Therapeutic Drug Monitoring of Tumor Necrosis Factor Antagonists in Crohn Disease: A Theoretical Construct to Apply Pharmacokinetics and Guidelines to Clinical Practice

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.

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.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Comparison of Two Clinical Laboratory Assays for Measuring Serum Adalimumab and Antibodies to Adalimumab

BACKGROUND

Adalimumab is a fully human monoclonal antibody developed against tumor necrosis factor (TNF), used for the treatment of autoimmune and chronic inflammatory diseases. Immunogenicity to this drug may lead to therapeutic failure. Various laboratory assays are used for measuring serum adalimumab and anti-drug antibodies (ADA) to adalimumab, for therapeutic monitoring and evaluation of clinical non-responsiveness. This study compared the performance of 2 clinical assays used by different reference laboratories.

METHODS

In total, 120 residual clinical samples were tested at both laboratories. A sandwich ELISA for adalimumab detecting free drug and a bridging ELISA capable of detecting both free and bound ADA were performed at the Mayo Clinic. A functional cell-based reporter gene assay (RGA) was used at ARUP Laboratories for measuring bioactive serum drug concentrations, and neutralizing ADA.

RESULTS

Seventy-eight samples had measurable concentrations of adalimumab by both methods and yielded a correlation coefficient r = 0.93, slope = 0.886, and intercept = 0.950. Overall agreement of 92.5% was observed between the assays, with most discrepant drug results being attributed to a higher positivity rate with ELISA (8/9). One outlier positive with RGA and negative with ELISA was confirmed by LC-MS/MS to be attributed to infliximab. Overall agreement of 79.2% was observed between the ADA assays. Differences in ADA results may be due to the bridging ELISA detecting total ADA (free, drug-bound, neutralizing, and non-neutralizing), while RGA detects free, neutralizing ADA only.

CONCLUSIONS

Although the assays are fundamentally different, the results show significant concordance between the clinically validated tests performed in different laboratories.

Anti-TNF Agents and New Biological Agents (Vedolizumab and Ustekinumab) in the Prevention and Treatment of Postoperative Recurrence After Surgery in Crohn's Disease

Surgery for Crohn's disease (CD) is not curative, as postoperative recurrence (POR) after ileocolonic resection is the rule in the absence of prophylactic treatment. In the present article, we critically review available data on the role of anti-tumour necrosis factor (TNF) agents and new biologics (including vedolizumab and ustekinumab) in the prevention and treatment of POR after surgery in CD. Several studies (summarised in various meta-analyses) have confirmed the efficacy of anti-TNFs in the prevention of POR. We identified 37 studies, including 1863 CD patients, with mean endoscopic POR at 6-12 months of 29%. Only few randomised controlled trials (RCTs) have directly compared thiopurines and anti-TNFs, with controversial results, although the superiority of the latter is supported by several meta-analyses. Infliximab and adalimumab seem equally effective. The combination of anti-TNFs and immunosuppressives should be considered in patients previously exposed to anti-TNFs. Several studies have shown that anti-TNFs remain an effective option to prevent POR also in patients with anti-TNF failure before surgery. In fact, the use of the same anti-TNF before and after surgery might be effective for the prevention of POR. Prophylactic anti-TNF treatment, once started, should be continued long term. Anti-TNFs are also effective for the treatment of established POR. Retreatment with anti-TNFs for POR is a valid strategy even after their preoperative failure. In six studies (including 156 patients) evaluating vedolizumab, mean endoscopic POR at 6-12 months was 41%. The non-randomised comparison of anti-TNFs and vedolizumab has provided controversial results. One placebo-controlled RCT confirmed that vedolizumab is quite effective in preventing POR in CD patients with increased risk of recurrence. Seven studies (including 162 patients) evaluated ustekinumab, with a mean endoscopic POR at 6-12 months of 41%. The comparative efficacy of ustekinumab and anti-TNFs is still unclear. Ustekinumab and vedolizumab seem to be equally effective, although the experience is very limited. In conclusion, to date, anti-TNFs are the most effective agents in preventing and treating POR in CD. Anti-TNFs remain an effective option to prevent POR also in patients with anti-TNF failure before surgery. Vedolizumab seems to be quite effective in the prevention of POR in patients with increased risk of recurrence. Ustekinumab is probably also effective in the postoperative setting, although the comparative efficacy with anti-TNFs or vedolizumab is still unclear.

Simplified Histologic Mucosal Healing Scheme (SHMHS) for inflammatory bowel disease: a nationwide multicenter study of performance and applicability

BACKGROUND

Assessment of mucosal healing is important for the management of patients with inflammatory bowel disease (IBD), but endoscopy can miss microscopic disease areas that may relapse. Histological assessment is informative, but no single scoring system is widely adopted. We previously proposed an eight-item histological scheme for the easy, fast reporting of disease activity in the intestine. The aim of the present study was to evaluate the performance of our Simplified Histologic Mucosal Healing Scheme (SHMHS).

METHODS

Between April and May 2021 pathologists and gastroenterologists in Italy were invited to contribute to this multicenter study by providing data on single endoscopic-histological examinations for their IBD patients undergoing treatment. Disease activity was expressed using SHMHS (maximum score, 8) and either Simple Endoscopic Score for Crohn's Disease (categorized into grades 0-3) or Mayo Endoscopic Subscore (range 0-3).

RESULTS

Thirty hospitals provided data on 597 patients (291 Crohn's disease; 306 ulcerative colitis). The mean SHMHS score was 2.96 (SD = 2.42) and 66.8% of cases had active disease (score ≥ 2). The mean endoscopic score was 1.23 (SD = 1.05), with 67.8% having active disease (score ≥ 1). Histologic and endoscopic scores correlated (Spearman's ρ = 0.76), and scores for individual SHMHS items associated directly with endoscopic scores (chi-square p < 0.001, all comparisons). Between IBD types, scores for SHMHS items reflected differences in presentation, with cryptitis more common and erosions/ulcerations less common in Crohn's disease, and the distal colon more affected in ulcerative colitis.

CONCLUSIONS

SHMHS captures the main histological features of IBD. Routine adoption may simplify pathologist workload while ensuring accurate reporting for clinical decision making.

Perspectives on Subcutaneous Infliximab for Rheumatic Diseases and Inflammatory Bowel Disease: Before, During, and After the COVID-19 Era

The coronavirus disease 2019 (COVID-19) pandemic has prompted significant changes in patient care in rheumatology and gastroenterology, with clinical guidance issued to manage ongoing therapy while minimising the risk of nosocomial infection for patients and healthcare professionals (HCPs). Subcutaneous (SC) formulations of biologics enable patients to self-administer treatments at home; however, switching between agents may be undesirable. CT-P13 SC is the first SC formulation of infliximab that received regulatory approval and may be termed a biobetter as it offers significant clinical advantages over intravenous (IV) infliximab, including improved pharmacokinetics and a convenient mode of delivery. Potential benefits in terms of reduced immunogenicity have also been suggested. With a new SC formulation, infliximab provides an additional option for dual formulation, which enables patients to transition from IV to SC administration route without changing agent. Before COVID-19, clinical trials supported the efficacy and safety of switching from IV to SC infliximab for patients with rheumatoid arthritis and inflammatory bowel disease (IBD), and SC infliximab may have been selected on the basis of patient and HCP preferences for SC agents. During the pandemic, patients with rheumatic diseases and IBD have successfully switched from IV to SC infliximab, with some clinical benefits and high levels of patient satisfaction. As patients switched to SC therapeutics, the reduction in resource requirements for IV infusion services may have been particularly welcome given the pandemic, facilitating reorganisation and redeployment in overstretched healthcare systems, alongside pharmacoeconomic benefits and a reduction in exposure to nosocomial infection. Telemedicine and contactless healthcare have been pushed to the forefront during the pandemic, and a lasting shift towards remote patient management and community/home-based drug administration is anticipated. SC infliximab supports the implementation of this paradigm for future improvements of healthcare value delivered. The accumulation of real-world data during the pandemic supports the high level of confidence, with patients, physicians, and healthcare systems benefitting from its uptake.

Promising Tools to Facilitate the Implementation of TDM of Biologics in Clinical Practice

Therapeutic drug monitoring (TDM) of biologics—encompassing the measurement of (trough) concentrations and anti-drug antibodies—is emerging as a valuable tool for clinical decision making. While this strategy needs further validation, attention on its implementation into the clinic is warranted. Rapid testing and easy sampling are key to its implementation. Here, we aimed to evaluate the feasibility and volunteers’ perception of home microsampling for quantification of adalimumab (ADM) concentrations in psoriasis patients. In addition, we compared lateral flow testing (LFT) with enzyme-linked immunosorbent assay (ELISA). Patients participating in the SUPRA-A study (clinicaltrials.gov NCT04028713) were asked to participate in a substudy where volumetric absorptive microsampling (VAMS) was performed at home. At three time points, whole blood and corresponding serum samples were collected for ADM measurement using an in-house ELISA. In addition, the patients’ perspective on microsampling was evaluated via a questionnaire. LFT-obtained ADM concentrations agreed very well with ELISA results (Pearson’s correlation = 0.95 and R² = 0.89). ADM concentrations determined in both capillary (via finger prick) and corresponding venous blood VAMS samples correlated strongly with serum concentrations (Pearson’s correlation = 0.87). Our preliminary data (n = 7) on rapid testing and home-based microsampling are considered promising with regard to TDM implementation for adalimumab, warranting further research.

A Clinical Prediction Model to Determine Probability of Response to Certolizumab Pegol for Crohn's Disease

BACKGROUND

Certolizumab pegol (CZP) is effective for moderately to severely active Crohn's disease (CD). Higher plasma concentrations are associated with better outcomes and increased drug clearance is the driver of subtherapeutic CZP concentrations.

OBJECTIVE

We aimed to develop a prediction model incorporating predicted CZP clearance and patient variables to allow estimation of the probability for remission prior to initiating therapy.

METHODS

A population pharmacokinetic model estimated baseline CZP clearance in patients with CD from nine phase II and III trials. Multivariable prediction models were developed and validated using the PRECiSE 1 and PRECiSE 2 datasets to identify candidate predictors for a composite remission outcome (Crohn's Disease Activity Index ≤ 150 and fecal calprotectin concentration ≤ 250 μg/g) at Weeks 6 or 26. An online clinical decision support tool (CDST) was developed.

RESULTS

Baseline predicted CZP clearance ≥ 0.5 L/day was associated with subtherapeutic Week 6 CZP plasma concentrations. Baseline weight (odds ratio [OR] 1.04; 95% confidence interval [CI] 1.02-1.07), calculated CZP clearance (OR 0.92; 95% CI 0.87-0.96), hematocrit (OR 2.55; 95% CI 1.43-4.54), and fecal calprotectin (OR 0.66; 95% CI 0.54-0.80) were associated with Week 6 remission (p ≤ 0.0015 for all predictors). Baseline weight (OR 1.04; 95% CI 1.02-1.07), calculated CZP clearance (OR 0.93; 95% CI 0.88-0.97), and Patient-Reported Outcome-2 (PRO2) (OR 0.93; 95% CI 0.87-0.99) were associated with Week 26 remission (p ≤ 0.033 for all predictors).

CONCLUSIONS

Patients who are predicted to have accelerated baseline CZP clearance are at risk of subtherapeutic CZP concentrations. Patient-level probabilities for a composite remission outcome can be predicted for patients with CD by entering commonly available patient- and disease-related factors into an online CDST ( https://premedibd.com ) incorporating predicted CZP clearance.

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

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