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

Tumour necrosis factor inhibitors in Ulcerative colitis: real-world data on Therapeutic drug monitoring and evaluation of current treatment targets (STRIDE II)

BACKGROUND

The benefit of therapeutic drug monitoring (TDM) and implementation of recommendations from the Selection of Therapeutic Targets in Inflammatory Bowel Disease (IBD, STRIDE) are discussed in the IBD community. We report real-world data in ulcerative colitis patients receiving first-line tumour necrosis factor inhibitor (TNFi) treatment followed by TDM, and assess how implementation of the STRIDE II recommendations might affect clinical practice.

METHODS

Adult, biologically naïve UC patients starting TNFi between 2014 and 2021 at Oslo University Hospital were included in a medical chart review study, and data were collected at three and twelve months after the start of treatment. Target serum drug levels were defined as ≥7.5 mg/L for adalimumab and ≥5 mg/L for infliximab.

RESULTS

Of 141 included patients, 36% were in clinical and biochemical (combined) remission after twelve months. Among 102 treatment persistent patients, 54% were in combined remission after twelve months. Target drug level at three months was associated with clinical remission at twelve months (OR = 2.97, 95% CI [1.24-7.12]) and biochemical remission at twelve months (OR = 2.64, 95% CI [1.03-6.77]). In total, 56% of recorded dosage adjustments were related only to serum drug levels.

CONCLUSIONS

Combined remission rates at twelve months for treatment persistent patients suggest that 46% should have been considered for a change of treatment according to the STRIDE II recommendations. A majority of dosage adjustments were made proactively. Target drug level at three months was associated with remission at twelve months and supports the use of proactive TDM.

A simple automated assay format for measuring multiple immune checkpoint inhibitors

Immune checkpoint inhibitors (ICIs) have improved survival rates in oncology, but there is a rising concern for immune-related adverse health outcomes. Monitoring drug serum concentration would enable tailored dosing, however this strategy has not yet been evaluated for ICIs. Fully automated analyte capture assays with time-resolved fluorometry using protein A as tracer, were developed for three different ICIs; the cytotoxic T lymphocyte Antigen-4 (CTLA4) inhibitor ipilimumab (Yervoy; Bristol-Myers Squibb) and the Programmed Death-1 (PD-1) inhibitors nivolumab (Opdivo; Bristol-Myers Squibb) and pembrolizumab (Keytruda; Merck). Drug trough levels were measured in serum samples from ICI-treated patients. Measuring ranges were 1-100 mg/L for all three drugs. Automation allowed for 110 samples to be analyzed in < 4 h. Median drug trough-levels after 5-7 weeks of treatment were 20 (range <1.0-45) mg/L for ipilimumab (n = 113), 60 (range 14-75) mg/L) for nivolumab (n = 21) and 19 (range 7.4-39) mg/L for pembrolizumab (n = 20). Routine drug concentration monitoring for ipilimumab, nivolumab and pembrolizumab is feasible using fully automated analyte capture assays constructed with commercially available reagents. The large drug serum concentration ranges in samples from real-world patients, should be further investigated to assess the clinical relevance of ICI concentration monitoring.

Therapeutic Drug Monitoring of Biologics: Current Practice, Challenges and Opportunities - a Workshop Report

Therapeutic drug monitoring (TDM) for dose modification of biologics has the potential to improve patient outcomes. The US Food and Drug Administration (FDA) and the American Association of Pharmaceutical Scientists (AAPS) hosted the first US-based public workshop on TDM of biologics with contributions from a broad array of interested parties including healthcare providers, clinical pharmacologists, test developers, bioanalysis and immunogenicity scientists, health economics and outcomes research (HEOR) experts and regulators. The key insight was that despite a body of evidence to support TDM in certain therapeutic areas, there remain substantial challenges to widespread clinical implementation. There is a lack of consensus regarding the integration of TDM in clinical guidelines, and a lack of consensus on the cost-effectiveness of TDM; both factors contribute to the difficulty that healthcare providers face in obtaining reimbursement for TDM (both coverage of testing itself, and coverage of potential dosing modifications). The HEOR experts outlined alternative routes to obtaining reimbursement and suggested advocating for changes in coverage policies to promote TDM use in the clinic. Reaching alignment across policy makers, patients and advocacy groups, payers, and healthcare providers, on specific treatment settings where TDM will be clearly beneficial, was identified as an important step to advancing TDM implementation for the benefit of patients.

Assessing early therapeutic drug monitoring of adalimumab as a predictor of treatment efficacy and immunogenicity in rheumatic diseases: "early therapeutic drug monitoring of adalimumab"

INTRODUCTION

Therapeutic drug monitoring (TDM) in inflammatory rheumatic diseases (RMDs) is gaining interest. However, there are unresolved questions about the best practices for implementing TDM effectively in clinical settings.

OBJECTIVE

The primary objective of this study was to evaluate whether early TDM of adalimumab predicts drug survival at 52 weeks in patients with RMDs. The secondary objective was to identify factors associated with pharmacokinetic failure and treatment discontinuation.

METHODS

A retrospective cohort study included patients aged ≥ 18 years with RMDs who initiated adalimumab therapy. Early TDM was performed within the first 26 weeks, and adalimumab trough levels (ATL) and anti-drug antibodies were measured. Drug survival was assessed at 52 weeks and defined as the time from adalimumab initiation to discontinuation for any reason. Multivariate analyses were conducted to identify factors influencing outcomes.

RESULTS

The study included 194 patients, of whom 56.7% exhibited ATL below the therapeutic range during the first 26 weeks. In the multivariate analysis, subtherapeutic concentrations were significantly associated with higher weight (OR = 1.02; p = 0.040) and ankylosing spondylitis diagnosis (OR = 3.68; p < 0.001). At 52 weeks, 43.8% of patients had discontinued adalimumab. Low ATL (< 1 µg/mL) was strongly associated with treatment discontinuation (OR = 7.31; p < 0.001), while concomitant methotrexate reduced this risk (OR = 0.46; p = 0.026).

CONCLUSIONS

Early TDM of adalimumab predicts drug persistence and underscores its clinical relevance as a proactive tool to guide personalized treatment and reduce the risk of treatment failure. These findings highlight the importance of incorporating TDM into routine practice to optimize therapeutic outcomes. Key Points • Early TDM of adalimumab in rheumatic diseases shows that low drug exposure predicts reduced drug survival at 52 weeks. • Approximately half of the patients exhibit low adalimumab exposure with the standard dose (40 mg every other week). • Body weight and methotrexate use significantly impact adalimumab levels. • Immunogenicity, found in 14.4% of patients with low ADL levels, underscores the need for early ADA detection to prevent non-response and discontinuation.

Laboratory Tests in Inflammatory Bowel Disease: An Evidence-Based Approach to Daily Practice

Inflammatory bowel diseases (IBDs) comprise a group of chronic gastrointestinal disorders characterized by periods of relapse and remission. The mainstay of treatment is medical, involving medications such as steroids, immune modulators, monoclonal antibodies (categorized as biologics), and small molecules. These medications can provide profound therapeutic benefits, but they can also cause severe and irreversible toxicities. Clinicians may utilize laboratory tests in the diagnosis and management of IBD including assessment of disease activity, monitoring medication response or toxicity, surveillance of infectious complications, and detection of nutritional deficiencies. Routine use of laboratory tests may help clinicians avoid reactivation of life-threatening infections such as tuberculosis or hepatitis B virus upon initiation of immune suppressive therapy. They can also be used to detect vitamin deficiencies such as B12 deficiency, which has the potential to cause irreversible neurologic damage. While some laboratory tests constitute established practices, the utility of newer tests such therapeutic drug monitoring (TDM) in the era of biologics is an evolving topic. Although clinical assessment with imaging, endoscopic, and histopathological examination is standard practice, laboratory tests serve as valuable adjuncts. We aim to explore the broad range of laboratory tests available to clinicians and to summarize their application in the current management of IBD in daily clinical practice, with special attention to updates in therapeutic drug monitoring.

Anti-tumor Necrosis Factor Drug Concentration Is Not Associated with Disease Outcomes in Pouchitis: A Retrospective, International Study

BACKGROUND

Therapeutic drug monitoring is important for optimizing anti-tumor necrosis factor-α (TNF-α) therapy in inflammatory bowel disease. However, the exposure-response relationship has never been assessed in pouchitis.

AIMS

To explore associations between anti-TNF-α drug concentration and pouchitis disease activity in patients with a background of ulcerative colitis.

METHODS

A retrospective, multicenter, cross-sectional study was conducted in adult patients with pouchitis requiring anti-TNF-α treatment. Rates of clinical and endoscopic remission were calculated, and drug concentrations during maintenance therapy were compared between remission and non-remission cohorts.

RESULTS

Sixty-three patients were included: median age, 48 years (IQR 36-59) and median time since pouchitis diagnosis, 7 years (IQR 2-13). Patients received infliximab, n = 27 (43%), adalimumab, n = 29 (46%), or both n = 7 (11%). Thirty-two (51%) patients received concomitant immunomodulation. Median infliximab trough concentrations (mg/ml) were similar between patients in clinical remission (n = 21) vs non-remission (n = 11), 5.3 vs. 4.4, p = 0.73. For adalimumab, median drug concentrations did not significantly differ between remission/non-remission groups based on clinical (n = 18/18), 11.4 vs 7.6, p = 0.32, or endoscopic assessment, (n = 7/29), 9.0 vs. 7.8, p = 0.78. Four patients had positive anti-drug antibodies with undetectable drug concentration.

CONCLUSION

In a cohort of patients with pouchitis, higher anti-TNF-α drug concentrations were not associated with more clinical or endoscopic remission.

Vedolizumab serum trough concentrations with and without thiopurines in ulcerative colitis: The prospective VIEWS pharmacokinetics study

BACKGROUND

Ulcerative colitis (UC) is a chronic inflammatory condition requiring continuous treatment and monitoring. There is limited pharmacokinetic data on vedolizumab during maintenance therapy and the effect of thiopurines on vedolizumab trough concentrations is unknown.

AIM

To investigate the exposure-response relationship of vedolizumab and the impact of thiopurine withdrawal in UC patients who have achieved sustained clinical and endoscopic remission during maintenance therapy.

METHODS

This is a post-hoc analysis of prospective randomized clinical trial (VIEWS) involving UC patients across 8 centers in Australia from 2018 to 2022. Patients in clinical and endoscopic remission were randomized to continue or withdraw thiopurine while receiving vedolizumab. We evaluated vedolizumab serum trough concentrations, presence of anti-vedolizumab antibodies, and clinical outcomes over 48 weeks to assess exposure-response association and impact of thiopurine withdrawal.

RESULTS

There were 62 UC participants with mean age of 43.4 years and 42% were females. All participants received vedolizumab as maintenance therapy with 67.7% withdrew thiopurine. Vedolizumab serum trough concentrations remained stable over 48 weeks regardless of thiopurine use, with no anti-vedolizumab antibodies detected. Patients with clinical remission had higher trough concentrations at week 48. In quartile analysis, a threshold of > 11.3 μg/mL was associated with sustained clinical remission, showing a sensitivity of 82.4%, specificity of 60.0%, and an area of receiver operating characteristic of 0.71 (95%CI: 0.49-0.93). Patients discontinuing thiopurine required higher vedolizumab concentrations for achieving remission.

CONCLUSION

A positive exposure-response relationship between vedolizumab trough concentrations and UC outcomes suggests that monitoring drug levels may be beneficial. While thiopurine did not influence vedolizumab levels, its withdrawal may necessitate higher vedolizumab trough concentrations to maintain remission.

Immunogenicity of Therapeutic Antibodies Used for Inflammatory Bowel Disease: Treatment and Clinical Considerations

The introduction of tumor necrosis factor inhibitors has led to a paradigm shift in the management of inflammatory bowel disease (IBD). The subsequent introduction of both anti-integrins and cytokine blockers has since expanded the biologic armamentarium. However, immunogenicity, defined as the production of anti-drug antibodies (ADAs) to the prescribed biopharmaceutical, means a significant fraction of patients exposed to biologic agents will experience a secondary loss of response to one or more of the drugs. In clinical settings, immunogenicity may be caused by several factors, both patient related (e.g., underlying chronic disease, systemic immune burden, including previous biologic therapy failure, and [epi]genetic background) and treatment related (e.g., dose and administration regimens, drug physical structure, photostability, temperature, and agitation). Here, we outline these elements in detail to enhance biopharmaceutical delivery and therapy for patients with IBD. Moreover, concurrent immunomodulator medication may reduce the risks of ADA generation, especially when using the chimeric drug infliximab. Summarizing the latest developments and knowledge in the field, this review aims to provide strategies to prevent ADA production and information on managing non-responsiveness or loss of response to biologics. Better understanding of the molecular mechanisms underlying the formation of ADAs and the critical factors influencing the immunogenicity of biopharmaceuticals may lead to improved health outcomes in the IBD community that may benefit both the individual patient and society through lower healthcare expenses.

Model-informed precision dosing in inflammatory bowel diseases

Therapeutic drug monitoring (TDM) for biologic therapies in inflammatory bowel disease (IBD) primarily aims to optimize dosing. However, several unmet needs remain. These include the identification of optimal drug concentrations, accounting for variability in pharmacokinetics (PK) and pharmacodynamics (PD), and the frequent delays between sampling and clinical decision-making. Recent technical advances, such as population PK/PD modeling and model-informed precision dosing (MIPD) tools developed from such models, as well as point-of-care (POC) and self-sampling assays and novel software programs, offer potential solutions. Successful implementation of these innovations may help to establish MIPD for patients with IBD. This would enable personalized dosing, advancing a one-size-fits-all approach to TDM that currently is inadequate to fulfill the needs for every patient with IBD.

Adalimumab Autoantibodies in Uveitis Patients: Do We Need Routine Drug Monitoring?

BACKGROUND

Adalimumab, an anti-TNF-α biologic agent, has emerged as a principal treatment option for patients with non-infectious uveitis. The influence of adalimumab anti-drug antibodies (AAA) on the efficacy of adalimumab therapy is not yet fully understood. We aim to understand their clinical implications in the context of therapeutic drug monitoring and the factors contributing to the formation of these antibodies.

METHODS

We conducted a retrospective analysis of 114 patients with non-infectious uveitis who developed AAA while undergoing adalimumab therapy.

RESULTS

Among the 114 AAA-positive uveitis patients, a significant correlation was observed between AAA levels and reduced adalimumab serum levels (r = -0.58, p < 0.001). The mean time to AAA detection was 2.1 years (range 0.1-11.9 years), with 45.6% of cases identified through routine testing. If AAA levels were initially low, subsequent measurements for AAA were more likely to become negative during treatment (r = 0.63, p < 0.001). Higher AAA concentrations were associated with a shorter time to detection (r = -0.27, p = 0.01) and younger age (r = -0.21, p = 0.03). There was a trend, though no significant influence, of concomitant immunosuppression with prednisolone ≤ 7.5 mg or methotrexate on antibody formation (p = 0.18). No significant difference was observed in AAA levels between uveitis subtypes.

CONCLUSIONS

Higher AAA concentrations are associated with lower adalimumab serum levels in uveitis patients. Routine clinical testing is essential for optimal therapeutic drug monitoring to prevent early loss of effectiveness.

The pathogenesis and targeted therapies of intervertebral disc degeneration induced by cartilage endplate inflammation

Intervertebral disc degeneration (IVDD) is the leading cause of low back pain, where degeneration and death of nucleus pulposus cells within the intervertebral disc (IVD) can be obviously revealed. This degeneration can result in an imbalance in the extracellular matrix due to the loss of proteoglycans and water content, which can further lead to catabolic and anabolic dysfunction of the IVD. Recently, the dysfunction of cartilage endplate (CEP) during aging has drawn large attention due to its essential functions in contributing nutrient exchange and maintaining IVD homeostasis. Furthermore, the inflammation and disturbed homeostasis of CEP not only accelerate the degradation of nucleus pulposus extracellular matrix, but also exacerbate IVDD by causing nucleus pulposus cell death through other pathological factors. Here in this review, we summarized the possible pathological factors and the underlying mechanisms of the CEP inflammation-induced IVDD, including exosomes degeneration, CEP calcification, ferroptosis, mechanical changes, and cell senescence. Besides, changes of miRNAs, pain-related neural reflex arc and pathways associated with CEP inflammation-induced IVDD are also reviewed. In addition, new strategies specifically designed for CEP inflammation-induced IVDD are also discussed in the last section. We hope this paper can not only offer some new insights for advancing novel strategies for treating IVDD, but also serve as a valuable reference for researchers in this field.

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

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

Autoimmune diseases and cardiovascular risk: Mendelian randomization analysis for the impact of 19 autoimmune diseases on 14 cardiovascular conditions

Backgroud

Autoimmune diseases (AIDs) have been associated with various cardiovascular diseases (CVDs) in observational data. However, the causality of these associations remains uncertain. Therefore, a systematic assessment of the impact of AIDS on cardiovascular risk is required.

Results

We assessed the impact of 19 common AIDs on 14 CVDs using bidirectional Mendelian randomization (MR). Celiac disease (odds ratio [OR] = 2.949, 95 % confidence interval [CI]: 1.111-7.827, P = 0.030) and type 1 diabetes mellitus (T1DM) (OR = 1.044, 95 % CI: 1.021-1.068, P = 1.82e-4) were associated with an increased risk of peripheral arterial disease (PAD). Additionally, celiac disease was linked to an increased risk of arrhythmia (OR = 1.008, 95 % CI: 1.002-1.013, P = 0.004), multiple sclerosis to venous thromboembolism (OR = 1.001, 95 % CI: 1.000-1.001, P = 0.010), and psoriasis to heart failure (OR = 1.048, 95 % CI: 1.021-1.077, P = 0.001). Sensitivity analyses were conducted to enhance the robustness of these findings. Predominantly, immune response and inflammation-related pathways were enriched in the aforementioned associations. Mediation analysis identified human leukocyte antigen-DR positive myeloid dendritic cells as partially mediating the effect of T1DM on PAD, with a mediated proportion of 16.61 % (P = 0.028). Potential therapeutic agents, such as tumor necrosis factor-alpha inhibitors and interferon, may have efficacy in treating AID-related CVDs.

Conclusions

This study presents genetic evidence of certain AIDs impacting specific CVDs and identifies potential mediators and drugs.

Therapeutic serum level for adalimumab in rheumatoid arthritis: explorative analyses of data from a randomised phase III trial

OBJECTIVES

The objectives of this study are to identify a therapeutic serum level for adalimumab associated with remission and low disease activity in patients with rheumatoid arthritis.

METHODS

Associations between serum adalimumab trough levels and disease activity were examined using longitudinal data from a 48-week randomised phase III trial including patients with tumour necrosis factor inhibitor-naïve rheumatoid arthritis with active disease starting adalimumab treatment. Disease activity was classified according to 28-joint Disease Activity Score (DAS28)-erythrocyte sedimentation rate and C reactive protein (CRP) levels.

RESULTS

Adalimumab trough levels were recorded longitudinally for 336, 330 and 302 patients at weeks 12, 24 and 48, respectively. All patients received concomitant methotrexate. Median adalimumab trough levels were 6.4 mg/L (IQR 3.4-9.5) at week 12, 7.5 mg/L (IQR 3.5-10.9) at week 24 and 7.6 mg/L (IQR 3.6-12.0) at week 48. In serial serum samples from weeks 12, 24 and 48, trough levels ≥3.9 mg/L were associated with DAS28 remission (OR 3.88 (95% CI 1.80, 8.38), p<0.001) and lower CRP levels (p<0.001). Week 12 trough levels ≥3.5 mg/L were associated with DAS28 low disease activity at week 24 (OR 2.62 (1.50, 4.56), p<0.001) and remission at week 48 (OR 1.99 (1.02, 3.88), p=0.04), as well as lower CRP levels at both time points (p<0.001).

CONCLUSION

Adalimumab trough levels above 4.0 mg/L were associated with remission/low disease activity throughout the first year of adalimumab therapy and can be considered a lower target level for therapeutic drug monitoring of adalimumab therapy.

A guideline on biomarkers in the diagnosis and evaluation in axial spondyloarthritis

Objective

To develop a guideline for selecting biomarkers in the diagnosis and assessment in patients with axial spondyloarthritis (axSpA).

Method

A joint effort was carried out by the core team, the literature review team and the multidisciplinary voting panel to formulate recommendations regarding biomarkers in axSpA, using an evidence-based and consensus-based strategy. Certainty of evidence and strength of recommendation were determined, and levels of agreement within the voting panel were calculated.

Results

A total of 20 recommendations were formulated in this guideline, with levels of agreement ranging from 6.48 to 9.71. The two strong recommendations, HLA-B27 testing in patients suspected of axSpA and regular-interval monitoring of CRP/ESR represent the status quo of axSpA evaluation, while the 13 conditional recommendations represent the promising biomarkers with clinical utility in diagnosis, disease activity assessment, prediction of radiographic progression and therapeutic responses. This guideline does not dictate clinical choices of tests on axSpA, and decisions should be made based on comprehensive consideration of costs, accessibility, patients' values and willingness as well as the objective of testing in the local context.

Conclusion

This guideline addresses the interpretation of the clinical significance of biomarkers in axSpA, and the biomarkers endorsed in this guideline composed a clinical toolkit for healthcare professionals to choose from.

Proactive therapeutic drug monitoring of biologic drugs in adult patients with inflammatory bowel disease, inflammatory arthritis, or psoriasis: a clinical practice guideline

CLINICAL QUESTION

In adult patients with inflammatory bowel disease, inflammatory arthritis (rheumatoid arthritis, spondyloarthritis, psoriatic arthritis), or psoriasis taking biologic drugs, does proactive therapeutic drug monitoring (TDM) improve outcomes as compared with standard care?

CONTEXT AND CURRENT PRACTICE

Standard care for immune mediated inflammatory diseases includes prescribing biologic drugs at pre-determined doses. Dosing may be adjusted reactively, for example with increased disease activity. In proactive TDM, serum drug levels and anti-drug antibodies are measured irrespective of disease activity, and the drug dosing is adjusted to achieve target serum drug levels, usually within pre-specified therapeutic ranges. The role of proactive TDM in clinical practice remains unclear, with conflicting guideline recommendations and emerging evidence from randomised controlled trials.

THE EVIDENCE

Linked systematic review and pairwise meta-analysis which identified 10 trials including 2383 participants. Inflammatory bowel disease, inflammatory arthritis, and psoriasis were grouped together as best current research evidence on proactive TDM did not suggest heterogeneity of effects on outcomes of interest. Proactive TDM of intravenous infliximab during maintenance treatment may increase the proportion of patients who experience sustained disease control or sustained remission without considerable additional harm. For adalimumab, it remains unclear if proactive TDM during maintenance treatment has an effect on sustained disease control or sustained remission. At induction (start) of treatment, proactive TDM of intravenous infliximab may have little or no effect on achieving remission. No eligible trial evidence was available for proactive TDM of adalimumab at induction (start) of treatment. No eligible trial evidence was available for proactive TDM of other biologic drugs in maintenance or at induction (start) of treatment.

RECOMMENDATIONS

The guideline panel issued the following recommendations for patients with inflammatory bowel disease, inflammatory arthritis, or psoriasis:1. A weak recommendation in favour of proactive TDM for intravenous infliximab during maintenance treatment2. A weak recommendation against proactive TDM for adalimumab and other biologic drugs during maintenance treatment3. A weak recommendation against proactive TDM for intravenous infliximab, adalimumab, and other biologic drugs during induction (start) of treatment.

UNDERSTANDING THE RECOMMENDATIONS

When considering proactive TDM, clinicians and patients should engage in shared decision making to ensure patients make choices that reflect their values and preferences. The availability of laboratory assays to implement proactive TDM should also be considered. Further research is warranted and may alter recommendations in the future.

HOW THIS GUIDELINE WAS CREATED

An international panel including patient partners, clinicians, and methodologists produced these recommendations based on a linked systematic review and pairwise meta-analysis which identified 10 trials including 2383 participants. The panel followed standards for trustworthy guidelines and used the GRADE approach, explicitly considering the balance of benefits and harms and burdens of treatment from an individual patient perspective.

Proactive therapeutic drug monitoring of biologic drugs in patients with inflammatory bowel disease, inflammatory arthritis, and psoriasis: systematic review and meta-analysis

Objective

To address the efficacy and safety of proactive therapeutic drug monitoring of biologic drugs for patients with inflammatory bowel disease, inflammatory arthritis, and psoriasis.

Design

Systematic review and meta-analysis.

Data sources

Medline, Embase, Central, and CINAHL, from database inception to 23 May 2024.

Eligibility criteria for selecting studies

Trials including people with inflammatory bowel disease, inflammatory arthritis, and psoriasis were selected. Selected trials also randomly assigned people to either proactive therapeutic drug monitoring of tumour necrosis factor-alpha inhibitors or other biologic drugs in the intervention group, and to either no therapeutic drug monitoring or standard care in the control group. Reviewers worked independently and in duplicate to screen search records and collect data from eligible trials. For each outcome, a frequentist, pairwise, random effects meta-analysis was done and the certainty of evidence was assessed using GRADE (grading of recommendations, assessment, development, and evaluations).

Results

Of 10 eligible trials identified, reporting on 2383 patients, two investigated induction with infliximab (533 patients), four assessed maintenance with infliximab (901 patients), and three assessed maintenance with adalimumab (710 patients). One trial was of maintenance with infliximab, adalimumab, and etanercept (239 patients). For patients who had induction with infliximab, the effects of proactive therapeutic drug monitoring on remission and adverse events were uncertain. Low certainty evidence suggested that proactive therapeutic drug monitoring may have little or no effect on disease activity, physical function, mental health, and quality of life. For patients who had maintenance with infliximab, low certainty evidence suggested that proactive therapeutic drug monitoring may increase the proportion of patients who had sustained disease control or remission (relative risk 1.26 (95% confidence interval (CI) 1.14 to 1.40), absolute risk difference of 146 more per 1000 patients treated for one year (95% CI 78 to 224). Additionally, this treatment and monitoring may reduce disease worsening, and may have little or no effect on disease activity, physical function, mental health, and quality of life. The effects of proactive therapeutic drug monitoring of infliximab on adverse events and formation of anti-drug antibodies were uncertain. For patients who had maintenance with adalimumab, the effects of proactive therapeutic drug monitoring were uncertain.

Conclusion

Proactive therapeutic drug monitoring of infliximab during maintenance may help patients to have sustained disease control or remission. No compelling evidence supported the effectiveness of proactive therapeutic drug monitoring of infliximab during induction or proactive therapeutic drug monitoring of adalimumab during maintenance.

Systematic review registration

https://osf.io/x4m28/.

Improved high-performance liquid chromatography tandem mass spectrometry method for quantification of infliximab in pediatric plasma and its application in therapeutic drug monitoring

RATIONALE

The application of infliximab (IFX) to immune-mediated disease is limited by the significant individual variability and associated clinical nonresponse, emphasizing the importance of therapeutic drug monitoring (TDM). Because of the cross-reactivity, limited linear range, and high costs, the clinical application of the previous reported methods was limited. Here, an improved high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method was developed to address the issues.

METHODS

This study developed an improved bioanalytical HPLC-MS/MS method coupling nanosurface and molecular-orientation limited proteolysis technology. The commercially available compound P14R was selected as the internal standard. This method was developed with fewer volume of reagents and was thoroughly validated. The validated method was applied to TDM in pediatric inflammatory bowel disease (IBD).

RESULTS

Chromatography was performed using a Shim-pack GISS-HP C18 metal-free column (3 μm, 2.1 × 100 mm) with a gradient elution of 0.1% formic acid in water and acetonitrile at 0.4 mL/min. Detection and quantitation were performed using electrospray ionization (ESI) and multiple reaction monitoring in the positive ion mode. The method was validated to demonstrate its selectivity, linearity, accuracy, precision, recovery, matrix effect, and stability. The method exhibited a linear dynamic range of 0.3-100 μg/mL, with intra- and inter-day precision and relative errors below 15%. The recovery and matrix effect were measured as 87.28%-89.72% and 41.98%-67.17%, respectively, which were effectively compensated by the internal standard. A total of 32 samples collected from 24 pediatric patients with IBD were analyzed using the validated method, and only 46.9% achieved the reported targeted trough level.

CONCLUSION

This study developed an improved HPLC-MS/MS method for the quantitative determination of IFX concentration in human plasma. The accurate, reliable, and cost-effective method was validated and utilized in the analysis of clinical samples. The results confirmed the importance of TDM on IFX and the clinical application prospects of the improved method.

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.

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

BACKGROUND AND AIMS

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

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

Evaluation of intra- and inter-individual variations in plasma belimumab concentrations in adult patients with systemic lupus erythematosus

In this study, plasma belimumab concentrations were measured over the course of treatment in systemic lupus erythematosus (SLE) patients on belimumab therapy, and intra- and interindividual variations in plasma belimumab concentration were evaluated. A single-center prospective study was conducted at Oita University Hospital to evaluate trough plasma concentrations over the course of treatment in 13 SLE patients treated with intravenous belimumab. Plasma belimumab concentrations were measured by a validated ultra-high performance liquid chromatography with tandem mass spectrometry method. The median age of the patients was 40 (interquartile range: 35-51) years and the median weight was 51.8 (47.0-58.1) kg. A mean of 9.4 (range: 1-13) blood samples was collected per patient at routine visits. The mean (± SD) plasma belimumab concentration was 33.4 ± 11.9 μg/mL in the patient with the lowest concentration and 170.0 ± 16.6 μg/mL in the patient with the highest concentration, indicating a 5-fold difference between patients. On the other hand, the within-patient coefficient of variation ranged from 7.1% to 35.7%, showing no large variations. No significant correlation was observed between plasma belimumab concentration and belimumab dose (mg/kg) (Spearman's rank correlation coefficient = 0.22, p = .54). Examinations of trough plasma belimumab concentrations over the course of treatment in patients with SLE showed small intraindividual variation but large interindividual variation. Plasma belimumab trough concentration varied widely among patients administered the approved dose.

Evaluating the Performance of Two Automated Anti-drug Antibodies Assays for Infliximab and Adalimumab Without Acid Dissociation

Monitoring anti-drug antibodies (ADAs) to infliximab and adalimumab is critical to treatment management in various autoimmune disorders. The growing need for proactive therapeutic monitoring further requires the detection of ADAs in the presence of measurable concentrations of infliximab or adalimumab. To provide robust analytical assays for clinical application, we evaluated two automated immunoassays developed using ImmunoCAP™ technology and based on the bridging format to measure serum ADAs to infliximab and adalimumab respectively. Without an acid-dissociation step, these research prototype assays can detect a positive control monoclonal ADA towards infliximab and adalimumab, ranging from < 25 ng/ml to 10,000 ng/mL. Both assays exhibit imprecision less than 20% at different ADA titer levels and can distinguish ADAs towards different drug targets. In method comparison using authentic patient samples, the quantitative results of the ADA assays are not directly comparable to two existing clinical immunoassays for ADAs (correlation coefficient rs = 0.673 for infliximab ADAs; rs = 0.510 for adalimumab ADAs), presumably due to the lack of commutable ADA standards and the polyclonal nature of ADAs. Nevertheless, there is qualitative agreement between the methods when evaluating putative positive and negative patient samples (overall agreement 0.83 for infliximab ADAs; 0.76 for adalimumab ADAs). Biotin and high levels of rheumatoid factors may interfere with the performance of the automated assays due to competitive binding with the biotinylated drug and non-specific formation of bridging complexes. The two ImmunoCAP assays can provide new analytical methods for proactive therapeutic monitoring of adalimumab and infliximab.

High-throughput, low-cost quantification of 11 therapeutic antibodies using caprylic acid precipitation and LC-MS/MS

BACKGROUND

Therapeutic drug monitoring of treatment with therapeutic antibodies is hampered by the application of a wide range of different methods in the quantification of serum levels. LC-MS based methods could significantly improve comparability of results from different laboratories, but such methods are often considered complicated and costly. We developed a method for LC-MS/MS based quantification of 11 therapeutic antibodies concomitantly measured in a single run, with emphasis on simplicity in sample preparation and low cost.

RESULTS

After a single-step sample purification using caprylic acid precipitation to remove interfering proteins, the sample underwent proteolysis followed by LC-MS/MS analysis. Infliximab is used as internal standard for sample preparation while isotope-labeled signature peptides identified for each analyte are internal standards for the LC-MS/MS normalization. The method was validated according to recognized guidelines, and pipetting steps can be performed by automated liquid handling systems. The total precision of the method ranged between 2.7 and 7.3 % (5.1 % average) across the quantification range of 4-256 μg/ml for all 11 drugs, with an average accuracy of 96.3 %. Matrix effects were xamined in 55 individual patient samples instead of the recommended 6, and 147 individual patient samples were screened for interfering compounds.

SIGNIFICANCE AND NOVELTY

Our method for simultaneous quantification of 11 t-mAb in human serum allows an unprecedented integration of robustness, speed and reduced complexity, which could pave the way for uniform use in research projects and clinical settings alike. In addition, the first LC-MS protocol for signature peptide-based quantification of durvalumab is described. This high throughput method can be readily adapted to a drug panel of choice.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Tocilizumab Dose Tapering Based on a Model-Based Algorithm is Feasible in Clinical Practice: A Short Communication

BACKGROUND

Tocilizumab in the treatment of rheumatoid arthritis (RA) is a potential candidate for concentration-guided tapering because the standard dose of tocilizumab results in a wide range of serum concentrations, usually above the presumed therapeutic window, and an exposure-response relationship has been described. However, no clinical trials have been published to date on this subject. Therefore, the objective of this study was to assess the feasibility of the tapering of intravenous (iv) tocilizumab with the use of a pharmacokinetic model-based algorithm in RA patients.

METHODS

A randomized controlled trial with a double-blind design and follow-up of 24 weeks was conducted. RA patients who received the standard of tocilizumab for at least the past 24 weeks, which is 8 mg/kg every 4 weeks, were included. Patients with a tocilizumab serum concentration above 5 mg/L at trough were randomized between concentration-guided dose tapering, referred to as therapeutic drug monitoring (TDM), or the standard 8 mg/kg dose. In the TDM group, the tocilizumab dose was tapered with a recently published model-based algorithm to achieve a target concentration of 4-6 mg/L after 20 weeks of dose tapering.

RESULTS

Twelve RA patients were included and 10 were randomized between the TDM and standard dose group. The study was feasible regarding the predefined feasibility criteria and patients had a positive attitude toward therapeutic drug monitoring. In the TDM group, the tocilizumab trough concentration within patients decreased on average by 24.5 ± 18.3 mg/L compared with a decrease of 2.8 ± 12 mg/L in the standard dose group. None of the patients in the TDM group reached the drug range of 4-6 mg/L. Instead, tocilizumab concentrations of 1.6 and 1.5 mg/L were found for the 2 patients who completed follow-up on the tapered dose. No differences in RA disease activity were observed between the 2 study groups.

CONCLUSIONS

This study was the first to show that it is feasible to apply a dose-reduction algorithm based on a pharmacokinetic model in clinical practice. However, the current algorithm needs to be optimized before it can be applied on a larger scale.

Challenges in IBD Research 2024: Pragmatic Clinical Research

Pragmatic clinical research is 1 of the 5 focus areas of the Challenges in IBD Research 2024, a multidisciplinary effort by scientists, clinicians, patients, and funders to identify priorities for patient-centric research. This summary provides a comprehensive overview of current gaps in inflammatory bowel disease (IBD) clinical research and actionable approaches to address them. This review is focused on identifying research that is needed to achieve the best outcomes for patients in clinical practice. Research gaps include understanding the needs of understudied patient groups and addressing barriers to care so all patients receive optimal care, validating and using biomarkers to enable early diagnosis and result in better outcomes for adults and children with IBD, and determining the optimal sequencing of treatments (medical, surgical, adjunct) in children and adults. Inclusive pragmatic research is needed to address these gaps and lead to improvements in patient care and outcomes for all populations of patients with IBD.

Efficacy and safety of pharmacological treatment of psoriatic arthritis: a systematic literature research informing the 2023 update of the EULAR recommendations for the management of psoriatic arthritis

OBJECTIVES

To obtain an overview of recent evidence on efficacy and safety of pharmacological treatments in psoriatic arthritis (PsA).

METHODS

This systematic literature research (SLR) investigated the efficacy and safety of conventional synthetic (cs), biological (b) and targeted synthetic (ts) disease-modifying antirheumatic drugs (DMARDs) in patients with PsA. A systematic database search using Medline, EMBASE, Cochrane CENTRAL was conducted to identify relevant articles published since the previous update in 2019 until 28 December 2022. Efficacy was assessed in trials while for safety observational data were also considered. Adverse events of special interest were infections (including herpes zoster, influenza and tuberculosis), malignancies, major adverse cardiovascular events, venous thromboembolisms, liver disease, laboratory changes and psychiatric adverse events. No meta-analyses were performed.

RESULTS

For efficacy, of 3946 articles screened, 38 articles (30 trials) were analysed. The compounds investigated included csDMARDs (leflunomide, methotrexate), bDMARDs inhibiting IL17 (bimekizumab, brodalumab, ixekizumab, izokibep, secukinumab,), IL-23 (guselkumab, risankizumab, tildrakizumab), IL-12/23 (ustekinumab) as well as TNF (adalimumab, certolizumab-pegol, etanercept, infliximab, golimumab) and Janus Kinase inhibitors (JAKi) (brepocitinib, deucravacitinib, tofacitinib, upadacitinib). The compounds investigated were efficacious in improving signs and symptoms of PsA, improving physical functioning and quality of life. For safety, 2055 abstracts were screened, and 24 articles analysed: 15 observational studies and 9 long-term follow-ups of trials, assessing glucocorticoids, TNFi, IL-17i, JAKi, IL-12/23i and PDE4i (apremilast). Safety indicators were generally coherent with the previous SLR in 2019.

CONCLUSION

The results of this SLR informed the task force responsible for the 2023 update of the European Alliance of Associations for Rheumatology recommendations for pharmacological management of PsA.

Adalimumab serum levels and anti-drug antibodies: associations to treatment response and drug survival in inflammatory joint diseases

OBJECTIVES

To explore associations between serum adalimumab level, treatment response and drug survival in order to identify optimal drug levels for therapeutic drug monitoring of adalimumab. Also, to assess the occurrence and risk factors of anti-drug antibody (ADAb) formation.

METHODS

Non-trough adalimumab and ADAb levels were measured by automated fluorescence assays in serum collected after 3 months of adalimumab treatment in patients with RA, PsA or axial SpA (axSpA) included in the observational NOR-DMARD study. Treatment response was evaluated after 3 months and drug survival was evaluated during long-term follow-up.

RESULTS

In 340 patients (97 RA, 69 PsA, 174 axSpA), the median adalimumab level was 7.3 mg/l (interquartile range 4.0-10.3). A total of 33 (10%) patients developed ADAbs. Findings were comparable across diagnoses. In RA and PsA, adalimumab levels ≥6.0 mg/l were associated with treatment response [odds ratio (OR) 2.2 (95% CI 1.0, 4.4)] and improved drug survival [hazard ratio 0.49 (95% CI 0.27, 0.80)]. In axSpA, a therapeutic level could not be identified, but higher adalimumab levels were associated with response. Factors associated with ADAb formation were previous bDMARD use, no methotrexate comedication and the use of adalimumab originator compared with GP2017.

CONCLUSION

Higher adalimumab levels were associated with a better response and improved drug survival for all diagnoses, with a suggested lower threshold of 6.0 mg/l for RA/PsA. This finding, the large variability in drug levels among patients receiving standard adalimumab dose and the high proportion of patients developing ADAbs encourages further investigations into the potential role of therapeutic drug monitoring of adalimumab.

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

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Clinical consequences of infliximab immunogenicity and the effect of proactive therapeutic drug monitoring: exploratory analyses of the randomised, controlled NOR-DRUM trials

BACKGROUND

Antidrug antibodies to TNF inhibitors might affect clinical outcomes. Proactive therapeutic drug monitoring allows for early detection of antidrug antibodies and might reduce negative clinical consequences. We aimed to explore how antidrug antibodies to the TNF inhibitor infliximab influence treatment outcomes, and to assess the effect of proactive therapeutic drug monitoring.

METHODS

This was a predefined exploratory analysis of data from the randomised, controlled NOR-DRUM trials. The trials were conducted in rheumatology, gastroenterology, and dermatology departments at 21 Norwegian hospitals. Adult patients (aged 18-75 years) with immune-mediated inflammatory diseases were randomly assigned to proactive therapeutic drug monitoring or standard infliximab dosing in the NOR-DRUM A trial (30-week follow-up) and the NOR-DRUM B trial (52-week follow-up). Antidrug antibodies were assessed with a drug-sensitive assay before each infusion. The outcomes of remission (at week 30), disease worsening (during 52 weeks), infusion reactions, and infliximab discontinuation were assessed according to the presence of antidrug antibodies and use of therapeutic drug monitoring.

FINDINGS

Between March 1, 2017, and Dec 12, 2019, 616 patients were included in the NOR-DRUM trials, of whom 615 had at least one serum infliximab and antidrug antibody assessment and were included in the present analyses. Mean age was 45 years (IQR 32-56), 305 (50%) patients were women, and 310 (50%) patients were men. Antidrug antibodies were detected in 147 (24%) patients. Remission at week 30 occurred in 25 (35%) of 72 patients with antidrug antibodies and 180 (54%) of 335 without antidrug antibodies (risk ratio 0·62 [95% CI 0·45-0·86]; p=0·0037). In patients with antidrug antibodies compared with patients without antidrug antibodies, higher rates were found for: disease worsening over 52 weeks (0·76 per person-year vs 0· 35 per person-year, hazard ratio [HR] 2·02 [95% CI 1·33-3·07]; p=0·0009), infusion reactions (0·16 per person-year vs 0·03 per person-year, HR 17·02 [6·98-41·47]; p<0·0001), and infliximab discontinuation (1·00 per person-year vs 0·20 per person-year, HR 6·64 [4·84-9·11]; p<0·0001). These associations were more pronounced in patients with high concentrations of antidrug antibodies than in those with low concentrations of antidrug antibodies. Independent of antibody status, therapeutic drug monitoring was associated with a lower risk of disease worsening (HR 0·41 [0·29-0·59]; p=0·0001) or an infusion reaction (HR 0·30 [0·12-0·73]; p=0·0076), and was associated with an increase in the rate of infliximab discontinuation (HR 1·37 [1·02-1·83]; p=0·037).

INTERPRETATION

In patients where antidrug antibodies were detected, remission was less likely to be reached and sustained, and infusion reaction or discontinuation of infliximab was more likely. Timely detection of antidrug antibodies by proactive therapeutic drug monitoring facilitated treatment decisions that reduced the negative consequences, both regarding infliximab effectiveness and safety. This highlights the role of proactive therapeutic drug monitoring in optimising infliximab therapy.

FUNDING

Inter-regional KLINBEFORSK grants and South-Eastern Norway Regional Health Authority grants.

Therapeutic drug monitoring of monoclonal antibodies in chronic inflammatory diseases: A snapshot of laboratories and applications across Europe

The European Cooperation in Science and Technology (COST) action ENOTTA (The European Network on Optimising Treatment with Therapeutic Antibodies in chronic inflammatory diseases) was launched in 2022. To pave the way for harmonization of analytical methods for quantitation of serum levels of therapeutic antibodies in research and clinical settings, ENOTTA recently performed an online survey mapping laboratories in the field. The survey, which contained 30 questions surrounding therapeutic drug monitoring of relevant drugs and anti-drug antibodies, was distributed via the ENOTTA and European Federation of Clinical Chemistry and Laboratory networks. Among 63 respondents across Europe, 45 reported analytical activity, with a range of utilized methods. Future engagement of as many sites as possible will enable comparison of methodologies and facilitate progress in the field.

Therapeutic drug monitoring, liquid biopsies or pharmacogenomics for prediction of human drug metabolism and response

Pharmacokinetics plays a central role in understanding the significant interindividual differences that exist in drug metabolism and response. Effectively addressing these differences requires a multi-faceted approach that encompasses a variety of tools and methods. In this review, we examine three key strategies to achieve this goal, namely pharmacogenomics, therapeutic drug monitoring (TDM) and liquid biopsy-based monitoring of hepatic ADME gene expression and highlight their advantages and limitations. We note that larger cohort studies are needed to validate the utility of liquid biopsy-based assessment of hepatic ADME gene expression, which includes prediction of drug metabolism in the clinical setting. Modern mass spectrometers have improved traditional TDM methods, offering versatility and sensitivity. In addition, the identification of endogenous or dietary markers for CYP metabolic traits offers simpler and more cost-effective alternatives to determine the phenotype. We believe that future pharmacogenomic applications in clinical practice should prioritize the identification of missing heritable factors, using larger, well-characterized patient studies and controlling for confounding factors such as diet, concomitant medication and physical health. The intricate regulation of ADME gene expression implies that large-scale studies combining long-read next-generation sequencing (NGS) of complete genomes with phenotyping of patients taking different medications are essential to identify these missing heritabilities. The continuous integration of such data into AI-driven analytical systems could provide a comprehensive and useful framework. This could lead to the development of highly effective algorithms to improve genetics-based precision treatment by predicting drug metabolism and response, significantly improving clinical outcomes.

Overcoming provider barriers to therapeutic drug monitoring of tumour necrosis factor inhibitors for rheumatoid arthritis: a qualitative analysis

Objective

Therapeutic drug monitoring (TDM) of tumour necrosis factor-α inhibitors (TNFi), by measuring drug levels and/or anti-drug antibodies, is being considered by various international bodies to improve patient health outcomes and the value of care for people with rheumatoid arthritis. Rheumatology care providers may perceive barriers to adopting TNFi TDM within their own clinical practice, limiting the potential for patients and health care systems to benefit. This study aimed to explore the barriers perceived by rheumatologists that may reduce their uptake of TNFi TDM for rheumatoid arthritis.

Method

Semi-structured one-to-one telephone interviews were performed with a convenience sample of senior rheumatologists with experience of managing people with rheumatoid arthritis. The interviews explored the rheumatologists' understanding of TDM and their beliefs about how it can be integrated into their own routine practice. Interviews were audio recorded, transcribed verbatim and anonymized. Transcripts were coded inductively and barriers to using TNFi TDM were identified by thematic framework analysis.

Result

A sample of eleven senior rheumatologists were interviewed. The rheumatologists described five barriers to adopting TNFi TDM in routine practice: (i) observing clinical need; (ii) understanding how testing can improve practice; (iii) insufficient clinical evidence; (iv) insufficient resources to pay for testing; and (v) insufficient capability to deliver testing.

Conclusion

Barriers to adopting TNFi TDM in routine care settings will restrict the ability for patients to benefit from effective monitoring strategies as they begin to emerge. Strategies to overcome these barriers are suggested which will require a coordinated response from stakeholders across health care systems.

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.

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.

Training the next generation of pharmacometric modelers: a multisector perspective

The current demand for pharmacometricians outmatches the supply provided by academic institutions and considerable investments are made to develop the competencies of these scientists on-the-job. Even with the observed increase in academic programs related to pharmacometrics, this need is unlikely to change in the foreseeable future, as the demand and scope of pharmacometrics applications keep expanding. Further, the field of pharmacometrics is changing. The field largely started when Lewis Sheiner and Stuart Beal published their seminal papers on population pharmacokinetics in the late 1970's and early 1980's and has continued to grow in impact and use since its inception. Physiological-based pharmacokinetics and systems pharmacology have grown rapidly in scope and impact in the last decade and machine learning is just on the horizon. While all these methodologies are categorized as pharmacometrics, no one person can be an expert in everything. So how do you train future pharmacometricians? Leading experts in academia, industry, contract research organizations, clinical medicine, and regulatory gave their opinions on how to best train future pharmacometricians. Their opinions were collected and synthesized to create some general recommendations.

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 Pharmacokinetic and Pharmacodynamic Considerations in the Treatment of Moderate-to-Severe Psoriasis

Psoriasis is a common inflammatory immune disorder due to chronic activation of the adaptive and innate immune responses. Therapies for psoriasis target reducing inflammatory cytokines such as tumor necrosis factor-alpha, interleukin-17, and interleukin-22. Patients with inflammatory disorders have reduced metabolism by cytochrome P450 enzymes in the liver. The pharmacokinetic and pharmacodynamic changes due to psoriasis also have an impact on reaching therapeutic concentrations of the drug. Pharmacokinetic and pharmacodynamic data help determine the safety and clinical considerations necessary when utilizing drugs for plaque psoriasis. A literature search was performed on PubMed and Ovid MEDLINE for the pharmacokinetic and pharmacodynamic data of oral therapies and biologics utilized for moderate-to-severe plaque psoriasis. The findings from the literature search were organized into two sections: oral therapies and biologics. The pharmacokinetic and pharmacodynamic parameters in healthy patients, patients with psoriasis, and special populations are discussed in each section. The oral therapies described in this review include methotrexate, cyclosporine, apremilast, tofacitinib, and deucravacitinib. Biologics include tumor necrosis factor-alpha inhibitors, interleukin-17 inhibitors, ustekinumab, and interleukin-23 inhibitors. Clinical considerations for these therapies include drug toxicities, dosing frequency, and anti-drug antibodies. Methotrexate and cyclosporine have a risk for hepatoxicity and renal impairment, respectively. Moreover, drugs metabolized via cytochrome P450, including tofacitinib and apremilast have decreased clearance in patients with psoriasis, requiring dose adjustments. Patients treated with therapies such as adalimumab can develop anti-drug antibodies that reduce the long-term efficacy of the drug. Additionally, overweight patients benefit from more frequent dosing to achieve better psoriasis clearance.

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.