Proactive Therapeutic Drug Monitoring Versus Conventional Management for Inflammatory Bowel Diseases: A Systematic Review and Meta-Analysis

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

OBJECTIVES

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

What are the benefits of therapeutic drug monitoring in the optimization of adalimumab therapy? a systematic review and meta-analysis up to 2022

Aims

Persistent uncertainties exist surrounding the therapeutic drug monitoring (TDM) of adalimumab in clinical settings. To address these issues, we conducted a systematic review to assess the current evidence regarding the benefits of TDM for adalimumab.

Methods

PubMed, EMBASE, and Cochrane Databases were searched from inception to October 2022. The trials regarding to the list three key questions were considered: 1) Could routine proactive TDM assist in improving outcomes in patients receiving adalimumab? 2) Could reactive TDM assist in guiding subsequent treatment strategies for patients with treatment failure to adalimumab? 3) Could TDM assist in informing dose reduction or discontinuation in patients with low disease activity or in remission treated with adalimumab? Two reviewers independently selected the studies and extracted the data. Meta-analysis was performed to calculate the relative risk (RR) and 95% confidence interval (CI).

Results

A total of 9 studies was included in this review. For proactive TDM, meta-analysis indicated that proactive TDM (n = 163/257, 63.42%) showed no significant superiority over reactive TDM and/or conventional management (n = 336/606, 55.44%) in achieving and/or maintaining clinical remission by random effects model (RR: 1.24, 95% CI 0.98-1.58, I 2 = 73%). There were three studies that supporting the reactive TDM, low drug levels in the absence of anti-drug antibodies (ADA) strongly indicate the need for dose intensification, and infliximab is a feasible choice for patients with low drug levels and ADA positivity. While swapping to another class should be considered in patients with adequate drug levels. In addition, TDM can help clinicians optimize dosing schedules and prevent overtreatment in patients who have achieved low disease activity and sufficient drug concentrations, with no predictive value for successful adalimumab discontinuation.

Conclusion

Current evidence suggests that proactive TDM is numerically but not statistically significant superiority over reactive TDM and/or conventional management. Reactive TDM can aid in understanding treatment failure and developing subsequent therapy. For patients reaching low disease activity and remission, TDM can help successful dose reduction, while it cannot inform the successful drug discontinuation. However, existing trials are limited, and more well-designed trials are necessary to clarify the role of TDM in adalimumab treatment.

HLA-DQA1*05 Was Not Associated With Primary Nonresponse or Loss of Response to First Anti-TNF in Real-World Inflammatory Bowel Disease Patients

BACKGROUND

We lack predictors of response to biologics in the management of patients with inflammatory bowel disease (IBD). A recent study has shown a significant association between HLA-DQA1*05 carriers and the development of loss of response to anti-tumor necrosis factor (TNF) mediated by immunogenicity.

METHODS

Retrospective single-center cohort study including IBD patients who had received anti-TNF therapy as a first biologic and whose HLA-DQA1*05 had been determined. Primary nonresponse and secondary failure (assessed by survival analysis) have been evaluated as well as safety outcomes.

RESULTS

A total of 199 IBD patients (161 [81%] with Crohn's disease and 38 [19%] with ulcerative colitis) were included. A total of 42.4% were HLA-DQA1*05 carriers and 60% received combination therapy at the start of anti-TNF treatment. Median follow-up was 24 (interquartile range, 11-66) months. No statistically significant differences were found in primary nonresponse to anti-TNF (89.3% vs 87.8%; P = .825), depending on HLA carriers and noncarriers. No differences in secondary loss of response according to HLA variant in any of the analyses performed (full cohort, according to IBD or anti-TNF type) were observed. Again, no differences were observed in patients treated with combination therapy. In terms of safety, no significant differences were found in the rate of infusion reactions or serious adverse events.

CONCLUSION

In our real-life cohort of IBD patients treated for the first time with anti-TNF, being an HLA-DQA1*05 carrier did not act as a predictor of response failure, either primary or secondary. The safety of anti-TNF treatment has also not been influenced by the variant.

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

Background

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

Objectives

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

Design

Cross-sectional study.

Methods

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

Results

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

Conclusion

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

Therapeutic drug monitoring guidelines in oncology: what do we know and how to move forward? Insights from a systematic review

Background

Compared with anti-infective drugs, immunosuppressants and other fields, the application of therapeutic drug monitoring (TDM) in oncology is somewhat limited.

Objective

We aimed to provide a comprehensive understanding of TDM guidelines for antineoplastic drugs and to promote the development of individualized drug therapy in oncology.

Design

This study type is a systematic review.

Data sources and methods

This study was performed and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 statement. Databases including PubMed, Embase, the official websites of TDM-related associations and Chinese databases were comprehensively searched up to March 2023. Two investigators independently screened the literature and extracted data. The methodological and reporting quality was evaluated using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) and the Reporting Items for Practice Guidelines in Healthcare (RIGHT), respectively. Recommendations and quality evaluation results were presented by visual plots. This study was registered in PROSPERO (No. CRD42022325661).

Results

A total of eight studies were included, with publication years ranging from 2014 to 2022. From the perspective of guideline development, two guidelines were developed using evidence-based methods. Among the included guidelines, four guidelines were for cytotoxic antineoplastic drugs, three for small molecule kinase inhibitors, and one for antineoplastic biosimilars. Currently available guidelines and clinical practice provided recommendations of individualized medication in oncology based on TDM, as well as influencing factors. With regard to methodological quality based on AGREE II, the average overall quality score was 55.21%. As for the reporting quality by RIGHT evaluation, the average reporting rate was 53.57%.

Conclusion

From the perspective of current guidelines, TDM in oncology is now being expanded from cytotoxic antineoplastic drugs to newer targeted treatments. Whereas, the types of antineoplastic drugs involved are still small, and there is still room for quality improvement. Furthermore, the reflected gaps warrant future studies into the exposure-response relationships and population pharmacokinetics models.

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

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

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

INTRODUCTION

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

AIM

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

METHODS

A systematic bibliographic search was performed.

RESULTS

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

CONCLUSIONS

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

Inflammatory bowel disease: recent developments

Paediatric-onset inflammatory bowel disease (IBD) is a complex and heterogenous condition. Incidence of disease in those aged <18 years has doubled over the last 25 years, with concurrent increased prevalence and no decrease in disease severity. The tools available at diagnosis for investigation have developed over the last 10 years, including better utilisation of faecal calprotectin, improved small bowel imaging and video capsule endoscopy. Alongside this, management options have increased and include biological and small molecule therapies targeting alternative pathways (such as interleukin 12/23, integrins and Janus kinase/signal transducers and activators of transcription, JAK-STAT pathways) and better understanding of therapeutic drug monitoring for more established agents, such as infliximab. Dietary manipulation remains an interesting but contentious topic.This review summarises some of the recent developments in the diagnosis, investigation and management of IBD in children and young people. IBD is increasingly recognised as a continuum of disease, with a proportion of patients presenting with classical Crohn's disease or ulcerative colitis phenotypes. Future implementation of personalisation and stratification strategies, including clinical and molecular biomarkers, implementation of predictors of response and outcome and use of additional therapies, will continue to require working within clinical networks and multiprofessional teams.

The association between drugs and repeated treatment with budesonide in patients with microscopic colitis: a retrospective observational study

Background

Smoking and the use of non-steroidal anti-inflammatory drugs (NSAIDs) acetylsalicylic acid (ASA), proton pump inhibitors (PPIs), serotonin reuptake inhibitors (SSRIs), and statins have been associated with microscopic colitis (MC).

Objectives

We investigated whether these factors were associated with repeated budesonide treatments in patients diagnosed with MC.

Design

Retrospective observational study.

Methods

All patients with a histologically verified diagnosis of MC at our clinic between the years 2006 and 2022 were identified. Baseline factors and drugs prescribed before and after diagnosis were registered. The influence of risk factors on the odds of having a prescription of oral budesonide and the odds of having a second course of budesonide was studied.

Results

Patients with MC (n = 183) with a mean age of 62.3 years [standard deviation (SD): 13.3 years] were followed for a median of 5 years (25th-75th percentile 4-10 years) after diagnosis. In all, 138 patients (75%) had at least one prescription of budesonide after diagnosis, and 90 patients (49%) had at least one clinical relapse treated with budesonide. Patients who had been prescribed NSAIDs within 1 year before clinical relapse had higher odds for clinical relapse [odds ratio (OR): 3.70, 95% confidence interval (CI): 1.06-12.9] but there was no increased risk for clinical relapse for the use of ASA (OR: 0.99, 95% CI: 0.39-2.90), PPIs (OR: 1.09, 95% CI: 0.45-2.63), SSRI (OR: 1.41, 95% CI: 0.82-2.44), or statins (OR: 0.83, 95% CI: 0.35-1.99). No association was seen between being a smoker and/or being prescribed NSAID, ASA, PPI, SSRI, and statins at baseline and the odds of having a prescription of oral budesonide within 1 year after diagnosis.

Conclusion

The risk of being prescribed a second course of budesonide is associated with receiving a prescription of NSAIDs but not with the use of ASA, PPIs, SSRIs, and statins.

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

BACKGROUND AND AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

INTRODUCTION

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

AREA COVERED

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

EXPERT OPINION

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

Effect of huankuile on colon injury in rats with ulcerative colitis by reducing TNF-α and MMP9

OBJECTIVE

To explore the mechanism of huankuile (HKL) in colon injury repair in rats with ulcerative colitis (UC).

METHODS

Fifty SPF Wistar male rats were divided randomly into a normal group, a negative control group, an HKL intervention group ('HKL group') and a 5-aminosalicylic acid intervention group ('5-ASA group'). After 14 days of intervention with corresponding drugs, pathological scores were obtained using the results of immunohistochemical staining; morphological changes were observed by hematoxylin-eosin staining, and the mRNA expression levels of tumour necrosis factor-α (TNF-α), matrix metalloproteinase 9 (MMP9) and interleukin-13 (IL-13) were detected by real-time quantitative PCR.

RESULTS

After the successful construction of the rat model, it was compared with the rats in the normal group. In the negative group, it was found that the expression of TNF-α and MMP9 was significantly increased in the colonic mucosal epithelia of the rats, the pathological score was significantly increased (P < 0.05), and the mRNA expression levels of TNF-α, MMP9 and IL-13 were increased (P < 0.05). After treatment with HKL, the colonic morphology of the rats returned to normal, the expression of TNF-α and MMP9 in the colonic mucosal epithelium of the rats returned to normal, the pathological score grade was significantly reduced (P < 0.05), and the mRNA expression levels of TNF-α, MMP9 and IL-13 were reduced; these results were largely consistent with those of the normal group, with no statistically significant difference.

CONCLUSION

HKL effectively improved the general symptoms and tissue injury in UC rats, and the therapeutic effect was better than that of 5-ASA group. Ulcerative colitis in rats increased the expression of TNF-α, MMP9 and IL-13. HKL repaired UC-induced colonic injury in rats by decreasing the expression of TNF-α, MMP9 and IL-13.

Therapeutic drug monitoring in inflammatory bowel disease: A practical approach

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

Clinical trial: Clinical and endoscopic outcomes with ustekinumab in patients with Crohn's disease: Results from the long-term extension period of STARDUST

BACKGROUND

STARDUST, a phase 3b randomised trial, compared ustekinumab therapeutic strategies in patients with Crohn's disease (CD) using early endoscopic assessment and treat-to-target (T2T) versus standard of care (SoC).

AIM

To assess the efficacy of ustekinumab extended treatment in a long-term extension (LTE) of up to 104 weeks with dosing adapted according to clinical, biomarker and endoscopy outcomes.

METHODS

Adults with moderately-to-severely active CD received intravenous ustekinumab approximating 6 mg/kg at Week 0 and subcutaneous ustekinumab 90 mg at Week 8. At Week 16, 440 ≥70-point responders were randomised to T2T or SoC and 323 entered the LTE. At Week 48, a unified, protocol-defined ustekinumab dose frequency escalation/de-escalation was applied based on achieving endoscopic remission and corticosteroid-free clinical remission. Achieving corticosteroid-free clinical remission and biomarker remission at consecutive visits determined ustekinumab dosing frequency. Dichotomous variables were analysed using non-responder imputation.

RESULTS

Among patients who entered the LTE, 7.7%, 48.6% and 43.7% received doses every 4, 8 and 12 weeks, respectively. Ustekinumab dose frequency was escalated in 23.5% and de-escalated in 19.7%. Endoscopic response and remission rates were 28.9% and 10.73% (all randomised) and 39.3% and 14.6% (patients entering the LTE), respectively, at Week 104. Clinical remissiona rates at week 104 were 50.2% (all randomised) and 68.4% (patients entering the LTE). There were no new safety signals.

CONCLUSION

STARDUST LTE is the first interventional ustekinumab efficacy study to show a favourable benefit-risk profile with preservation of clinical and endoscopic outcomes through Week 104 using flexible, algorithm-driven dose adjustment including de-escalation.

Proactive Infliximab Monitoring Improves the Rates of Transmural Remission in Crohn's Disease: A Propensity Score-Matched Analysis

BACKGROUND

Few patients can reach transmural remission in Crohn's disease (CD) with currently available therapies. Proactive optimization of infliximab (IFX) based on trough levels may potentially improve these results.

METHODS

Retrospective cohort study including consecutive CD patients starting treatment with IFX. Rates of transmural remission were compared between patients with and without therapeutic drug monitoring (target level: 5-7 µg/mL). A propensity score-matched analysis was performed to adjust for potential confounders.

RESULTS

A total of 195 CD patients were included, 57.9% receiving proactive therapeutic drug monitoring. The rates of transmural remission were higher in patients under proactive therapeutic drug monitoring (37.2% vs 18.3%; P = .004) with similar results in the propensity score-matched analysis (34.2% vs 17.1%; P = .025). In multivariate analysis, proactive therapeutic drug monitoring was independently associated with transmural remission (odds ratio, 2.95; 95% confidence interval, 1.44-6.06; P = .003).

CONCLUSIONS

Proactive optimization of IFX based on trough levels increases the rates of transmural remission in CD.

Practical Management of Biosimilar Use in Inflammatory Bowel Disease (IBD): A Global Survey and an International Delphi Consensus

As the patents for biologic originator drugs expire, biosimilars are emerging as cost-effective alternatives within healthcare systems. Addressing various challenges in the clinical management of inflammatory bowel disease (IBD) remains crucial. To shed light on physicians' current knowledge, beliefs, practical approaches, and concerns related to biosimilar adoption-whether initiating a biosimilar, transitioning from an originator to a biosimilar, or switching between biosimilars (including multiple switches and reverse switching)-a global survey was conducted. Fifteen physicians with expertise in the field of IBD from 13 countries attended a virtual international consensus meeting to develop practical guidance regarding biosimilar adoption worldwide, considering the survey results. This consensus centered on 10 key statements covering biosimilar effectiveness, safety, indications, rationale, multiple switches, therapeutic drug monitoring of biosimilars, non-medical switching, and future perspectives. Ultimately, the consensus affirmed that biosimilars are equally effective and safe when compared to originator drugs. They are considered suitable for both biologic-naïve patients and those who have previously been treated with originator drugs, with cost reduction being the primary motivation for transitioning from an originator drug to a biosimilar.

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.

The 2023 Impact of Inflammatory Bowel Disease in Canada: Treatment Landscape

The therapeutic landscape for inflammatory bowel disease (IBD) has changed considerably over the past two decades, owing to the development and widespread penetration of targeted therapies, including biologics and small molecules. While some conventional treatments continue to have an important role in the management of IBD, treatment of IBD is increasingly moving towards targeted therapies given their greater efficacy and safety in comparison to conventional agents. Early introduction of these therapies-particularly in persons with Crohn's disease-combining targeted therapies with traditional anti-metabolite immunomodulators and targeting objective markers of disease activity (in addition to symptoms), have been shown to improve health outcomes and will be increasingly adopted over time. The substantially increased costs associated with targeted therapies has led to a ballooning of healthcare expenditure to treat IBD over the past 15 years. The introduction of less expensive biosimilar anti-tumour necrosis factor therapies may bend this cost curve downwards, potentially allowing for more widespread access to these medications. Newer therapies targeting different inflammatory pathways and complementary and alternative therapies (including novel diets) will continue to shape the IBD treatment landscape. More precise use of a growing number of targeted therapies in the right individuals at the right time will help minimize the development of expensive and disabling complications, which has the potential to further reduce costs and improve outcomes.

Validation Study of Novel Point-of-Care Tests for Infliximab, Adalimumab and C-Reactive Protein in Capillary Blood and Calprotectin in Faeces in an Ambulatory Inflammatory Bowel Disease Care Setting

Background and aims: Point-of-care tests (POCT) allow instant measurement of inflammatory markers and drug concentrations. Here, we studied agreement between a novel POCT device and reference methods of measuring infliximab (IFX) and adalimumab (ADL) serum concentrations and C-reactive protein (CRP) and faecal calprotectin (FCP) concentrations of patients with inflammatory bowel disease (IBD). Methods: In this single-centre validation study, IBD patients were recruited in which IFX, ADL, CRP and/or FCP tests were required. IFX, ADL and CRP POCT were performed on capillary whole blood (CWB), obtained via finger prick. Additionally, IFX POCT was performed on serum samples. FCP POCT was performed on stool samples. Agreement between POCT and reference methods was tested using Passing-Bablok regression, intra-class correlation coefficients (ICC) and Bland-Altman plots. Results: In total, 285 patients participated. Passing-Bablok regression identified differences between the reference method and IFX CWB POCT (intercept = 1.56), IFX serum POCT (intercept = 0.71, slope = 1.10) and ADL CWB POCT (intercept = 1.44). There were also differences in the Passing-Bablok regressions of CRP (intercept = 0.81, slope = 0.78) and FCP (intercept = 51 and slope = 0.46). Bland-Altman plots demonstrated that IFX and ADL concentrations were slightly higher with the POCT and CRP and FCP were slightly lower with POCT. The ICC demonstrated almost perfect agreement with IFX CWB POCT (ICC = 0.85), IFX serum POCT (ICC = 0.96), ADL CWB POCT (ICC = 0.82) and CRP CWB POCT (ICC = 0.91) and moderate agreement with FCP POCT (ICC = 0.55). Conclusions: IFX and ADL results were slightly higher with this novel rapid and user-friendly POCT, whereas CRP and FCP results were slightly lower compared to the reference methods.

Personalized Dosing of Infliximab in Patients With Inflammatory Bowel Disease Using a Bayesian Approach: A Next Step in Therapeutic Drug Monitoring

Although biological agents have revolutionized the management of inflammatory bowel diseases (IBDs), a significant proportion of patients show primary non-response or develop secondary loss of response. Therapeutic drug monitoring (TDM) is advocated to maintain the efficacy of biologic agents. Reactive TDM can rationalize the management of primary non-response and secondary loss of response and has shown to be more cost-effective compared with empiric dose escalation. Proactive TDM is shown to increase clinical remission and the durability of the response to a biologic agent. However, the efficacy of proactive and reactive TDM has been questioned in recent studies and meta-analyses. Hence, we need a different approach to TDM, which addresses inflammatory burden, the individual patient, and disease factors. Bayesian approaches, which use population pharmacokinetic models, enable clinicians to make better use of TDM for dose adjustment. With rapid improvement in computer technology, these Bayesian model-based software packages are now available for clinical use. Bayesian dashboard systems allow clinicians to apply model-based dosing to understand an individual's pharmacokinetics and achieve a target serum drug concentration. The model is updated using previously measured drug concentrations and relevant patient factors, such as body weight, C-reactive protein, and serum albumin concentration, to maintain effective drug concentrations in the serum. Initial studies have found utility for the Bayesian approach in induction and maintenance, in adult and pediatric patients, in clinical trials, and in real-life situations for patients with IBD treated with infliximab. This needs confirmation in larger studies. This article reviews the Bayesian approach to therapeutic drug monitoring in IBD.

Recent Advances in the Optimization of Anti-TNF Treatment in Patients with Inflammatory Bowel Disease

Despite the evolution in inflammatory bowel disease (IBD) management during the last 20 years owing to the advent of new advanced therapies, anti-TNF agents still remain the cornerstone of therapy for both Crohn's disease and ulcerative colitis. However, this does not only secure favorable outcomes for patients considering the progressive disease character and the high likelihood of primary or secondary loss of response. Therefore, trying to reach a better treatment approach and maximize the benefits anti-TNF agents offer, optimization strategies should be examined. It has been indicated that optimizing treatment with anti-TNF enhances drug efficacy and has been associated with improved disease outcomes and a complication-free disease course. From this perspective, we aim to provide an overview of currently available data and recent advances in the practices of anti-TNF treatment optimization. Special focus has been given to the role of therapeutic drug monitoring (TDM), as well as the utility of combining anti-TNF with an immunomodulator and the treat-to-target approach.

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.