Azathioprine or 6-mercaptopurine for induction of remission in Crohn's disease

The Future of Advanced Therapies for Pediatric Crohn's Disease

Pediatric Crohn's disease commonly presents with moderate-to-severe intestinal inflammation with a greater risk of complications if remission is not achieved. Anti-tumor necrosis factor therapies have offered the possibility of deep and durable remission; however, many children do not respond or no longer respond over time. Further, some children do not require broader systemic immunosuppression to achieve remission and are better served by an alternative treatment strategy. Proper utilization of advanced biologic and small-molecule therapies, which have become available for adult patients since anti-tumor necrosis factor medications, is paramount for tighter disease control for a large proportion of children. Newer advanced therapies such as anti-integrin and anti-interleukin biologics, and several small-molecule agents capitalize on various mechanisms through narrower immunologic targets and reduced immunogenicity. Given limited regulatory approvals of these agents for use in children with Crohn's disease, clinicians continue to rely on data extrapolated from clinical trials in adult patients, sparse pediatric studies, and a growing real-world experience for treatment selection and optimization. In this article, we discuss currently available treatment options, pipeline drugs, and relevant data as they pertain to some of the most pressing clinical challenges faced in treating pediatric Crohn's disease.

Recent developments in the assessment and management of inflammatory bowel disease in childhood: a narrative review

Background and Objective

The landscape of paediatric inflammatory bowel disease (pIBD) continues to evolve in an era of increasing incidence. There have been rapid developments in understanding, as we begin to perceive IBD as a spectrum of conditions, alongside advancements in monitoring and treatment. The objective of this article was to provide an overview of recent advances and challenges in the management of pIBD, with a focus on sustainable healthcare, personalised therapy, genomics, new drugs and avenues for future optimisation.

Methods

We present a narrative review that synthesises and summarises recent research (2017-2022) related to pIBD. We undertook a structured search of the literature (PubMed and Medline) and additional articles were identified through manual searches of reference lists. Evidence tables were compiled for disease outcomes.

Key Content and Findings

In this review we outline current practice, integrating clinical guidelines and contemporary research. We discuss initial investigations (including suggested threshold for paediatric faecal calprotectin), specialist investigations for disease monitoring [with reference to video capsule endoscopy (VCE) and therapeutic drug levels] and outline new and established treatment options. Biomarkers and genomic testing are examined as important tools for individualising care and identifying potential therapeutic targets, including for top-down therapy. Despite these advances, significant challenges remain, including the need for further research to understand the mechanisms of disease and the translation of these advances into real-world improvements in practice.

Conclusions

Recent advances in understanding of the pathogenesis of pIBD, alongside genomic and pharmacological developments have added more tools to the armamentarium for the treatment of these conditions and highlighted ongoing areas of research need.

Targeting ferroptosis, a novel programmed cell death, for the potential of alcohol-related liver disease therapy

Ferroptosis is a new iron-dependent cell death mode, which is different from the other types of programmed cell death, such as apoptosis, necrosis, and autophagy. Ferroptosis is characterized by a process in which fatal lipids from lipid peroxidation accumulate in cells and eventually lead to cell death. Alcohol-related liver disease (ALD) is a type of liver injury caused by excessive alcohol intake. Alcohol-related liver disease is a broad-spectrum disease category, which includes fatty liver, steatohepatitis, hepatitis, cirrhosis, and hepatocellular tumors. Recent studies have found that ferroptosis is involved in the pathological development of non-viral liver diseases. Therefore, ferroptosis may be an ideal target for the treatment of non-viral liver diseases. In this review article, we will elaborate the molecular mechanism and regulatory mechanism of ferroptosis, explore the key role of ferroptosis in the Alcohol-related liver disease process, and summarize the existing targeted ferroptosis drugs and their feasibility for the treatment of Alcohol-related liver disease.

Comparative efficacy and safety of combination therapy with infliximab for Crohn's disease: a systematic review and network meta-analysis

PURPOSE

There is not enough information to position medications for the treatment of Crohn's disease (CD). Therefore, using a network meta-analysis and systematic review, we evaluated the efficacy and safety of combination therapy and infliximab (IFX) monotherapy in CD patients.

METHODS

We identified randomized controlled trials (RCTs) in CD patients who were given IFX-containing combination therapy versus IFX monotherapy. Induction and maintenance of clinical remission were the efficacy outcomes, while adverse events were the safety outcomes. The surface under cumulative ranking (SUCRA) probabilities was used to assess ranking in the network meta-analysis.

RESULTS

In total, 15 RCTs with 1586 CD patients were included in this study. There was no statistical difference between different combination therapies in induction and maintenance of remission. In terms of inducing clinical remission, IFX + EN (SUCRA: 0.91) ranked highest; in terms of maintaining clinical remission, IFX + AZA (SUCRA: 0.85) ranked highest. There was no treatment that was significantly safer than the others. In terms of any adverse events, serious adverse events, serious infections, and infusion/injection-site reactions, IFX + AZA (SUCRA: 0.36, 0.12, 0.19, and 0.24) was ranked lowest for all risks; while IFX + MTX (SUCRA: 0.34, 0.06, 0.13, 0.08, 0.34, and 0.08) was rated lowest for risk of abdominal pain, arthralgia, headache, nausea, pyrexia, and upper respiratory tract infection.

CONCLUSION

Indirect comparisons suggested that efficacy and safety of different combination treatments are comparable in CD patients. For maintenance therapies, IFX + AZA was ranked highest for clinical remission and lowest for adverse events. Further head-to-head trials are required.

Systematic review: The effectiveness of 6-thioguanine nucleotide-based dose optimisation of thiopurines in the treatment of inflammatory bowel disease

Introduction: Clinical guidelines highlight the potential utility of metabolite-based thiopurine dose optimisation strategies in inflammatory bowel disease (IBD). The aim of this review was to summarise the evidence of effectiveness and safety of a 6-thioguanine nucleotide (6-TGN) metabolite-based dosing strategy for maintenance of remission using azathioprine or mercaptopurine in Crohn's disease and ulcerative colitis. Methods: We searched the Cochrane central register of controlled trials, EMBASE, clinicaltrials.gov, the WHO international clinical trials registry platform, and relevant grey literature, up to 1 December 2021. Inclusion criteria were: all randomised (active comparator) controlled trials of azathioprine or mercaptopurine used for the purposes of maintenance of remission in Crohn's disease or ulcerative colitis where the dose in the intervention arm was optimised based on 6-TGN metabolite assay results. Studies of any duration were eligible for inclusion, and no age restrictions were applied. Results: No studies met the eligibility criteria for this review. Four randomised controlled studies (two of which are currently underway) were identified that assessed the effectiveness of metabolite-based dose optimisation for thiopurine therapy, but were not eligible either because they did not differentiate between induction and maintenance therapy or because of a lack of an appropriate active comparator. Conclusions: There is no RCT-based evidence for dose optimisation using a 6-TGN metabolite-based dosing strategy for maintenance of remission in Crohn's disease or ulcerative colitis. Where evidence is available from combination induction and maintenance trials, it suggests that such a strategy is no better than weight-based dosing. Cochrane protocol registration: CD014795

Personalize, participate, predict, and prevent: 4Ps in inflammatory bowel disease

Inflammatory bowel disease (IBD), which includes Crohn's disease (CD) and ulcerative colitis (UC), is a complex, immune-mediated, disorder which leads to several gastrointestinal and systemic manifestations determining a poor quality of life, disability, and other negative health outcomes. Our knowledge of this condition has greatly improved over the last few decades, and a comprehensive management should take into account both biological (i.e., disease-related, patient-related) and non-biological (i.e., socioeconomic, cultural, environmental, behavioral) factors which contribute to the disease phenotype. From this point of view, the so called 4P medicine framework, including personalization, prediction, prevention, and participation could be useful for tailoring ad hoc interventions in IBD patients. In this review, we discuss the cutting-edge issues regarding personalization in special settings (i.e., pregnancy, oncology, infectious diseases), patient participation (i.e., how to communicate, disability, tackling stigma and resilience, quality of care), disease prediction (i.e., faecal markers, response to treatments), and prevention (i.e., dysplasia through endoscopy, infections through vaccinations, and post-surgical recurrence). Finally, we provide an outlook discussing the unmet needs for implementing this conceptual framework in clinical practice.

Impact of thiopurine dose in anti-tumor necrosis factor combination therapy on outcomes in inflammatory bowel disease

Background

Combination therapy with thiopurines and anti-tumor necrosis factor (TNF) is superior to monotherapy in Crohn's disease (CD) and ulcerative colitis (UC). The optimal dose of thiopurines in combination therapy remains unclear. We investigated the impact of thiopurine dose in combination therapy on outcomes in inflammatory bowel disease (IBD).

Methods

This was a single-center, retrospective study of patients with IBD treated with thiopurine and anti-TNF combination therapy between 1/2012 and 11/2020. A therapeutic dose of thiopurines was defined as ≥1 mg/kg for 6-mercaptopurine and ≥2 mg/kg for azathioprine. The primary outcome was anti-drug antibody (ADA) formation in patients on a therapeutic thiopurine dose vs. a lower thiopurine dose group. Secondary outcomes included steroid-free clinical remission, endoscopic healing (absence of ulcers/erosions in CD and Mayo endoscopic score ≤1 for UC), and normal serum C-reactive protein (CRP) in patients who were on combination therapy.

Results

A total of 108 patients were included (median age 31.5 years; 58.3% male). A therapeutic dose of thiopurine was used in 19%. In the therapeutic thiopurine dose group, 23.8% developed ADA vs. 29.9% (P=0.58) in the lower dose group. No significant differences were noted between the therapeutic and lower dose thiopurine groups in terms of steroid-free clinical remission (57.1% vs. 60.9%, P=0.75), endoscopic healing (55% vs. 60%, P=0.69), and normal CRP (52.4% vs. 52.9%, P=0.27).

Conclusion

In our cohort of patients with IBD on anti-TNF combination therapy, thiopurine dose was not associated with significant differences in anti-TNF immunogenicity and clinical outcomes.

Stem cell transplantation for induction of remission in medically refractory Crohn's disease

BACKGROUND

Crohn's disease (CD) is an inflammatory bowel disease that causes inflammation and stricture, of any part of the mucosa and the gut wall. It forms skip lesions, sparing the areas in between the affected parts of the gastrointestinal tract. Crohn's disease could have one of three complications; fistula, intestinal obstruction due to stricture, or gastrointestinal inflammation presenting as severe diarrhoea. Stem cell therapy (SCT) is an innovative treatment that has been recently used in CD. The exact role of SCT in CD is still unclear. Stem cells modify the immunity of the patients or act as a "reset tool" for the immune system as in the case of systemically-injected stem cells, or regenerate the affected area of necrotic and inflammatory tissue as in the case of local injection into the lesion. Stem cells are a wide variety of cells including pluripotent stem cells or differentiated stem cells. The hazards range from rejection to symptomatic manifestations as fever or increase infection.  OBJECTIVES: The objective of this Cochrane systematic review is to assess the effects of stem cell transplantation compared to standard of care alone or with placebo on efficacy and safety outcomes in patients with refractory CD.

SEARCH METHODS

We searched MEDLINE, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and clinical trial registries (Clinicaltrials.gov, World Health Organization-International Clinical Trials Registry Platform WHO ICTRP) from inception to 19 March 2021, without any language, publication year, or publication status restrictions. In addition, we searched references of included studies and review articles for further references. An update of the published studies was done during the writing of the review.

SELECTION CRITERIA

We included only randomised controlled trials (RCTs) that assessed the effectiveness and safety of SCT in refractory CD versus standard care alone (control) or with placebo.

DATA COLLECTION AND ANALYSIS

Two review authors (SEN and SFA) independently screened the studies retrieved from the search results for inclusion, extracted data and assessed the risk of bias. Any disagreement was resolved through a consensus between the authors. We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We conducted our search on 19 March 2021 and identified 639 records. We added two records by a manual search of the published reviews on the topic to a total of 641 records. The Covidence program removed 125 duplicates making a total of 516 reports. Two review authors (SEN and SFA) screened titles and abstracts and excluded 451 records with the remaining 65 for full-text records screened independently by the two authors; only 18 studies were considered for inclusion.  We included seven RCTs with a total of 442 participants for the meta-analysis. The intervention group included 234 patients, and the control group included 208 patients. Nine trials are ongoing and, two abstracts are awaiting classification. All patients in the control and intervention groups received the standard therapy for CD. Only three studies used blinding methods for the control group in the form of a placebo, with one study of the three stated that the blinding method was inefficient. The patients and personnel were aware of the intervention in the rest of the four studies as they were open-label trials. However, the effect of unblinding was balanced by the low risk of detection bias in five of the included studies. The evidence is uncertain about the effect of SCT on achieving clinical remission as compared to control/placebo (risk ratio (RR) 1.88, 95% Confidence Interval (CI) 0.80 to 4.41; 3 studies; low-certainty evidence). The evidence is very uncertain about the effect of SCT on achieving Crohn's Disease Activity Index (CDAI) <150 at 24 weeks compared to control (RR1.02 95% CI 0.67 to 1.56; 4 studies; very-low certainty evidence). SCT is likely to achieve fistula closure as compared to the control/placebo both in the short term (RR 1.48, 95% CI 1.12 to 1.96); low-certainty evidence) and in the long term (RR 1.42, 95% CI 1.09 to 1.87; 4 studies; low-certainty evidence) follow-up. The evidence is very uncertain about the effect of SCT to cause no difference in the number of total adverse events as compared to the control/placebo (RR 0.99, 95% CI [0.88 to  1.13); 4 studies; very-low-certainty evidence). However, SCT is likely to increase the number of serious adverse events as compared to the control/placebo (RR 1.22, 95% CI 0.88 to 1.67; 7 studies; low-certainty evidence). The evidence is very uncertain about the effect of SCT to decrease the withdrawal due to adverse events as compared to the control/placebo (RR 0.78, 95% CI 0.32 to 1.89; 3 studies; very-low certainty evidence). Funding by pharmaceutical companies was found in three studies, with one including more than 50% of our studied population.

AUTHORS' CONCLUSIONS

SCT shows an uncertain effect on clinical remission with low certainty of evidence. SCT shows an uncertain effect on CDAI score to reach <150 after 24 weeks of treatment, with very low certainty evidence. SCT shows beneficial effects on fistula-closure during short and long-term follow-up with low-certainty evidence in both outcomes. There was no change in the total number of adverse events with SCT as compared to control, with very low certainty evidence. While there was a moderate effect on increasing the number of serious adverse events in the SCT group, as compared to the control with low-certainty evidence. Withdrawal due to adverse events was slightly higher in the control group with very low certainty evidence. All the participants were refractory to standard medical treatment, but the number of participants was small, this may limit the generalizability of the results. Further research is needed for validation. More objective outcomes are needed in the assessment of stem cell effectiveness in the treatment of Crohn's disease, especially the intestinal CD subtype; with standardization of the dose, methods of stem cell preparation, route of administration, and inclusion criteria to the studies to achieve clear results.

Azathioprine with Allopurinol Is a Promising First-Line Therapy for Inflammatory Bowel Diseases

BACKGROUND

Beneficial response to first-line immunosuppressive azathioprine in patients with inflammatory bowel disease (IBD) is low due to high rates of adverse events. Co-administrating allopurinol has been shown to improve tolerability. However, data on this co-therapy as first-line treatment are scarce.

AIM

Retrospective comparison of long-term effectiveness and safety of first-line low-dose azathioprine-allopurinol co-therapy (LDAA) with first-line azathioprine monotherapy (AZAm) in patients with IBD without metabolite monitoring.

METHODS

Clinical benefit was defined as ongoing therapy without initiation of steroids, biologics or surgery. Secondary outcomes included CRP, HBI/SCCAI, steroid withdrawal and adverse events.

RESULTS

In total, 166 LDAA and 118 AZAm patients (median follow-up 25 and 27 months) were evaluated. Clinical benefit was more frequently observed in LDAA patients at 6 months (74% vs. 53%, p = 0.0003), 12 months (54% vs. 37%, p = 0.01) and in the long-term (median 36 months; 37% vs. 24%, p = 0.04). Throughout follow-up, AZAm patients were 60% more likely to fail therapy, due to a higher intolerance rate (45% vs. 26%, p = 0.001). Only 73% of the effective AZA dose was tolerated in AZAm patients, while LDAA could be initiated and maintained at its target dose. Incidence of myelotoxicity and elevated liver enzymes was similar in both cohorts, and both conditions led to LDAA withdrawal in only 2%. Increasing allopurinol from 100 to 200-300 mg/day significantly lowered liver enzymes in 5/6 LDAA patients with hepatotoxicity.

CONCLUSIONS

Our poor AZAm outcomes emphasize that optimization of azathioprine is needed. We demonstrated a long-term safe and more effective profile of first-line LDAA. This co-therapy may therefore be considered standard first-line immunosuppressive.

Serum inter-alpha-trypsin inhibitor heavy chain 4 in patients with inflammatory bowel disease: correlation with disease risk, inflammation, activity, and its variation after treatment

BACKGROUND

Inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4) plays vital roles in inflammatory and auto-immune diseases, but its correlations with disease risk and clinical features in inflammatory bowel disease (IBD) need further investigation. The present study intended to explore the correlation of ITIH4 with disease activity and inflammation, as well as its change after treatment in IBD patients.

METHODS

Totally, 40 active Crohn's disease (A-CD) patients, 40 clinical-remission CD (R-CD) patients, 40 active ulcerative colitis (A-UC) patients, 40 clinical-remission UC (R-UC) patients, and 40 health controls (HCs) were enrolled. ITIH4 in serum was assessed by ELISA.

RESULTS

ITIH4 was lower in A-CD, R-CD, A-UC, and R-UC patients than in HCs (P < 0.001). Notably, ITIH4 reduced in A-CD patients than in R-CD patients (P = 0.017), and in A-UC patients compared with R-UC patients (P = 0.010). Besides, in A-CD patients, ITIH4 negatively correlated with tumor necrosis factor-alpha (TNF-α), interleukin (IL)-17A, IL-1β, C-reactive protein (CRP), and clinical disease activity index score (all P < 0.05). In A-UC patients, ITIH4 negatively correlated with TNF-α, IL-17A, IL-1β, IL-6, CRP, and Mayo score (all P < 0.05). However, in R-CD and R-UC patients, these correlations were less obvious than in A-CD and A-UC patients. ITIH4 was increased after treatment (all P < 0.05), and its expression at W12 after treatment was higher in response patients compared with no response patients in A-CD (P = 0.022) and A-UC groups (P = 0.038).

CONCLUSION

ITIH4 correlates with IBD susceptibility, active risk, inflammation level, and its elevation after treatment relates to clinical response in IBD patients.

Guidelines for the management of patients with Crohn's disease. Recommendations of the Polish Society of Gastroenterology and the Polish National Consultant in Gastroenterology

This paper is an update of the diagnostic and therapeutic recommendations of the National Consultant for Gastroenterology and the Polish Society of Gastroenterology from 2012. It contains 46 recommendations for the diagnosis and treatment, both pharmacological and surgical, of Crohn's disease in adults. The guidelines were developed by a group of experts appointed by the Polish Society of Gastroenterology and the National Consultant in the field of Gastroenterology. The methodology related to the GRADE methodology was used to assess the quality and strength of the available recommendations. The degree of expert support for the proposed statement, assessment of the quality of evidence and the strength of the recommendation was assessed on a 6-point Likert scale. Voting results, quality and strength ratings with comments are included with each statement.

Role of Ferroptosis in Non-Alcoholic Fatty Liver Disease and Its Implications for Therapeutic Strategies

Non-alcoholic fatty liver disease (NAFLD) has become the chronic liver disease with the highest incidence throughout the world, but its pathogenesis has not been fully elucidated. Ferroptosis is a novel form of programmed cell death caused by iron-dependent lipid peroxidation. Abnormal iron metabolism, lipid peroxidation, and accumulation of polyunsaturated fatty acid phospholipids (PUFA-PLs) can all trigger ferroptosis. Emerging evidence indicates that ferroptosis plays a critical role in the pathological progression of NAFLD. Because the liver is the main organ for iron storage and lipid metabolism, ferroptosis is an ideal target for liver diseases. Inhibiting ferroptosis may become a new therapeutic strategy for the treatment of NAFLD. In this article, we describe the role of ferroptosis in the progression of NAFLD and its related mechanisms. This review will highlight further directions for the treatment of NAFLD and the selection of corresponding drugs that target ferroptosis.

Biomarkers for gastrointestinal adverse events related to thiopurine therapy

Thiopurines are immunomodulators used in the treatment of acute lymphoblastic leukemia and inflammatory bowel diseases. Adverse reactions to these agents are one of the main causes of treatment discontinuation or interruption. Myelosuppression is the most frequent adverse effect; however, approximately 5%-20% of patients develop gastrointestinal toxicity. The identification of biomarkers able to prevent and/or monitor these adverse reactions would be useful for clinicians for the proactive management of long-term thiopurine therapy. In this editorial, we discuss evidence supporting the use of PACSIN2, RAC1, and ITPA genes, in addition to TPMT and NUDT15, as possible biomarkers for thiopurine-related gastrointestinal toxicity.

Evolving Role of Thiopurines in Inflammatory Bowel Disease in the Era of Biologics and New Small Molecules

In recent years, with the increasing availability of biologic therapies and due to safety concerns, the role of thiopurines in the management of inflammatory bowel disease has been questioned. While acknowledging that the benefit/risk ratio of biologic therapies is very high, they are expensive and are not required by a majority of patients. Therefore, thiopurines do retain an important role as steroid-sparing and maintenance agents when used as monotherapy, and in combination therapy with biologics due to their clinical and pharmacokinetic optimization of anti-tumor necrosis factor agents in particular. Safety concerns with thiopurines are real but also relatively rare, and with careful pre-treatment screening and ongoing monitoring thiopurine benefits outweigh risks in the majority of appropriately selected patients. Measurement of newer pharmacogenomic markers such as nudix hydrolase 15 (NUDT15), when combined with knowledge of existing known mutations (e.g., thiopurine S-methyltransferase-TPMT), will hopefully minimize the risk of potentially life-threatening leukopenia by allowing for pre-treatment dosing stratification. Further optimization of thiopurine dosing via measurement of thiopurine metabolites should be performed routinely and is superior to weight-based dosing. The association of thiopurines with malignancies including lymphoproliferative disorders needs to be recognized in all patients and individualized in each patient. The decrease in lymphoma risk after thiopurine cessation provides an incentive for thiopurine de-escalation in appropriate patients after a period of prolonged deep remission. This review will summarize the current role of thiopurines in inflammatory bowel disease management and provide recommendations for commencing and monitoring therapy, and when to consider de-escalation.

Biologic monotherapy versus combination therapy with immunomodulators in the induction and maintenance of remission of Crohn's disease and ulcerative colitis

Despite current guidelines, the optimal treatment of patients with inflammatory bowel disease (IBD) remains challenging. The available medications are not without risk and there is not a single correct treatment regimen for every patient. Personalizing treatment and selecting the most appropriate therapy is crucial for optimal response, remission, quality of life, and healthcare utilization. Biologics, especially anti-tumor necrosis factor-α medications, are widely used in the induction and maintenance of disease remission in patients with IBD. Similarly, immunomodulators, including thiopurines and methotrexate, are traditionally popular for the maintenance of remission. In this manuscript, we review the use of biologic monotherapy vs. combination therapy with immunomodulators for the treatment of ulcerative colitis and Crohn’s disease. We examine overall remission, immunogenicity and adverse effects, mainly serious infections and malignancy, in an effort to help guide treatment decisions and weigh the risks and benefits of biologic monotherapy vs. combination therapy.

Use of thiopurines in inflammatory bowel disease: an update

Inflammatory bowel disease (IBD), once considered a disease of the Western hemisphere, has emerged as a global disease. As the disease prevalence is on a steady rise, management of IBD has come under the spotlight. 5-Aminosalicylates, corticosteroids, immunosuppressive agents and biologics are the backbone of treatment of IBD. With the advent of biologics and small molecules, the need for surgery and hospitalization has decreased. However, economic viability and acceptability is an important determinant of local prescription patterns. Nearly one-third of the patients in West receive biologics as the first/initial therapy. The scenario is different in developing countries where biologics are used only in a small proportion of patients with IBD. Increased risk of reactivation of tuberculosis and high cost of the therapy are limitations to their use. Thiopurines hence become critical for optimal management of patients with IBD in these regions. However, approximately one-third of patients are intolerant or develop adverse effects with their use. This has led to suboptimal use of thiopurines in clinical practice. This review article discusses the clinical aspects of thiopurine use in patients with IBD with the aim of optimizing their use to full therapeutic potential.

CROHN'S DISEASE. CLINICAL RECOMMENDATIONS (PRELIMINARY VERSION)

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Update on therapeutic management of spondyloarthritis associated with inflammatory bowel disease

Management of spondyloarthritis (SpA) in patients with inflammatory bowel disease (IBD) remains a challenging task that requires multidisciplinary collaboration. Separate guidelines for each disease are well-established. However, the management of SpA co-occurring with Crohn's disease (CD) or ulcerative colitis (UC) has hardly been studied. There are few specific reports that focus on this therapeutic area. The main issue is that some therapeutic options used to treat one disease can negatively influence the other disease course. This study aims to evaluate the therapeutic alternatives that would allow for the appropriate management of patients with both SpA and IBD. Key Points • Collaboration between gastroenterologists and rheumatologists is recommended to improve the management of patients with spondyloarthritis (SpA) and inflammatory bowel disease (IBD). • When treating SpA occurring simultaneously with IBD, it would be appropriate to give priority to the active disease. • Considering its well-proven efficacy in both conditions, anti-tumor necrosis factor (TNF) therapy remains the corner stone in the treatment of these patients. • Other therapeutic options such as Janus kinases (JAK) inhibitors, interleukin (IL)-23 and IL-12 inhibitors, and vedolizumab are still under investigation.

Positioning Therapies in the Management of Crohn's Disease

In the past decade, several new therapies with different mechanisms of action have been approved for the management of moderate to severe Crohn's disease. However, there is limited guidance on optimal positioning of agents as first- or second-line therapies because of the absence of head-to-head trials. Furthermore, given the lack of comparative studies, treatment guidelines have provided limited insight. In this review, we discuss data on key treatment attributes, comparative efficacy and safety, factors predictive of response to each agent, and propose an algorithm for positioning therapies for the management of patients with low-risk and high-risk Crohn's disease.

Crohn's disease

Crohn's disease is an inflammatory bowel disease that is characterized by chronic inflammation of any part of the gastrointestinal tract, has a progressive and destructive course and is increasing in incidence worldwide. Several factors have been implicated in the cause of Crohn's disease, including a dysregulated immune system, an altered microbiota, genetic susceptibility and environmental factors, but the cause of the disease remains unknown. The onset of the disease at a young age in most cases necessitates prompt but long-term treatment to prevent disease flares and disease progression with intestinal complications. Thus, earlier, more aggressive treatment with biologic therapies or novel small molecules could profoundly change the natural history of the disease and decrease complications and the need for hospitalization and surgery. Although less invasive biomarkers are in development, diagnosis still relies on endoscopy and histological assessment of biopsy specimens. Crohn's disease is a complex disease, and treatment should be personalized to address the underlying pathogenetic mechanism. In the future, disease management might rely on severity scores that incorporate prognostic factors, bowel damage assessment and non-invasive close monitoring of disease activity to reduce the severity of complications.

The Evolving Role of Thiopurines in Inflammatory Bowel Disease

PURPOSE OF REVIEW

With the advent of biologic therapies for the treatment of inflammatory bowel disease, the roles of thiopurines have continued to evolve. This review will focus on recent advances in pharmacology and the safety and efficacy of thiopurines as maintenance therapies for steroid-induced remissions and post-surgical maintenance of remission and as combination therapies to reduce immunogenicities of biologic agents.

RECENT FINDINGS

Due to pharmacogenetics of thiopurine S-methyltransferase, thiopurine dosing is more effectively based on monitoring of thiopurine metabolites rather than weight-based dosing. Thiopurines continue to have a role as maintenance therapy after steroid-induced remissions and in combination with biologics to induce and maintain remission. Safety monitoring includes measurements of blood counts, liver chemistries, and dermatologic evaluations and protection from sun exposure. Thiopurines appear to be safe during pregnancies and while very uncommon, lymphomas (including hepatosplenic T cell lymphomas) remain a recognized risk, particularly in younger and older males.

Sustained effectiveness, safety and therapeutic drug monitoring of tioguanine in a cohort of 274 IBD patients intolerant for conventional therapies

BACKGROUND

Tioguanine (or thioguanine) is an alternative drug for IBD patients who fail prior conventional immunomodulating therapy.

AIM

To report effectiveness, safety and therapeutic drug monitoring in a cohort of patients with prolonged tioguanine maintenance therapy.

METHODS

In this nationwide, multicentre study, medical records of tioguanine- using IBD patients were retrospectively reviewed. Response to therapy was defined as clinical effectiveness without (re)initiation of corticosteroids, concurrent biological therapy or surgical intervention. All adverse events that occurred during the follow-up were listed and graded according to the common terminology criteria (CTC).

RESULTS

Two hundred and seventy-four patients (female 63%, Crohn's disease in 68%) were included with median treatment duration of 51 months, 1567 patient-years of follow-up and median 20 mg/d tioguanine dosage. Tioguanine was tolerated in 79%, clinical effectiveness at 6 months was documented in 66% and sustained clinical effectiveness during 12 months in 51% of patients. Forty-one per cent of patients developed adverse events: 5% were graded as severe. Adverse events comprised infection requiring hospitalisation in three and skin cancer in eight patients (two melanomas). Asymptomatic nodular regenerative hyperplasia of the liver occurred in two out of 52 patients with liver biopsies (3.8%) and portal hypertension in three whereof one potentially associated with tioguanine (0.4%). Clinical effectiveness was correlated with 6-thioguanine nucleotide threshold concentrations >682 pmol/8×10⁸ RBC (P < 0.05).

CONCLUSIONS

Long-term tioguanine therapy for at least 12 months was effective in 51% and well tolerated as a maintenance treatment for IBD in about 70% of patients. Adverse events were common, but mainly mild or moderate. 6-Thioguanine nucleotide threshold concentration ≥ 700 pmol/8×10⁸ RBC is proposed as target level with higher odds for clinical effectiveness.

Recent advances in the management of perianal fistulizing Crohn's disease: lessons for the clinic

Managing fistulizing perianal disease is among the most challenging aspects of treating patients with Crohn's disease. Perianal fistulas are indicative of poor long-term prognosis. They are commonly associated with significant morbidities and can have detrimental effects on quality of life. While durable fistula closure is ideal, it is uncommon. In optimal circumstances, reported long-term fistula healing rates are only slightly higher than 50% and recurrence is common. Achieving these results requires a combined medical and surgical approach, highlighting the importance of a highly skilled and collaborative multidisciplinary team. In recent years, advances in imaging, biologic therapies and surgical techniques have lent to growing enthusiasm amongst treatment teams, however the most advantageous approach is yet to be determined. Areas covered: Here we review current management approaches, incorporating recent guidelines and novel therapies. Additionally, we discuss recently published and ongoing studies that will likely impact practice in the coming years. Expert opinion: Investing in concerted collaborative multi-institutional efforts will be necessary to better define optimal timing and dosing of medical therapy, as well as to identify ideal timing and approach of surgical interventions. Standardizing outcome measures can facilitate these efforts. Clearly, experienced multidisciplinary teams will be paramount in this process.

Preclinical evaluation of EPHX2 inhibition as a novel treatment for inflammatory bowel disease

Epoxyeicosatrienoic acids (EETs) are signaling lipids produced by cytochrome P450 epoxygenation of arachidonic acid, which are metabolized by EPHX2 (epoxide hydrolase 2, alias soluble epoxide hydrolase or sEH). EETs have pleiotropic effects, including anti-inflammatory activity. Using a Connectivity Map (CMAP) approach, we identified an inverse-correlation between an exemplar EPHX2 inhibitor (EPHX2i) compound response and an inflammatory bowel disease patient-derived signature. To validate the gene-disease link, we tested a pre-clinical tool EPHX2i (GSK1910364) in a mouse disease model, where it showed improved outcomes comparable to or better than the positive control Cyclosporin A. Up-regulation of cytoprotective genes and down-regulation of proinflammatory cytokine production were observed in colon samples obtained from EPHX2i-treated mice. Follow-up immunohistochemistry analysis verified the presence of EPHX2 protein in infiltrated immune cells from Crohn's patient tissue biopsies. We further demonstrated that GSK2256294, a clinical EPHX2i, reduced the production of IL2, IL12p70, IL10 and TNFα in both ulcerative colitis and Crohn's disease patient-derived explant cultures. Interestingly, GSK2256294 reduced IL4 and IFNγ in ulcerative colitis, and IL1β in Crohn's disease specifically, suggesting potential differential effects of GSK2256294 in these two diseases. Taken together, these findings suggest a novel therapeutic use of EPHX2 inhibition for IBD.

Conventional therapy for moderate to severe inflammatory bowel disease: A systematic literature review

BACKGROUND

Despite the advent of biological drugs, conventional therapy continues to be used in moderate to severe inflammatory bowel disease (MS-IBD). This study hypothesized that as a standard of treatment and the primary alternative to biologics, conventional therapy should present robust effectiveness results in IBD outcomes.

AIM

To investigate the effectiveness of conventional therapy for MS-IBD.

METHODS

A systematic review with no time limit was conducted in July 2017 through the Cochrane Collaboration, MEDLINE, and LILACS databases. The inclusion criteria encompassed meta-analyses, systematic reviews, randomized clinical trials, observational and case-control studies concerning conventional therapy in adult patients with MS-IBD, including Crohn’s disease (CD) and ulcerative colitis (UC). Corticosteroids (prednisone, hydrocortisone, budesonide, prednisolone, dexamethasone), 5-aminosalicylic acid (5-ASA) derivatives (mesalazine and sulfasalazine) and immunosuppressants [azathioprine (AZA), methotrexate (MTX), mycophenolate, cyclosporine, tacrolimus, 6-mercaptopurine (6-MP)] were considered conventional therapy. The exclusion criteria were sample size below 50; narrative reviews; specific subpopulations (e.g., pregnant women, comorbidities); studies on postoperative IBD; and languages other than English, Spanish, French or Portuguese. The primary outcome measures were clinical remission (induction or maintenance), clinical response and mucosal healing. As secondary outcomes, fecal calprotectin, hospitalization, death, and surgeries were analyzed. The quality of the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation criteria.

RESULTS

The search strategy identified 1995 citations, of which 27 were considered eligible (7 meta-analyses, 20 individual studies). For induction of clinical remission, four meta-analyses were selected (AZA and 6-MP showed no advantage over placebo, MTX or 5-ASA in CD; MTX showed no statistically significant difference versus placebo, 6-MP, or 5-ASA in UC; tacrolimus was superior to placebo for UC in two meta-analyses). Only one meta-analysis evaluated clinical remission maintenance, showing no statistically significant difference between MTX and placebo, 5-ASA, or 6-MP in UC. AZA and 6-MP had no advantage over placebo in induction of clinical response in CD. Three meta-analyses showed the superiority of tacrolimus vs placebo for induction of clinical response in UC. The clinical response rates for cyclosporine were 41.7% in randomized controlled trials (RCTs) and 55.4% in non-RCTs for UC. For induction of mucosal healing, one meta-analysis showed a favorable rate with tacrolimus versus placebo for UC. For secondary outcomes, no meta-analyses specifically evaluated fecal calprotectin, hospitalization or death. Two meta-analyses were retrieved evaluating colectomy rates for tacrolimus and cyclosporine in UC. Most of the twenty individual studies retrieved contained a low or very low quality of evidence.

CONCLUSION

High-quality evidence assessing conventional therapy in MS-IBD treatment is scarce, especially for remission maintenance, mucosal healing and fecal calprotectin.

Treatment Perspectives in Crohn's Disease

BACKGROUND

Crohn's disease (CD) is a chronic immune-mediated disorder of the gastrointestinal tract. The pathophysiological understanding of this disease is limited and no curative therapy is available so far. Therefore, most patients require long-lasting or even life-long immunosuppressive therapies for the suppression of symptoms to improve quality of life and reduction of long-term risks. However, in a relevant subgroup of patients, these therapeutic goals cannot be sufficiently attained.

SUMMARY

Clinically established therapies in active CD comprise corticosteroids and immunosuppressants such as azathioprine. After the introduction of anti-TNFα (Tumor necrosis factor alpha) antibodies, other biologicals (e.g., vedolizumab and ustekinumab) have also been approved. New drugs in the pipeline like filgotinib, upadacitinib, risankizumab or rifaximin could improve the therapy of CD in the near future. Thus, an individualized therapy management, based on optimal selection of therapeutic agents will become more important. Additionally, the local application of mesenchymal stem cells might be helpful in the management of fistulas. Key Messages: The targeted biological therapeutic agents (anti-TNFα antibodies, vedolizumab, ustekinumab) are well established for therapy in CD. There are several new substances in the pipeline with promising results in phase II trials (filgotinib, rifaximin, risankizumab, upadacitinib). The upcoming extension of the therapeutic arsenal will require methods for an optimized selection of substances, thus enabling a more individualized therapy.

Burden and outcomes for complex perianal fistulas in Crohn's disease: Systematic review

AIM

To systematically review the literature on epidemiology, disease burden, and treatment outcomes for Crohn's disease (CD) patients with complex perianal fistulas.

METHODS

PubMed, Embase, and Cochrane were searched for relevant articles (published 2000-November 2016) and congress abstracts (published 2011-November 2016).

RESULTS

Of 535 records reviewed, 62 relevant sources were identified (mostly small observational studies). The cumulative incidence of complex perianal fistulas in CD from two referral-centre studies was 12%-14% (follow-up time, 12 years in one study; not reported in the second study). Complex perianal fistulas result in greatly diminished quality of life; up to 59% of patients are at risk of faecal incontinence. Treatments include combinations of medical and surgical interventions and expanded allogeneic adipose-derived stem cells. High proportions of patients experience lack of or inadequate response to treatment (failure and relapse rates, respectively: medical, 12%-73% and 0%-41%; surgical: 0%-100% and 11%-20%; combined medical/surgical: 0%-80% and 0%-50%; stem cells: 29%-47% and not reported). Few studies (1 of infliximab; 3 of surgical interventions) have been conducted in treatment-refractory patients, a population with high unmet needs. Limited data exist on the clinical value of anti-tumour necrosis factor-α dose escalation in patients with complex perianal fistulas in CD.

CONCLUSION

Complex perianal fistulas in CD pose substantial clinical and humanistic burden. There is a need for effective treatments, especially for patients refractory to anti-tumour necrosis factor-α agents, as evidenced by high failure and relapse rates.

Crohn's disease: management in adults, children and young people - concise guidance

Crohn's disease (CD) is a chronic inflammatory condition of the gastrointestinal tract. Individuals with CD present with acute inflammatory exacerbations as well as acute and chronic complications. Management requires specialist input from gastroenterologists, colorectal surgeons, nurse specialists and pharmacists as well as general and primary care physicians to allow appropriate selection of treatment options including surgery and rapid assessment and treatment of those with acute exacerbations. Monitoring of the individual and their medication is crucial in preventing and recognising complications including those associated with treatment. This concise guideline focuses on recommendations from National Institute for Health and Care Excellence (NICE) -Clinical -Guideline 152 (CG152) considered of key importance for implementation.

Strategies for remission induction of inflammatory bowel disease

Inflammatory bowel diseases (IBD) is an abnormal immune-mediated, chronic, recurrent gastrointestinal inflammatory disorder, which is caused by a variety of factors, including ulcerative colitis (UC) and Crohn's disease (CD). IBD is characterized by alternating periods of relapse and remission. During the active period of IBD, clinicians usually formulate an appropriate medical management plan based on the disease activity, location, extent, and the medication history. In this way, remission can be induced as soon as possible. This paper summarizes the strategies for remission induction of IBD.

Emerging oral targeted therapies in inflammatory bowel diseases: opportunities and challenges

To improve quality of life and prevent long-term risks in patients with inflammatory bowel diseases (IBDs: Crohn's disease, ulcerative colitis), it is essential to suppress inflammatory activity adequately. However, corticosteroids are only suitable for therapy of acute flares and the evidence for positive effects of immunosuppressive substances like azathioprine or 6-mercapropurine is mainly limited to maintenance of remission. In addition, only subgroups of patients benefit from biologicals targeting tumour necrosis factor α or α4β7 integrins. In summary, until now the disease activity is not sufficiently controlled in a relevant fraction of the patients with IBD. Thus, there is an urge for the development of new substances in the therapy of ulcerative colitis and Crohn's disease. Fortunately, new oral and parenteral substances are in the pipeline. This review will focus on oral substances, which have already passed phase II studies successfully at this stage. In this article, we summarize data regarding AJM300, phosphatidylcholine (LT-02), mongersen, ozanimod, filgotinib and tofacitinib. AJM300 and ozanimod were tested in patients with ulcerative colitis and target lymphocyte trafficking through inhibition of the α subunit of integrin, respectively binding to the sphingosine-1-phosphate receptor (subtypes 1 and 5) on lymphocytes. Mongersen was utilized in patients with Crohn's disease and accelerates the degradation of SMAD7 mRNA, which consequently strengthens the mainly anti-inflammatory signalling pathway of transforming growth factor β1. Various Janus kinase (JAK) inhibitors were developed, which inhibit the intracellular signalling pathway of cytokines. For example, the JAK1 blocker filgotinib was tested in Crohn's disease, whereas the JAK1/3 inhibitor tofacitinib was tested in clinical trials for both Crohn's disease and ulcerative colitis. A different therapeutic approach is the substitution of phosphatidylcholine (LT-02), which might recover the colonic mucus. Taken together, clinical trials with these new agents have opened avenues for further clinical studies and it can be expected that at least some of these agents will be finally approved for clinical therapy.

Combination therapy for inflammatory bowel disease

Biologic therapies such as infliximab and adalimumab have become mainstays of treatment for inflammatory bowel disease. Early studies suggested that combination therapy (CT) with infliximab and an immunomodulator drug such as azathioprine may help optimize biologic pharmacokinetics, minimize immunogenicity, and improve outcomes. The landmark SONIC trial in Crohn's disease and the UC SUCCESS trial in ulcerative colitis demonstrated CT with infliximab and azathioprine to be superior to monotherapy with either agent alone at inducing clinical remission in treatment naïve patients with moderate to severe disease. However, many unanswered questions linger. The role of CT in non-naive patients as well as the optimal duration of CT remains unknown. The effectiveness of CT with alternate biologics and/or alternate immunomodulators is not as clear, and it is unknown whether SONIC's conclusions can be extrapolated beyond infliximab and azathioprine. Also looming are the risks of CT including opportunistic infection and malignancy; specifically, lymphoma. This review lays out the evidence as it pertains to the risks and benefits of CT as well as the areas that require further research. With this information in hand, the practitioner may develop a treatment strategy that best suits each individual patient.

Azathioprine, Mercaptopurine, and 5-Aminosalicylic Acid Affect the Growth of IBD-Associated Campylobacter Species and Other Enteric Microbes

Campylobacter concisus is a bacterium that is associated with inflammatory bowel disease (IBD). Immunosuppressive drugs including azathioprine (AZA) and mercaptopurine (MP), and anti-inflammatory drug such as 5-aminosalicylic acid (5-ASA) are commonly used to treat patients with IBD. This study aimed to examine the effects of AZA, MP, and 5-ASA on the growth of IBD-associated bacterial species and to identify bacterial enzymes involved in immunosuppressive drug metabolism. A total of 15 bacterial strains of five species including 11 C. concisus strains, Bacteroides fragilis, Bacteroides vulgatus, Enterococcus faecalis, and Escherichia coli were examined. The impact of AZA, MP, and 5-ASA on the growth of these bacterial species was examined quantitatively using a plate counting method. The presence of enzymes involved in AZA and MP metabolism in these bacterial species was identified using bioinformatics tools. AZA and MP significantly inhibited the growth of all 11 C. concisus strains. C. concisus strains were more sensitive to AZA than MP. 5-ASA showed inhibitory effects to some C. concisus strains, while it promoted the growth of other C. concisus strains. AZA and MP also significantly inhibited the growth of B. fragilis and B. vulgatus. The growth of E. coli was significantly inhibited by 200 μg/ml of AZA as well as 100 and 200 μg/ml of 5-ASA. Bacterial enzymes related to AZA and MP metabolism were found, which varied in different bacterial species. In conclusion, AZA and MP have inhibitory effects to IBD-associated C. concisus and other enteric microbes, suggesting an additional therapeutic mechanism of these drugs in the treatment of IBD. The strain dependent differential impact of 5-ASA on the growth of C. concisus may also have clinical implication given that in some cases 5-ASA medications were found to cause exacerbations of colitis.