Therapeutic drug monitoring of vedolizumab in inflammatory bowel disease: current data and future directions

Antibodies Targeting the Tumor Necrosis Factor-Like Ligand 1A in Inflammatory Bowel Disease: A New Kid on the (Biologics) Block?

BACKGROUND

The treatment options for inflammatory bowel disease (IBD) have grown over the last years. However, a significant fraction of patients either do not respond to their treatment or lose response over time.

SUMMARY

Future treatment options could include antibodies that target the tumor necrosis factor-like ligand 1A (TL1A). TL1A is a key cytokine involved in the pathogenesis of a variety of autoimmune diseases including IBD. Studies have shown that IBD disease severity correlates well with serum levels of TL1A. Phase 2 data from two agents currently in clinical testing have been released. In line with requirements for modern therapeutics, companion diagnostic was part of these trials. This aims to identify those patients that are more likely to respond to the agents tested.

KEY MESSAGES

With regard to the available data the risk/benefit profile of TL1A inhibitors seems to be promising. This article gives a short update and overview, where we are at this point in time with antibodies targeting the TL1A protein in IBD.

Mathematical Modeling of Vedolizumab Treatment's Effect on Microbiota and Intestinal Permeability in Inflammatory Bowel Disease Patients

Growing evidence suggests that impaired gut permeability and gut microbiota alterations are involved in the pathogenesis of Inflammatory Bowel Diseases (IBDs), which include Ulcerative Colitis (UC) and Crohn's Disease (CD). Vedolizumab is an anti-α4β7 antibody approved for IBD treatment, used as the first treatment or second-line therapy when the first line results in inadequate effectiveness. The aim of this study is to develop a mathematical model capable of describing the pathophysiological mechanisms of Vedolizumab treatment in IBD patients. In particular, the relationship between drug concentration in the blood, colonic mucosal permeability and fecal microbiota composition was investigated and modeled to detect and predict trends in order to support and tailor Vedolizumab therapies. To pursue this aim, clinical data from a pilot study on a cluster of 11 IBD patients were analyzed. Enrolled patients underwent colonoscopy in three phases (before (t0), after 24 weeks of (t1) and after 52 weeks of (t2 ) Vedolizumab treatment) to collect mucosal biopsies for transepithelial electrical resistance (TEER) evaluation (permeability to ions), intestinal permeability measurement and histological analysis. Moreover, fecal samples were collected for the intestinal microbiota analysis at the three time points. The collected data were compared to those of 11 healthy subjects at t0, who underwent colonoscopy for screening surveillance, and used to implement a three-compartmental mathematical model (comprising central blood, peripheral blood and the intestine). The latter extends previous evidence from the literature, based on the regression of experimental data, to link drug concentration in the peripheral blood compartment with Roseburia abundance and intestinal permeability. The clinical data showed that Vedolizumab treatment leads to an increase in TEER and a reduction in intestinal permeability to a paracellular probe, improving tissue inflammation status. Microbiota analysis showed increasing values of Roseburia, albeit not statistically significant. This trend was adequately reproduced by the mathematical model, which offers a useful tool to describe the pathophysiological effects of Vedolizumab therapy on colonic mucosal permeability and fecal microbiota composition. The model's satisfactory predictive capabilities and simplicity shed light on the relationship between the drug, the microbiota and permeability and allow for its straightforward extension to diverse therapeutic conditions.

Precision therapy for ulcerative colitis: insights from mitochondrial dysfunction interacting with the immune microenvironment

Background

Accumulating evidence reveals mitochondrial dysfunction exacerbates intestinal barrier dysfunction and inflammation. Despite the growing knowledge of mitochondrial dysfunction and ulcerative colitis (UC), the mechanism of mitochondrial dysfunction in UC remains to be fully explored.

Methods

We integrated 1137 UC colon mucosal samples from 12 multicenter cohorts worldwide to create a normalized compendium. Differentially expressed mitochondria-related genes (DE-MiRGs) in individuals with UC were identified using the "Limma" R package. Unsupervised consensus clustering was utilized to determine the intrinsic subtypes of UC driven by DE-MiRGs. Weighted gene co-expression network analysis was employed to investigate module genes related to UC. Four machine learning algorithms were utilized for screening DE-MiRGs in UC and construct MiRGs diagnostic models. The models were developed utilizing the over-sampled training cohort, followed by validation in both the internal test cohort and the external validation cohort. Immune cell infiltration was assessed using the Xcell and CIBERSORT algorithms, while potential biological mechanisms were explored through GSVA and GSEA algorithms. Hub genes were selected using the PPI network.

Results

The study identified 108 DE-MiRGs in the colonic mucosa of patients with UC compared to healthy controls, showing significant enrichment in pathways associated with mitochondrial metabolism and inflammation. The MiRGs diagnostic models for UC were constructed based on 17 signature genes identified through various machine learning algorithms, demonstrated excellent predictive capabilities. Utilizing the identified DE-MiRGs from the normalized compendium, 941 patients with UC were stratified into three subtypes characterized by distinct cellular and molecular profiles. Specifically, the metabolic subtype demonstrated enrichment in epithelial cells, the immune-inflamed subtype displayed high enrichment in antigen-presenting cells and pathways related to pro-inflammatory activation, and the transitional subtype exhibited moderate activation across all signaling pathways. Importantly, the immune-inflamed subtype exhibited a stronger correlation with superior response to four biologics: infliximab, ustekinumab, vedolizumab, and golimumab compared to the metabolic subtype.

Conclusion

This analysis unveils the interplay between mitochondrial dysfunction and the immune microenvironment in UC, thereby offering novel perspectives on the potential pathogenesis of UC and precision treatment of UC patients, and identifying new therapeutic targets.

Meta-analysis of etrolizumab versus placebo in ulcerative colitis: safety and efficacy outcomes

Background

The existing body of scientific literature offers inconclusive findings on the safety and therapeutic effectiveness of etrolizumab (ETR) for the treatment of ulcerative colitis (UC).

Objectives

The goal of this meta-analysis is to furnish a comprehensive synthesis of evidence that evaluates the safety and therapeutic effects of ETR in the management of UC.

Design

Meta-analysis.

Data sources and methods

PubMed, Embase, and Web of science were searched to collect relevant English studies, and the reference lists of eligible studies were manually searched to avoid missing any eligible studies. Outcome measures encompassed clinical response, incidence of adverse events, histological remission, endoscopic remission, endoscopic improvement, and antidrug antibodies. Relevant data were extracted by two independent investigators.

Results

The meta-analysis incorporated five eligible studies, involving a total of 1528 patients, with 1015 treated with ETR and 513 with placebo. The pooled analysis indicates that ETR is both effective and safe. The adverse event rates, endoscopic and histological response, as well as overall remission were comparable between the two groups. The monoclonal antibody group had a lower incidence rate of adverse reactions than the placebo group [odds ratio (OR): 0.81; 95% confidence interval (CI): 0.63-1.03; p = 0.09)]. Clinical response was higher in the ETR group than in the placebo group (OR: 1.56; 95% CI: 1.20-2.02; p = 0.0009), and endoscopic improvement was more favorable in the ETR group (OR: 1.88; 95% CI: 1.45-2,45; p < 0.00001). A higher rate of endoscopic remission was found in the ETR group than in the placebo group (OR: 2.48; 95% CI: 1.75-3.50; p < 0.00001); histological remission was significantly higher in the ETR group than in the placebo group (OR: 2.11; 95% CI: 1.55-2.86; p < 0.00001). The placebo group had a lower rate of positive antidrug antibodies (OR: 1.31; 95% CI: 0.79-2.17; p < 0.29), and the incidence of complications was significantly higher in the ETR group compared with the placebo group (OR: 2.05; 95% CI: 1.48-2.83; p < 0.0001).

Conclusion

Given the heterogeneity and potential biases in the included studies, gastroenterologists should cautiously tailor drug delivery strategies based on their clinical experience and the unique needs of individual patients.

PROSPERO registration

CRD42023396100.

Therapeutic Drug Monitoring as a Tool for the Clinical Outcome Prediction in Vedolizumab-Treated Patients: An Italian Pilot Study

Over the years, vedolizumab (VDZ) has emerged as a more effective target therapy for inflammatory bowel disease. The aim of this work was to analyze a cohort of inflammatory bowel disease patients, evaluating the association between VDZ serum concentrations at 6 months from starting therapy and their clinical and biochemical indexes within one year of treatment, correlating drug levels with response and clinical remission. Forty patients treated with VDZ were enrolled. Drug concentrations were quantified through ELISA methods. VDZ levels correlated with hemoglobin levels at twelve months of therapy (p = 0.03) and with clinical remission at twelve months of therapy (p = 0.03); patients who reached clinical remission showed higher VDZ concentrations. A VDZ cut-off value of 43.1 μg/mL was suggested, predicting clinical remission at twelve months of therapy. A statistically significant association between VDZ levels at T6 and calprotectin <250 μg/g at T12 was found (p = 0.04). Furthermore, the optimal threshold value of VDZ levels at T6 associated with calprotectin <250 μg/g at T12 was identified: through levels higher than 45.2 µg/mL, we were able to predict remission one year after therapy. In the final regression multivariate model, no factor was retained as a predictor of clinical remission at one year of treatment. In conclusion, this is the first pilot study reporting a possible VDZ serum cut-off value able to predict not only the clinical remission at twelve months of therapy but also the calprotectin level, which is very important, as it is a surrogate marker of mucosal healing.

Exposure-efficacy relationship of vedolizumab subcutaneous and intravenous formulations in Crohn's disease and ulcerative colitis

BACKGROUND AND AIMS

This posthoc analysis of the GEMINI and VISIBLE studies in ulcerative colitis (UC) and Crohn's Disease (CD) assessed exposure-efficacy of vedolizumab intravenous (IV) and subcutaneous (SC).

METHODS

A previously described population pharmacokinetic model was used to predict average serum and trough concentrations at steady state (Cav,ss, Ctrough,ss) and simulate the transition from vedolizumab IV to SC. Efficacy was defined as clinical remission at week 52: complete Mayo score ≤ 2 points and no individual subscore > 1 point (UC), and CD activity index score ≤ 150 points (CD).

RESULTS

Data were from 1968 patients (GEMINI 1 [n = 334], VISIBLE 1 [n = 216], GEMINI 2 [n = 1009], VISIBLE 2 [n = 409]) who received maintenance treatment with vedolizumab IV-Q8W, IV-Q4W, SC-Q2W, or placebo. Model-predicted Cav,ss for IV-Q8W and SC-Q2W was similar in UC and CD. Cav,ss was higher for IV-Q4W than IV-Q8W and SC-Q2W. Ctrough,ss values from IV and SC aligned well with pooled observed Ctrough by treatment group in UC and CD. Cav,ss was equivalent for SC and IV. For UC and CD, efficacy rates were greater in patients in the highest quartiles of vedolizumab exposure for both formulations.

CONCLUSION

Exposure-efficacy relationships for IV and SC vedolizumab administration were comparable, confirming that both are equally effective during maintenance treatment.

Therapeutic Drug Monitoring for Biologic and Small-Molecule Therapies for Inflammatory Bowel Disease

Background: Inflammatory bowel disease (IBD), encompassing ulcerative colitis and Crohn's disease, necessitates long-term medical therapy to manage symptoms and prevent complications. Therapeutic drug monitoring (TDM) has emerged as a strategy to optimize treatment efficacy, particularly with anti-tumour necrosis factor (anti-TNF) alpha drugs. This review explores the role of TDM for non-anti-TNF advanced therapies in IBD, focusing on vedolizumab, ustekinumab, tofacitinib, upadacitinib, risankizumab and ozanimod. Methods: The literature search, conducted through OVID (Medline) and PubMed, delves into proactive versus reactive TDM, timing of monitoring and methods for measuring drug levels and anti-drug antibodies. Results: While ustekinumab and vedolizumab exhibit exposure-response relationships, consensus on target levels and the role of TDM adjustments remains elusive. Limited data on risankizumab suggest a dose-dependent response, while for small molecule therapies (janus kinase inhibitors and ozanimod), the absence of real-world data and commercially available TDM tools pose challenges. Conclusion: At present, with the available data, there is a limited role for TDM in non-anti-TNF biologic and small-molecule therapies. This review underscores the need for further research to delineate the utility of TDM in guiding treatment decisions for these agents.

A Single-Center Study of Long-Term Effectiveness of Vedolizumab in Anti-TNF Refractory Pediatric Inflammatory Bowel Disease

Vedolizumab is an anti-α4β7 integrin antibody that has been used successfully in the treatment of adult-onset inflammatory bowel diseases (IBDs: Crohn disease [CD] and ulcerative colitis [UC]). Its off-label use in the pediatric IBD (PIBD) population is increasing, but knowledge on durability beyond 6 months of treatment is limited.

Methods

A real-life, single-center, retrospective study of PIBD patients treated with vedolizumab was performed. Data on demographics, prior and concomitant treatments, and disease activity were obtained at 14 weeks, 26 weeks, 1 year, and 2 years of therapy. Primary outcome was corticosteroid- and other biologic-free remission (based on pediatric ulcerative colitis activity index [PUCAI]).

Results

Thirty-nine patients were studied. By 1 year, 65% of CD and 68% of UC patients continued on vedolizumab therapy. Corticosteroid- and other biologic-free remission was 29% in CD and 16% in UC. By 2 years, 36% of CD and 47% of UC patients continued therapy. Corticosteroid- and other biologic-free remission was 21% in CD and 40% in UC. By 2 years, 80% of CD and 100% of UC patients were on intensified treatment regimen compared to the manufacturer guidance. Nine patients (23%) required surgical intervention within 26 months of starting vedolizumab indicating the severity of IBD in this cohort.

Conclusions

Vedolizumab is a useful therapeutic modality in PIBD patients refractory to anti-TNF therapy, although with declining effectiveness by 2 years. Intensified treatment regimens are associated with long-term durability. Larger prospective trials in children are warranted.

Pharmacokinetics, Pharmacodynamics, and Safety of Etrolizumab in Children With Moderately to Severely Active Ulcerative Colitis or Crohn's Disease: Results from a Phase 1 Randomized Trial

BACKGROUND

Etrolizumab, a humanized anti-β7 antibody, has not been studied in children. Here, we evaluate the pharmacokinetics, pharmacodynamics, and safety of etrolizumab in children with inflammatory bowel disease.

METHODS

Patients age 4 to 17 years with moderately to severely active ulcerative colitis or Crohn's disease were randomized 1:1 to receive 1.5mg/kg of etrolizumab subcutaneously every 4 weeks (q4w) or 3.0mg/kg every 8 weeks (q8w) for 16 weeks in this open-label phase 1 trial. Pharmacokinetics, pharmacodynamics, safety, and efficacy were assessed.

RESULTS

Of the 24 patients treated, 21 completed the study. In the groups of 1.5mg/kg q4w and 3.0mg/kg q8w, respectively, mean (SD) maximum concentration (Cmax) was 9.8 (4.86) µg/mL and 18.1 (6.25) µg/mL; and mean (SD) area under the curve within a dosing interval (AUCtau) was 167 (86.9) and 521 (306) μg·day/mL after the last dose. The Cmax increased dose proportionally. The AUC over an 8-week period was slightly higher in the 3.0mg/kg q8w dose group. Median half-life was similar for both dosing regimens. Median numbers of free β7high gut-homing T and B cell subsets declined below 10% of baseline, confirming β7 target engagement and complete/near-complete receptor occupancy. Adverse events were consistent with the safety profile in adults. Approximately 60% of patients achieved a clinical response.

CONCLUSIONS

Etrolizumab showed a dose-proportional increase in Cmax and a slightly greater than dose-proportional increase in AUCtau. Both regimens achieved complete/near-complete β7 receptor occupancy, with a similar relationship to concentration as adults. Etrolizumab was well tolerated and demonstrated clinical activity in children.

Residual homing of α4β7-expressing β1+PI16+ regulatory T cells with potent suppressive activity correlates with exposure-efficacy of vedolizumab

OBJECTIVE

The anti-α4β7 integrin antibody vedolizumab is administered at a fixed dose for the treatment of IBDs. This leads to a wide range of serum concentrations in patients and previous studies had suggested that highest exposure levels are associated with suboptimal clinical response. We aimed to determine the mechanisms underlying these non-linear exposure-efficacy characteristics of vedolizumab.

DESIGN

We characterised over 500 samples from more than 300 subjects. We studied the binding of vedolizumab to T cells and investigated the functional consequences for dynamic adhesion, transmigration, gut homing and free binding sites in vivo. Employing single-cell RNA sequencing, we characterised α4β7 integrin-expressing T cell populations 'resistant' to vedolizumab and validated our findings in vitro and in samples from vedolizumab-treated patients with IBD. We also correlated our findings with a post-hoc analysis of the Gemini II and III studies.

RESULTS

Regulatory T (T_Reg) cells exhibited a right-shifted vedolizumab binding profile compared with effector T (T_Eff) cells. Consistently, in a certain concentration range, the residual adhesion, transmigration, homing of and availability of functional α4β7 on T_Reg cells in vivo was higher than that of/on T_Eff cells. We identified a vedolizumab-'resistant' α4β7-expressing β1⁺PI16⁺ T_Reg cell subset with pronounced regulatory properties as the substrate for this effect. Our observations correlated with exposure-efficacy data from Gemini II and III trials.

CONCLUSION

Completely blocking T_Eff cell trafficking with vedolizumab, while simultaneously permitting residual homing of powerful T_Reg cells in an optimal 'therapeutic window' based on target exposure levels might be a strategy to optimise treatment outcomes in patients with IBD.

Real-world multicentre observational study including population pharmacokinetic modelling to evaluate the exposure-response relationship of vedolizumab in inflammatory bowel disease: ERELATE Study

BACKGROUND

ERELATE was a phase 4, multinational, retrospective, observational study.

AIM

To evaluate the relationship between intravenous vedolizumab exposure and treatment outcomes over 52 weeks in adults with ulcerative colitis (UC) or Crohn's disease (CD).

METHODS

Real-world data from patients with UC or CD treated with intravenous vedolizumab in nine centres in six countries were collected retrospectively. Treatment outcomes were collected at Weeks 14, 26 and 52. An established population pharmacokinetic model (incorporating observed vedolizumab concentrations based on a Bayesian approach) was used to predict individual vedolizumab exposure. Vedolizumab exposure-response relationship was evaluated overall, by indication and based on baseline characteristics.

RESULTS

The study population (n = 695; UC, n = 304; CD, n = 391) had a median age of 39 years; 47.9% were male and 86.9% had prior tumour necrosis factor antagonist exposure. By Week 14, clinical, endoscopic, deep (clinical plus endoscopic) and biologic remission was achieved by 47.3%, 59.6%, 30.7% and 19.0% of patients respectively. Higher vedolizumab trough concentration early in treatment was consistently associated with clinical remission at later time points. Clinical remission at Week 14 and Week 52 was associated with Week 6 trough concentrations of ≥31.0 and ≥32.0 μg/ml respectively. Importantly, multivariable analysis identified baseline clearance as the only exposure measure predictive of clinical and deep remission at Week 52.

CONCLUSIONS

In this real-world study, a positive exposure-response relationship was observed for vedolizumab. Vedolizumab concentration during induction may be an important predictor of short- and long-term outcomes, and similarly, vedolizumab baseline clearance may be an important predictor of remission.

Proposed pathway for therapeutic drug monitoring and dose escalation of vedolizumab

Vedolizumab is a gut-selective monoclonal antibody approved for the management of Crohn's disease and ulcerative colitis. The available data demonstrate a favourable response to dose escalation in patients with primary non-response or secondary loss of response to vedolizumab. While therapeutic drug monitoring has a proven clinical utility for tumour necrosis factor antagonists, the available guidance for therapeutic drug monitoring and dose escalation of vedolizumab is rather limited. The present review proposes a practical algorithm to use vedolizumab trough levels in the management of treatment failure. Therapeutic drug monitoring can differentiate underexposed patients from those with mechanistic failure. Underdosed patients can respond to dose escalation instead of unnecessarily switching to other treatment modalities. We also review the safety and potential cost-effectiveness of vedolizumab dose escalation, the role of antidrug antibodies and the possible applicability of this strategy to subcutaneous vedolizumab.

Proactive versus Reactive Therapeutic Drug Monitoring: Why, When, and How?

BACKGROUND

Up to a third of inflammatory bowel disease) patients show primary nonresponse to antitumor necrosis factor (anti-TNF) biological therapy, and of those who respond, up to 40% develop secondary loss of response (LOR). Therapeutic drug monitoring (TDM) plays a crucial role in assessing patients with LOR to guide therapy by giving more of the drug or switching to a different biological agent. Although reactive TDM is suggested or recommended by the majority of gastroenterology associations, proactive TDM seems to be more controversial.

SUMMARY

In this article, we discuss the updated guidelines on TDM and will also discuss the available data supporting proactive and reactive TDM in patients with Crohn's disease and those with ulcerative colitis using the different available biological agents.

KEY MESSAGES

Therapeutic drug monitoring (TDM) is a valuable tool to aid in inflammatory bowel disease (IBD) therapy optimization. Reactive TDM is widely accepted in IBD patients with suspected loss of response, especially in those receiving antitumor necrosis factor (anti-TNF) agents. Proactive TDM is emerging as a reasonable approach to patients initiated on anti-TNF therapy, specifically infliximab and, to some extent, adalimumab, particularly for patients with severe ulcerative colitis and fistulizing Crohn's disease. Similarly, TDM may play a role in patients considering de-escalation from combination therapy. To date, proactive TDM is not widely applied to ustekinumab and vedolizumab and more data are required before this becomes part of clinical practice.

Etrolizumab for maintenance therapy in patients with moderately to severely active ulcerative colitis (LAUREL): a randomised, placebo-controlled, double-blind, phase 3 study

BACKGROUND

Etrolizumab is a gut-targeted anti-β7 integrin monoclonal antibody. In a previous phase 2 induction study, etrolizumab significantly improved clinical remission versus placebo in patients with moderately to severely active ulcerative colitis. We aimed to evaluate the efficacy and safety of etrolizumab for maintenance of remission in patients with moderately to severely active ulcerative colitis.

METHODS

We conducted a randomised, placebo-controlled, double-blind, phase 3 study (LAUREL) across 111 treatment centres worldwide. We included adults (age 18-80 years) with moderately to severely active ulcerative colitis (Mayo Clinic total score [MCS] of 6-12 with an endoscopic subscore of ≥2, a rectal bleeding subscore of ≥1, and a stool frequency subscore of ≥1) who were naive to tumour necrosis factor inhibitors. Patients were required to have had an established diagnosis of ulcerative colitis for at least 3 months, corroborated by both clinical and endoscopic evidence, and evidence of disease extending at least 20 cm from the anal verge. During open-label induction, participants received subcutaneous etrolizumab 105 mg once every 4 weeks. Participants who had clinical response at week 10 (MCS with ≥3-point decrease and ≥30% reduction from baseline, plus ≥1-point decrease in rectal bleeding subscore or absolute rectal bleeding score of 0 or 1) proceeded into the double-blind maintenance phase and were randomly assigned (1:1) to receive subcutaneous etrolizumab 105 mg once every 4 weeks or matched placebo until week 62. Randomisation was stratified by baseline concomitant treatment with corticosteroids, treatment with immunosuppressants, baseline disease activity, and week 10 remission status. All participants and study site personnel were masked to treatment assignment. The primary endpoint was remission at week 62 (MCS ≤2, with individual subscores ≤1, and rectal bleeding subscore of 0) among patients with a clinical response at week 10, measured in the modified intention-to-treat population (all randomised patients who received at least one dose of study drug). This trial is registered with ClinicalTrials.gov, NCT02165215, and is now closed to recruitment.

FINDINGS

Between Aug 12, 2014, and June 4, 2020, 658 patients were screened for eligibility and 359 were enrolled into the induction phase. 214 (60%) patients had a clinical response at week 10 and were randomly assigned to receive etrolizumab (n=108) or placebo (n=106) in the maintenance phase. 80 (74%) patients in the etrolizumab group and 42 (40%) in the placebo group completed the study through week 62. Four patients in the placebo group did not receive study treatment and were excluded from the analyses. At week 62, 32 (29·6%) of 108 patients in the etrolizumab group and 21 (20·6%) of 102 in the placebo group were in remission (adjusted treatment difference 7·7% [95% CI -4·2 to 19·2]; p=0·19). A greater proportion of patients reported one or more adverse events in the placebo group (82 [80%] of 102) than in the etrolizumab group (70 [65%] of 108); the most common adverse event in both groups was ulcerative colitis (16 [15%] patients in the etrolizumab group and 37 [36%] in the placebo group). Ten (9%) patients in the etrolizumab group and eight (8%) in the placebo group reported one or more serious adverse events. No deaths were reported in either treatment group.

INTERPRETATION

No significant differences were observed between maintenance etrolizumab and placebo in the primary endpoint of remission at week 62 among patients who had a clinical response at week 10. Etrolizumab was well tolerated in this population and no new safety signals were identified.

FUNDING

F Hoffmann-La Roche.

Etrolizumab versus adalimumab or placebo as induction therapy for moderately to severely active ulcerative colitis (HIBISCUS): two phase 3 randomised, controlled trials

BACKGROUND

Etrolizumab is a gut-targeted anti-β7 integrin monoclonal antibody. In an earlier phase 2 induction study, etrolizumab significantly improved clinical remission relative to placebo in patients with moderately to severely active ulcerative colitis. The HIBISCUS studies aimed to compare the efficacy and safety of etrolizumab to adalimumab and placebo for induction of remission in patients with moderately to severely active ulcerative colitis.

METHODS

HIBISCUS I and HIBISCUS II were identically designed, multicentre, phase 3, randomised, double-blind, placebo-controlled and active-controlled studies of etrolizumab, adalimumab, and placebo in adult (18-80 years) patients with moderately to severely active ulcerative colitis (Mayo Clinic total score [MCS] of 6-12 with an endoscopic subscore of ≥2, a rectal bleeding subscore of ≥1, and a stool frequency subscore of ≥1) who were naive to tumour necrosis factor inhibitors. All patients had an established diagnosis of ulcerative colitis for at least 3 months, corroborated by both clinical and endoscopic evidence, and evidence of disease extending at least 20 cm from the anal verge. In both studies, patients were randomly assigned (2:2:1) to receive subcutaneous etrolizumab 105 mg once every 4 weeks; subcutaneous adalimumab 160 mg on day 1, 80 mg at week 2, and 40 mg at weeks 4, 6, and 8; or placebo. Randomisation was stratified by baseline concomitant treatment with corticosteroids, concomitant treatment with immunosuppressants, and baseline disease activity. All patients and study site personnel were masked to treatment assignment. The primary endpoint was induction of remission at week 10 (defined as MCS of 2 or lower, with individual subscores of 1 or lower, and rectal bleeding subscore of 0) with etrolizumab compared with placebo. Pooled analyses of both studies comparing etrolizumab and adalimumab were examined for several clinical and endoscopic endpoints. Efficacy was analysed using a modified intent-to-treat population, defined as all randomly assigned patients who received at least one dose of study drug. These trials are registered with ClinicalTrials.gov, NCT02163759 (HIBISCUS I), NCT02171429 (HIBISCUS II).

FINDINGS

Between Nov 4, 2014, and May 25, 2020, each study screened 652 patients (HIBISCUS I) and 613 patients (HIBISCUS II). Each study enrolled and randomly assigned 358 patients (HIBISCUS I etrolizumab n=144, adalimumab n=142, placebo n=72; HIBISCUS II etrolizumab n=143; adalimumab n=143; placebo n=72). In HIBISCUS I, 28 (19·4%) of 144 patients in the etrolizumab group and five (6·9%) of 72 patients in the placebo group were in remission at week 10, with an adjusted treatment difference of 12·3% (95% CI 1·6 to 20·6; p=0·017) in favour of etrolizumab. In HIBISCUS II, 26 (18·2%) of 143 patients in the etrolizumab group and eight (11·1%) of 72 patients in the placebo group were in remission at week 10, with an adjusted treatment difference of 7·2% (95% CI -3·8 to 16·1; p=0·17). In the pooled analysis, etrolizumab was not superior to adalimumab for induction of remission, endoscopic improvement, clinical response, histological remission, or endoscopic remission; however, similar numerical results were observed in both groups. In HIBISCUS I, 50 (35%) of 144 patients in the etrolizumab group reported any adverse event, compared with 61 (43%) of 142 in the adalimumab group and 26 (36%) of 72 in the placebo group. In HIBISCUS II, 63 (44%) of 143 patients in the etrolizumab group reported any adverse event, as did 62 (43%) of 143 in the adalimumab group and 33 (46%) in the placebo group. The most common adverse event in all groups was ulcerative colitis flare. The incidence of serious adverse events in the pooled patient population was similar for etrolizumab (15 [5%] of 287) and placebo (seven [5%] of 144) and lower for adalimumab (six [2%] of 285). Two patients in the etrolizumab group died; neither death was deemed to be treatment related.

INTERPRETATION

Etrolizumab was superior to placebo for induction of remission in HIBISCUS I, but not in HIBISCUS II. Etrolizumab was well tolerated in both studies.

FUNDING

F Hoffmann-La Roche.

Etrolizumab as induction and maintenance therapy for ulcerative colitis in patients previously treated with tumour necrosis factor inhibitors (HICKORY): a phase 3, randomised, controlled trial

BACKGROUND

Etrolizumab is a gut-targeted, anti-β7 integrin, monoclonal antibody. In an earlier phase 2 induction study, etrolizumab significantly improved clinical remission compared with placebo in patients with moderately to severely active ulcerative colitis. We aimed to evaluate the efficacy and safety of etrolizumab in patients with moderately to severely active ulcerative colitis who had been previously treated with anti-tumour necrosis factor (TNF) agents.

METHODS

HICKORY was a multicentre, phase 3, double-blind, placebo-controlled study in adult (18-80 years) patients with moderately to severely active ulcerative colitis (Mayo Clinic total score [MCS] of 6-12 with an endoscopic subscore of ≥2, a rectal bleeding subscore of ≥1, and a stool frequency subscore of ≥1) previously treated with TNF inhibitors. Patients were recruited from 184 treatment centres across 24 countries in North America, South America, Europe, Asia, Oceania, and the Middle East. Patients needed to have an established diagnosis of ulcerative colitis for at least 3 months, corroborated by both clinical and endoscopic evidence, and evidence of disease extending at least 20 cm from the anal verge. In cohort 1, patients received open-label etrolizumab 105 mg every 4 weeks for a 14-week induction period. In cohort 2, patients were randomly assigned (4:1) to receive subcutaneous etrolizumab 105 mg or placebo every 4 weeks for the 14-week induction phase. Patients in either cohort achieving clinical response to etrolizumab induction were eligible for the maintenance phase, in which they were randomly assigned (1:1) to receive subcutaneous etrolizumab 105 mg or placebo every 4 weeks through to week 66. Randomisation was stratified by baseline concomitant treatment with corticosteroids, concomitant treatment with immunosuppressants (induction randomisation only), baseline disease activity, week 14 MCS remission status (maintenance randomisation only), and induction cohort (maintenance randomisation only). All patients and study site personnel were masked to treatment assignment. Primary endpoints were remission (Mayo Clinic total score [MCS] ≤2, with individual subscores of ≤1 and a rectal bleeding subscore of 0) at week 14, and remission at week 66 among patients with a clinical response (MCS with ≥3-point decrease and ≥30% reduction from baseline, plus ≥1 point decrease in rectal bleeding subscore or absolute rectal bleeding score of 0 or 1) at week 14. Efficacy was analysed using a modified intent-to-treat population. Safety analyses included all patients who received at least one dose of study drug during the induction phase. This study is registered at ClinicalTrials.gov, NCT02100696.

FINDINGS

HICKORY was conducted from May 21, 2014, to April 16, 2020, during which time 1081 patients were screened, and 609 deemed eligible for inclusion. 130 patients were included in cohort 1. In cohort 2,479 patients were randomly assigned to the induction phase (etrolizumab n=384, placebo n=95). 232 patients were randomly assigned to the maintenance phase (etrolizumab to etrolizumab n=117, etrolizumab to placebo n=115). At week 14, 71 (18·5%) of 384 patients in the etrolizumab group and six (6·3%) of 95 patients in the placebo group achieved the primary induction endpoint of remission (p=0·0033). No significant difference between etrolizumab and placebo was observed for the primary maintenance endpoint of remission at week 66 among patients with a clinical response at week 14 (27 [24·1%] of 112 vs 23 [20·2%] of 114; p=0·50). Four patients in the etrolizumab group reported treatment-related adverse events leading to treatment discontinuation. The proportion of patients reporting at least adverse event was similar between treatment groups for induction (etrolizumab 253 [66%] of 384; placebo 63 [66%] of 95) and maintenance (etrolizumab to etrolizumab 98 [88%] of 112; etrolizumab to placebo 97 [85%] of 114). The most common adverse event in both groups was ulcerative colitis flare. Most adverse events were mild or moderate. During induction, the most common serious adverse event was ulcerative colitis flare (etrolizumab ten [3%] of 384; placebo: two [2%] of 95). During maintenance, the most common serious adverse event in the etrolizumab to etrolizumab group was appendicitis (two [2%] of 112) and the most common serious adverse events in the etrolizumab to placebo group were ulcerative colitis flare (two [2%] of 114) and anaemia (two [2%] of 114).

INTERPRETATION

HICKORY demonstrated that a significantly higher proportion of patients with moderately to severely active ulcerative colitis who had been previously treated with anti-TNF agent were able to achieve remission at week 14 when treated with etrolizumab compared with placebo; however, there was no significant difference between groups in remission at week 66 among patients with a clinical response at week 14.

FUNDING

F Hoffmann-La Roche.

Etrolizumab versus infliximab for the treatment of moderately to severely active ulcerative colitis (GARDENIA): a randomised, double-blind, double-dummy, phase 3 study

BACKGROUND

Etrolizumab is a gut-targeted anti-β7 integrin monoclonal antibody. In a previous phase 2 induction study, etrolizumab significantly improved clinical remission versus placebo in patients with moderately to severely active ulcerative colitis. We aimed to compare the safety and efficacy of etrolizumab with infliximab in patients with moderately to severely active ulcerative colitis.

METHODS

We conducted a randomised, double-blind, double-dummy, parallel-group, phase 3 study (GARDENIA) across 114 treatment centres worldwide. We included adults (age 18-80 years) with moderately to severely active ulcerative colitis (Mayo Clinic total score [MCS] of 6-12 with an endoscopic subscore of ≥2, a rectal bleeding subscore of ≥1, and a stool frequency subscore of ≥1) who were naive to tumour necrosis factor inhibitors. Patients were required to have had an established diagnosis of ulcerative colitis for at least 3 months, corroborated by both clinical and endoscopic evidence, and evidence of disease extending at least 20 cm from the anal verge. Participants were randomly assigned (1:1) to receive subcutaneous etrolizumab 105 mg once every 4 weeks or intravenous infliximab 5 mg/kg at 0, 2, and 6 weeks and every 8 weeks thereafter for 52 weeks. Randomisation was stratified by baseline concomitant treatment with corticosteroids, concomitant treatment with immunosuppressants, and baseline disease activity. All participants and study site personnel were masked to treatment assignment. The primary endpoint was the proportion of patients who had both clinical response at week 10 (MCS ≥3-point decrease and ≥30% reduction from baseline, plus ≥1-point decrease in rectal bleeding subscore or absolute rectal bleeding score of 0 or 1) and clinical remission at week 54 (MCS ≤2, with individual subscores ≤1); efficacy was analysed using a modified intention-to-treat population (all randomised patients who received at least one dose of study drug). GARDENIA was designed to show superiority of etrolizumab over infliximab for the primary endpoint. This trial is registered with ClinicalTrials.gov, NCT02136069, and is now closed to recruitment.

FINDINGS

Between Dec 24, 2014, and June 23, 2020, 730 patients were screened for eligibility and 397 were enrolled and randomly assigned to etrolizumab (n=199) or infliximab (n=198). 95 (48%) patients in the etrolizumab group and 103 (52%) in the infliximab group completed the study through week 54. At week 54, 37 (18·6%) of 199 patients in the etrolizumab group and 39 (19·7%) of 198 in the infliximab group met the primary endpoint (adjusted treatment difference -0·9% [95% CI -8·7 to 6·8]; p=0·81). The number of patients reporting one or more adverse events was similar between treatment groups (154 [77%] of 199 in the etrolizumab group and 151 [76%] of 198 in the infliximab group); the most common adverse event in both groups was ulcerative colitis (55 [28%] patients in the etrolizumab group and 43 [22%] in the infliximab group). More patients in the etrolizumab group reported serious adverse events (including serious infections) than did those in the infliximab group (32 [16%] vs 20 [10%]); the most common serious adverse event was ulcerative colitis (12 [6%] and 11 [6%]). There was one death during follow-up, in the infliximab group due to a pulmonary embolism, which was not considered to be related to study treatment.

INTERPRETATION

To our knowledge, this trial is the first phase 3 maintenance study in moderately to severely active ulcerative colitis to use infliximab as an active comparator. Although the study did not show statistical superiority for the primary endpoint, etrolizumab performed similarly to infliximab from a clinical viewpoint.

FUNDING

F Hoffmann-La Roche.

Photodynamic Therapy of Novel Photosensitizer Ameliorates TNBS-Induced Ulcerative Colitis via Inhibition of AOC1

Ulcerative colitis (UC), a chronic, nonspecific inflammatory bowel disease characterized by continuous and diffuse inflammatory changes in the colonic mucosa, requires novel treatment method. Photodynamic therapy (PDT), as a promising physico-chemical treatment method, were used to treat UC rats’ model with novel photosensitizer LD₄ in this paper, the treatment effect and mechanism was investigated. LD₄-PDT could improve the survival rate of 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced UC model rats, decrease expression of interleukin (IL)-6, IL-1, tumor necrosis factor (TNF)-α, malondialdehyde (MDA), myeloperoxidase (MPO) and increase the expression of glutathione (GSH) and superoxide oxidase (SOD), while protecting the integrity of the intestinal epithelium. LD₄-PDT treatment could rebuild the intestinal microflora composition and reprogram the colonic protein profiles in TNBS-induced rats to almost the normal state. Proteomics analysis based upon TNBS-induced UC model rats revealed that Amine oxidase copper-containing 1 (AOC₁) was a potential target of LD₄-PDT. Novel photosensitizer agent LD₄-PDT represents an efficient treatment method for UC, and AOC₁ may be a promising target.

Vedolizumab Tissue Concentration Correlates to Mucosal Inflammation and Objective Treatment Response in Inflammatory Bowel Disease

BACKGROUND

The association between vedolizumab (VDZ) exposure and treatment response is unclear and seems insufficiently explained by serum levels. The aim of this study was to assess the correlation between VDZ concentrations in serum and intestinal tissue and their association with mucosal inflammation and response to VDZ.

METHODS

This prospective study included 37 adult patients with inflammatory bowel disease with endoscopic inflammation at baseline who started VDZ. At week 16, serum and biopsies were collected for VDZ measurement by enzyme-linked immunosorbent assay. Nonlinear mixed-effects modeling was used to calculate serum trough concentrations and to assess intestinal tissue concentrations. Validated clinical and endoscopic scores were used to define clinical and endoscopic response and remission, and fecal calprotectin levels were used to assess biochemical response. Histologic remission was determined by the Nancy score.

RESULTS

A positive correlation was observed between VDZ concentrations in serum and tissue (r2 = 0.83; P < 0.0001). High mucosal rather than serum VDZ levels correlated with a reduced endoscopic (P = 0.06) grade of mucosal inflammation. Furthermore, patients with a positive biochemical and endoscopic outcome had higher tissue levels of VDZ than patients without biochemical and endoscopic response (P < 0.01 and P = 0.04, respectively).

CONCLUSIONS

Tissue levels of VDZ may provide a better marker than serum levels for mucosal inflammation and objective treatment outcome at week 16. The potential of VDZ tissue levels for therapeutic drug monitoring in inflammatory bowel disease warrants further exploration.

Therapeutic drug monitoring in inflammatory bowel disease: The dawn of reactive monitoring

Inflammatory bowel disease (IBD) is a chronic condition that significantly affects the quality of life of its patients. Biologic drugs have been the mainstay treatment in the management of IBD patients but despite their significant contribution, there remains a proportion of patients that do not respond or lose response to treatment. Therapeutic drug monitoring (TDM) involves measuring levels of serum drug concentrations and anti-drug antibodies. TDM of biologic drugs initially emerged to understand treatment failure in other immune mediated inflammatory diseases. This was then introduced in IBD to rationalize primary non-response or secondary loss of response, given that low serum drug concentrations or the formation of anti-drug antibodies are variably associated with treatment failure. The aim of this narrative review is to provide an overview regarding the current use of TDM in clinical practice and to present the evidence available regarding its use in both proactive and reactive clinical settings in preventing and managing treatment failure. This review also presents the existing evidence regarding the association of various clinical outcomes with specific thresholds of drug concentrations, in everyday practice. A narrative review of published articles and conference abstracts regarding the use of TDM in IBD management, through an electronic search using PubMed and ScienceDirect. TDM has proven to be superior and more cost effective in guiding management of patients with treatment failure compared to empiric dose escalation or change in treatment. Despite a trend towards an association between clinical outcomes and drug concentrations, proactive TDM based strategies have not been shown to achieve clear benefit in long-term outcomes. In the clinical setting, TDM has proven to be useful in managing IBD patients, and its use in the reactive setting, as an additional tool to help manage patients with treatment failure, is being promoted as newer guidelines and consensus groups implement TDM as part of the management plan.

Association of Infliximab and Vedolizumab Trough Levels with Reported Rates of Adverse Events: A Cross-Sectional Study

Infliximab and vedolizumab are effective treatments for inflammatory bowel disease (IBD), although associated with adverse events (AE). While low or non-existent drug levels and positive antidrug antibodies have been associated with therapeutic failure, there is no clear association between higher drug levels and AE. A cross-sectional study consisting of Crohn’s disease (CD) and ulcerative colitis (UC) patients receiving infliximab or vedolizumab at the Sheba Medical Center was performed. Patients completed a questionnaire regarding AEs related to biological therapy. Serum trough levels obtained on the same day were analyzed. Objective measures of outcomes were retrieved from medical records. Questionnaires were completed by infliximab (n = 169) and vedolizumab (n = 88)-treated therapy patients. Higher infliximab levels were only numerically associated with the occurrence of at least one AE (p = 0.08). When excluding fatigue and abdominal pain, higher infliximab levels were statistically associated with the occurrence of at least one AE (p = 0.03). Vedolizumab drug levels > 18 μg/mL were also linked with the occurrence of more AEs. No specific association was observed between the increased levels of either infliximab or vedolizumab and specific AEs (neurological symptoms, upper GI symptoms, infectious complications, and musculoskeletal symptoms). As significant AEs are very rare, additional multi-center studies are required.

A phase 2a randomized clinical trial of intravenous vedolizumab for the treatment of steroid-refractory intestinal acute graft-versus-host disease

Steroid-refractory (SR) acute graft-versus-host disease (aGvHD) remains a significant complication after allogeneic hematopoietic cell transplantation. Systemic corticosteroids are first-line therapy for aGvHD, but apart from ruxolitinib, there are no approved treatments for SR aGvHD. Vedolizumab is approved for treatment of ulcerative colitis and Crohn’s disease, and may be effective for treatment of SR intestinal aGvHD. We conducted a phase 2a trial (NCT02993783) to evaluate the clinical efficacy, tolerability, and safety of vedolizumab 300 and 600 mg for SR intestinal aGvHD. This study was terminated before full enrollment was completed because early results failed to demonstrate positive proof-of-concept in efficacy. Before termination, 17 participants had enrolled and an early response in intestinal aGvHD was observed in 11 and eight participants at days 15 and 28, respectively. All adverse events observed were consistent with those expected in a population with SR intestinal aGvHD. Overall, vedolizumab did not meet the primary efficacy endpoint (overall response at day 28), likely owing to premature study drug discontinuation, lack of efficacy, and the competing risks inherent with a population with advanced SR intestinal aGvHD. Nevertheless, this study provides valuable insights into the considerations needed when conducting studies in patients with SR intestinal aGvHD.

Update on TDM (Therapeutic Drug Monitoring) with Ustekinumab, Vedolizumab and Tofacitinib in Inflammatory Bowel Disease

The goal of therapeutic drug monitoring (TDM) is to optimize anti-TNF (tumor necrosis factor) biologic treatment in patients with inflammatory bowel disease (IBD). Although commercial assays are readily available for both ustekinumab and vedolizumab, the use of TDM with these newer biologic medications is at its infancy. The clinical utility of TDM with non-anti-TNF mechanisms of action is not clear. This review summarizes the latest available data on the pharmacokinetics of newer biologic and oral small molecules and highlights the threshold concentrations that have been associated with improved outcomes in IBD patients.

Inpatient Therapy With Calcineurin Inhibitors in Severe Ulcerative Colitis

BACKGROUND

Inpatient management of severe ulcerative colitis is complicated by the use of prior immunosuppressant therapies. Our aim was to determine the rate of 1-year colectomy among individuals receiving inpatient calcineurin inhibitor (CNI)-based therapy stratified by prior biologic therapy.

METHODS

A retrospective cohort study was performed between January 1, 2013 and April 1, 2018. Only individuals requiring inpatient administration of intravenous cyclosporine or oral tacrolimus were included in the analysis. Individuals were stratified according to prior biologic therapy exposure. The primary outcome of interest was 1-year risk of colectomy. Kaplan-Meier curves were generated for time-to-event data, and regression models were performed to examine the effects of covariates on the clinical endpoint.

RESULTS

Sixty-nine (62.3% male) patients were treated with an inpatient CNI-based therapy and were included in the analysis. Fifteen (21.7%) patients were biologic-naïve, 42 (60.9%) patients had prior exposure to 1 class of biologic therapy, and 12 (17.4%) patients had prior exposure to 2 classes of biologic therapy (third-line CNI therapy). Third-line CNI therapy showed a greater risk of 1-year colectomy risk when compared with the risk for patients who were biologic-naïve (hazard ratio, 3.63; 95% confidence interval, 1.17-13.45; P = 0.025). In a multivariate proportional hazards model, third-line CNI therapy remained significantly associated with 1-year colectomy risk (hazard ratio, 7.94; 95% confidence interval, 1.97-39.76; P = 0.003).

CONCLUSIONS

The use of CNI-based therapy in individuals exposed to multiple classes of prior biologic therapies leads to a significantly increased risk of 1-year colectomy. Future studies will be required to compare inpatient management strategies with the expanding novel therapies in UC.

Therapeutic drug monitoring of anti-tumour necrosis factor-α agents in inflammatory bowel disease: Limits and improvements

AIMS

Since the publication of the American Gastroenterological Association's recommendations in 2017, there have been no significant changes in the biological monitoring recommendations in inflammatory bowel disease. Possible limitations are the lack of evidence to recommend proactive therapeutic drug monitoring (pTDM) over reactive TDM (rTDM), and the limited information about individualized dosing methods. This article aims to review the TDM strategy updates and the use of individualized dosing methods.

METHODS

For the analysis of the TDM strategies and individualized dosing method, a search was carried out in PubMed and Cochrane Central. In the TDM case, since August 2017.

RESULTS

A total of 263 publications were found, but only 7 related to proactive TDM. Five of these publications directly compared pTDM vs rTDM and 2 were randomized clinical trials. Six studies found benefits of pTDM and 1 found no differences. Regarding the individualized dosing method, 229 distinct results were found. Population pharmacokinetics was the most widely used method to develop individual dosage models and to analyse the influence of factors on drug concentrations (albumin concentration, weight, presence of anti-drug antibodies etc).

CONCLUSION

We have found no major changes in TDM strategies. There is a growing trend towards the use of pTDM because it has shown a longer duration of treatment response, lower rates of discontinuation and relapses. However, the available evidence is limited and of low quality. Despite the common use of population pharmacokinetic methods to analyse pharmacokinetic factors, they are not commonly used for personalized dosing.

Circulating exosomes express α4β7 integrin and compete with CD4+ T cells for the binding to Vedolizumab

Vedolizumab (VDZ) is a therapeutic monoclonal antibody approved for the treatment of inflammatory bowel diseases (IBD). VDZ selectively binds to the α4β7 integrin and blocks trafficking of a specific subset of gastrointestinal-homing T-lymphocytes to inflamed tissue. Although VDZ has shown promising results in numerous clinical studies a subgroup of patients do not respond adequately. Mechanistic insights and prognostic biomarkers able to predict which patients might benefit from VDZ therapy are currently lacking. Circulating exosomes were isolated from serum of blood donors and VDZ-treated patients by polymer-based precipitation. The surface expression of α4β7 integrin was evaluated by flow cytometry and the levels of exosome-bound VDZ were investigated by Promonitor-VDZ ELISA kit. The capacity of exosomes to interfere with the adhesion of VDZ-treated CD4+ T cells was assessed by adhesion assay. In this study, we showed that serum exosomes isolated from both blood donor and ulcerative colitis patients express on their surface the VDZ target α4β7 integrin. We observed an increased exosomal sequestration of VDZ in anti-TNF exposed patients compared to anti- TNFα naïve patients, according to a greater expression of α4β7 integrin on vesicles surface. Circulating exosomes could compete for VDZ binding with CD4+ T cells since we found that the amount of VDZ bound to T cells was impaired in the presence of exosomes. In addition, we demonstrated that exosomes bind VDZ, which consequently becomes unable to block MadCAM-1-mediated adhesion of lymphocytes. Circulating exosomes might contribute to drug sequestration, possibly affecting the therapeutic efficacy of VDZ in IBD patients. Our data suggest that previous biologic therapy may have altered the sequestration capacity of circulating exosomes, thus reducing the efficacy of VDZ in patients who failed anti-TNF agents.

Infliximab, adalimumab and vedolizumab concentrations across pregnancy and vedolizumab concentrations in infants following intrauterine exposure

BACKGROUND

The impact of pregnancy on levels of biologic agents in patients with IBD is undefined and time to elimination in vedolizumab-exposed infants is unknown.

AIMS

To determine the effect of pregnancy on infliximab, adalimumab and vedolizumab levels and to study infant vedolizumab clearance METHODS: In a prospective observational study, maternal drug levels were measured pre-conception, in each trimester, at delivery and postpartum. The association between drug levels and gestation in weeks was assessed using generalised estimating equation modelling. Infant vedolizumab levels were performed at birth (cord blood), 6 weeks and 3 months or until undetectable.

RESULTS

We included 50 IBD patients (23 on infliximab, 15 on adalimumab and 12 on vedolizumab) with at least two intrapartum observations, plus 5 patients on vedolizumab with only mother and baby samples at delivery. Modelling showed no change in adalimumab levels, an increase in infliximab levels of 0.16 (95% CI 0.08-0.24) µg/L/week (P < 0.001) and a decrease of 0.18 (95% CI: -0.33 to -0.02) µg/L/week (P = 0.03) for vedolizumab. In 17 mother-baby pairs, median infant vedolizumab levels at birth were lower than maternal levels (P < 0.05) with an infant:maternal ratio of 0.7 (IQR 0.5-0.9). Vedolizumab was undetectable between 15 and 16 weeks of age in all 12 infants completing follow-up testing.

CONCLUSIONS

During pregnancy, adalimumab levels remain stable, while infliximab levels increase and vedolizumab levels decrease. However, the increments were small suggesting that intrapartum therapeutic drug monitoring and dose adjustment are not indicated. Unlike infliximab and adalimumab, infant vedolizumab levels are lower in cord blood than in mothers and appear to clear rapidly.

Optimizing biologic therapy in IBD: how essential is therapeutic drug monitoring?

Proposed treatment targets for the management of inflammatory bowel disease (IBD) have moved beyond symptomatic improvement towards more objective end points, such as healing of the intestinal mucosa. This treat-to-target approach has been associated with improved disease outcomes such as diminished bowel damage, surgery and hospitalizations. Many patients with IBD require biologic therapy to achieve and maintain clinical and endoscopic remission, and antitumour necrosis factor antibodies remain the first-line biologic therapy in most areas of the world. Unfortunately, up to one-third of patients receiving this treatment are primary non-responders, and some patients that show an initial response can also lose response over time. Therapeutic drug monitoring (TDM) has been suggested as a useful tool to manage patients on antitumour necrosis factor treatment, including monitoring for dose escalation, de-escalation or to switch treatment. In this Perspective, we aim to summarize evidence and guidelines related to TDM in IBD management and also discuss potential strategies to optimize biologic treatment where TDM is not available.

Janus Kinase inhibitors in the New Treatment Paradigms of Inflammatory Bowel Disease

This review provides guidance in the decision-making process regarding when to choose a janus kinase [JAK] inhibitor as medical treatment strategy. The focus will be on ulcerative colitis, because the only yet available JAK inhibitor, tofacitinib, has approval for use in ulcerative colitis. The guidance path will include consideration of disease activity, previous treatment, comorbidities, family planning, patient preferences, pharmacology as well as concurrent chronic inflammatory diseases or extraintestinal manifestations. The suggested guidance path illustrates our daily difficulties in the decision-making process regarding best choice for the individual patient. However if predictive biomarkers are lacking, the named criteria can be applied to any other strategy and hence provide support in daily practice.

Acute Graft-versus-Host Disease: Emerging Insights and Updates into Detection, Prevention, and Treatment

Acute graft-versus-host disease remains a devastating complication following hematopoietic cell transplantation, resulting in increased morbidity and mortality. Vast research efforts continue to refine or develop new means of prediction, assessment, prevention, and treatment of this syndrome. Recent updates in acute graft-versus-host disease include more definitive guidance and definitions for its grading and diagnosis. Biomarker use is being incorporated into early stages following hematopoietic cell transplantation to aid in the detection and prediction of long-term outcomes. New preventive strategies under investigation include the use of vedolizumab or tocilizumab as upfront prophylaxis. Finally, although steroids remain the backbone of therapy once treatment is warranted, the efficacy of several agents including vedolizumab, tocilizumab, ruxolitinib, and α1 antitrypsin are being evaluated as potential therapeutic options.

Higher vedolizumab serum levels do not increase the risk of adverse events in patients with inflammatory bowel disease

Background: Although its mechanism of action may confer a safety benefit, vedolizumab has still been associated with adverse events (AE). We investigated whether inflammatory bowel disease (IBD) patients with higher trough vedolizumab serum levels experienced an increased risk of AEs.Methods: This was a retrospective study of 76 IBD patients with at least one measurement of serum vedolizumab available. Vedolizumab levels ranged from <3.5 mcg/mL to 87.2 mcg/mL (median = 15.8 mcg/mL). The primary outcome was the rate of overall AEs. Secondary outcomes included the rates of infections, dermatologic reactions, infusion reactions, and other AEs. Multivariate logistic regression analysis was performed to evaluate the relationship between serum vedolizumab levels and AEs.Results: 19 patients out of 76 reported AEs. In patients with higher vedolizumab levels, there were 10 AEs reported out of 38 patients, which was not significantly different from the 9 AEs reported in 38 patients with lower vedolizumab levels (26.3% vs. 23.7%, p = .79). After adjustment for potential covariates, IBD patients with higher vedolizumab levels did not have higher odds of an AE than patients with lower levels (OR 0.92, 95% CI 0.30-2.81). Longer duration of therapy had higher odds of AEs, (OR of 1.04 at 95% CI 1.00-1.09, p = .0494 per additional month). None of the other variables were associated with a greater risk of AEs.Conclusions: There does not appear to be an increased risk of adverse events in IBD patients with higher vedolizumab levels, but duration of therapy may increase the risk of AEs.

Vedolizumab quantitation using high-resolution accurate mass-mass spectrometry middle-up protein subunit: method validation

Background While quantitation methods for small-molecule and tryptic peptide bottom-up mass spectrometry (MS) have been well defined, quantitation methods for top-down or middle-up MS approaches have not been as well defined. Therapeutic monoclonal antibodies (t-mAbs) are a group of proteins that can be used to both demonstrate the advantages of top-down or middle-up detection methods over classic tryptic peptide bottom-up along with the growing need for robust quantitation strategies/software for these top-down or middle-up methods. Bottom-up proteolytic digest methods for the t-mAbs tend to suffer from challenges such as limited peptide selection due to potential interference from the polyclonal immunoglobulin background, complicated workflows, and inadequate sensitivity and specificity without laborious purification steps, and therefore have prompted the search for new detection and quantitation methods. Time-of-flight along with Orbitrap MS have recently evolved from the research and/or pharmaceutical setting into the clinical laboratory. With their superior mass measurement accuracy, resolution and scanning speeds, these are ideal platforms for top-down or middle-up characterization and quantitation. Methods We demonstrate a validated, robust, middle-up protein subunit detection and quantitation method for the IgG1 t-mAb, vedolizumab (VEDO), which takes advantage of the high resolution of the Orbitrap MS detection and quantitation software to increase specificity. Results Validated performance characteristics met pre-defined acceptance criteria with simple workflows and rapid turnaround times: characteristics necessary for implementation into a high-volume clinical MS laboratory. Conclusions While the extraction method can easily be used with other IgG1 t-mAbs, the detection and quantitation method may become an option for measurement of other proteins.

Therapeutic Drug Monitoring of Biologics During Induction to Prevent Primary Non-Response

Biologic therapies have revolutionized the management of inflammatory bowel disease [IBD], but primary and secondary non-responses occur in a significant proportion of patients. Therapeutic drug monitoring [TDM] now has an established role in the treatment algorithm for managing secondary loss of response to anti-tumour necrosis factor [anti-TNF] agents during maintenance therapy. Data to support the use of TDM in the management of secondary loss of response to vedolizumab and ustekinumab are emerging. The potential to prevent primary non-response to biologic agents during induction is of equal, and potentially greater, clinical importance. Again, most data supporting the use of 'proactive' TDM during induction pertains to the use of anti-TNF agents, but signals of efficacy for the use of TDM during induction with other biologic classes are now appearing. This review aims to summarize data on the use of TDM during induction to prevent pharmacokinetic primary non-response to all three classes of biologic therapy currently available for the treatment of IBD.

Recent advances in monoclonal antibody therapy in IBD: practical issues

The advent of monoclonal antibody therapies has revolutionised inflammatory bowel disease (IBD) treatment and delivered great benefits to patients. The optimal use of this class of drugs requires careful management and a clear understanding of their properties. In this review article, we consider how to maximise the benefit of our most novel biological agents, vedolizumab and ustekinumab. For each agent, we consider practical aspects including dose flexibility, evidence for use in combination with a conventional immunomodulator and the potential role of therapeutic drug monitoring. We also address positioning of the various mechanisms and agents in treatment algorithms as well as important aspects of managing patients receiving monoclonal antibodies, such as disease reassessment. Finally, we look ahead to the future of monoclonal antibodies, where not only have biosimilars increased the number of agents available but there are also a range of novel mechanisms currently in late phase clinical trials.

Management of Biological Therapy Before Elective Inflammatory Bowel Disease Surgeries

Increasing uptake of biologic therapy has contributed to declining surgical rates for inflammatory bowel disease (IBD). However, a significant number of patients on biologic therapy will go on to require surgery. The literature is conflicted with regard to the preoperative management of biologic therapy before urgent or elective IBD surgery. This article reviews the available data on postoperative complications following preoperative treatment with anti-tumor necrosis factor alpha therapy, anti-integrin therapy, and anti-interleukin therapy.

Biologic therapies for Crohn's disease: optimising the old and maximising the new

The era of biologic agents for the treatment of Crohn’s disease has brought about significant benefits for patients, and since the introduction of infliximab at the turn of the century, the entire field has moved on rapidly. Clinicians now have multiple agents at their disposal and a choice between several different anti-inflammatory mechanisms of action. This has allowed unprecedented improvements not only in symptoms and quality of life for patients previously refractory to conventional treatments but also for demonstrated healing of the intestinal mucosa and resolution of perianal fistulation. However, despite the undisputed efficacy of these agents, there remains a significant proportion of patients who fail to gain a meaningful benefit. Through years of studying infliximab and its counterpart anti-tumour necrosis factor (anti-TNF) agent, adalimumab, we now understand that strategies such as combining use with a conventional immunomodulator or measuring serum levels can help to optimise outcomes and reduce the proportion of patients for whom treatment fails. Work is ongoing to understand whether these principles apply to newer biologics such as vedolizumab and ustekinumab. In addition, novel approaches are being investigated in an attempt to maximise the benefit that these agents could offer. In this article, we summarise these new understandings and consider ways in which they could be integrated into clinical practice for the benefit of patients.

Immunogenicity is not the driving force of treatment failure in vedolizumab-treated inflammatory bowel disease patients

BACKGROUND AND AIM

The pivotal GEMINI trials reported low immunogenicity of vedolizumab. However, anti-vedolizumab antibodies (AVA) are frequently underestimated because most assays are not drug-tolerant and unable to detect antidrug antibodies while there is drug in the circulation. This study aimed to explore which antidrug antibody assay is best suited to detect AVA and investigated immunogenicity of vedolizumab in inflammatory bowel disease (IBD) patients discontinuing vedolizumab therapy.

METHODS

A drug-tolerant affinity capture elution (ACE) assay was developed for the measurement of AVA in the presence of vedolizumab and compared with the previously established drug-resistant and drug-sensitive assays. Vedolizumab and AVA were measured at week 6, at the last infusion, and 12-20 weeks after treatment discontinuation in a cohort of 40 vedolizumab-treated IBD patients who stopped treatment due to primary non-response, loss of response, or adverse events.

RESULTS

The drug-tolerant ACE assay could detect AVA in samples that the drug-resistant and drug-sensitive assays were unable to. Using the drug-tolerant ACE assay, 3 (8%) out of 40 vedolizumab-treated IBD patients who discontinued therapy were AVA positive at week 6, whereas no AVA were detected at the last infusion nor after treatment discontinuation. Primary non-responders had numerically lower median vedolizumab concentrations at week 6 compared with patients with loss of response (20.3 vs 30.7 μg/mL, respectively, P = 0.0570).

CONCLUSIONS

Immunogenicity of vedolizumab is not the driving force of treatment failure, and AVA do not increase upon treatment discontinuation in vedolizumab-treated IBD patients. Underexposure during induction might partially be responsible for primary non-response.