Thomas Billiet

A Panel to Predict Long-term Outcome of Infliximab Therapy for Patients With Ulcerative Colitis

BACKGROUND & AIMSnInfliximab is effective for patients with refractory ulcerative colitis (UC), but few factors have been identified that predict long-term outcome of therapy. We aimed to identify a panel of markers associated with outcome of infliximab therapy to help physicians make personalized treatment decisions.nnnMETHODSnWe collected data from the first 285 patients with refractory UC (41% female; median age, 39 y) treated with infliximab before July 2012 at University Hospitals Leuven, in Belgium. We performed a Cox regression analysis to identify independent factors that predicted relapse-free and colectomy-free survival, and used these factors to create a panel of markers (risk panel).nnnRESULTSnDuring a median follow-up period of 5 years, 61% of patients relapsed and 20% required colectomy. Independent predictors of relapse-free survival included short-term complete clinical response (odds ratio [OR], 3.75; 95% confidence interval [CI], 2.35-5.97; P < .001), mucosal healing (OR, 1.87; 95% CI, 1.17-2.98; Pxa0= .009), and absence of atypical perinuclear antineutrophil cytoplasmic antibodies (pANCA) (OR, 1.96; 95% CI, 1.23-3.12; Pxa0= .005). Independent predictors of colectomy-free survival included short-term clinical response (OR, 7.74; 95% CI, 2.76-21.68; P < .001), mucosal healing (OR, 4.02; 95% CI, 1.16-13.97; Pxa0= .028), baseline level of C-reactive protein (CRP) of 5 mg/L or less (OR, 2.95; 95% CI, 1.26-6.89; Pxa0= .012), and baseline level of albumin of 35 g/L or greater (OR, 3.03; 95% CI, 1.12-8.22; Pxa0= .029). Based on serologic analysis of a subgroup of 112 patients, levels of infliximab greater than 2.5 μg/mL at week 14 of treatment predicted relapse-free survival (P < .001) and colectomy-free survival (Pxa0= .034). A risk panel that included levels of pANCA, CRP, albumin, clinical response, and mucosal healing identified patients at risk for UC relapse or colectomy (both P < .001).nnnCONCLUSIONSnClinical response and mucosal healing were confirmed as independent predictors of long-term outcome from infliximab therapy in patients with UC. We identified additional factors (levels of pANCA, CRP, and albumin) to create a risk panel that predicts long-term outcomes of therapy. Serum levels of infliximab at week 14 of treatment also were associated with patient outcomes. Our risk panel and short-term serum levels of infliximab therefore might be used to guide therapy.

Targeting TNF-α for the treatment of inflammatory bowel disease

Introduction: The advent of tumor necrosis factor (TNF) antagonists represented a radical change in the management of inflammatory bowel disease (IBD). Both in short- and long-term, anti-TNF therapy has been shown to reduce symptoms, heal mucosal ulcers, reduce hospitalizations and surgeries and spare corticosteroids. Areas covered: A literature search to August 2013 was performed to identify the most relevant reports on the use of TNF antagonists in IBD. First, the authors focused on the mechanism of action of TNF antagonists. Second, they evaluated different indications, contraindications, the optimal time to start and the role of combining TNF antagonists with immunomodulators. Third, they explored the importance of mucosal healing, followed by the controversial topic on when TNF antagonists should be stopped. This is followed by the subjects of treatment failure, immunogenicity and therapeutic drug monitoring. Last, they analyzed safety issues including exposure to TNF antagonists during pregnancy. Expert opinion: TNF antagonists have become indispensable in the management of IBD. Efforts to focus on treatment of inflammatory signs only and on optimization of treatment with therapeutic drug monitoring are underway. The advent of several new compounds and “biosimilars” will further challenge the position of TNF antagonists in the treatment algorithm of IBD.

Infliximab Concentration Thresholds During Induction Therapy Are Associated With Short-term Mucosal Healing in Patients With Ulcerative Colitis

BACKGROUND & AIMSnMucosal healing is an independent predictor of sustained clinical remission in patients with ulcerative colitis (UC) treated with infliximab. We investigated whether infliximab concentrations during induction therapy are associated with short-term mucosal healing (STMH) in patients with UC.nnnMETHODSnWe performed a retrospective, single-center analysis of data collected from a tertiary referral center from 101 patients with UC who received scheduled induction therapy with infliximab at weeks 0, 2, and 6 and had an endoscopic evaluation at baseline and after induction therapy. STMH was defined as Mayo endoscopic sub-score ≤1, assessed at weeks 10-14, with baseline sub-score ≥2. Infliximab concentrations were evaluated in serum samples collected at weeks 0, 2, 6, and 14 of infliximab therapy by using an enzyme-linked immunosorbent assay we developed.nnnRESULTSnFifty-four patients (53.4%) achieved STMH. Patients with STMH had a higher median infliximab concentration at weeks 2, 6, and 14 than patients without STMH. A receiver operating characteristic (ROC) analysis identified infliximab concentration thresholds of 28.3 (area under the ROC curve [AUROC], 0.638), 15 (AUROC, 0.688), and 2.1 μg/mL (AUROC, 0.781) that associated with STMH at weeks 2, 6, and 14, respectively. Multiple logistic regression analysis identified infliximab concentration ≥15 at week 6 (Pxa0= .025; odds ratio, 4.6; 95% confidence interval, 1.2-17.1) and ≥2.1 μg/mL at week 14 (Pxa0= .004; odds ratio, 5.6; 95% confidence interval, 1.7-18) as independent factors associated with STMH.nnnCONCLUSIONSnIn an analysis of data from real-life clinical practice, we associated infliximab concentrations during the induction therapy with STMH in patients with UC.

An Optimized Anti-infliximab Bridging Enzyme-linked Immunosorbent Assay for Harmonization of Anti-infliximab Antibody Titers in Patients with Inflammatory Bowel Diseases

Background:The formation of anti-infliximab antibodies (ATI) is associated with loss of response and adverse events in patients with inflammatory bowel diseases, leading to the introduction of ATI monitoring for guiding treatment adjustments. However, a lack of standardization among current available assays exists, hampering comparison of results from different studies. This study aimed to improve the harmonization of clinically validated ATI enzyme-linked immunosorbent assays (ELISAs) by introducing a monoclonal anti-infliximab antibody (MA-IFX). Methods:A panel of MA-IFX was evaluated as calibrator in the first generation ATI ELISA. After selection of 1 MA-IFX, assay conditions were optimized and biotin-streptavidin-enhanced detection of bound infliximab was introduced. The novel second generation ELISA was used for reanalysis of 127 serum samples from a cohort of 12 patients with inflammatory bowel disease, previously identified as ATI positive. Results:Of 55 MA-IFX, MA-IFX10F9 was selected as calibrator in the ATI ELISA. After optimization of the assay conditions, a 4-fold improvement in sensitivity was obtained. Reanalysis of 127 serum samples revealed that in 5 of 12 patients (46%), ATI were detected at least 1 time point earlier with the second generation ELISA compared with the first generation ELISA. In 1 patient, the second generation ELISA allowed to detect ATI before the reinitiation of IFX after a drug holiday. Conclusions:In addition to the improved sensitivity and specificity of the second generation ATI ELISA, MA-IFX10F9 can serve as a universal calibrator to achieve assay harmonization. Moreover, the superiority of the second generation assay in analyzing serum of restarters was demonstrated.

Long-Term Outcome of Patients with Ulcerative Colitis and Primary Non-response to Infliximab.

BACKGROUND AND AIMSnWe studied the long-term outcome of patients with ulcerative colitis [UC] and primary non response [PNR] to infliximab and searched for predictors of colectomy in these patients.nnnMETHODSnThis retrospective, multi-centre study included UC patients from three European referral centres, with PNR to infliximab defined as a lack of clinical improvement after the induction therapy, leading to drug discontinuation. Relapse, for patients who continued on biologicals after PNR to infliximab, was defined as drug discontinuation for PNR, loss of response, or serious adverse event. Serum infliximab concentrations at Weeks 2 and 6 were evaluated using an enzyme-linked immunosorbent assay [ELISA] developed in house.nnnRESULTSnThe study population consisted of 99 anti-tumour necrosis factor [TNF]-naïve patients with UC and PNR to infliximab. At the end of follow-up (median: 3.2 [interquartile range 1-6.3] years), 55 [55.6%] of these patients underwent colectomy. Multiple Cox regression analysis identified acute severe UC (hazard ratio [HR]: 24; 95% confidence interval [CI]: 2.5-231; p = 0.006], baseline C-reactive protein [CRP] > 5mg/l [HR: 11; 95% CI: 2.1-58.8; p = 0.005], baseline albumin < 40g/l [HR: 9.5; 95% CI: 1.3-71.4; p = 0.026], and infliximab concentration at Week 2 < 16.5 μg/ml [HR: 5.6; 95% CI: 1.1-27.8; p = 0.034] as independent predictors of colectomy. Regarding patients who continued on biologicals after PNR to infliximab, there was a marginally higher cumulative probability for relapse in patients switching to another anti-TNF agent compared with those swapping to vedolizumab [p logrank = 0.08].nnnCONCLUSIONSnAbout half of UC patients with PNR to infliximab will undergo colectomy. Patients with severe inflammation and low serum infliximab concetrations during the induction phase are at greatest risk.

Immunogenicity to infliximab is associated with HLA-DRB1

Dear Editor,nnWe read with great interest the manuscript by Ungar and colleagues describing the temporal evolution of antibodies to infliximab (ATI) in patients with IBD treated with infliximab (IFX).1 By prospectively following 125 patients with IBD, they showed that ATI formation is a dynamic process. Clinically relevant ATI were typically formed within the first 12u2005months but transient ATI, which are of little clinical significance, can be formed at any time during treatment. They furthermore demonstrated that the evolution of ATI correlates with clinical loss of response and that concomitant immunomodulator use prolonged ATI-free survival, which is in line with previous reports. Nevertheless, patient-related factors possibly influencing ATI formation werent considered and havent been studied extensively. We hypothesised that ATI formation may be triggered by HLA-DRB1 alleles, as was shown for immunogenicity to interferon-β therapy in multiple sclerosis.2 We retrospectively analysed 192 patients with IBD: 76 patients developed ATI during IFX maintenance treatment (=ATI+) (44 Crohns disease (CD), 32 UC) and these were matched with 116 patients (64 CD, 52 UC) who never developed ATI (=ATI−). All patients were antitumour necrosis factor naive before IFX …

Prognostic factors for long-term infliximab treatment in Crohn's disease patients: a 20-year single centre experience.

The long‐term efficacy of infliximab in patients with Crohns disease is suboptimal.

A Matrix-based Model Predicts Primary Response to Infliximab in Crohn's Disease

BACKGROUNDnPrediction of primary non-response [PNR] to anti-tumour necrosis factors [TNFs] in inflammatory bowel disease [IBD] is direly needed to select the optimal therapeutic class for a given patient. We developed a matrix-based prediction tool to predict response to infliximab [IFX] in Crohns disease [CD] patients.nnnMETHODSnThis retrospective single-centre study included 201 anti-TNF naïve CD patients who started with IFX induction therapy. PNR occurred in 16 [8%] patients. Clinical, biological [including serum TNF and the IBD serology 6 panel and genetic [the 163 validated IBD risk loci] markers were collected before start. Based on the best fitted regression model, probabilities of primary response to IFX were calculated and arranged in a prediction matrix tool.nnnRESULTSnMultiple logistic regression withheld three final independent predictors [p < 0.05] for PNR: age at first IFX, {odds ratio (OR) (95% confidence interval [CI] of 1.1 (1.0-1.1)}, body mass index [BMI] (0.86 [0.7-1.0]), and previous surgery (4.4 [1.2-16.5]). The accuracy of this prediction model did not improve when the genetic markers were added (area under the curve [AUC] from 0.80 [0.67-0.93] to 0.78 [0.65-0.91]). The predicted probabilities for PNR to IFX increased from 1% to 53% depending on the combination of final predictors.nnnCONCLUSIONSnReadily available clinical factors [age at first IFX, BMI, and previous surgery] outperform serological and IBD risk loci in prediction of primary response to infliximab in this real-life cohort of CD patients. This matrix tool could be useful for guiding physicians and may avoid unnecessary or inappropriate exposure to IFX in IBD patients unlikely to benefit.

Prevention of Antidrug Antibody Formation to Infliximab in Crohn's Patients With Prior Failure of Thiopurines

BACKGROUND & AIMS: Combination thiopurine‐infliximab (IFX) therapy is associated with reduced generation of antidrug antibodies (ADA) compared with IFX monotherapy. Whether past clinical response to thiopurine therapy bears an effect on ADA prevention is unknown. METHODS: This was a retrospective observational multicenter study of patients with Crohns disease (CD) treated by IFX and thiopurines who had serial ADA measurements. Therapy was classified into past thiopurine response or its lack of, de novo combination, or IFX monotherapy. The primary endpoint was risk of ADA appearance. RESULTS: Out of 494 patients with serial ADA measurements 207 eligible patients were included in the final analysis. The 1‐year cumulative risk of ADA development was similar in past thiopurine responders (19.3%) compared with past thiopurine failures (16.1%) (log rank P = .54). ADA was found in 46.6% of the monotherapy group and was significantly different compared with past thiopurine responders (P = .007) and past thiopurine failures (P = .007). The adjusted hazards for ADA development were significantly lower in past responders and past failures compared with the monotherapy group (hazard ratio, 0.47 [95% CI, 0.22–1.00] and 0.32 [95% CI, 0.11–0.93], respectively). CONCLUSIONS: Thiopurines‐IFX cotherapy in patients with Crohns disease is associated with reduced ADA formation compared with IFX monotherapy. This is probably regardless of initial thiopurine therapeutic effect.

The use of prognostic factors in inflammatory bowel diseases.

The disease spectrum and natural course of Crohn’s disease and ulcerative colitis are highly variable. The majority of Crohn’s disease patients will require surgery at a certain stage in their disease compared to only a fraction of the ulcerative colitis patients. Similarly, some patients are destined to experience an indolent disease course while others will require early intensive therapy. Ideally, these subtypes of patients should be identified as early as possible with the help of reliable prognostic factors in order to guide personalized therapeutic decisions. In this review, the authors focused on the most relevant reports on the use of different prognostic factors to predict disease course, postoperative recurrence and response to therapy in patients with inflammatory bowel disease. The last 15xa0years have seen a wealth of novel genetic and serological markers of disease severity. Nevertheless, none of these markers have proven to be superior to careful clinical phenotyping and endoscopic features early in the disease course. Future attempts should apply an integrated approach that unites clinical, serological and (epi)genetic information with environmental influences, with a clear focus on the microbiome to ultimately identify molecular-based and clinically relevant subgroups.