, early intervention is key in preventing complications. The therapeutic approaches to management can be broken down to nutritional therapy, biologic agents, immunomodulators (including corticosteroids), aminosalicylates and antibiotics. There are numerous other therapies, such as small molecule agents recently approved in adults, which are garnering a great deal of interest.

Early proactive monitoring of DNA-thioguanine in patients with Crohn's disease predicts thiopurine-induced late leucopenia in NUDT15/TPMT normal metabolizers

BACKGROUND

Thiopurine-induced leucopenia significantly hinders the wide application of thiopurines. Dose optimization guided by nudix hydrolase 15 (NUDT15) has significantly reduced the early leucopenia rate, but there are no definitive biomarkers for late risk leucopenia prediction.

AIM

To determine the predictive value of early monitoring of DNA-thioguanine (DNATG) or 6-thioguanine nucleotides (6TGN) for late leucopenia under a NUDT15-guided thiopurine dosing strategy in patients with Crohn's disease (CD).

METHODS

Blood samples were collected within two months after thiopurine initiation for detection of metabolite concentrations. Late leucopenia was defined as a leukocyte count < 3.5 × 109/L over two months.

RESULTS

Of 148 patients studied, late leucopenia was observed in 15.6% (17/109) of NUDT15/thiopurine methyltransferase (TPMT) normal and 64.1% (25/39) of intermediate metabolizers. In patients suffering late leucopenia, early DNATG levels were significantly higher than in those who did not develop late leucopenia (P = 4.9 × 10-13). The DNATG threshold of 319.43 fmol/μg DNA could predict late leucopenia in the entire sample with an area under the curve (AUC) of 0.855 (sensitivity 83%, specificity 81%), and in NUDT15/TPMT normal metabolizers, the predictive performance of a threshold of 315.72 fmol/μg DNA was much more remarkable with an AUC of 0.902 (sensitivity 88%, specificity 85%). 6TGN had a relatively poor correlation with late leucopenia whether in the entire sample (P = 0.021) or NUDT15/TPMT normal or intermediate metabolizers (P = 0.018, P = 0.55, respectively).

CONCLUSION

Proactive therapeutic drug monitoring of DNATG could be an effective strategy to prevent late leucopenia in both NUDT15/TPMT normal and intermediate metabolizers with CD, especially the former.

Biologics, Small Molecules and More in Inflammatory Bowel Disease: The Present and the Future

Inflammatory bowel disease (IBD) is a group of heterogeneous chronic inflammatory diseases of the gut presenting with intestinal and extraintestinal manifestations. Most cases fit in predominantly two types, namely, ulcerative colitis and Crohn’s disease. The incidence of IBD has been increasing steadily in the past three decades. Focused research has resulted in many therapeutic options. Biologics (derived from humans or animals) and small molecules have emerged as the cornerstone in the management of IBD and have become widely available. Currently, monoclonal antibodies against tumor necrosis factor-alpha (infliximab, adalimumab, certolizumab, and golimumab), integrins (vedolizumab and natalizumab), and interleukin (IL)-12 and IL-23 antagonists (ustekinumab), along with small molecules (tofacitinib), are approved for use. This article summarizes various aspects of these drugs, like clinical pharmacology, indications for use in IBD, safety in pregnancy and lactation, and the adverse effects profile based on the studies leading to their approval. This review also focuses on the recent advances and future perspectives specific to biologics in IBD.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Is tumor necrosis factor-α monoclonal therapy with proactive therapeutic drug monitoring optimized for inflammatory bowel disease? Network meta-analysis

BACKGROUND

The efficacy and safety of anti-tumor necrosis factor-α (TNF-α) monoclonal antibody therapy [adalimumab (ADA) and infliximab (IFX)] with therapeutic drug monitoring (TDM), which has been proposed for inflammatory bowel disease (IBD) patients, are still controversial.

AIM

To determine the efficacy and safety of anti-TNF-α monoclonal antibody therapy with proactive TDM in patients with IBD and to determine which subtype of IBD patients is most suitable for proactive TDM interventions.

METHODS

As of July 2023, we searched for randomized controlled trials (RCTs) and observational studies in PubMed, Embase, and the Cochrane Library to compare anti-TNF-α monoclonal antibody therapy with proactive TDM with therapy with reactive TDM or empiric therapy. Pairwise and network meta-analyses were used to determine the IBD patient subtype that achieved clinical remission and to determine the need for surgery.

RESULTS

This systematic review and meta-analysis yielded 13 studies after exclusion, and the baseline indicators were balanced. We found a significant increase in the number of patients who achieved clinical remission in the ADA [odds ratio (OR) = 1.416, 95% confidence interval (CI): 1.196-1.676] and RCT (OR = 1.393, 95%CI: 1.182-1.641) subgroups and a significant decrease in the number of patients who needed surgery in the proactive vs reactive (OR = 0.237, 95%CI: 0.101-0.558) and IFX + ADA (OR = 0.137, 95%CI: 0.032-0.588) subgroups, and the overall risk of adverse events was reduced (OR = 0.579, 95%CI: 0.391-0.858) according to the pairwise meta-analysis. Moreover, the network meta-analysis results suggested that patients with IBD treated with ADA (OR = 1.39, 95%CI: 1.19-1.63) were more likely to undergo TDM, especially in comparison with patients with reactive TDM (OR = 1.38, 95%CI: 1.07-1.77).

CONCLUSION

Proactive TDM is more suitable for IBD patients treated with ADA and has obvious advantages over reactive TDM. We recommend proactive TDM in IBD patients who are treated with ADA.

Immunogenicity and Loss of Effectiveness of Biologic Therapy for Inflammatory Bowel Disease Patients Due to Anti-Drug Antibody Development

Many patients with inflammatory bowel disease (IBD) experience a loss of effectiveness to biologic therapy (i.e., anti-TNF therapy, etc.). Therefore, in addition to the adverse effects of the treatment, these patients also face failure to achieve and maintain remission. Immunogenicity, the process of production of antibodies to biological agents, is fundamental to the evolution of loss of response to treatment in IBD patients. The presence of these antibodies in patients is linked to decreased serum drug levels and inhibited biological activity. However, immunogenicity rates exhibit significant variability across inflammatory disease states, immunoassay formats, and time periods. In this review, we aimed to elucidate the immunogenicity and immune mechanisms of antibody formation to biologics, the loss of therapy response, clinical results of biological treatment for IBD from systematic reviews and meta-analyses, as well as to summarize the most recent strategies for overcoming immunogenicity and approaches for managing treatment failure in IBD.

Therapeutic drug monitoring in inflammatory bowel disease patients on vedolizumab

OBJECTIVE

We aimed to investigate whether vedolizumab (VDZ) levels were associated with inflammatory markers or clinical or endoscopic scoring in inflammatory bowel disease (IBD).

METHODS

Besides demographic data, clinical scoring, endoscopic data, and laboratory markers of IBD patients treated with VDZ from 2015 to 2020 who had trough levels drawn on maintenance therapy were collected at baseline and at follow-up (after at least 8 weeks on VDZ therapy or after change in dose frequency). Low drug levels were defined as VDZ trough <20 μg/mL.

RESULTS

We identified 89 patients with a mean age of 42.9 years. Of the 90 total trough levels drawn, 61.1% were low. Among patients on every 8 week (Q8 week) VDZ dosing, 81.5% had low troughs. After increasing dosing frequency to Q4 weeks, all patients showed improvement in VDZ levels, but 30.6% remained <20 μg/mL. Higher VDZ levels on Q8 week dosing were associated with higher albumin levels (P = 0.01). While higher VDZ levels on Q4 week dosing were associated with higher albumin (P = 0.02), lower erythrocyte sedimentation rate (P = 0.04) and higher likelihood of having mild disease or endoscopic remission (P = 0.01). No significant association was found between VDZ levels and clinical scoring, body mass index, hemoglobin, vitamin D or platelet levels on either Q8 or Q4 week dosing.

CONCLUSIONS

Higher VDZ troughs were associated with higher albumin, mild endoscopic disease or endoscopic remission. Patients who continue to have low VDZ troughs despite Q4 week dosing may require a change in therapy.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Point-of-care therapeutic drug monitoring of tumour necrosis factor-α inhibitors using a single step immunoassay

Therapeutic drug monitoring (TDM) of tumor necrosis factor-α (TNFα)-inhibitors adalimumab and infliximab is important to establish optimal drug dose and maximize treatment efficacy. Currently, TDM is primarily performed with ELISA techniques in clinical laboratories, resulting in a long sample-to-result workflow. Point-of-care (POC) detection of these therapeutic antibodies could significantly decrease turnaround times and allow for user-friendly home-testing. Here, we adapted the recently developed bioluminescent dRAPPID (dimeric Ratiometric Plug-and-Play Immunodiagnostics) sensor platform to allow POC TDM of infliximab and adalimumab. We applied the two best performing dRAPPID sensors, with limit-of-detections of 1 pM and 17 pM, to measure the infliximab and adalimumab levels in 49 and 40 patient serum samples, respectively. The analytical performance of dRAPPID was benchmarked with commercial ELISAs and yielded Pearson's correlation coefficients of 0.93 and 0.94 for infliximab and adalimumab, respectively. Furthermore, a dedicated bioluminescence reader was fabricated and used as a readout device for the TDM dRAPPID sensors. Subsequently, infliximab and adalimumab patient serum samples were measured with the TDM dRAPPID sensors and bioluminescence reader, yielding Pearson's correlation coefficients of 0.97 and 0.86 for infliximab and adalimumab, respectively, and small proportional differences with ELISA (slope was 0.97 ± 0.09 and 0.96 ± 0.20, respectively). The adalimumab and infliximab dRAPPID sensors, in combination with the dedicated bioluminescence reader, allow for ease-of-use TDM with a fast turnaround time and show potential for POC TDM outside of clinical laboratories.

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

PURPOSE OF THE REVIEW

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

RECENT FINDINGS

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

Higher Adalimumab Trough Levels Are Associated with Histologic Remission and Mucosal Healing in Inflammatory Bowel Disease

(1) Many patients with inflammatory bowel disease (IBD) in endoscopic remission have persistent histologic activity, which is associated with worse outcomes. There are limited data on the association between adalimumab drug concentrations and histologic outcomes using validated histologic indices. We aimed to assess the relationship between adalimumab concentrations and the Robarts Histopathology Index (RHI). (2) Patients from a tertiary IBD center from 2013 to 2020 with serum adalimumab (ADA) trough concentrations measured during maintenance therapy (≥14 weeks) and a colonoscopy or flexible sigmoidoscopy with biopsies performed within 90 days of drug level were included. Blinded histologic scoring using the RHI was performed. Primary analysis assessed the relationship between adalimumab drug concentrations and histologic remission using receiver operating characteristic curve analysis. (3) In 36 patients (26 Crohn's Disease, 9 ulcerative colitis, 1 indeterminate), median adalimumab concentrations were higher (17.3 ug/mL, 12.2-24.0) in patients with histologic remission compared to those without (10.3 ug/mL, 6.8-13.9, p = 0.008). The optimal ADA concentration identified using the Youden threshold was ≥16.3 ug/mL (sensitivity 70%, specificity 90%). Patients with ADA ≥ 16.3 ug/mL had higher histologic remission rates (78%) compared to lower ADA concentrations (14%, p= 0.002), as well as higher mucosal healing rates (86%) compared to lower levels (12%, p = 0.001). Symptoms correlated weakly and non-significantly with both histologic (RHI) scores (r = 0.25, p = 0.2) and adalimumab concentrations (r = 0.05, p = 0.8). (4) The current study demonstrated that higher serum adalimumab concentrations (≥16.3 ug/mL) are needed for histologic remission and mucosal healing assessed using the RHI.

Safety Summary of Pediatric Inflammatory Bowel Disease Therapies

Therapeutic options for the treatment of pediatric inflammatory bowel disease include aminosalicylates, enteral nutrition, corticosteroids, immunomodulators, biologics, and emerging small molecule agents. Infectious risk due to systemic immunosuppression should be mitigated by appropriate screening before therapy initiation. Rare but serious malignancies have been associated with thiopurine use alone and in combination with anti-tumor necrosis factor agents, often in the setting of a primary Epstein-Barr virus infection. Potential agent-specific adverse events such as cytopenias, hepatotoxicity, and nephrotoxicity warrant regular clinical and laboratory monitoring.

The Role of Therapeutic Drug Monitoring in Children

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

Safety and Durability of Accelerated Infliximab Dosing Strategies in Pediatric IBD: A Single Center, Retrospective Study

OBJECTIVES

Infliximab (IFX) is commonly used to treat children with inflammatory bowel disease (IBD). We previously reported that patients with extensive disease started on IFX at a dose of 10 mg/kg had greater treatment durability at year one. The aim of this follow-up study is to assess the long-term safety and durability of this dosing strategy in pediatric IBD.

METHODS

We performed a retrospective single-center study of pediatric IBD patients started on IFX over a 10-year period.

RESULTS

Two hundred ninety-one patients were included (mean age = 12.61, 38% female) with a follow-up range of 0.1-9.7 years from IFX induction. One hundred fifty-five (53%) were started at a dose of 10 mg/kg. Only 35 patients (12%) discontinued IFX. The median duration of treatment was 2.9 years. Patients with ulcerative colitis ( P ≤ 0.01) and patients with extensive disease ( P = 0.01) had lower durability, despite a higher starting dose of IFX ( P = 0.03). Adverse events (AEs) were observed to occur at a rate of 234 per 1000 patient-years. Patients with a higher serum IFX trough level (≥20 µg/mL) had a higher rate of AEs ( P = 0.01). Use of combination therapy had no impact on risk of AEs ( P = 0.78).

CONCLUSIONS

We observed an excellent IFX treatment durability, with only 12% of patients discontinuing therapy over the observed timeframe. The overall rate of AEs was low, the majority being infusion reactions and dermatologic conditions. Higher IFX dose and serum trough level> 20 µg/mL were associated with higher risk of AEs, the majority being mild and not resulting in cessation of therapy.

Therapeutic Drug Monitoring of Anti-TNFα Inhibitors: A Matter of Cut-Off Ranges

Therapeutic drug monitoring (TDM) is a useful tool for optimising the use of anti-TNFα inhibitors in patients with inflammatory bowel diseases (IBDs). Recently, point-of-care methods for the quantification of drug levels and anti-drug antibodies (ADAs) have been developed to overcome the limitations of conventional enzyme-linked immunoabsorbent assays (ELISAs). Here, we evaluated the performance, interchangeability, and agreement between an automated ELISA-based immunoassay (CHORUS Promonitor) and the lateral flow assay (RIDA^®QUICK) for the quantification of infliximab (IFX, n = 65) and adalimumab (ADM, n = 58) plasma levels in IBD patients. Thirty-two samples for IFX and twenty-three samples for ADM that tested positively for the presence of ADAs were also used. Overall, data analysis showed a good agreement of ADM trough concentrations (R² = 0.75) between the two assays as well as for ADA measurement (K > 0.8). However, IFX levels highlighted a weak correlation (R² = 0.58) between the two kits, with the RIDA^®QUICK assay overestimating IFX plasma values by 30% when compared to the CHORUS Promonitor kit. Results from this study show that the two assays are not quantitatively and qualitatively interchangeable due to substantial discrepancies in some results. Accordingly, the same assay should be used for the longitudinal follow-up of IBD patients.

Identification of Specific Biomarkers and Pathways in the Treatment Response of Infliximab for Inflammatory Bowel Disease: In-Silico Analysis

Background: Inflammatory bowel disease (IBD) is characterized by chronic inflammation of the gastrointestinal tract. In biological therapy, infliximab became the first anti-tumor necrosis factor (TNF) agent approved for IBD. Despite this success, infliximab is expensive, often ineffective, and associated with adverse events. Prediction of infliximab resistance would improve overall potential outcomes. Therefore, there is a pressing need to widen the scope of investigating the role of genetics in IBD to their association with therapy response. Methods: In the current study, an in-silico analysis of publicly available IBD patient transcriptomics datasets from Gene Expression Omnibus (GEO) are used to identify subsets of differentially expressed genes (DEGs) involved in the pathogenesis of IBD and may serve as potential biomarkers for Infliximab response. Five datasets were found that met the inclusion criteria. The DEGs for datasets were identified using limma R packages through the GEOR2 tool. The probes’ annotated genes in each dataset intersected with DGEs from all other datasets. Enriched gene Ontology Clustering for the identified genes was performed using Metascape to explore the possible connections or interactions between the genes. Results: 174 DEGs between IBD and healthy controls were found from analyzing two datasets (GSE14580 and GSE73661), indicating a possible role in the pathogenesis of IBD. Of the 174 DEGs, five genes (SELE, TREM1, AQP9, FPR2, and HCAR3) were shared between all five datasets. Moreover, these five genes were identified as downregulated in the infliximab responder group compared to the non-responder group. Conclusions: We hypothesize that alteration in the expression of these genes leads to an impaired response to infliximab in IBD patients. Thus, these genes can serve as potential biomarkers for the early detection of compromised infliximab response in IBD patients.

GADECCU 2022 Guideline for the treatment of Ulcerative Colitis. Adaptation and updating of the GETECCU 2020 Guideline

INTRODUCTION

Ulcerative colitis (UC) is a chronic inflammatory disease that compromises the colon, affecting the quality of life of individuals of any age. In practice, there is a wide spectrum of clinical situations. The advances made in the physio pathogenesis of UC have allowed the development of new, more effective and safer therapeutic agents.

OBJECTIVES

To update and expand the evaluation of the efficacy and safety of relevant treatments for remission induction and maintenance after a mild, moderate or severe flare of UC.

RECIPIENTS

Gastroenterologists, coloproctologists, general practitioners, family physicians and others health professionals, interested in the treatment of UC.

METHODOLOGY

GADECCU authorities obtained authorization from GETECCU to adapt and update the GETECCU 2020 Guide for the treatment of UC. Prepared with GRADE methodology. A team was formed that included authors, a panel of experts, a nurse and a patient, methodological experts, and external reviewers. GRADE methodology was used with the new information.

RESULTS

A 118-page document was prepared with the 44 GADECCU 2022 recommendations, for different clinical situations and therapeutic options, according to levels of evidence. A section was added with the new molecules that are about to be available.

CONCLUSIONS

This guideline has been made in order to facilitate decision-making regarding the treatment of UC, adapting and updating the guide prepared by GETECCU in the year 2020.

Therapeutic drug monitoring in inflammatory bowel disease: implementation, utilization, and barriers in clinical practice in Scandinavia

BACKGROUND AND AIMS

Therapeutic drug monitoring (TDM) may optimize biologic and thiopurine therapies in inflammatory bowel disease (IBD). The study aimed to investigate implementation and utilization of TDM in Scandinavia.

METHODS

A web-based questionnaire on the use of TDM was distributed to Scandinavian gastroenterologists via the national societies.

RESULTS

In total, 297 IBD physicians prescribing biologic therapies, equally distributed between community and university hospitals, were included (response rate 42%) (Norway 118 (40%), Denmark 86 (29%), Sweden 50 (17%), Finland 33 (11%), Iceland 10 (3%)). Overall, TDM was applied during biologic therapies by 87%, and for TNF-inhibitors >90%. Among the users, reactive and proactive TDM were utilized by 90% and 63%, respectively. Danish physicians were significantly less inclined to use TDM compared to other Scandinavian countries; (58% vs 98%); OR 0.03 [0.01-0.09], p < 0.001). Reactive TDM was commonly applied at primary (74%) and secondary (99%) treatment failure. Proactive TDM was used by 80% during maintenance therapy and 56% during induction and more commonly utilized in Norway (p < 0.001), and by physicians managing >10 IBD patients/week (p = 0.005). TDM scenarios were interpreted in accord with available evidence but with discrepancies for proactive TDM. The main barriers to TDM were lack of guidelines (51%) and time lag between sampling and results (49%). TDM of thiopurines was routinely used by 87%.

CONCLUSION

TDM of biologic and thiopurine therapies has been broadly implemented into clinical practice in Scandinavia. However, physicians call for TDM guidelines detailing indications and interpretations of test results along with improved test response times.

Supratherapeutic Infliximab Levels Do Not Predict Risk of Short-term Complications in Adults With Crohn's Disease

BACKGROUND

It is uncertain if higher infliximab trough levels (TLs) confer a greater risk of infectious/noninfectious complications (IC/NIC). We aimed to assess the risk of IC and NIC in patients with different TLs.

METHODS

We retrospectively evaluated a cohort of Crohn's disease (CD) patients treated with infliximab who underwent therapeutic drug monitoring (TDM), at a tertiary inflammatory bowel disease center, between January 1, 2010, and December 1, 2019. TDM was defined as checking of infliximab trough and antibody levels within a 48-hour period before administration. Patients with a minimum of 3-month assessment pre-TDM and post-TDM were included. In the case of multiple TDMs, the highest TL was considered, and patients were distributed across 4 predefined TL groups (A: <5 µg/mL, B: 5 to 10 µg/mL, C: 10 to 15 µg/mL, and D: ≥15 µg/mL). Rates of IC and NIC during the 3-month prior and following TDM were compared across the groups. In addition, duration of exposure, in terms of months up to TDM, was collected to analyze differences in rates of IC and NIC.

RESULTS

Our study included 341 CD patients (median age: 35 y, 58% men). IC and NIC occurred in 52 (15%) and 30 (9%) patients, respectively. Rates of IC and NIC were similar across the 4 TL groups ( P =0.9 and 0.7, respectively for IC and NIC). On multivariable analysis, exposure to infliximab >40 months (as determined by receiver operating characteristic curve analysis) was associated with decreased odds for IC (adjusted odds ratio=0.51, P =0.04), but not NIC (adjusted odds ratio=0.72, P =0.46).

CONCLUSIONS

In this large CD cohort, there was no association between infliximab TL and risk of short-term IC or NIC. Interestingly, a shorter duration of exposure predicted higher rates of IC. This supports the safety of targeting higher infliximab TLs when necessary and greater vigilance during the early stages of treatment.

Early Infliximab Clearance Predicts Remission in Children with Crohn's Disease

BACKGROUND AND AIMS

Children with Crohn's disease have lower response rates to infliximab, lower infliximab levels, and higher infliximab clearance on weight-based dosing than adults. We hypothesize infliximab clearance is a predictive of later outcomes on infliximab in children with Crohn's disease.

METHODS

In this single-center retrospective study, data were collected from charts on diagnosis, anthropometry, routine labs, infliximab therapeutic drug monitoring, infliximab dosing, disease activity, and other treatments. With these data we generated a population pharmacokinetic model using non-linear mixed effects modeling and calculated infliximab clearance for each patient over time. Patients were classified as in remission, responder-only or non-responder at 5, 10 and 16 months. Regression and ROC analyses were used to assess for early predictors of remission and response to infliximab.

RESULTS

Eighty-five subjects were included, with a median follow-up of 22.3 months (IQR 10.1-36.8). Our pharmacokinetic model showed infliximab clearance was positively associated with CRP and weight, while negatively associated with albumin. In regression analyses, early infliximab clearance was the only significant, consistent predictor of remission. A 0.1 L/day increase in infliximab clearance predicted remission with an OR between 0.179 and 0.426. Differences in dosing did not account for differences in outcome. Infliximab clearance alone had moderate predictive accuracy of remission, with an AUC between 0.682 and 0.738.

CONCLUSIONS

Early infliximab clearance is strongly associated with remission in children with Crohn's disease. It may be useful as a marker of response in proactive therapeutic drug monitoring to guide early dose optimization and/or changes in treatment for betterment of long-term outcomes.

Meta-analysis: The efficacy of therapeutic drug monitoring of anti-TNF-therapy in inflammatory bowel disease

BACKGROUND AND AIMS

This systematic review and meta-analysis aimed to determine whether the use of therapeutic drug monitoring (TDM) in inflammatory bowel disease (IBD) patients on anti-tumour necrosis factor (anti-TNF) therapy results in improved rates of clinical and endoscopic remission, surgery, corticosteroid-free remission and hospitalisation.

METHODS

MEDLINE, EMBASE, EMBASE classic, PubMed, Cochrane central databases register of controlled trials and Cochrane Specialised Trials Register were searched between 01 Janurary 1946 and 08 April 2022. Randomised controlled trials (RCTs) and prospective and retrospective observational studies were included, comparing TDM to standard of care (SOC) or reactive vs proactive TDM. Results were reported as pooled relative risks (RR) with 95% confidence intervals (95% CI).

RESULTS

Twenty-six studies, including 9 RCTs, were included. Compared to SOC, proactive TDM was associated with a significantly decreased risk of treatment failure (RR 0.64, 95% CI 0.48-0.85 p<0.01), and a non-significant decrease in need for surgery (RR 0.51, 95% CI 0.25-1.02) and hospitalisation (RR 0.64, 95% CI 0.40-1.00). Furthermore compared to SOC, Proactive TDM was associated with higher rates of endoscopic remission (RR 1.19, 95% CI 0.93-1.53) and clinical remission (RR 1.07, 95% CI 0.97-1.18). Compared to reactive TDM, proactive TDM was associated with significant decreased risk of treatment failure (RR 0.46, 95% CI 0.21 = 0.98, p = 0.04) and significant reduction in hospitalisation (RR 0.33, 95% CI 0.21-0.54, p < 0.01).

CONCLUSIONS

Compared to SOC, proactive TDM was associated with significant benefit in reducing treatment failure. Compared to reactive TDM, proactive TDM led to a significant reduction in hospitalisation and treatment failure. More studies with larger RCTs and standardised assays are needed to substantiate these results and validate the cost-effectiveness of TDM.

Optimized Infliximab Induction Predicts Better Long-Term Clinical and Biomarker Outcomes Compared to Standard Induction Dosing

OBJECTIVES

To evaluate the efficacy of standard and optimized infliximab induction dosing in attaining corticosteroid (CS) free clinical remission at week 52 and the effect that post-induction trough levels have on long-term outcome.

METHODS

Inflammatory bowel disease (IBD) patients ≤18 years commenced on infliximab between August 1, 2016, and August 1, 2018, from Vancouver, Canada, and Glasgow, Scotland, were included. The Glasgow cohort followed standard induction while the Vancouver cohort undertook induction optimization based on clinical, biomarker, and proactive infliximab trough levels. Baseline characteristics and laboratory values were documented.

RESULTS

In total, 140 children were included [median age 14.1 years (interquartile range (IQR) 12.0-16.0)]; 54% male. CS-free clinical remission at week 52 was higher in the optimized group compared to the standard cohort [65/78 (83%) vs. 32/62 (52%), P < 0.001]. Combined CS-free clinical and biomarker remission (CRP < 5 mg/L) was also higher in the optimized compared to the standard cohort [65/78 (83%) vs 25/62 (40%), P < 0.001]. The median post-induction trough level was higher in children who were in CS-free clinical remission at week 52 [3.6 mg/L (1.5-7.1)] vs. those who were not [2.0 mg/L (0.8-4.1), P = 0.04]. The odds of attaining a therapeutic post-induction trough level were almost 4-fold higher in the optimized group than the standard cohort (OR 3.97, 95% CI: 1.89-8.68, P < 0.001).

CONCLUSIONS

Standard infliximab induction resulted in less favorable long-term outcomes for pediatric IBD patients. Optimizing induction using clinical, biomarker, and proactive trough levels resulted in higher post-induction trough levels and a greater odds of attaining long-term clinical remission.

Higher serum infliximab concentrations during induction predict short-term endoscopic response in patients with inflammatory bowel disease

OBJECTIVE

Measuring of serum infliximab (IFX) induction concentrations might reduce primary non-response rates in inflammatory bowel diseases (IBD), but optimal target concentrations are unclear. We investigated whether IFX induction concentrations predict short-term endoscopic response at week 12 or treatment persistence at week 52.

METHODS

Sixty-nine IBD patients (Crohn's disease, n=24; ulcerative colitis, n=45) received standard IFX induction of 5 mg/kg bodyweight at weeks 0, 2, and 6. Responders continued maintenance therapy and underwent follow-up until week 52 or treatment discontinuation. We measured IFX concentrations at weeks 2, 6, and 12, and evaluated treatment response around week 12 with endoscopy or with clinical scores and fecal calprotectin. Using the receiver operating characteristic analysis, we determined optimal IFX concentration thresholds associated with treatment response. We further compared IFX induction concentrations between patients persisting on IFX at week 52 and patients discontinuing treatment due to insufficient response.

RESULTS

Responders (74%, 51 out of 69 patients) had significantly higher median IFX concentrations than non-responders at weeks 6 (25.06 vs. 19.68 µg/ml; P = 0.04) and 12 (18.03 vs. 10.02 µg/ml; P = 0.03), but not at week 2 (33.12 vs. 34.20 µg/ml; P = 0.97). Optimal IFX concentration thresholds for induction response were 21.33 and 5.13 µg/ml at weeks 6 and 12, respectively. Fifty-three patients continued IFX maintenance therapy until week 52. Induction concentrations failed to predict persistence on IFX therapy at week 52.

CONCLUSION

Higher IFX induction concentrations predict endoscopic short-term response. However, induction concentrations failed to predict long-term persistence on IFX treatment.

Dashboard-Driven Accelerated Infliximab Induction Dosing Increases Infliximab Durability and Reduces Immunogenicity

BACKGROUND AND AIMS

Accelerated infliximab (IFX) induction is often based on clinical parameters as opposed to pharmacokinetics (PK). We aimed to investigate the impact of dashboard-guided optimized induction dosing on IFX durability and immunogenicity in a real-world inflammatory bowel disease (IBD) setting.

METHODS

Pediatric and adult IBD patients were enrolled in a prospective single arm intervention trial. Cumulative data from each infusion (INF), weight, albumin, C-reactive protein, IFX dose, IFX trough level, and antidrug antibody presence were used to inform subsequent INF dosing. Forecasts driven by adaptive Bayesian modeling were generated to maintain trough levels for the third (INF3) and fourth (INF4) infusions of 17 μg/mL and 10 μg/mL, respectively. The primary outcome was proportion of patients prescribed accelerated dosing (AD) intervals by INF3 (<22 days) or INF4 (<49 days). Secondary outcomes included week 52 clinical and PK outcomes. Multivariate analyses and Kaplan-Meier curves compared outcomes based on adherence to dashboard forecasts.

RESULTS

Of the 180 per-protocol population, AD was forecast for 41% (INF3) and 69% (INF4) of patients with median intervals of 17 (INF3) and 39 (INF4) days. Baseline age >18 years, albumin >3.5 g/L, and 10-mg/kg dose were independently associated with lower rates of AD by INF4. Nonadherence with the INF4 forecast (n = 39) was an independent predictor of antidrug antibody (P < .0001) and IFX discontinuation (P = .0006). A total of 119 of 123 patients on IFX at week 52 were in steroid-free remission.

CONCLUSIONS

The application of a PK dashboard during induction can optimize dosing early to improve IFX durability and immunogenicity.

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.

Updates in therapeutic drug monitoring in inflammatory bowel disease

Biologics and immunomodulators (IMM) are generally considered the most effective therapies for the treatment of ulcerative colitis and Crohn's disease. However, despite the efficacy of these therapies, many patients either have a primary lack of response or a secondary loss of response to these medications. Therapeutic drug monitoring (TDM) is a systematic approach to managing such patients. In this review, we summarize the latest data on TDM, including reactive and proactive TDM, in patients with inflammatory bowel disease on biologics and/or IMM.

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.

Cost-Effectiveness of Therapeutic Drug Monitoring of Anti-TNF Therapy in Inflammatory Bowel Disease: A Systematic Review

Infliximab and adalimumab are monoclonal antibodies against tumor necrosis factor (anti-TNF) used to manage inflammatory bowel disease (IBD). Therapeutic Drug Monitoring (TDM) has been proven to prevent immunogenicity, to achieve better long-term clinical results and to save costs in IBD treatment. The aim of this study was to conduct a systematic review on cost-effectiveness analyses of studies that apply TDM of anti-TNF in IBD and to provide a critical analysis of the best scientific knowledge available in the literature. The quality of the included studies was assessed using Consolidated Health Economic Evaluation Reporting Standards (CHEERS). Cost-effectiveness of the TDM strategies was presented as total costs, cost savings, quality-adjusted life-years (QALY) and incremental cost-effectiveness ratio (ICER). Thirteen studies that examined the health economics of TDM of anti-TNF in IBD from 2013 to 2021 were included. Eight of them (61.5%) achieved a score between 17 and 23 on the CHEERS checklist. The comparison between the TDM strategy and an empirical strategy was cost saving. The ICER between reactive TDM and an empirical strategy was dominated (favorable) by reactive TDM, whereas the ICER value for proactive TDM compared to an empirical strategy ranged from EUR 56,845 to 3,901,554. This systematic review demonstrated that a TDM strategy is cost-effective or cost-saving in IBD.

Hierarchical Structured Component Analysis for Microbiome Data Using Taxonomy Assignments

The recent advent of high-throughput sequencing technology has enabled us to study the associations between human microbiome and diseases. The DNA sequences of microbiome samples are clustered as operational taxonomic units (OTUs) according to their similarity. The OTU table containing counts of OTUs present in each sample is used to measure correlations between OTUs and disease status and find key microbes for prediction of the disease status. Various statistical methods have been proposed for such microbiome data analysis. However, none of these methods reflects the hierarchy of taxonomy information. In this paper, we propose a hierarchical structural component model for microbiome data (HisCoM-microb) using taxonomy information as well as OTU table data. The proposed HisCoM-microb consists of two layers: one for OTUs and the other for taxa at the higher taxonomy level. Then we calculate simultaneously coefficient estimates of OTUs and taxa of the two layers inserted in the hierarchical model. Through this analysis, we can infer the association between taxa or OTUs and disease status, considering the impact of taxonomic structure on disease status. Both simulation study and real microbiome data analysis show that HisCoM-microb can successfully reveal the relations between each taxon and disease status and identify the key OTUs of the disease at the same time.

Proactive infliximab optimisation using a pharmacokinetic dashboard versus standard of care in patients with Crohn's disease: study protocol for a randomised, controlled, multicentre, open-label study (the OPTIMIZE trial)

INTRODUCTION

Preliminary data indicates that proactive therapeutic drug monitoring (TDM) is associated with better outcomes compared with empiric dose escalation and/or reactive TDM, and that pharmacokinetic (PK) modelling can improve the precision of individual dosing schedules in Crohn's disease (CD). However, there are no data regarding the utility of a proactive TDM combined PK-dashboard starting early during the induction phase, when disease activity and drug clearance are greatest. The aim of this randomised, controlled, multicentre, open-label trial is to evaluate the efficacy and safety of a proactive TDM combined PK dashboard-driven infliximab dosing compared with standard of care (SOC) dosing in patients with moderately to severely active CD.

METHODS AND ANALYSIS

Eligible adolescent and adult (aged ≥16-80 years) patients with moderately to severely active CD will be randomised 1:1 to receive either infliximab monotherapy with proactive TDM using a PK dashboard (iDose, Projections Research) or SOC infliximab therapy, with or without a concomitant immunomodulator (IMM) (thiopurine or methotrexate) at the discretion of the investigator. The primary outcome of the study is the proportion of subjects with sustained corticosteroid-free clinical remission and no need for rescue therapy from week 14 throughout week 52. Rescue therapy is defined as any IFX dose escalation other than what is forecasted by iDose either done empirically or based on reactive TDM; addition of an IMM after week 2; reintroduction of corticosteroids after initial tapering; switch to another biologic or need for CD-related surgery. The secondary outcomes will include both efficacy and safety end points, such as endoscopic and biological remission, durability of response and CD-related surgery and hospitalisation.

ETHICS AND DISSEMINATION

The protocol has been approved by the Institutional Review Board Committee of the Beth Israel Deaconess Medical Center (IRB#:2021P000391). Results will be disseminated in peer-reviewed journals and presented at scientific meetings.

TRIAL REGISTRATION NUMBER

NCT04835506.

Advantages of Proactive Therapeutic Drug Monitoring in a Prospective Cohort of Children With Inflammatory Bowel Disease Treated With Anti-Tumour Necrosis Factor

Few studies have addressed whether proactive therapeutic drug monitoring (TDM) results in improved clinical outcomes in children with inflammatory bowel disease (IBD) treated with anti-tumour necrosis factor. The aim of this study was to investigate the impact of using proactive TDM in this patient group.Pilot single-centre observational study to accrue data on patients managed with proactive TDM.More patients in the proactive TDM cohort were managed by escalating the infliximab (IFX) regime (P < 0.001). The need for switching to different biologics was significantly lower in this patient group (P < 0.001).The introduction of proactive TDM resulted in a significant reduction of patients requiring switch of their primary biologic. The results of this study are indicators that proactive TDM offers a better method of managing children with IBD on IFX therapy.

Therapeutic drug monitoring in Crohn's disease patients treated with anti-TNF: a comparison of two techniques

BACKGROUND

Therapeutic drug monitoring is a useful clinical decision aid in managing patients with inflammatory bowel disease treated with anti-tumor necrosis factor (anti-TNF). Various techniques are available to evaluate drug trough levels, and among these a point-of-care (POC) method has been proposed to overcome the limitations inherent to other methodologies. In this study we aimed to evaluate the capability of POC to discriminate between relapse and remission disease phases, and to assess the concordance of the POC and homogeneous mobility shift assay (HMSA) results.

METHODS

Drug trough level of 46 Crohn's disease patients treated with either adalimumab or infliximab were evaluated with both a POC technique and an HMSA at various time points (week-16 and -48) during anti-TNF treatment.

RESULTS

Median adalimumab trough level of patients in remission were significantly higher as compared to relapsing patients using both HMSA (week 16, P = 0.0001; week48, P = 0.001) and POC (week 16, P = 0.0003; week 48, P = 0.0012), and similar results were observed with infliximab trough level at week 16 (HMSA, P = 0.019; POC, P = 0.0072). Overall, we observed a good correlation between the techniques for both infliximab (r = 0.76; P  < 0.0001) and adalimumab (r = 0.75; P  < 0.0001), with no difference in discriminatory accuracy between assays (infliximab: HMSA versus POC c-index, 0.921 versus 0.895, P =0.149; adalimumab: HMSA versus POC c-index, 0.817 versus 0.850, P = 0.197).

CONCLUSION

Both POC and HMSA assays are able to reliably differentiate relapse and remission phases in Crohn's disease patients treated with anti-TNF. These techniques showed good concordance and we feel that their preferential use should be based on local accessibility, physicians' experience and preference, and the need for timeliness availability of results.

Therapeutic drug monitoring for biological medications in inflammatory bowel disease

Therapeutic drug monitoring (TDM) is the measurement of serum drug concentrations and anti-drug-antibodies (ADA) for biologic therapies used to treat inflammatory bowel disease (IBD). The aim of this article is to review the current literature concerning reactive and proactive TDM for both adults and children with IBD. Although optimal trough concentration windows for some of these medications are not well defined, there is mounting evidence to suggest that reactive TDM is associated with favorable therapeutic outcomes, including less immunogenicity, greater drug exposure, and a decreased risk of treatment failure. Moreover, while the exact mechanism of loss of response is not fully elucidated, the vast majority of studies have reported a decreased incidence of nonresponse and secondary loss of response when TDM is implemented. Proactive TDM, while even less understood in the literature, employs a schedule of preemptive analysis of serum trough concentrations to accordingly adjust the patient's biologic dosage. Proactive TDM may decrease the need for IBD-related surgery/hospitalization, and therefore merits future studies of investigation.

Proportionate Cardiovascular Mortality in Chronic Inflammatory Disease in Adults in the United States From 1999 to 2019

BACKGROUND

Despite a rising prevalence of chronic inflammatory disease (CID), the recent trends in cardiovascular disease (CVD) mortality of patients with CID is scarce. In this study, we investigated patterns of CVD mortality in systemic lupus erythematosus (SLE), inflammatory bowel disease (IBD), and rheumatoid arthritis (RA) compared with the general population.

METHODS

We used the 1999 to 2019 multiple causes of death files from the national center for health statistics to analyze patterns and trends of proportionate CVD mortality in CID compared with the general population.

RESULTS

We analyzed a total of 11,154 CVD deaths in IBD, 58,337 CVD deaths in RA, 6227 CVD deaths in SLE, and 17,826,871 CVD deaths in the general population. Between 1999 and 2019, we found that proportionate CVD mortality decreased significantly in the IBD group (25% to 16%), RA group (34% to 25%), and the general population (41% to 31%), but did not change for the SLE group (15% to 15%). Patients with SLE who died of CVD were approximately 10 years younger compared with CVD decedents with RA, IBD, or general population. The White population had higher proportionate CVD mortality than African American (IBD [19% vs 16%-18%] and SLE [14%-16% vs 12-14%], respectively).

CONCLUSIONS

This study identifies current trends in CVD mortality in the CID population and elucidates current demographics in CVD mortality in CID. Although proportionate CVD mortality decreased in the general population, and in patients with RA and IBD, there was no change among patients with SLE. Further studies are needed to elucidate these differences.

Ultra-proactive Therapeutic Drug Monitoring of Infliximab Based on Point of Care Testing in Inflammatory Bowel Disease: Results of a Pragmatic Trial

BACKGROUND

With point of care testing [POCT] for infliximab [IFX], ultraproactive therapeutic drug monitoring [TDM] with ad-hoc dose optimisation is possible in patients with inflammatory bowel disease [IBD].

AIM

To compare the clinical outcomes of an ultraproactive TDM algorithm of IFX based on POCT with reactive TDM in patients with IBD, in a pragmatic clinical trial.

METHODS

All patients with IBD and maintenance IFX treatment were included between June and August 2018 in two centres. Centre A applied an ultra-proactive TDM algorithm incorporating POCT, and centre B applied reactive TDM. Primary endpoint was failure of IFX therapy after 1 year. Secondary endpoints included sustained clinical remission and mucosal remission.

RESULTS

In total 187 patients [n = 115/72 cohort A/B] were included. Cohort A had more trough level [TL] measurements compared with cohort B [8.8 vs 1/patient/year; p <0.0001], leading to a significant higher number of dose optimisations. POCT testing was required in 27% after the first round of ultra-proactive TDM and in a mean of 6.3% (standard deviation [SD] 1.9) in the subsequent rounds. Ad-hoc extra dosing was needed in 13% of the POCT. After 1 year, no difference was seen between cohort A and cohort B in IFX failure [19% vs 10%; p = 0.08], nor in sustained clinical remission [75% vs 83%; p = 0.17]. Mucosal remission was evaluated in 71 patients [38%], and was more frequent in the reactive TDM cohort [p = 0.02].

CONCLUSIONS

Ultra-proactive TDM in patients with IBD and maintenance IFX treatment leads to equal clinical outcomes as reactive TDM after 1 year of follow-up.

Therapeutic drug monitoring of biologics in inflammatory bowel disease: unmet needs and future perspectives

Therapeutic drug monitoring (TDM) has emerged as a useful tool for optimising the use of biologics, and in particular anti-tumour necrosis factor (anti-TNF) therapy, in inflammatory bowel disease (IBD). However, challenges remain and are hindering the widespread implementation of TDM in clinical practice. These barriers include identification of the optimal drug concentration to target, the lag time between sampling and results, and the proper interpretation of anti-drug antibody titres among different assays. Solutions to overcome these barriers include the harmonisation of TDM assays and the use of point-of-care testing. Other unmet needs include well designed prospective studies and randomised controlled trials focusing on proactive TDM, particularly during induction therapy. Future studies should also investigate the utility of TDM for biologics other than anti-TNF therapies in both IBD and other immune-mediated inflammatory diseases such as rheumatoid arthritis and psoriasis, and the use of pharmacokinetic modelling dashboards and pharmacogenetics towards individual personalised medicine.

Comparison of Timing to Develop Anti-Drug Antibodies to Infliximab and Adalimumab Between Adult and Pediatric Age Groups, Males and Females

OBJECTIVE

To compare the timing of serum anti-drug antibodies in adult and pediatric age groups, males and females, treated for inflammatory bowel disease or arthritis with adalimumab or infliximab by retrospectively combining data collected during a 2-year therapeutic drug monitoring period.

METHODS

Four hundred thirty sera were divided in groups collected at 0, 3, 6, 12, and 24 months (T0, T3, T6, T12, and T24) after initiation of therapy and assayed for drug and relative anti-drug antibodies levels. At each time point, the percentage of sera presenting anti-drug antibodies, as well as the drug concentrations, were calculated and correlated with patient age and sex.

RESULTS

Anti-drug antibodies were present in 31.5% of sera and were significantly higher in the pediatric age group than in the adult age group, through all time points. The percentages of sera showing anti-drug antibodies were significantly different as early as 3 months and were sera from pediatric female group. The percentages of sera showing anti-drug antibodies reached the highest value at 6 months in the pediatric age group and at 12 months in the adult age group.

CONCLUSIONS

Sera from pediatric had an earlier presence of anti-drug antibodies than adults. In particular, pediatric females sera showed the fastest anti-drug antibodies development.

The efficacy of immunomodulators in the prevention and suppression of anti-drug antibodies to anti-tumor necrosis factor therapy in inflammatory bowel disease

The development of biological agents against tumor necrosis factor (TNF) has revolutionized the management of inflammatory bowel disease (IBD), frequently achieving induction and maintenance of remission in both ulcerative colitis and Crohn's disease. However, a loss of response due to the development of anti-drug antibodies (ADA) is seen annually in approximately 20% of IBD patients receiving anti-TNF therapy. Current evidence suggests that the use of immunomodulators (IMM), such as thiopurines (azathioprine and 6-mercaptopurine) or methotrexate, may prevent or suppress ADA formation. In this article, we present a comprehensive review of the available literature regarding the efficacy of IMM in the prevention and suppression of ADA development to anti-TNF therapy in patients with IBD.

Ustekinumab Therapeutic Drug Monitoring-Impact on Clinical Practice: A Multicenter Cross-Sectional Observational Trial

BACKGROUND AND AIMS

The value of ustekinumab (UST) therapeutic drug monitoring (TDM) in clinical practice remains unclear. This study examined the impact of UST TDM on clinical decision making in patients with Crohn's disease (CD).

METHODS

A total of 110 consecutive UST-treated CD patients were enrolled in this multicenter, single-arm cross-sectional study. During a single study visit, clinical decisions, disease characteristics, and serum and fecal samples were obtained. The primary outcome was congruency of the actual and two hypothetical clinical decisions based on provision of UST TDM (with and without fecal calprotectin [FCP]) to participating clinicians. Decisions were compared against those of a review panel. A sub-study retrospectively measured the associations of clinical outcomes at the next follow-up visit with serum UST concentration [UST].

RESULTS

No differences in the pattern of decisions by clinicians were observed before and after provision of UST TDM (P = 1.0) or UST TDM + FCP (P = 0.86). However, 39% (TDM) and 50% (TDM + FCP) of hypothetical decisions differed from the initial decisions. The review panel's decisions differed with the addition of TDM + FCP (P = 0.0006), but not TDM alone (P = 0.16). The sub-study (n = 53) failed to detect an association between therapeutic serum [UST] at the initial study visit and clinical outcomes at the next visit.

CONCLUSIONS

In consecutive CD patients treated with UST, the addition of TDM into routine clinical practice did not significantly impact clinical decisions and there was no association between short-term clinical outcomes and serum [UST]. Further studies are warranted before clinicians routinely implement UST TDM into clinical practice.

Effect of Therapeutic Drug Monitoring vs Standard Therapy During Maintenance Infliximab Therapy on Disease Control in Patients With Immune-Mediated Inflammatory Diseases: A Randomized Clinical Trial

IMPORTANCE

Proactive therapeutic drug monitoring (TDM), consisting of individualized treatment based on scheduled assessments of serum drug levels, has been proposed as an alternative to standard therapy to optimize efficacy and safety of infliximab and other biologic drugs. However, it remains unclear whether proactive TDM improves clinical outcomes during maintenance therapy.

OBJECTIVE

To assess whether proactive TDM during maintenance therapy with infliximab improves treatment efficacy by preventing disease worsening compared with standard infliximab therapy without TDM.

DESIGN, SETTING, AND PARTICIPANTS

Randomized, parallel-group, open-label clinical trial including 458 adults with rheumatoid arthritis, spondyloarthritis, psoriatic arthritis, ulcerative colitis, Crohn disease, or psoriasis undergoing maintenance therapy with infliximab in 20 Norwegian hospitals. Patients were recruited from June 7, 2017, to December 12, 2019. Final follow-up took place on December 14, 2020.

INTERVENTIONS

Patients were randomized 1:1 to proactive TDM with dose and interval adjustments based on scheduled monitoring of serum drug levels and antidrug antibodies (TDM group; n = 228) or to standard infliximab therapy without drug and antibody level monitoring (standard therapy group; n = 230).

MAIN OUTCOME AND MEASURES

The primary outcome was sustained disease control without disease worsening, defined by disease-specific composite scores or consensus about disease worsening between patient and physician leading to a major change in treatment (switching to another biologic drug, adding an immunosuppressive drug including glucocorticoids, or increasing the infliximab dose), during the 52-week study period.

RESULTS

Among 458 randomized patients (mean age, 44.8 [SD, 14.3] years; 216 women [49.8%]), 454 received their randomly allocated intervention and were included in the full analysis set. The primary outcome of sustained disease control without disease worsening was observed in 167 patients (73.6%) in the TDM group and 127 patients (55.9%) in the standard therapy group. The estimated adjusted difference was 17.6% (95% CI, 9.0%-26.2%; P < .001) favoring TDM. Adverse events were reported in 137 patients (60%) and 142 patients (63%) in the TDM and standard therapy groups, respectively.

CONCLUSIONS AND RELEVANCE

Among patients with immune-mediated inflammatory diseases undergoing maintenance therapy with infliximab, proactive TDM was more effective than treatment without TDM in sustaining disease control without disease worsening. Further research is needed to compare proactive TDM with reactive TDM, to assess the effects on long-term disease complications, and to evaluate the cost-effectiveness of this approach.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03074656.