Therapeutic drug monitoring in patients with inflammatory bowel disease

Analysis of Azathioprine Metabolites in Autoimmune Hepatitis Patient Blood-Method Development and Validation

Autoimmune hepatitis (AIH) is a chronic inflammatory liver disease treated by steroids and immunomodulator thiopurine drugs such as azathioprine (AZA). AZA is metabolized in the human body into bioactive forms such as 6-thioguanine (6-TG) and 6-methyl-mercaptopurine (6-MMP). Monitoring the levels of bioactive AZA metabolites is very important for proper treatment of patients. In this study, our aim was to develop and validate a fast and sensitive ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS) method for the analysis of 6-TG and 6-MMP from blood samples of patients with AIH to monitor the level of these bioactive metabolites. The detection and quantification of the analytes was carried out by Selected Reaction Monitoring (SRM)-based targeted mass spectrometry. The method was validated according to the EMA guidelines. Blood samples from patients with AIH treated with AZA were analysed with the developed method. The method was successfully validated with appropriate accuracy and precision for the target biomolecules and their concentration in the samples from patients with AIH was determined. The developed and validated UHPLC-MS method enables the fast and precise analysis of AZA metabolites.

Microalgae polysaccharides exert antioxidant and anti-inflammatory protective effects on human intestinal epithelial cells in vitro and dextran sodium sulfate-induced mouse colitis in vivo

Microalgae polysaccharides (MAPS) have emerged as novel prebiotics, but their direct effects on intestinal epithelial barrier are largely unknown. Here, MAPS isolated from Chlorella pyrenoidosa, Spirulina platensis, and Synechococcus sp. PCC 7002 were characterized as mainly branched heteropolysaccharides, and were bioavailable to Caco-2 cells based on fluorescein isothiocyanate labeling and flow cytometry analysis. These MAPS were equally effective to scavenge hydroxyl and superoxide radicals in vitro and to attenuate the H2O2-, dextran sodium sulfate-, tumor necrosis factor α-, and interleukin 1β-induced burst of intracellular reactive oxygen species and mitochondrial superoxide radicals, interleukin-8 production, cyclooxygenase-2 and inducible nitric oxide synthase expression, and/or tight junction disruption in polarized Caco-2 cells. MAPS and a positive drug Mesalazine were intragastrically administered to C57BL/6 mice daily for 7 d during and after 4-d dextran sodium sulfate exposure. Clinical signs and colon histopathology revealed equivalent anti-colitis efficacies of MAPS and Mesalazine, and based on biochemical analysis of colonic tight junction proteins, goblet cells, mucin 2 and trefoil factor 3 transcription, and colonic and peripheral pro-inflammatory cytokines, MAPS alleviated dextran sodium sulfate-induced intestinal epithelial barrier dysfunction, and their activities were even superior than Mesalazine. Overall, MAPS confer direct antioxidant and anti-inflammatory protection to intestinal epithelial barrier function.

Crohn's disease and clinical management today: How it does?

Crohn's Disease (CD) is an Inflammatory Bowel Disease and is characterized by an immune-mediated nature. Its etiology results from the interaction between genetic, enviromental and microbial factors. Regarding pathophysiology, it involves high levels of interleukin (IL)-12, IL-17, and Th1 profile, along with loss of tolerance mechanisms, an increase in pro-inflammatory interleukins, beyond the possibility to affect any part of the gastrointestinal tract. Its symptoms include abdominal pain, chronic diarrhea, weight loss, anorexia, and fatigue, as well as blood in the stool or rectum. Additionally, conditions comprising musculoskeletal, cutaneous, ocular, hepatic, and hematological alterations may be associated with this scenario and extra-intestinal presentation, such as erythema nodosum, anterior uveitis, osteoporosis, and arthritis can also occur. Today, clinical history, exams as fecal calprotectin, ileocolonocopy, and capsule endoscopy can be performed in the diagnosis investigation, along with treatments to induce and maintain remission. In this sense, anti-inflammatory drugs, such as corticosteroids, immunomodulators, and biological agents, as well as surgery and non-pharmacological interventions plays a role in its therapy. The aim of this review is to bring more current evidence to clinical management of CD, as well as to briefly discuss aspects of its pathophysiology, surveillance, and associated disorders.

Genotype-Guided Prescription of Azathioprine Reduces the Incidence of Adverse Drug Reactions in TPMT Intermediate Metabolizers to a Similar Incidence as Normal Metabolizers

Introduction

Thiopurine drugs are purine nucleoside analogues used for treatment of different immune-related conditions. To date, different studies highlighted the importance of thiopurine methyltransferase (TPMT) genotyping in patients who initiate treatment with thiopurines to make an adequate dose adjustment. We aimed to investigate the influence of TPMT phenotype, concomitant treatments, and demographic characteristics on the incidence of adverse reactions (ADRs) in patients who start treatment with azathioprine (AZA).

Methods

This was an observational and retrospective study. The study population comprised 109 patients who started treatment with AZA following routine TPMT genotyping before June 2019 and who were routinely followed up at Hospital Universitario de La Princesa. The incidence of ADRs and treatment duration were evaluated according to TPMT phenotype.

Results

Forty-five men and 64 women were recruited, with a mean age of 67.6 ± 18.5. The medical specialty with the most requests was dermatology (45.9%) and the most frequent disease for which genotyping was requested was bullous pemphigoid (27.5%). All patients were normal metabolizers (NM), except for eight intermediate metabolizers (IM) (7.3%); no poor metabolizers (PM) were found. The initial azathioprine dose was subtherapeutic in both groups (103.2 ± 45.4 mg in NMs and 75 ± 32.3 mg in IMs), increasing during the first months of treatment, especially in NMs (120.3 ± 41.3 vs. 78.6 ± 30.4 mg in IMs, p = 0.011). Most patients (73.4%) received corticosteroids to keep the disease under control; and for 41.2% of NMs, physicians were able to reduce the dose at 6 months post treatment. No IMs completed 6 months of treatment. Hepatotoxicity, gastric intolerance, and blood disorders were the most common ADRs. The incidence of ADRs in the sample was 28.4% (n = 31) with a similar trend between IMs (37.5%) and NMs (27.8%). Patients undergoing concomitant treatment with allopurinol were associated with a higher incidence of ADRs (n = 4, 100% vs. n = 105, 20%; p = 0.002).

Conclusion

TPMT genotyping before AZA prescription reduces ADR incidence in IMs to a similar level as NMs in the Spanish population. However, it is important to note no IMs completed 6 months of treatment, suggesting that there may be some differences in drug tolerability according to phenotype. In addition, most NMs are treated with subtherapeutic doses, are poorly followed up, and thus suffer avoidable ADRs. Finally, concomitant therapies that inhibit the xanthine oxidase enzyme (XDH), such as allopurinol, predispose to ADRs. Therefore, pharmacogenetic testing should be integrated as an additional clinical tool, in such a way that each patient receives personalized, precision treatment, where all factors influencing drug response are considered.

Thiopurines: Use them or lose them? International survey on current and future use of thiopurines in inflammatory bowel disease

BACKGROUND AND AIMS

The role of thiopurines in therapeutic algorithms of Crohn's disease (CD) and Ulcerative colitis (UC) is being questioned. This work aimed to investigate current practice and future perspectives of Inflammatory Bowel Disease (IBD) physicians regarding the efficacy, safety, and role of precision medicine with thiopurines in IBD.

METHODS

A 29-questions web-based survey was developed and distributed to IBD physicians worldwide.

RESULTS

We collected the complete answers of 408 physicians from 50 countries. Most participants were experienced physicians in IBD; 26.0% met our definition of "IBD expert". Four physicians reported to not use thiopurines in clinical practice. Most respondents used thiopurines in monotherapy and in combination therapy, both in CD and UC. Respondents tended to consider thiopurines as drugs with a good safety profile, with the agreement of 61.5% of the overall cohort. A minority of physicians (~6%) considered that thiopurines will not be used in the future in IBD patients, while 57.8% believed that these drugs will still be used, in mono and combination therapy.

CONCLUSION

Despite the many emerging treatments in IBD, according to the beliefs of most physicians surveyed, thiopurines will still be an important part of the treatment algorithm of both CD and UC.

Analysis of the Immunogenicity from Abatacept-Treated Pediatric Patients With Polyarticular-Course Juvenile Idiopathic Arthritis: Findings From Two Phase III Clinical Trials

Objective

The goal of this article is to present the analysis of anti‐abatacept antibody data from children with polyarticular‐course juvenile idiopathic arthritis (pJIA), treated with abatacept. The data are from 395 participants with pJIA from two abatacept registrational trials.

Methods

We analyzed immunogenicity data according to age groups, administration route (intravenous [IV] or subcutaneous [SC]), drug treatment interruption, and co‐medications (with or without methotrexate [MTX]) to assess impact on the incidence of anti‐abatacept antibodies.

Results

The overall immunogenicity incidences observed in both JIA trials ranged between 4.7% and 23.3%. There was a slightly higher immunogenicity incidence in the 2–5‐year‐old participants (15.2%) compared with 6–17‐year‐old participants (4.7%). In the study with SC dosing, the overall incidence on treatment was 2.3% (3% if co‐dosed with MTX), similar to the incidence for Period A of the IV study (similar duration of treatment as the SC study), which was 2.1% (1.4% if co‐dosed with MTX). In the IV study, the period following a 6‐month interruption in treatment had comparable immunogenicity incidences (22.9% with interruption vs. 18.2% without interruption, both co‐dosed with MTX and 0% for both not co‐dosed with MTX). In most cases, participants co‐dosed with MTX had higher immunogenicity incidences than those on abatacept alone.

Conclusion

Although some trends were noted in terms of incidence according to age and MTX co‐dosing, none where conclusive owing to differences in population size. Drug holiday had no impact on immunogenicity incidence once treatment was resumed, and incidences across SC and IV dosing were comparable. There was no impact of immunogenicity on pharmacokinetics, safety, and efficacy.

Optimizing Thiopurine Therapy with a Xanthine Oxidase Inhibitor in Patients with Systemic Autoimmune Diseases: A Single-Centre Experience

Background

Thiopurines are a mainstay of therapy for autoimmune diseases. However, up to 20% to 30% of patients experience overproduction of the methylated metabolites, known as 6-MMP, to the detriment of the active metabolite, 6-thioguanine nucleotide (6-TGN). These patients, commonly referred to as "shunters", are predisposed to thiopurine resistance and hepatotoxicity. In patients with inflammatory bowel diseases, the combination of thiopurine with a xanthine oxidase inhibitor (XOI) is used to reverse this skewed metabolism and to prevent treatment failure or hepatotoxicity. Data on the use of this strategy for patients with other diseases are limited.

Objectives

To investigate and describe the use of thiopurine-XOI combination therapy in shunters with systemic autoimmune diseases.

Methods

Shunters treated in the study hospital between January 1, 2005, and December 31, 2015, were identified using the hospital's laboratory database, and clinical data were collected retrospectively. For each patient with optimization of thiopurine therapy, clinical and laboratory data were assessed over a 6-month period.

Results

Thirty-four patients were identified as shunters; for 14 of these patients, thiopurine therapy was optimized with an XOI. In these 14 patients, the median dose of azathioprine was reduced from 1.95 to 0.78 mg/kg with combination therapy. In addition, median 6-TGN level increased from 135 to 385 pmol/8 × 10⁸ erythrocytes (p = 0.001); furthermore, 6-TGN levels rose to above 235 pmol/8 ×10⁸ erythrocytes for 11 of the 14 patients. Conversely, the median 6-MMP level decreased from 6267 to 271 pmol/8 × 10⁸ erythrocytes (p = 0.001). Except for a 12% increase in mean corpuscular volume, no clinically significant changes in blood count were recorded. Notable infections were reported in 3 patients, and 1 patient had to discontinue treatment because of cytopenia. After 6 months, median prednisone daily dose was reduced by 74%, from 16.7 mg to 4.4 mg (p = 0.005), and 4 patients had been weaned off corticosteroids. Of the 14 patients, 11 (79%) were in full remission, and 2 (14%) were in partial remission.

Conclusion

Optimizing thiopurine therapy with an XOI may be a safe and effective strategy for patients with systemic autoimmune diseases.

Noncanonical NF-κB Signaling Upregulation in Inflammatory Bowel Disease Patients is Associated With Loss of Response to Anti-TNF Agents

Objectives: Targeting tumor necrosis factor (TNF) with biologic agents, such as infliximab and adalimumab, is a widely used and effective therapeutic strategy in inflammatory bowel disease (IBD). Unfortunately, a significant number of patients fail to respond or lose response over time to these agents. Previous studies have defined multiple complex roles for canonical NF-κB signaling in the pathogenesis of IBD. However, preliminary evidence suggests that the lesser defined noncanonical NF-κB signaling pathway also contributes to disease pathogenesis and response to anti-TNF agents. The objective of this study was to evaluate this hypothesis in Crohn’s disease (CD) and ulcerative colitis (UC) patients.

Design: A total of 27 subjects with IBD (19 with CD and 8 with UC) and 15 control subjects were tested. Clinical criteria, patient history, and endoscopic disease activity were factors used to categorize patients and define therapeutic response. Biopsy specimens were collected during colonoscopy and expression was determined for 88 target genes known to be associated with noncanonical NF-κB signaling and IBD.

Results: Noncanonical NF-κB signaling was significantly upregulated in IBD patients and was associated with increased gastrointestinal inflammation, epithelial cell death, lymphocyte migration, and Nod-like receptor signaling. Furthermore, noncanonical NF-κB signaling was further upregulated in patients unresponsive to anti-TNF agents and was suppressed in responsive patients. MAP3K14, NFKB2, CCL19, CXCL12, and CXCL13 were significantly dysregulated, as were genes that encode pathway regulators, such as CYLD, NLRP12, and BIRC2/3.

Conclusion: Our study identifies a previously uncharacterized role for the understudied noncanonical NF-κB signaling pathway in the pathogenesis of IBD and anti-TNF therapy responsiveness. The genes and pathways identified may ultimately prove useful in IBD management and could potentially be used as biomarkers of drug response.

Thiopurine-induced Myelosuppression with Severe Sepsis in a Patient with Crohn's Disease: A Case Report

Thiopurines by their glucocorticoid-sparing property help in maintaining remission for patients with inflammatory bowel disease (IBD), when glucocorticoids are reduced and withdrawn. However, due to bone marrow suppression, it cannot be used in various conditions where it is indicated. A 17-year-old patient presented with pancytopenia with neutropenic sepsis and alopecia after 3 weeks of starting azathioprine for her underlying Crohn's disease. Thiopurine S-methyltransferase (TPMT;*2, *3A, *3C) analysis resulted in a wild-type genotype, whereas homozygous Nudix hydrolase 15 (NUDT 15 C415T) variant was positive. Azathioprine was stopped immediately, and she was started on broad-spectrum antibiotics that led to some clinical improvements initially, but later on, the patient developed intestinal obstruction along with postoperative complications leading to death. In this report, we highlight a case of serious hematological toxicity associated with azathioprine use in a patient with Crohn's disease with homozygous NUDT 15 variant, thus favoring the implementation of a pharmacogenomic approach before starting azathioprine, particularly in the Asian population.

How to cite this article

Debnath P, Nair S, Jain S, Udgirkar S, Contractor Q, Rathi P. Thiopurine-induced Myelosuppression with Severe Sepsis in a Patient with Crohn's Disease: A Case Report. Indian J Crit Care Med 2021;25(2):228-230.

Prior presentation of case report at professional meeting

The case was presented in abstract form at the American College of Gastroenterology Annual Scientific Meeting, held at San Antonio, TX, USA 2019.

Informed consent for publication of case details

Obtained from patient's relatives.

Therapeutic Drug Monitoring for Current and Investigational Inflammatory Bowel Disease Treatments

This article reviews therapeutic drug monitoring (TDM) use for current inflammatory bowel disease (IBD) treatments. IBD comprises Crohn's disease and ulcerative colitis-chronic gastrointestinal inflammatory disorders. Treatment options for moderate to severe IBD include thiopurines; methotrexate; biologic agents targeting tumor necrosis factor, α4β7 integrin or interleukins 12 and 23; and Janus kinase inhibitors. TDM is recommended to guide treatment decisions for some of these agents. Published literature concerning TDM for IBD treatments was reviewed. S.D.L., R.S., and E.V.L. drew on their clinical experiences. Polymorphisms resulting in altered enzymatic activity inactivating thiopurine metabolites can lead to myelotoxicity and hepatotoxicity. Increased elimination of biologic agents can result from immunogenicity or higher disease activity, leading to low drug concentration and consequent nonresponse or loss of response. TDM may aid treatment and dose decisions for individual patients, based on monitoring metabolite levels for thiopurines, or serum drug trough concentration and antidrug antibody levels for biologic agents. Challenges remain around TDM implementation in IBD, including the lack of uniform assay methods and guidance for interpreting results. The Janus kinase inhibitor tofacitinib is not impacted by enzyme polymorphisms or disease activity, and is not expected to stimulate the formation of neutralizing antidrug antibodies. TDM is associated with implementation challenges, despite the recommendation of its use for guiding many IBD treatments. Newer small molecules with less susceptibility to patient variability factors may fulfill the unmet need of treatment options that do not require TDM, although further study is required to confirm this.

Differences in the need for adalimumab dose optimization between Crohn's disease and ulcerative colitis

AIM

to compare the need for and time to adalimumab dose escalation and de-escalation between patients with Crohn's disease (CD) and ulcerative colitis (UC).

METHODS

this observational cohort study included patients with luminal CD or patients with UC treated with adalimumab. Adalimumab dose optimization was decided based on the Harvey-Bradshaw index (CD) or the partial Mayo score (UC). The co-primary endpoints were the differences in the rate of dose escalation and the cumulative probability of escalation-free survival between cohorts. We also evaluated the rates of de-escalation and predictors of adalimumab dose escalation and de-escalation.

RESULTS

twenty-four of 43 CD patients (56%) and 28 of 43 UC patients (65%) required adalimumab dose escalation. UC patients had a higher adjusted rate of dose escalation (hazard ratio [HR] 2.33, 95% confidence interval [CI] 1.19-4.56; p = 0.013) than CD patients. The median time to dose escalation was significantly shorter for UC than CD patients (3.2 months, interquartile range [IQR]: 2.0-10.3 vs 12.2 months, IQR: 6.1-35.7; p = 0.001). Survival curves showed that UC patients had an increased probability of dose escalation (p < 0.001). Prior anti-TNF therapy was associated with dose escalation (HR 2.13, 95% CI 1.05-4.34; p = 0.037). Adalimumab dose de-escalation was attempted in 32% of UC patients and 50% of CD patients. Survival curves showed that CD patients had an increased probability of dose de-escalation (p = 0.030).

CONCLUSION

UC patients more frequently required adalimumab dose escalation than CD patients. UC patients required optimization earlier than CD patients. More CD patients than UC patients can be dose de-escalated later on during treatment.

Thiopurine S-methyltransferase genetic polymorphisms in adult patients with inflammatory bowel diseases in the Latvian population

BACKGROUND

Thiopurine methyltransferase (TPMT) plays a significant role in the metabolism of thiopurines, and, for patients with inflammatory bowel disease (IBD), it is useful to perform TPMT genotyping prior to azathioprine (AZA) treatment. In this study, we determined TPMT gene polymorphisms in a cohort of IBD patients in Latvia.

METHODS

DNA samples were obtained from 244 IBD patients, and qPCR was performed for detection of rs1800462, rs1800460, and rs1142345 single-nucleotide polymorphisms (SNPs). Three common, non-functional TPMT alleles (TPMT*2, *3B, and *3C) were identified (women, 51%; men, 49%). TPMT*2, *3A, *3B, and *3C allelic variants detected using qPCR were consistent with restriction fragment length polymorphism (RFLP) data.

RESULTS

Among patients, 78% had ulcerative colitis and 22% had Crohn's disease, with 93.9% of the former carrying a wild-type homozygous TPMT*1/*1 genotype and 6.1% carrying heterozygous genotypes. The most frequent polymorphisms were TPMT*1/*3A (5.3%: two variants: TPMT*3B and TPMT*3C), TPMT*1/*3C (0.4%), and TPMT*1/*2 (0.4%). None of the patients carried a TPMT*3B polymorphism and no patients were homozygous for any mutation.

CONCLUSION

This is the first study to identify TPMT gene polymorphisms in adult IBD patients in Latvia. The results indicate that the frequency of common TPMT alleles is similar to that of other European populations.

Ficus carica polysaccharide attenuates DSS-induced ulcerative colitis in C57BL/6 mice

The Ficus carica polysaccharide (FCPS) components of the common fig fruit have been demonstrated to exhibit antioxidant and immunity-enhancing activities. However, it is unclear whether it could prevent the ulcerative colitis development. Here, we reported that 5 week orally administered FCPS (150-300 mg per kg bw) significantly prevented DSS-induced colitis in C57BL/6J mice by improving the colon length and suppressing the infiltration of inflammatory cells in the gut. FCPS treatment protected the goblet cells, elevated the expression of tight junction protein claudin-1, and suppressed the formation of cytokines including TNF-α and IL-1β. FCPS supplementation significantly reformed the gut microbiome by enhancing the abundance of S24-7, Bacteroides, and Coprococus, and suppressing the abundance of Escherichia and Clostridium at the genus level. Consistently, the formation of beneficial microbial metabolites, short chain fatty acids, especially acetate and butyrate, were improved in FCPS-treated colitis mice. The correlation analysis indicated that the protective effects of FCPS on ulcerative colitis might be highly correlated with the microbiota composition changes and the formation of SCFAs. In conclusion, these results indicated that FCPS supplementation could be a promising nutritional strategy for reducing inflammatory bowel disease and the gut microbes play essential roles in providing these beneficial effects.

Real-World Use of Azathioprine Metabolites Changes Clinical Management of Inflammatory Bowel Disease

Background

Thiopurines such as 6-mercaptopurine and azathioprine have complex metabolism, resulting in significant inter-individual differences in clinical efficacy and risk of drug toxicity, making conventional weight-based dosing inaccurate and potentially unsafe. Therapeutic drug monitoring (TDM) of thiopurine metabolites improves clinical outcomes through dose optimization and toxicity monitoring. Despite evidence for TDM, use is limited, due in part to test availability and awareness. The objectives of this study were twofold: (1) to investigate how thiopurine TDM impacts clinical management of IBD patients and (2) to evaluate proportion of patients outside therapeutic 6TGN levels or exhibiting signs of toxicity

Methods

Patients who received thiopurine TDM as part of routine care underwent chart review of demographics, disease activity, medication dosing, metabolite levels, and adverse events. Changes in clinical management following TDM were measured. Additionally, we conducted a retrospective review of clinical decision making blinded and unblinded to TDM result.

Results

A total of 92 IBD patients were included. Levels of 6TGN were therapeutic in 29% of patients. 6TGN levels correlated weakly with weight-based dosing (r² = 0.057, P = 0.02). Adverse reactions were observed in 6.5%. TDM informed clinical management in 64%. Significantly more changes to clinical management occurred in those with active disease than in remission (73% versus 48%; P = 0.02) and in those on mono- versus combination therapy (48% versus 27.5%; P = 0.03).

Conclusions

TDM informs clinical decision making in over two-thirds of patients. The demonstrated poor efficacy of weight-based dosing and impact of TDM on clinical management contributes to the evidence supporting the need for greater availability and uptake of thiopurine TDM.

Echinochrome A Reduces Colitis in Mice and Induces In Vitro Generation of Regulatory Immune Cells

Echinochrome A (Ech A), a natural pigment extracted from sea urchins, is the active ingredient of a marine-derived pharmaceutical called ‘histochrome’. Since it exhibits several biological activities including anti-oxidative and anti-inflammatory effects, it has been applied to the management of cardiac injury and ocular degenerative disorders in Russia and its protective role has been studied for other pathologic conditions. In the present study, we sought to investigate the therapeutic potential of Ech A for inflammatory bowel disease (IBD) using a murine model of experimental colitis. We found that intravenous injection of Ech A significantly prevented body weight loss and subsequent lethality in colitis-induced mice. Interestingly, T cell proliferation was significantly inhibited upon Ech A treatment in vitro. During the helper T (Th) cell differentiation process, Ech A stimulated the generation regulatory T (Treg) cells that modulate the inflammatory response and immune homeostasis. Moreover, Ech A treatment suppressed the in vitro activation of pro-inflammatory M1 type macrophages, while inducing the production of M2 type macrophages that promote the resolution of inflammation and initiate tissue repair. Based on these results, we suggest that Ech A could provide a beneficial impact on IBD by correcting the imbalance in the intestinal immune system.

Early dose optimization of golimumab induces late response and long-term clinical benefit in moderately to severely active ulcerative colitis

Aim: To evaluate outcomes of early dose optimization of golimumab in ulcerative colitis (UC) patients with inadequate response to golimumab induction treatment. Methods: This observational, multicenter, cohort study included patients with moderate-to-severe active UC and with inadequate response to subcutaneous golimumab induction doses, in whom weight-based golimumab maintenance dose (European labeling) of 50 mg every 4 weeks (q4wk) was optimized before week 14 to 100 mg q4wk. At week 14, we assessed clinical response and remission using the partial Mayo score. In the long term we evaluate the cumulative probabilities of golimumab failure-free survival and colectomy-free survival. Results: A total of 209 patients who received golimumab induction doses were eligible. Of these, 151 patients (72.2%) weighing less than 80 kg were assigned to a golimumab maintenance dose of 50 mg q4wk. Twenty-four patients (15.9% [12.5% overall]), in whom scheduled doses of 50 mg q4wk were optimized to 100 mg q4wk before week 14, compose the study population. At week 14, 16 patients (66.7%, 95% CI 45.7-87.6) had clinical response, of these 12 were corticosteroid free. Four patients (16.7%) achieved corticosteroid-free remission. After a median follow-up of 12 months (IQR 10-22), 13 patients (54.2%) maintained clinical benefit. Thirteen of 16 patients (81.2%) with clinical response at week 14 maintained clinical benefit at last follow-up. All patients avoided colectomy. In none of the patients was golimumab dose de-escalated. There were no adverse events leading to golimumab withdrawal. Conclusion: Early optimization of golimumab dose induces clinical response at week 14 in two thirds of UC patients and leads to long-term clinical benefit in over half of patients.

Autoimmune hepatitis - update on clinical management in 2017

Autoimmune hepatitis (AIH) is a progressive immune mediated liver disease of unknown origin. Key diagnostic features include hypergammaglobulinemia/elevated serum-IgG, characteristic circulating autoantibodies, periportal hepatitis with interface activity on liver biopsy and the exclusion of hepatotropic viruses. However, the diagnosis is challenging in cholestatic and severe presentations. It can be difficult to differentiate AIH from drug-induced liver injury. Although many patients initially respond to standard immunosuppressive therapy, a significant proportion experiences intolerable side effects or insufficient treatment response. This underlines the need for effective alternative treatment options, which are still very limited and based on rather poor evidence. This review summarises core aspects of the clinical management of AIH with focus on recent achievements and unmet needs.

Therapeutic drug monitoring was helpful in guiding the decision-making process for children receiving infliximab for inflammatory bowel disease

AIM

This study examined the impact of therapeutic drug monitoring (TDM) on clinical decision-making for children receiving infliximab for inflammatory bowel disease (IBD).

METHODS

The medical records of children with IBD who had infliximab trough levels (ITLs) measured between January 2013 and December 2015 at two Canadian tertiary-care centres were examined. The indications for TDM, clinical and laboratory disease activity indices and TDM-driven treatment changes to infliximab therapy were documented.

RESULTS

We included 107 consecutive serum measurements of ITLs in 73 children (40 boys), with a median age of 16.1 years, including 52 with Crohn's disease. TDM was performed due to concerns about clinical disease activity in 24/107 (22.4%) measurements and 83 (77.6%) were ordered as routine tests. Of these, 38 (35.5%) ITLs were suboptimal (<3.5 μg/mL) and 36 (34.0%) resulted in more frequent doses of infliximab, with subsequent improvements in disease biomarkers. Interval changes were implemented as a result of 34 (32.0%) ITLs, with shorter intervals in 19 (17.0%) cases, and seven (6.5%) ITLs resulted in adding or increasing doses of immunomodulators. In addition, four children were switched to adalimumab.

CONCLUSION

Therapeutic drug monitoring was helpful in guiding the decision-making process for children with IBD on infliximab.

Reactivation of Intestinal Inflammation Is Suppressed by Catestatin in a Murine Model of Colitis via M1 Macrophages and Not the Gut Microbiota

While there is growing awareness of a relationship between chromogranin-A (CHGA) and susceptibility to inflammatory conditions, the role of human catestatin [(hCTS); CHGA_352–67] in the natural history of established inflammatory bowel disease is not known. Recently, using two different experimental models, we demonstrated that hCTS-treated mice develop less severe acute colitis. We have also shown the implication of the macrophages in this effect. The aims of this study were to determine (1) whether hCTS treatment could attenuate the reactivation of inflammation in adult mice with previously established chronic colitis; (2) whether this effect is mediated through macrophages or the gut microbiota. Quiescent colitis was induced in 7–8-week-old C57BL6 mice using four cycles (2–4%) of dextran sulfate sodium. hCTS (1.5 mg/kg/day) treatment or vehicle started 2 days before the last induction of colitis and continuing for 7 days. At sacrifice, macro- and microscopic scores were determined. Colonic pro-inflammatory cytokines [interleukin (IL)-6, IL-1β, and TNF- α], anti-inflammatory cytokines (IL-10, TGF- β), classically activated (M1) (iNOS, Mcp1), and alternatively activated (M2) (Ym1, Arg1) macrophages markers were studied using ELISA and/or RT-qPCR. In vitro, peritoneal macrophages isolated from naïve mice and treated with hCTS (10⁻⁵ M, 12 h) were exposed to either lipopolysaccharide (100 ng/ml, 12 h) to polarize M1 macrophages or to IL-4/IL-13 (20 ng/ml) to polarize M2 macrophages. M1/M2 macrophage markers along with cytokine gene expression were determined using RT-qPCR. Feces and mucosa-associated microbiota (MAM) samples were collected, and the V4 region of 16 s rRNA was sequenced. Micro- and macroscopic scores, colonic IL-6, IL-1β, TNF- α, and M1 macrophages markers were significantly decreased in the hCTS-treated group. Treatment did not have any effect on colonic IL-10, TGF-β, and M2 markers nor modified the bacterial richness, diversity, or the major phyla in colitic fecal and MAM samples. In vitro, pro-inflammatory cytokines levels, as well as their gene expression, were significantly reduced in hCTS-treated M1 macrophages. hCTS treatment did not affect M2 macrophage markers. These findings suggest that hCTS treatment attenuates the severity of inflammatory relapse through the modulation of the M1 macrophages and the release of pro-inflammatory cytokines.

Pharmacokinetics and pharmacodynamics of thiopurines in an in vitro model of human hepatocytes: Insights from an innovative mass spectrometry assay

AIM

To apply an innovative LC-MS/MS method to quantify thiopurine metabolites in human hepatocytes and to associate them to cytotoxicity.

METHODS

Immortalized human hepatocytes (IHH cells) were treated for 48 and 96 h, with 1.4 × 10^-4 M azathioprine and 1.1 × 10^-3 M mercaptopurine, concentrations corresponding to the IC₅₀ values calculated after 96 h exposure in previous cytotoxicity analysis. After treatments, cells were collected for LC-MS/MS analysis to quantify 11 thiopurine metabolites with different level of phosphorylation and viable cells were counted by trypan blue exclusion assay to determine thiopurines in vitro effect on cell growth and survival. Statistical significance was determined by analysis of variance (ANOVA).

RESULTS

Azathioprine and mercaptopurine had a significant time-dependent cytotoxic effect (p-value ANOVA = 0.012), with a viable cell count compared to controls of 55.5% and 67.5% respectively after 48 h and 23.7% and 36.1% after 96 h; no significant difference could be observed between the two drugs. Quantification of thiopurine metabolites evidenced that the most abundant metabolite was TIMP, representing 57.1% and 40.3% of total metabolites after 48 and 96 h. Total thiopurine metabolites absolute concentrations decreased over time: total mean content decreased from 469.9 pmol/million cells to 83.6 pmol/million cells (p-value ANOVA = 0.0070). However, considering the relative amount of thiopurine metabolites, TGMP content significantly increased from 11.4% cells to 26.4% (p-value ANOVA = 0.017). A significant association between thiopurine effects and viable cell counts could be detected only for MeTIMP: lower MeTIMP concentrations were associated with lower cell survival (p-value ANOVA = 0.011). Moreover, the ratio between MeTIMP and TGMP metabolites directly correlated with cell survival (p-value ANOVA = 0.037).

CONCLUSION

Detailed quantification of thiopurine metabolites in a human hepatocytes model provided useful insights on the association between thioguanine and methyl-thioinosine nucleotides with cell viability.

Effects of Transient and Persistent Anti-drug Antibodies to Certolizumab Pegol: Longitudinal Data from a 7-Year Study in Crohn's Disease

BACKGROUND

Anti-drug antibodies (ADAbs) may decrease the efficacy of biologics and increase the risk of adverse events. A single positive test may not preclude further treatment because of variations in assays used, test timing, and patient variables. We evaluated the longitudinal patterns of immunogenicity during 7 years of antitumor necrosis factor-alpha drug certolizumab pegol (CZP) treatment for moderate-to-severe Crohn's disease.

METHODS

PRECiSE 3 patients (n = 595) received open-label CZP 400 mg every 4 weeks up to 7 years. CZP-ADAb expression, plasma CZP concentration, Harvey-Bradshaw Index, C-reactive protein, and fecal calprotectin concentrations were measured multiple times. Longitudinal data, examined for CZP-ADAb positivity and categorized as transient (with temporary/no effect on CZP concentration), persistent, or negative, were correlated with clinical and biological variables.

RESULTS

Of the CZP-ADAb-positive patients, 40 (22.6%) had transient CZP-ADAbs and 94 (77.4%) had persistent CZP-ADAbs. Demographic characteristics were similar between groups. Median C-reactive protein and fecal calprotectin were higher (P < 0.05 at some visits) and plasma CZP concentrations were significantly lower (P < 0.0001 at all visits) in the persistent CZP-ADAb-positive group relative to the CZP-ADAb-negative group. Transient CZP-ADAb-positive and CZP-ADAb-negative patients had similar plasma CZP, C-reactive protein, and fecal calprotectin concentrations. Median Harvey-Bradshaw Index scores and rates of adverse events were similar among groups.

CONCLUSIONS

This analysis demonstrates that persistent CZP-ADAb has negative effects on drug levels and efficacy, whereas transient expression may not. Serial measurements may be needed to characterize ADAb positivity. www.clinicaltrials.gov, Number NCT00160524.

Interactions Between Therapeutic Proteins and Small Molecules: The Shared Role of Perpetrators and Victims

Therapeutic proteins (TPs) are becoming increasingly important as therapeutic agents. A consequence of expanding their clinical indications is coadministration with well-established small-molecule drugs (sMDs), which could lead to unpredictable effects. According to the existing regulatory guidance, the development of an sMD includes the evaluation of potential drug-drug interactions (DDIs). For TPs, only a few drug interaction studies have been published. Limited clinically relevant models, long half-lives, and complex elimination pathways are among the associated difficulties.

Pharmacogenetics in inflammatory bowel disease: understanding treatment response and personalizing therapeutic strategies

Inflammatory bowel disease (IBD) is a chronic and heterogeneous disorder characterized by remitting and relapsing periods of activity. Pharmacogenetics refers to the study of the effect of inheritance on individual variation in drug responses. Several drug-related markers in IBD patients have been identified in order to predict the response to medical treatment including biological therapy as well as the reduction of adverse events. In the future, the treatment of IBD should be personalized in its specific profile to provide the most efficacious treatment with lack of adverse events.

Ulcerative colitis

Ulcerative colitis is a chronic inflammatory disease affecting the colon, and its incidence is rising worldwide. The pathogenesis is multifactorial, involving genetic predisposition, epithelial barrier defects, dysregulated immune responses, and environmental factors. Patients with ulcerative colitis have mucosal inflammation starting in the rectum that can extend continuously to proximal segments of the colon. Ulcerative colitis usually presents with bloody diarrhoea and is diagnosed by colonoscopy and histological findings. The aim of management is to induce and then maintain remission, defined as resolution of symptoms and endoscopic healing. Treatments for ulcerative colitis include 5-aminosalicylic acid drugs, steroids, and immunosuppressants. Some patients can require colectomy for medically refractory disease or to treat colonic neoplasia. The therapeutic armamentarium for ulcerative colitis is expanding, and the number of drugs with new targets will rapidly increase in coming years.

Insights on the use of biosimilars in the treatment of inflammatory bowel disease

Biologic therapy, such as those that target tumor necrosis factor (TNF) signaling, has proven to be an efficacious method of treatment for patients with inflammatory bowel disease (IBD) with regards to symptom management and mucosal healing. However, the rising prevalence of IBD worldwide and the ever-increasing burden of biologic pharmaceuticals in the health care industry is alarming for insurance companies, clinicians, and patients. The impending patent expiry and the relatively high costs of biologics, particularly anti-TNF agents, have paved the way for biosimilar development for IBD. The United States Food and Drug Administration defines a biosimilar as a biological product that is highly similar to its reference medicinal product, with no clinically meaningful differences in terms of safety, purity, and potency. The hope with biosimilars is that their entry into the market will be able to drive competition between pharmaceutical companies to reduce prices like that of the generic market, and that access to appropriate biologic treatments for IBD patients is increased in the long-term. Yet, there are challenging issues such as indication extrapolation and interchangeability that are still being debated in the field of IBD and must be addressed in future issued guidance. This review will discuss the issues and implications concerning the use of biosimilar therapy for IBD.

Role of Allopurinol in Optimizing Thiopurine Therapy in Patients with Autoimmune Hepatitis: A Review

Autoimmune hepatitis (AIH) is a chronic immune mediated liver disease characterized by elevated transaminases, hyper gammaglobulinemia, presence of autoantibodies and interface hepatitis in the absence of a known etiology of liver disease. Thiopurines (azathioprine [AZA]/6-mercaptopurine [6MP]) and steroids remain the first line of treatment of AIH in both children and adults. However, a small proportion of AIH patients are either non-responders or develop side effects with AZA. The metabolism of AZA is complex and mediated by multiple enzymes. After absorption and getting converted to 6MP, it is converted to 6-thiouric acid, 6-methyl mercaptopurine (6MMP) and 6-thioguanine (6TG) by different enzymes. Elevated 6MMP levels are associated with hepatotoxicity and also poor efficacy due to simultaneous lower levels of 6TG, which is the active drug metabolite related to both efficacy and myelosuppression. Allopurinol, a xanthine oxidase inhibitor shifts the metabolism of AZA away from 6MMP toward 6TG. This combination of allopurinol with reduced dose of AZA is an alternative to more expensive and toxic second line therapy to induce remission in patients with AIH. This article discusses the mechanism of action of allopurinol in inducing response to AZA, reviews the published literature on this combination therapy and gives guidelines on the use of allopurinol in patients with AIH.

Xanthine Oxidoreductase in Drug Metabolism: Beyond a Role as a Detoxifying Enzyme

The enzyme xanthine oxidoreductase (XOR) catalyzes the last two steps of purine catabolism in the highest uricotelic primates. XOR is an enzyme with dehydrogenase activity that, in mammals, may be converted into oxidase activity under a variety of pathophysiologic conditions. XOR activity is highly regulated at the transcriptional and post-translational levels and may generate reactive oxygen and nitrogen species, which trigger different consequences, ranging from cytotoxicity to inflammation. The low specificity for substrates allows XOR to metabolize a number of endogenous metabolites and a variety of exogenous compounds, including drugs.

The present review focuses on the role of XOR as a drug-metabolizing enzyme, specifically for drugs with anticancer, antimicrobial, antiviral, immunosuppressive or vasodilator activities, as well as drugs acting on metabolism or inducing XOR expression.

XOR has an activating role that is essential to the pharmacological action of quinone drugs, cyadox, antiviral nucleoside analogues, allopurinol, nitrate and nitrite. XOR activity has a degradation function toward thiopurine nucleotides, pyrazinoic acid, methylxanthines and tolbutamide, whose half-life may be prolonged by the use of XOR inhibitors.

In conclusion, to avoid potential drug interaction risks, such as a toxic excess of drug bioavailability or a loss of drug efficacy, caution is suggested in the use of XOR inhibitors, as in the case of hyperuricemic patients affected by gout or tumor lysis syndrome, when it is necessary to simultaneously administer therapeutic substances that are activated or degraded by the drug-metabolizing activity of XOR.

Therapeutic Drug Monitoring and Clinical Outcomes in Immune Mediated Diseases: The Missing Link

As the incidence of inflammatory bowel diseases and the number of patients treated with anti-TNF agents keep on increasing so are the phenomena of primary non response (PNR) and secondary loss of response (SLR) to these medications. Traditionally PNR and SLR have been managed empirically-that is, switching medications for PNR and increasing the anti-TNF dose for SNR. More recently an approach based on testing drug levels and antibodies to the drug (therapeutic drug monitoring) has gained increasing popularity in the management of inflammatory bowel diseases. However, while this strategy might offer an insight into the mechanisms leading to PNR/SLR it often falls short of providing a simple, reproducible method to manage these issues in clinical practice. Here, we will review the currently recommended therapeutic strategies when using therapeutic drug monitoring; the evidence for and against such approach and the current standard strategies in Rheumatology (the specialty with the largest and longest experience with anti-TNF agents). We will then discuss the possible reasons of the shortcomings of therapeutic drug monitoring and the rationale and need to move the therapeutic target to the disease burden in inflammatory bowel diseases-along with the supporting preliminary evidence. Finally, we will focus on future crucial studies that need to be done to make approaches to PNR/SLR more rigorous and at the same time user-friendly for the practicing gastroenterologist.

A Systematic Review on Infliximab and Adalimumab Drug Monitoring: Levels, Clinical Outcomes and Assays

BACKGROUND

Immunogenicity to therapeutic proteins has been linked to loss of response by a large percentage of patients taking anti-tumor necrosis factor-alpha agents. Drug monitoring can be extremely useful, allowing physicians to adjust the therapeutic scheme individually. This article aims to systematically review the published data with respect to cutoff levels of infliximab (IFX) and adalimumab (ADA) and relate them to the methodology adopted for quantification of IFX and ADA levels and clinical outcomes.

METHODS

The PubMed database was searched to identify studies focusing on the association between IFX or ADA cutoff levels and clinical outcomes in patients with inflammatory bowel disease.

RESULTS

Of the 1654 articles initially selected by queries, 20 were included. A receiver operating characteristic curve analysis was performed to identify cutoff levels of IFX or ADA that correlated with a clinical outcome, but only 6 studies performed the same analysis for antidrug antibody levels. Cutoff levels were different between studies. The methodology chosen for level quantifications, clinical outcomes, and sample size and characteristics were also different. Nevertheless, measurement of drug levels should be performed during maintenance, and with loss of response, with persistent high levels of C-reactive protein, and when mucosal lesions are still present. In these scenarios, drug and antidrug levels were correlated with clinical outcomes.

CONCLUSIONS

Concerning drug levels monitoring any methodology is adequate. With respect to antidrug antibody levels, it will be necessary to define a gold standard method or to establish different cutoff levels for different methodologies.

Impact of Specialized Inpatient IBD Care on Outcomes of IBD Hospitalizations: A Cohort Study

BACKGROUND

The management of inflammatory bowel diseases (IBDs; Crohn's disease, ulcerative colitis) is increasingly complex. Specialized care has been associated with improved ambulatory IBD outcomes.

AIMS

To examine if the implementation of specialized inpatient IBD care modified short-term and long-term clinical outcomes in IBD-related hospitalizations.

METHODS

This retrospective cohort study included IBD patients hospitalized between July 2013 and April 2015 at a single tertiary referral center where a specialized inpatient IBD care model was implemented in July 2014. In-hospital medical and surgical outcomes as well as postdischarge outcomes at 30 and 90 days were analyzed along with measures of quality of in-hospital care. Effect of specialist IBD care was examined on multivariate analysis.

RESULTS

A total of 408 IBD-related admissions were included. With implementation of specialized IBD inpatient care, we observed increased frequency of use of high-dose biologic therapy for induction (26% versus 9%, odds ratio 5.50, 95% confidence interval 1.30-23.17) and higher proportion of patients in remission at 90 days after discharge (multivariate odds ratio 1.60, 95% confidence interval 0.99-2.69). Although there was no difference in surgery by 90 days, among those who underwent surgery, early surgery defined as in-hospital or within 30 days of discharge, was more common in the study period (71%) compared with the control period (46%, multivariate odds ratio 2.73, 95% confidence interval 1.22-6.12). There was no difference in length of stay between the 2 years.

CONCLUSIONS

Implementation of specialized inpatient IBD care beneficially impacted remission and facilitated early surgical treatment.

The scientific and regulatory rationale for indication extrapolation: a case study based on the infliximab biosimilar CT-P13

Extrapolation of clinical data from other indications is an important concept in the development of biosimilars. This process depends on strict comparability exercises to establish similarity to the reference medicinal product. However, the extrapolation paradigm has prompted a fierce scientific debate. CT-P13 (Remsima(®), Inflectra(®)), an infliximab biosimilar, is a TNF antagonist used to treat immune-mediated inflammatory diseases. On the basis of totality of similarity data, the EMA approved CT-P13 for all indications held by its reference medicinal product (Remicade(®)) including inflammatory bowel disease. This article reviews the mechanisms of action of TNF antagonists in immune-mediated inflammatory diseases and illustrates the comparable profiles of CT-P13 and reference medicinal product on which the extrapolation of indications including inflammatory bowel disease is based.

The Importance of Intestinal Eotaxin-1 in Inflammatory Bowel Disease: New Insights and Possible Therapeutic Implications

BACKGROUND

Involvement of eotaxin-1 in inflammatory bowel disease has been previously suggested and increased levels of eotaxin-1 have been described in both ulcerative colitis and in Crohn's disease. The association between serum levels of eotaxin-1 and that within the colonic mucosa has not been well defined, as is the potential therapeutic value of targeting eotaxin-1.

AIMS

To characterize serum and intestinal wall eotaxin-1 levels in various inflammatory bowel disease patients and to explore the effect of targeting eotaxin-1 by specific antibodies in dextran sodium sulfate-induced colitis model.

METHODS

Eotaxin-1 levels were measured in colonic biopsies and in the sera of 60 ulcerative colitis patients, Crohn's disease patients and healthy controls. We also followed in experimental colitis the effect of targeting eotaxin-1 by a monoclonal antibody.

RESULTS

Colon eotaxin-1 levels were significantly increased in active but not in quiescent ulcerative colitis and Crohn's disease patients compared to healthy controls. Levels of eotaxin-1 in the colon were correlated with eosinophilia only in tissues from active Crohn's disease patients. Our results did not show any statistically significant change in serum eotaxin-1 levels among ulcerative colitis, Crohn's disease and healthy controls. Moreover, we demonstrate that in dextran sodium sulfate-induced colitis, targeting of eotaxin-1 with 2 injections of anti eotaxin-1 monoclonal antibody ameliorates disease activity along with decreasing colon weight and improving histologic inflammation.

CONCLUSION

Eotaxin-1 is increasingly recognized as a major mediator of intestinal inflammation. Our preliminary human and animal results further emphasize the value of targeting eotaxin-1 in inflammatory bowel disease.

A Personalized Approach to Managing Inflammatory Bowel Disease

The management of inflammatory bowel disease (IBD) requires a personalized approach to treat what is a heterogeneous group of patients with inherently variable disease courses. In its current state, personalized care of the IBD patient involves identifying patients at high risk for rapid progression to complications, selecting the most appropriate therapy for a given patient, using therapeutic drug monitoring, and achieving the individualized goal that is most appropriate for that patient. The growing body of research in this area allows clinicians to better predict outcomes for individual patients. Some paradigms, especially within the realm of therapeutic drug monitoring, have begun to change as therapy is targeted to individual patient results and goals. Future personalized medical decisions may allow specific therapeutic plans to draw on serologic, genetic, and microbial data for Crohn's disease and ulcerative colitis patients.

The Utility of Infliximab Therapeutic Drug Monitoring among Patients with Inflammatory Bowel Disease and Concerns for Loss of Response: A Retrospective Analysis of a Real-World Experience

Background. Infliximab (IFX) therapeutic drug monitoring (TDM) allows for objective decision making in patients with inflammatory bowel disease (IBD) and loss of response. Questions remain about whether IFX TDM improves outcomes. Methods. Patients with IBD who had IFX TDM due to concerns for loss of response were considered for inclusion. Serum IFX trough concentration and anti-drug antibody (ADA) concentrations were measured. Patients were grouped by TDM results: group 1, low IFX/high ADA; group 2, low IFX/low ADA; group 3, therapeutic IFX. Changes in management were analyzed according to groupings; remission rates were assessed at 6 months. Results. 71 patients were included of whom 37% underwent an appropriate change in therapy. Groups 1 (67%) and 2 (83%) had high adherence compared to only 9% in group 3. At 6 months, 57% had achieved remission. More patients who underwent an appropriate change in therapy achieved remission, though this did not reach statistical significance (69% versus 49%; P = 0.098). Conclusions. A trend towards increased remission rates was associated with appropriate changes in management following TDM results. Many patients with therapeutic IFX concentrations did not undergo an appropriate change in management, potentially reflecting a lack of available out-of-class options at the time of TDM or due to uncertainty of the meaning of the reported therapeutic range.

Progress with anti-tumor necrosis factor therapeutics for the treatment of inflammatory bowel disease

Anti-tumor necrosis factor (TNF) therapy is a valid, effective and increasingly used option in inflammatory bowel disease management. Nevertheless, further knowledge and therapeutic indications regarding these drugs are still evolving. Anti-TNF therapy may be essential to achieve recently proposed end points, namely mucosal healing, prevention of bowel damage and prevention of patient's disability. Anti-TNF drugs are also suggested to be more effective in early disease, particularly in early Crohn's disease. Moreover, its efficacy for prevention of postoperative recurrence in Crohn's disease is still debated. Costs and adverse effects, the relevance of drug monitoring and the possibility of anti-TNF therapy withdrawal in selected patients are still debated issues. This review aimed to describe and discuss the most relevant data about the progress with anti-TNF therapy for the management of inflammatory bowel disease.

Factors associated with treatment outcome, and long-term prognosis of patients with ulcerative colitis undergoing selective depletion of myeloid lineage leucocytes: a prospective multicenter study

BACKGROUND

Patients with ulcerative colitis (UC) have elevated/activated myeloid lineage leucocytes and may respond favorably to adsorptive granulocyte/monocyte apheresis (GMA). However, there are patients who respond well to GMA, and patients who do not benefit. Therefore, predictive factors of GMA efficacy need to be defined.

METHODS

In a prospective multicenter setting, 200 UC patients at 32 institutes received one GMA session per week over 10 weeks. Patients who achieved remission were followed for 12 months. The Clinical Activity Index (CAI) ≤3 meant remission, and response meant CAI decreased by ≥3. Quality of life was evaluated by the Inflammatory Bowel Disease Questionnaire (IBDQ).

RESULTS

After final GMA, remission, response and no response rates were 67.0%, 15.0% and 18%, respectively. The remission group had a significant decrease in myeloid leucocytes and platelets. Corticosteroid dose decreased (P < 0.001); 49 of 97 patients on corticosteroids became steroid-free. Baseline CAI was lower in the remission group versus non-remission (P < 0.01), whereas IBDQ was higher in the remission group versus non-remission (P < 0.05). After 12 months, 52 of 134 patients had maintained remission. Disease duration was longer in the relapsed group versus maintained remission group (P = 0.041). Male gender, first UC episode and corticosteroid responder were significant factors for maintaining remission, whereas corticosteroid dependent UC was associating with relapse.

DISCUSSION

Selective myeloid leucocyte depletion was effective for remission induction and improving patients' quality of life. Baseline demographics such as disease activity level, duration and corticosteroid dependency appear to predict response to GMA. Additionally, patients with a first UC episode who were drug naive responded well to GMA and achieved a favorable long-term disease course by avoiding pharmacologics from an early stage of their inflammatory bowel disease. These findings should help to end unnecessary use of medical resources by targeting GMA to patients who may respond well.

Tumor necrosis factor inhibitors: clinical utility in autoimmune diseases

Tumor necrosis factor (TNF) production is amplified in several autoimmune disorders. In the 1990s, it became a validated therapeutic target used for the treatment of conditions such as rheumatoid arthritis and inflammatory bowel disease. Biologic drugs targeting TNF include engineered monoclonal antibodies and fusion proteins. Currently, there are 5 Food and Drug Administration-approved TNF inhibitors (infliximab, etanercept, adalimumab, certolizumab, and golimumab), representing close to $20 billion in sales. Clinical trials remain open to test their efficacy and safety compared with one another, as well as to measure clinical outcomes in different conditions and patient populations. The industry is also eager to develop biotherapeutics that are similar but cheaper than the currently existing biologics or are safer with higher efficacy; these are the so-called "biosimilars." Clinical utility of TNF inhibitors and indications of mono- or combined therapy with immunomodulators are reviewed here. Pharmacokinetics of the TNF inhibitors is affected by routes of administration, clearance mechanisms of immunoglobulins, and immunogenicity. Finally, strategies for management of treatment efficacy and increasing evidence for monitoring of serum concentration of TNF inhibitors are discussed, assessing for the presence of the antidrug antibodies and the different analytical methods available for laboratory testing. As clinical applications of the TNF inhibitors expand, and other classes join the revolution in the treatment of chronic inflammatory disorders, therapeutic drug monitoring of biologics will become increasingly important, with the potential to dramatically improve patient care and management.

Role for therapeutic drug monitoring during induction therapy with TNF antagonists in IBD: evolution in the definition and management of primary nonresponse

: Primary nonresponse and primary nonremission are important limitations of tumor necrosis factor (TNF) antagonists, occurring in 10% to 40% and 50% to 80% of patients with inflammatory bowel disease, respectively. The magnitude of primary nonresponse differs between phase III clinical trials and cohort studies, indicating differences, e.g., in definition, patient population or blinding. The causes of nonresponse can be attributed to the drug (pharmacokinetics, immunogenicity), the patient (genetics, disease activity), the disease (type, location, severity), and/or the treatment strategy (dosing regimen, combination therapy). Primary nonresponse has been attributed to "non-TNF-driven disease" which is an overly simplified and potentially misleading approach to the problem. Many patients with primary nonresponse could successfully be treated with dose optimization during the induction phase or switching to another TNF antagonist. Therefore, primary nonresponse is frequently not a non-TNF-driven disease. Recent studies from rheumatoid arthritis and preliminary data from inflammatory bowel disease evaluating therapeutic drug monitoring have suggested that early measurement of drug and anti-drug antibody concentrations could help to define primary nonresponse and rationalize patient management of this problem. Moreover, a modeling approach including pharmacological parameters and patient-related covariants could potentially be predictive for response to the treatment. We describe an overview of this evolution in thinking, underpinned by previous findings, and assess the potential role of early measurement of drug and antidrug antibody concentrations in the definition and management of primary nonresponse.

Generation and characterization of small single domain antibodies inhibiting human tumor necrosis factor receptor 1

The cytokine TNF is a well known drug target for several inflammatory diseases such as Crohn disease. Despite the great success of TNF blockers, therapy could be improved because of high costs and side effects. Selective inhibition of TNF receptor (TNFR) 1 signaling holds the potential to greatly reduce the pro-inflammatory activity of TNF, thereby preserving the advantageous immunomodulatory signals mediated by TNFR2. We generated a selective human TNFR1 inhibitor based on Nanobody (Nb) technology. Two anti-human TNFR1 Nbs were linked with an anti-albumin Nb to generate Nb Alb-70-96 named "TNF Receptor-One Silencer" (TROS). TROS selectively binds and inhibits TNF/TNFR1 and lymphotoxin-α/TNFR1 signaling with good affinity and IC50 values, both of which are in the nanomolar range. Surface plasmon resonance analysis reveals that TROS competes with TNF for binding to human TNFR1. In HEK293T cells, TROS strongly reduces TNF-induced gene expression, like IL8 and TNF, in a dose-dependent manner; and in ex vivo cultured colon biopsies of CD patients, TROS inhibits inflammation. Finally, in liver chimeric humanized mice, TROS antagonizes inflammation in a model of acute TNF-induced liver inflammation, reflected in reduced human IL8 expression in liver and reduced IL6 levels in serum. These results demonstrate the considerable potential of TROS and justify the evaluation of TROS in relevant disease animal models of both acute and chronic inflammation and eventually in patients.

Tumour necrosis factor superfamily members in the pathogenesis of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a group of inflammatory conditions of the gastrointestinal tract of unclear aetiology of which two major forms are Crohn's disease (CD) and ulcerative colitis (UC). CD and UC are immunologically distinct, although they both result from hyperactivation of proinflammatory pathways in intestines and disruption of intestinal epithelial barrier. Members of the tumour necrosis factor superfamily (TNFSF) are molecules of broad spectrum of activity, including direct disruption of intestinal epithelial barrier integrity and costimulation of proinflammatory functions of lymphocytes. Tumour necrosis factor (TNF) has a well-established pathological role in IBD which also serves as a target in IBD treatment. In this review we discuss the role of TNF and other TNFSF members, notably, TL1A, FasL, LIGHT, TRAIL, and TWEAK, in the pathogenesis of IBD.