Rapid test detection of anti-infliximab antibodies: performance comparison with three different immunoassays

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.

Thiopurines have no impact on outcomes of Crohn's disease patients beyond 12 months of maintenance treatment with infliximab

BACKGROUND

The emergence of new treatments the inflammatory bowel diseases (IBD) raised questions regarding the role of older agents, namely thiopurines.

AIMS

To clarify the benefits of combination treatment with thiopurines on Crohn's disease (CD) patients in the maintenance phase of infliximab.

METHODS

In this analysis of the 2-year prospective multicentric DIRECT study, patients were assessed in terms of clinical activity, faecal calprotectin (FC), C-reactive protein (CRP), and infliximab pharmacokinetics. A composite outcome based on clinical- and drug-related items was used to define treatment failure.

RESULTS

The study included 172 patients; of these, 35.5 % were treated with combination treatment. Overall, 18 % of patients achieved the composite outcome, without statistically significant differences between patients on monotherapy and on combination treatment (21.6% vs 11.5 %, p = 0.098). Median CRP, FC, and infliximab pharmacokinetic parameters were similar in both groups. However, in the sub-analysis by infliximab treatment duration, in patients treated for less than 12 months, the composite outcome was reached in fewer patients in the combination group than in the monotherapy group (7.1% vs 47.1 %, p = 0.021).

CONCLUSION

In CD patients in maintenance treatment with infliximab, combination treatment does not seem to have benefits over infliximab monotherapy beyond 12 months of treatment duration.

How many biomarker measurements are needed to predict prognosis in Crohn's disease patients under infliximab?-A prospective study

BACKGROUND

Timely stratification of Crohn's disease (CD) is essential for patients' management. The use of noninvasive accurate biomarkers is key to monitor treatment and to pursue mucosal healing, the ultimate treatment endpoint in CD.

OBJECTIVE

We aimed to evaluate the performance of readily available biomarkers and develop risk matrices to predict CD progression.

METHODS

Data from 289 CD patients receiving infliximab (IFX) maintenance therapy for 2 years was collected; those patients were included in DIRECT, a prospective multicenter observational study. Disease progression was evaluated using two composite outcomes incorporating clinical and drug-related factors, the first including IFX dose and/or frequency adjustments. Univariate and multivariable logistic regressions were used to calculate the odds ratios (OR) and to develop risk matrices.

RESULTS

The isolated presence of anemia at least once during follow-up was a significant predictor of disease progression (OR 2.436 and 3.396 [p ≤ 0.001] for composite outcomes 1 and 2, respectively) regardless of confounding factors. Isolated highly elevated C-reactive protein (CRP; >10.0 mg/L) and fecal calprotectin (FC; >500.0 μg/g) in at least one visit were also significant predictors, while milder elevations (3.1-10.0 mg/L and 250.1-500.0 μg/g) were only relevant when detected in at least two visits (consecutive or not). The combination of biomarkers in risk matrices had good ability to predict progression; patients simultaneously presenting anemia, highly elevated CRP and FC at least once had 42%-63% probability of achieving the composite outcomes.

CONCLUSION

The combined evaluation of hemoglobin, CRP, and FC in at least one time point and their incorporation into risk matrices seems to be the optimal strategy for CD management, as data from additional visits did not meaningfully influence the predictions and may delay decision-making.

Assessing Immunogenicity of Biologic Drugs in Inflammatory Joint Diseases: Progress Towards Personalized Medicine

Biologic drugs have greatly improved treatment outcomes of inflammatory joint diseases, but a substantial proportion of patients either do not respond to treatment or lose response over time. Drug immunogenicity, manifested as the formation of anti-drug antibodies (ADAb), constitute a significant clinical problem. Anti-drug antibodies influence the pharmacokinetics of the drug, are associated with reduced clinical efficacy, and an increased risk of adverse events such as infusion reactions. The prevalence of ADAb differs among drugs and diseases, and the detection of ADAb also depends on the assay format. Most data exist for the tumor necrosis factor-alpha inhibitors infliximab and adalimumab, with a frequency of ADAb that ranges from 10 to 60% across studies. Measurement of ADAb and serum drug concentrations, therapeutic drug monitoring, has been suggested as a strategy to optimize therapy with biologic drugs. Although the recent randomized clinical Norwegian Drug Monitoring (NOR-DRUM) trials show promise towards a personalized medicine prescribing approach by therapeutic drug monitoring, several challenges remain. A plethora of assay formats, with widely differing properties, is currently used for measuring ADAb. Comparing results between different assays and laboratories is difficult, which complicates the development of cut-offs necessary for guidelines and the implementation of ADAb measurements in clinical practice. With the possible exception of infliximab, limited data on clinical relevance and cost effectiveness exist to support therapeutic drug monitoring as a routine clinical strategy to monitor biologic drugs in inflammatory joint diseases. The aim of this review is to provide an overview of the characteristics and prevalence of ADAb, predisposing factors to ADAb formation, commonly used assessment methods, clinical consequences of ADAb, and the potential implications of ADAb assessments for everyday treatment of inflammatory joint diseases.

Subclinical Persistent Inflammation as Risk Factor for Crohn's Disease Progression: Findings From a Prospective Real-World Study of 2 Years

BACKGROUND AND AIMS

Subclinical intestinal inflammation is common in Crohn's disease (CD). We aimed to explore its impact in the disease progression of infliximab-treated patients and the usefulness of fecal calprotectin (FC) and C-reactive protein (CRP) as surrogate minimally invasive biomarkers.

METHODS

The registry-based, prospective, observational, multicenter DIRECT (study to investigate the correlation of fecal calprotectin with serum Drug levels and development of an antI-dRug antibodiEs among adult patients with inflammatory bowel disease reCeiving anti-TNF-alfa treatment or vedoluzimab treatment) study followed infliximab-treated CD patients for 2 years in a tertiary care setting. Persistent inflammation definition was based on FC (>150 μg/g, >250 μg/g, or >350 μg/g) or serum CRP (>3 μg/mL) concentrations over 2 consecutive or at least 3 visits. Patients were categorized according to a composite outcome reflecting disease progression that incorporated surgery; hospitalizations; new fistulae, abscess, or stricture; and treatment escalation.

RESULTS

Of 322 DIRECT study patients, 180 asymptomatic, infliximab treated on maintenance regimen were included in the analysis. Patients developing the composite endpoint (n = 96) presented higher median levels of FC (205 [interquartile range, 98-515] μg/g; P = .045) but not of CRP (2.50 [interquartile range, 0.80-6.00] μg/mL; P = .895). Biomarker-defined persistent subclinical inflammation prevalence ranged from 24% to 81%. Considering FC >250 μg/g in 2 consecutive visits, prevalence was 50%, odds of achieving the endpoint were increased 3-fold (odds ratio, 2.996 [95% confidence interval, 1.557-5.776]), and time-to-outcome occurrence was significantly lower among subjects with persistent inflammation (median time: 11 months). Both clinical-related and treatment-related components were significantly associated with persistent inflammation. Definitions based on CRP >3 μg/mL, FC >150 μg/g, FC >350 μg/g, double biomarkers (FC >250 μg/g and/or CRP >3 μg/mL), or more visits did not improve predictive ability.

CONCLUSIONS

Persistent inflammation, defined simply and readily by FC >250 μg/g over 2 consecutive visits, was associated with a significantly higher risk and shorter time to occurrence of a composite outcome reflecting disease progression in asymptomatic infliximab-treated CD patients.

Therapeutic Drug Monitoring of Biologics in Crohn's Disease

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

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

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

Anti-TNF therapy and immunogenicity in inflammatory bowel diseases: a translational approach

Inflammatory bowel diseases are chronic illnesses that involve intestinal inflammation and are usually diagnosed as Crohn's disease or ulcerative colitis. As these diseases do not have a cure, the goal of treatment is to induce and maintain remission. Monoclonal antibodies have been recognized as the most advanced therapy to avoid complications and reduce the need for surgical approaches. However, although their effectiveness has been proven by several studies, they can trigger the immune system, induce the occurrence of immunogenicity, which may lead to the loss of response and treatment failure. The purpose of this review is to determine what are the main mechanisms involved in IBD; to assess the recommended treatments; to explore the mechanisms of immunogenicity. We also try to explain the detection and describe the existing advances that make possible the clinical application of these approaches.