Higher Mucosal Healing with Tumor Necrosis Factor Inhibitors in Combination with Thiopurines Compared to Methotrexate in Crohn's Disease

The Role of Low-Dose Oral Methotrexate in Increasing Anti-TNF Drug Levels and Reducing Immunogenicity in IBD

Concomitant immunomodulation is utilised in combination with anti-TNF therapy for IBD primarily to increase drug levels and prevent anti-drug antibody formation. Whilst thiopurines have traditionally been the immunomodulator of choice in IBD populations, there are concerns regarding the long-term safety of the prolonged use of these agents: particularly an association with lymphoproliferative disorders. Given this, we have explored the existing literature on the use of low-dose oral methotrexate as an alternative immunomodulator for this indication. Although there is a lack of data directly comparing the efficacies of methotrexate and thiopurines as concomitant immunomodulators, the available literature supports the use of methotrexate in improving the pharmacokinetics of anti-TNF agents. Furthermore, low-dose oral methotrexate regimens appear to have comparable efficacies to higher-dose parenteral administration and are better tolerated. We suggest that clinicians should consider the use of low-dose oral methotrexate as an alternative to thiopurines when the primary purpose of concomitant immunomodulation is to improve anti-TNF pharmacokinetics.

Combination of serological biomarkers and clinical features to predict mucosal healing in Crohn's disease: a multicenter cohort study

PURPOSE

Mucosal healing (MH) has become the treatment goal of patients with Crohn's disease (CD). This study aims to develop a noninvasive and reliable clinical tool for individual evaluation of mucosal healing in patients with Crohn's disease.

METHODS

A multicenter retrospective cohort was established. Clinical and serological variables were collected. Separate risk factors were incorporated into a binary logistic regression model. A primary model and a simple model were established, respectively. The model performance was evaluated with C-index, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy. Internal validation was performed in patients with small intestinal lesions.

RESULTS

A total of 348 consecutive patients diagnosed with CD who underwent endoscopic examination and review after treatment from January 2010 to June 2021 were composed in the derivation cohort, and 112 patients with small intestinal lesions were included in the validation cohort. The following variables were independently associated with the MH and were subsequently included into the primary prediction model: PLR (platelet to lymphocyte ratio), CAR (C-reactive protein to albumin ratio), ESR (erythrocyte sedimentation rate), HBI (Harvey-Bradshaw Index) score and infliximab treatment. The simple model only included factors of PLR, CAR and ESR. The primary model performed better than the simple one in C-index (87.5% vs. 83.0%, p = 0.004). There was no statistical significance between these two models in sensitivity (70.43% vs. 62.61%, p = 0.467), specificity (87.12% vs. 80.69%, p = 0.448), PPV (72.97% vs. 61.54%, p = 0.292), NPV (85.65% vs. 81.39%, p = 0.614), and accuracy (81.61% vs. 74.71%, p = 0.303). The primary model had good calibration and high levels of explained variation and discrimination in validation cohort.

CONCLUSIONS

This model can be used to predict MH in post-treatment patients with CD. It can also be used as an indication of endoscopic surveillance to evaluate mucosal healing in patients with CD after treatment.

Evidence-based efficacy of methotrexate in adult Crohn's disease in different intestinal and extraintestinal indications

INTRODUCTION

Methotrexate (MTX) is included in the therapeutic armamentarium of Crohn's disease (CD), although its positioning is currently uncertain in an era in which many effective biological drugs are available. No systematic reviews or meta-analysis have stratified the clinical outcomes of MTX according to the specific clinical scenarios of its use.

METHODS

Medline, PubMed and Scopus were used to extract eligible studies, from database inception to May 2021. A total of 163 studies were included. A systematic review was performed by stratifying the outcomes of MTX according to formulation, clinical indication and criteria of efficacy.

RESULTS

The use of MTX is supported by randomized clinical trials only in steroid-dependent CD, with similar outcomes to thiopurines. The use of MTX in patients with steroid-refractoriness, failure of thiopurines or in combination with biologics is not supported by high levels of evidence. Combination therapy with biologics can optimize the immunogenic profile of the biological drug, but the impact on long-term clinical outcomes is described only in small series with anti-TNFα. Other off-label uses, such as fistulizing disease, mucosal healing, postoperative prevention and extraintestinal manifestations, are described in small uncontrolled series. The best performance in most indications was shown by parenteral MTX, favouring higher doses (25 mg/week) in the induction phase.

DISCUSSION

Evidence from high-quality studies in favour of MTX is scarce and limited to the steroid-dependent disease, in which other drugs are the leading players today. Many limitations on study design have been found, such as the prevalence of retrospective underpowered studies and the lack of stratification of outcomes according to specific types of patients and formulations of MTX.

CONCLUSION

MTX is a valid option as steroid-sparing agent in steroid-dependent CD. Numerous other clinical scenarios require well-designed clinical studies in terms of patient profile, drug formulation and dosage, and criteria of efficacy.

Insights into the cellular pharmacokinetics and pharmacodynamics of thiopurine antimetabolites in a model of human intestinal cells

Thiopurines, immunomodulating drugs used in the management of different chronic autoimmune conditions and as anti-leukemic agents, may exert in some cases gastrointestinal toxicity. Moreover, since these agents are administered orally, they are absorbed across the gastrointestinal tract epithelium. On these premises, cellular and molecular events occurring in intestinal cells may be important to understand thiopurine effects. However, quantitative information on the biotransformation of thiopurines in intestinal tissues is still limited. To shed light on biotransformation processes specific of the intestinal tissue, in this study thiopurine metabolites concentrations were analyzed by an in vitro model of human healthy colon, the HCEC cell line, upon exposure to cytotoxic concentrations of azathioprine or mercaptopurine; the investigation was carried out using an innovative mass spectrometry method, that allowed the simultaneous quantification of 11 mono-, di-, and triphosphate thionucleotides. Among the 11 metabolites evaluated, TIMP, TGMP, TGDP, TGTP, MeTIMP, MeTIDP and MeTITP were detectable in HCEC cells treated with azathioprine or mercaptopurine, considering two different incubation times before the addition of the drugs (4 and 48 h). Different associations between metabolites concentrations and cytotoxicity were detected. In particular, the cytotoxicity was dependent on the TGMP, TGDP, TGTP and MeTITP concentrations after the 4 h incubation before the addition of thiopurines. This may be an indication that, to study the association between thiopurine metabolite concentrations and the cytotoxicity activity in vitro, short growth times before treatment should be used. Moreover, for the first time our findings highlight the strong correlation between cytotoxicity and thiopurine pharmacokinetics in HCEC intestinal cells in vitro suggesting that these cells could be a suitable in vitro model for studying thiopurine intestinal cytotoxicity.

Combination Therapy of Adalimumab With an Immunomodulator Is Not More Effective Than Adalimumab Monotherapy in Children With Crohn's Disease: A Post Hoc Analysis of the PAILOT Randomized Controlled Trial

BACKGROUND

The PAILOT trial was a randomized controlled trial aimed to evaluate proactive vs reactive therapeutic drug monitoring in children with Crohn's disease (CD) treated with adalimumab. Our aim in this post hoc analysis of the PAILOT trial was to assess the efficacy and safety of adalimumab combination treatment in comparison with monotherapy at week 72 after adalimumab induction.

METHODS

Participants were children 6-17 years old, biologic naïve, with moderate to severe CD, who responded to adalimumab induction at week 4. Patients receiving immunomodulators at baseline maintained a stable dose until week 24; patients could then discontinue immunomodulators. At each visit, patients were assessed for disease index, serum biomarkers, fecal calprotectin, adalimumab trough concentration, and anti-adalimumab antibodies.

RESULTS

Out of the 78 patients (29% female; mean age, 14.3 ± 2.6 years), 34 patients (44%) received combination therapy. During the study period, there was no significant difference in the rates of sustained corticosteroid-free clinical remission (25/34, 73%, vs 28/44, 63%; P = 0.35) or sustained composite outcome of clinical remission, C-reactive protein ≤0.5 mg/dL, and calprotectin ≤150 µg/g (10/34, 29%, vs 14/44, 32%; P = 0.77) between the combination group and the monotherapy group, respectively. Clinical and biological outcomes did not differ between the proactive and reactive subgroups within the combination and monotherapy groups. Adalimumab trough concentrations and immunogenicity were not significantly different between groups. The rate of serious adverse events was not significantly different between groups but was numerically higher in the monotherapy group.

CONCLUSIONS

Combination therapy of adalimumab and an immunomodulator was not more effective than adalimumab monotherapy in children with CD (ClinicalTrials.gov No. NCT02256462).

Efficacy and safety of methotrexate in the management of inflammatory bowel disease: A systematic review and meta-analysis of randomized, controlled trials

BACKGROUND

The therapeutic role of methotrexate (MTX) for management of inflammatory bowel disease (IBD) remains unclear.

METHODS

We systematically reviewed randomized, controlled trials (RCTs) of MTX for induction and maintenance of remission in IBD until January 2020 in accordance with PROSPERO protocol (#CRD42018115047). Relative risk (RR) of maintenance of remission, induction of remission, endoscopic disease activity, and adverse events were combined in a meta-analysis.

FINDINGS

MTX monotherapy was not superior to placebo for induction of clinical remission in Crohn's disease (CD). However, MTX was superior to placebo in maintaining clinical remission of CD. Concomitant therapy with MTX and the TNF inhibitor infliximab (IFX) was not superior to IFX monotherapy in CD. In ulcerative colitis (UC), MTX monotherapy was not superior to placebo neither for induction of clinical remission, nor for maintenance of clinical remission. MTX did not result in superior endoscopic outcomes during induction or maintenance therapy compared with placebo. Regarding adverse events (AEs), our meta-analysis on CD studies showed a significantly higher risk of AEs when comparing MTX versus placebo in studies investigating induction of remission, but not in maintenance of remission. In UC, no such differences in AEs between MTX or placebo were observed.

INTERPRETATION

Current data support the efficacy of parenteral MTX monotherapy for maintenance of clinical remission in CD. MTX is not confirmed to be effective for treatment of UC or for induction of remission in CD. No evidence supports concomitant MTX to improve efficacy of IFX (no other biologics investigated).