Publications by authors named "Sophie Tops"

Background: Histo-endoscopic outcomes are being proposed as new treatment targets in ulcerative colitis [UC]. Little is known about the pharmacokinetic-pharmacodynnamic [PK-PD] relationship of ustekinumab [UST] in UC patients or whether serum UST concentrations reflect tissue drug exposure. We aimed to study UST serum concentrations and their relation to tissue exposure and drug effectiveness in a real-world setting.

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Objectives: To study infliximab (IFX) pharmacokinetics in children with inflammatory bowel disease (IBD) during induction therapy to predict outcome and explore if other covariates influenced outcome.

Study Design: All children with IBD starting IFX therapy (5 mg/kg at weeks 0, 2, 6, and 12) for active luminal disease from May 2017 to May 2019 were included and followed prospectively. Patients were sampled at multiple timepoints during induction (trough concentrations and peak concentration at weeks 0, 2, 6, and 12, and intermediate concentration at weeks 1-4).

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An association between vedolizumab (VDZ) trough concentrations and therapeutic outcome has been observed in patients with inflammatory bowel diseases. VDZ samples are typically collected via venous sampling for therapeutic drug monitoring (TDM), but can alternatively be collected via dried blood spot (DBS) samples, which can be used for intensive sampling to investigate pharmacokinetic profiles. Therefore, we have developed a DBS method for determining VDZ concentrations and validated this method by comparing VDZ measurements in paired DBS and venous patient samples.

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Background: Anti-drug-antibodies (ADA) against infliximab are frequently measured in patients receiving infliximab treatment with loss of response and undetectable infliximab concentrations. Different ADA bridging assays (1st generation, 2nd generation and ready-to-use kit) have been developed successively and were applied over the last 10 years, making comparison between ADA concentrations very challenging. A cutoff of 8 μg/ml was established to discriminate low from high ADA concentrations using the 1st generation ADA bridging assay.

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Background And Objectives: Vedolizumab has demonstrated efficacy and safety in patients with Crohn's disease [CD] and ulcerative colitis [UC]. Endoscopic outcome data are limited, especially in anti-tumour necrosis factor [TNF] naïve patients. The present study compared endoscopic outcome in anti-TNF naïve and exposed patients, and explored if this was affected by drug exposure.

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Background: The use of infliximab biosimilar CT-P13 has increased in patients with inflammatory bowel disease. Nevertheless, doubts about switching from infliximab originator to biosimilar still exist among patients and health care professionals.

Methods: Our tertiary referral center underwent a mandatory switch from infliximab originator to CT-P13 in 2017.

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Background: Very little is known about the impact of the wash-out period on the pharmacokinetics of a second-line biologic.

Objective: The objective of this article is to explore the impact of two different wash-out periods on the pharmacokinetics of vedolizumab and infliximab.

Methods: Patients switching from infliximab to vedolizumab were retrospectively identified.

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Background: The relationship between vedolizumab trough levels and combined endoscopic and clinical remission is unknown.

Objective: To compare vedolizumab trough levels in patients with and without combined remission within the first year of treatment.

Methods: We prospectively collected vedolizumab trough levels in 51 consecutive patients (28 Crohn's disease (CD) and 23 ulcerative colitis (UC)) before all infusions up to week 22, and at weeks 38 and 54, with concentrations measured after study completion.

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Background: Vedolizumab (VDZ) is effective as an induction and maintenance treatment for Crohn's disease and ulcerative colitis, but, as observed with antitumour necrosis factor-α (anti-TNFα) agents, some patients are nonetheless experiencing loss of response.

Objective: The aim of this study was to investigate the impact of the pharmacokinetics of VDZ during induction on long-term treatment response.

Patients And Methods: This study focused on a single cohort of 103 inflammatory bowel disease patients treated with VDZ.

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Background: Ileocolonic expression of IL13RA2 has been identified as a predictive marker for nonresponsiveness to infliximab (IFX) in patients with Crohn's disease (CD).

Aim: To validate the IL13RA2 biomarker, study its anti-TNF specificity and get a better understanding of the underlying biology driving its expression.

Methods: IL13RA2 mucosal expression was studied in a cohort of adalimumab and vedolizumab treated patients.

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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.

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Development of a dried blood spot (DBS) method for golimumab will facilitate sample collection in a study setting and will give a more complete insight in the total drug exposure (area under the curve, AUC). We established a DBS method and assessed its robustness, user-friendliness and clinical usefulness in 10 patients with ulcerative colitis during golimumab induction and maintenance regimens. DBS was obtained through spotting of golimumab spiked in whole citrated blood to a filter paper.

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Background & Aims: Trough concentrations of vedolizumab were found to correlate with clinical response in phase 3 studies of patients with ulcerative colitis (UC) or Crohn's disease (CD). Nevertheless, there are no solid data to support monitoring of vedolizumab trough concentrations in treated patients. We investigated the correlation between vedolizumab exposure and response in a real-world population and aimed to identify patient factors that affect exposure and response.

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Background And Aims: Mucosal healing is associated with favourable therapeutic outcomes in patients with ulcerative colitis [UC]. We investigated whether adalimumab concentrations during induction therapy are associated with short-term mucosal healing [STMH] in UC patients.

Methods: This was a retrospective, single-centre study including consecutive UC patients treated with adalimumab from June 2005 to May 2014, who underwent an endoscopy both at baseline and after induction therapy [weeks 8-14] and at least one serum sample available at week 2 and/or week 4.

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A number of assays are currently available to support therapeutic drug monitoring of adalimumab. A complete characterization of the assays and comparison of different assays has not been performed. The aim of this study, therefore, is to generate and characterize of a panel of monoclonal antibodies towards adalimumab (MA-ADM); to use this panel to develop novel assays to determine adalimumab concentrations; to assess the impact of tumor necrosis factor (TNF) and (non-)neutralizing antibodies on adalimumab detection and to compare the performance of assays.

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Background & Aims: Mucosal 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.

Methods: We 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.

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Background: Determination of infliximab (IFX) serum concentrations has been used for treatment optimization of patients with inflammatory bowel disease. A wide range of enzyme-linked immunosorbent assays (ELISA) exists to quantitate IFX. Most of these assays lack specificity and cross-react with other anti-tumor necrosis factor (TNF) agents.

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Background & Aims: There are limited data on the effects of discontinuing infliximab therapy for Crohn's disease (CD). We investigated the long-term outcome of patients with CD who discontinued infliximab while in clinical remission, and searched for prognostic markers of continued remission after infliximab cessation.

Methods: We performed a retrospective, single-center study of 100 patients with CD who discontinued infliximab upon achieving clinical remission; 84 patients continued immunomodulator therapy.

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