Azathioprine in ulcerative colitis: final report on controlled therapeutic trial

Azathioprine and 6-mercaptopurine for maintenance of remission in ulcerative colitis

BACKGROUND

Maintenance of remission is essential in inflammatory bowel disease (IBD) in terms of disease course and long-term prognosis. The thiopurines azathioprine and 6-mercaptopurine have longstanding merit in ulcerative colitis, but more therapeutic options have been developed. This review is an update and extension of a review last published in 2016.

OBJECTIVES

To assess the effectiveness and safety of azathioprine and 6-mercaptopurine in monotherapy or combined therapy regimens compared to placebo or active controls for the maintenance of remission in ulcerative colitis.

SEARCH METHODS

We searched Cochrane Central Register of Controlled Trials (until May 2023), ClinicalTrials.gov (until May 2023), Embase (until August 2022), MEDLINE (until May 2023), and WHO ICTRP (until May 2023). We checked reference lists of the included studies and, if needed, contacted the authors to request more data or information.

SELECTION CRITERIA

Randomized controlled trials (RCTs) of at least 24 weeks' duration comparing azathioprine or 6-mercaptopurine with placebo or any other medication, or comparing different treatment modalities of azathioprine or 6-mercaptopurine, in persons of any age with quiescent ulcerative colitis were eligible. We only considered studies with mixed IBD populations or with a preceding induction period if separate results on participants with ulcerative colitis in remission were available or could be calculated. The primary outcome was failure to maintain clinical or endoscopic remission (relapse). Secondary outcomes included change in disease activity, quality of life, hospitalization, need for surgery, days off work, adverse events, and withdrawal due to adverse events.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data using standard forms, resolved any disagreements by consensus, and assessed study quality using the Cochrane risk of bias tool (RoB 2). We conducted separate analyses by type of control, calculated pooled risk ratios (RRs) or risk differences (RDs) using the fixed-effect model unless heterogeneity was likely, and assessed the certainty of evidence using the GRADE approach.

MAIN RESULTS

We included 10 studies in the review, including 468 adult participants with ulcerative colitis. The risk of bias across these was low for most outcomes, but we considered some outcomes to have some concerns or high risk of bias due to insufficient information on concealment of allocation and outcome measurement. Based on five placebo-controlled studies, azathioprine or 6-mercaptopurine may reduce the risk of failing to maintain remission. In the thiopurine group, 45% (64/143) of participants failed to maintain remission compared to 67% (96/143) of participants receiving placebo (RR 0.66, 95% confidence interval (CI) 0.54 to 0.82; 5 studies, 286 participants; low-certainty evidence). Three studies reported withdrawals due to adverse events. Among participants on azathioprine, 4% (3/80) withdrew due to adverse events compared to 0% (0/82) of placebo participants (RD 0.04, 95% CI -0.02 to 0.09; 3 studies, 162 participants; low-certainty evidence). The evidence is of low certainty when comparing 6-mercaptopurine to 5-aminosalicylate. Based on one three-armed trial, 27% (3/11) of 6-mercaptopurine participants failed to maintain remission compared to 100% (2/2) of 5-aminosalicylate participants (RR 0.35, 95% CI 0.13 to 0.97; 1 study, 13 participants; low-certainty evidence). This trial also involved an induction phase; we only included the results for participants in remission. The single trial comparing 6-mercaptopurine to 5-aminosalicylate did not report separate data on adverse events and withdrawals due to adverse events for the subgroup with successful induction of remission, so we could not analyze these outcomes for this comparison.

AUTHORS' CONCLUSIONS

Low-certainty evidence suggests that azathioprine or 6-mercaptopurine therapy may be more effective than placebo for the maintenance of remission in ulcerative colitis. More research is needed to evaluate the value of therapeutic drug monitoring and the effects of various treatment modalities on long-term safety.

Understanding the therapeutic toolkit for inflammatory bowel disease

Inflammatory bowel disease (IBD), encompassing ulcerative colitis and Crohn's disease, is a group of chronic, immune-mediated disorders of the gastrointestinal tract that present substantial clinical challenges owing to their complex pathophysiology and tendency to relapse. A treat-to-target approach is recommended, involving iterative treatment adjustments to achieve clinical response, reduce inflammatory markers and achieve long-term goals such as mucosal healing. Lifelong medication is often necessary to manage the disease, maintain remission and prevent complications. The therapeutic landscape for IBD has evolved substantially; however, a ceiling on therapeutic efficacy remains and surgery is sometimes required (owing to uncontrolled disease activity or complications). Effective IBD management involves comprehensive care, including medication adherence and a collaborative clinician-patient relationship. This Review discusses current therapeutic options for IBD, detailing mechanisms of action, efficacy, safety profiles and guidelines for use of each drug class. We also explore emerging therapies and the role of surgery. Additionally, the importance of a multidisciplinary team and personalized care in managing IBD is emphasized, advocating for patient empowerment and involvement in treatment decisions. By synthesizing current knowledge and emerging trends, this Review aims to equip healthcare professionals with a thorough understanding of therapeutic options for IBD, enhancing informed, evidence-based decisions in clinical practice.

Real-world NUDT15 genotyping and thiopurine treatment optimization in inflammatory bowel disease: a multicenter study

BACKGROUND

This study evaluated the effectiveness of NUDT15 codon 139 genotyping in optimizing thiopurine treatment for inflammatory bowel disease (IBD) in Japan, using real-world data, and aimed to establish genotype-based treatment strategies.

METHODS

A retrospective analysis of 4628 IBD patients who underwent NUDT15 codon 139 genotyping was conducted. This study assessed the purpose of the genotyping test and subsequent prescriptions following the obtained results. Outcomes were compared between the Genotyping group (thiopurine with genotyping test) and Non-genotyping group (thiopurine without genotyping test). Risk factors for adverse events (AEs) were analyzed by genotype and prior genotyping status.

RESULTS

Genotyping test for medical purposes showed no significant difference in thiopurine induction rates between Arg/Arg and Arg/Cys genotypes, but nine Arg/Cys patients opted out of thiopurine treatment. In the Genotyping group, Arg/Arg patients received higher initial doses than the Non-genotyping group, while Arg/Cys patients received lower ones (median 25 mg/day). Fewer AEs occurred in the Genotyping group because of their lower incidence in Arg/Cys cases. Starting with < 25 mg/day of AZA reduced AEs in Arg/Cys patients, while Arg/Arg patients had better retention rates when maintaining ≥ 75 mg AZA. Nausea and liver injury correlated with thiopurine formulation but not dosage. pH-dependent mesalamine reduced leukopenia risk in mesalamine users.

CONCLUSIONS

NUDT15 codon 139 genotyping effectively reduces thiopurine-induced AEs and improves treatment retention rates in IBD patients after genotype-based dose adjustments. This study provides data-driven treatment strategies based on genotype and identifies risk factors for specific AEs, contributing to a refined thiopurine treatment approach.

Thiopurine Exposure During Pregnancy is Not Associated With Anemia in Infants Born to Mothers With IBD

Background

Thiopurines are commonly used to treat inflammatory bowel disease (IBD). Thiopurines are considered safe throughout pregnancy. However, a published study suggested the risk of neonatal anemia was increased if exposed to thiopurines in utero. This prospective cohort study aimed to determine if there is an increased risk of cytopenia among infants born to pregnant people with IBD, exposed or unexposed to thiopurines, compared to infants born to those without IBD.

Methods

Pregnant IBD patients, with and without thiopurine exposure, and one cohort of control individuals were recruited over a 5-year period. Consenting individuals completed a questionnaire and infants had a complete blood cell count at the newborn heel prick. Anemia was defined as hemoglobin (Hb) < 140g/L. Descriptive statistics were used to characterize the study population. Fisher exact tests were used to examine differences in outcomes between groups, a P-value of < 0.05 was deemed significant.

Results

Three cohorts were recruited: 19 IBD patients on thiopurines, 50 IBD patients not on thiopurines, and 37 controls (total of 106). Neonatal median Hb was not different with 177g/L (IQR 38g/L) for the IBD thiopurine group, 180.5g/L (IQR 40g/L) for the IBD non-thiopurine group, and 181g/L (IQR 37g/L) for the controls. Nineteen infants (18%) were cytopenic with 12 (11%) anemic, 6 (5.6%) thrombocytopenic, and 1 (0.94%) lymphopenic. Thiopurine exposure was only in one, mildly anemic, infant.

Conclusions

These findings further support physicians and IBD patients contemplating pregnancy that current guidelines recommending thiopurine adherence do not lead to increased perinatal risk of anemia or cytopenia.

Guidelines for the management of ulcerative colitis. 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 2013. It contains 49 recommendations for the diagnosis and treatment, both pharmacological and surgical, of ulcerative colitis 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 of available evidence and the strength of therapeutic recommendations. The degree of expert support for the proposed statements was assessed on a 6-point Likert scale. Voting results, together with comments, are included with each statement.

Article Topic: Positioning Ulcerative Colitis Therapies in 2022 and Beyond

PURPOSE OF REVIEW

Ulcerative colitis (UC) is a chronic disease with an increasing incidence. Recent guidelines emphasize treating toward objective targets, requiring the use of effective, steroid-sparing therapies. This review summarizes the safety and efficacy data of available therapies as well comparative effectiveness studies in order to help the reader make rational treatment decisions.

RECENT FINDINGS

Following the approval of tumor necrosis factor alpha antagonists, we have seen recent regulatory approval of several additional biologic and small molecule agents from several therapeutic classes (integrin antagonists, interleukin 12/23 antagonists, Janus kinase inhibitors, and sphingosine-1-phosphate receptor antagonists) for UC. Randomized, controlled trials, real-world analyses, and network meta-analyses have investigated the comparative safety and efficacy of these therapies in order to help clinicians better position these therapies in clinical practice. Numerous agents are now approved for the treatment of UC. This evidence-based review will help the reader understand the important factors weighing into treatment decisions for patients with UC and enable patient education and discussion with a focus on a shared decision-making approach.

A review of the therapeutic management of ulcerative colitis

Ulcerative colitis (UC) is a chronic relapsing and remitting gastrointestinal disorder of uncertain aetiology. The last two decades have seen an expansion in the therapeutic arsenal used to treat UC. This has resulted in improved clinical remission and response rates. Nonetheless, staples in our current medical management originate from trials conducted in the early 20th century. In this review article, we aim to outline the key milestones in the history of the medical management of UC in addition to highlighting promising therapeutic developments for the future.

Classic drugs in the time of new drugs: real-world, long-term outcomes of thiopurine monotherapy in 1016 patients with inflammatory bowel disease

BACKGROUND

Thiopurines remain recommended as maintenance therapy in patients with inflammatory bowel disease (IBD). Despite their widespread use, long-term effectiveness data are sparse and safety is an increasingly debated topic which thwarts proper delineation in the current IBD treatment algorithm.

AIMS

To document effectiveness and safety of thiopurine monotherapy in patients with IBD, using the population-based IBD South-Limburg (IBDSL) cohort METHODS: All patients starting thiopurine monotherapy as maintenance between 1991 and 2014 were included. Therapy was defined as effective if there was no escalation to biologicals, no course of corticosteroids, no surgery and no hospitalisation for active disease during treatment. Long-term effectiveness was assessed by adjusting for differences in follow-up using Kaplan-Meier analyses. Mid- to long-term safety regarding cancer incidence and clinically relevant liver disease was documented.

RESULTS

In total, 1016 patients (643 Crohn's disease [CD]; 373 ulcerative colitis [UC]) received thiopurine monotherapy at a median of 15.2 (Q1-Q3 4.2-48.5) months after diagnosis. During follow-up, effectiveness rates at 1, 5 and 10 years were 64%, 45%, 32%, respectively, in CD and and 66%, 41%, 36%, respectively in UC. No statistically significant differences in effectiveness were observed after stratification for era of initiation (pre-biological vs biological, CD: p = 0.56; UC: p = 0.43). Sixteen non-melanoma skin cancers (incidence rate [IR] 3.33/1000 PY), five lymphomas (IR 1.04/1000 PY) and one urinary tract cancer (IR 0.21/1000 PY) were recorded. Two cases of portal hypertension were identified.

CONCLUSION

In real-world practice, thiopurine monotherapy remains effective, safe and durable for patients with CD or UC, including in the era of biologics.

Pharmacological Management of Inflammatory Bowel Disease: a Century of Expert Opinions in Cecil Textbook of Medicine

BACKGROUND

Advances in drug therapy for inflammatory bowel disease (IBD) [Crohn disease and ulcerative colitis (UC)] have contributed to a decrease in the severity of these chronic and disabling conditions.

STUDY QUESTION

What are the milestones of the changes in the expert approach to the pharmacological management of IBD in the past century?

STUDY DESIGN

To determine the changes in the experts' approach to the management of regional ileitis and UC, as presented in a widely used textbook in the United States.

DATA SOURCES

The chapters presenting the management of IBD in the 26 editions of Cecil Textbook of Medicine published from 1927 through 2020.

RESULTS

No specific interventions existed from 1927 through 1942. The pharmacological management of IBD has had 3 slightly overlapping eras starting in 1943. During the first period (1943-1951), the medical management relied on antibiotics, primarily sulfonamides and chloramphenicol. In the second (1955-75), experts recommended the use of adrenocorticotropic hormone or corticosteroids and 5-aminosalicylate. In the third era, which commenced in 1979 and is continuing to date, the pharmacological interventions have been expanded and refined to include 5 main drug classes, 5-aminosalicylates (sulfasalazine, mesalamine, and olsalazine), corticosteroids (prednisone and budesonide), immunomodulators (azathioprine, 6-mercaptopurine, cyclosporine, and tofacitinib), biologics (infliximab adalimumab certolizumab pegol, and natalizumab), and antibiotics (metronidazole and ciprofloxacin). A consensus exists that the monoclonal antibodies again tumor necrosis factor alpha are cost-effective for induction and maintenance of clinical remission in both UC (golimumab) and Crohn disease (certolizumab pegol). The newer agents ustekinumab (a monoclonal antibody to the interleukin p40 subunit) and vedolizumab (a monoclonal antibody to the homing receptor integrin complex) have also performed well.

CONCLUSIONS

The pharmacological management of IBD has been the focus of intense research and development in the past 60 years. The pillars of drug treatment have been 5-aminosalicylates and corticosteroids. Recent pharmacological innovations (immunomodulators and biologicals) constitute an encouraging paradigm shift in the treatment of UC and Crohn disease.

The Thiopurine Tale: An Unexpected Journey

Exactly 70 years ago [1951] mercaptopurine was discovered by Gertrude Elion as a novel treatment option for acute leukaemia. A total of three thiopurines (also thioguanine [1950] and azathioprine [1957]) were developed over time. These immunosuppressive drugs were also successfully introduced a few decades later to prevent rejection of transplanted organs and to treat several autoimmune diseases. For her discovery of thiopurines and other antimetabolite drugs, in 1988 Elion was rewarded, together with George Hitchings and James Black, with the Nobel Prize in Physiology or Medicine. Important steps have been made in recent years to unravel its metabolism, mode of action and pharmacogenetics. Today thiopurine [based] therapy remains an essential immunosuppressive approach in treating patients with inflammatory bowel disease.

Relapse rates after withdrawal of thiopurines in patients with inflammatory bowel disease

PURPOSE

Withdrawal of thiopurines after remission is associated with an increased risk of relapse in patients with inflammatory bowel disease (IBD). However, long-term data on thiopurine withdrawal is limited, especially from developing countries where the cost of long-term therapy poses a significant burden on patients.

METHODS

Patients with IBD on thiopurine monotherapy for ≥ 4 months, who stopped thiopurines while in clinical remission and were not on any other immunomodulator or biologics at the time of withdrawal, were included in this retrospective analysis.

RESULTS

Among 1093 patients with IBD on thiopurine monotherapy, 461 patients stopped thiopurine due to various reasons. Among these, 218 (ulcerative colitis (UC) = 179; Crohn's disease (CD) = 39) patients were in clinical remission and were continued on mesalamine. Overall, 36.7% (n = 80) relapsed after a median duration of 20 months (IQR: 9-49). Relapse rate was higher in UC than CD (39.7% vs 23%, p = 0.055). Cumulative probabilities of relapse were 17%, 34%, and 44% at the end of 1, 3, and 5 years, respectively. The relapse rate at 5 years was significantly lower in patients who had stopped azathioprine after 4 years of therapy (31% vs 54%, p = 0.007). On multi-variate cox regression analysis, male sex [HR: 1.6(1.0-2.6), p = 0.02] and short duration of therapy with thiopurines [HR: 1.02 (1.01-1.02), p = 0.004] before withdrawal were associated with increased risk of relapse.

CONCLUSION

Approximately 50% patients with IBD in remission would relapse after 5 years of thiopurine withdrawal. Male sex and shorter treatment duration predict relapse. Treatment should be continued in patients who tolerate and maintain remission on long-term thiopurine.

Emulation of a randomized controlled trial in ulcerative colitis with US and French claims data: Infliximab with thiopurines compared to infliximab monotherapy

PURPOSE

To understand the validity of real-world evidence (RWE) studies in ulcerative colitis (UC), we emulated the SUCCESS randomized controlled trial (RCT) on the effectiveness of infliximab plus thiopurines, using US and French healthcare insurance claims data.

METHODS

The SUCCESS trial showed improved remission with infliximab plus thiopurines combined compared to infliximab monotherapy in patients with UC. Based on two US commercial claims databases (IBM MarketScan and Optum) and the French nationwide health insurance database (SNDS) from 2004 through 2019, all patients with UC who initiated combination therapy or infliximab alone were identified. The primary outcome of treatment failure was emulated by: Hospitalization related to UC or colectomy, treatment switch to another biologic or immunosuppressant, or use of corticosteroids 16 weeks after infliximab initiation. We estimated risk ratios with 95% confidence intervals after 1:1 propensity score (PS) matching.

RESULTS

Among 620 PS-matched pairs of combination therapy and infliximab monotherapy users, treatment failure occurred in 124 (20%) of patients initiating combination therapy and 170 (27%) during monotherapy. Like in SUCCESS, the risk of treatment failure was decreased with combination therapy in the overall cohort (RR = 0.73; 95% CI: 0.60-0.90). Findings were consistent across MarketScan, Optum, and SNDS: RR = 0.76 (0.57-1.02), 0.82 (0.54-1.24), and 0.61 (0.41-0.90). Similar results were observed for each component endpoint.

CONCLUSIONS

RWE results across three large claims databases were consistent with RCT findings. These findings provide support for the use of RWE to assess treatment effectiveness in UC.

Poor Drug Sustainability in Inflammatory Bowel Disease Patients in Clinical Remission on Thiopurine Monotherapy

BACKGROUND

Immunomodulator monotherapy is an important component in the treatment of inflammatory bowel disease (IBD). However, there is conflicting literature about thiopurines maintaining long-term remission in patients with active IBD.

AIM

To determine the durable clinical remission rate in adults with Crohn's disease (CD) or ulcerative colitis (UC) on thiopurine monotherapy over 5 years.

METHODS

We performed a retrospective analysis of adult patients identified at McGill University Health Centre from 2009 to 2012. We included IBD patients who initiated thiopurine monotherapy and were in remission for at least 3 months (Harvey-Bradshaw Index (HBI) < 5 points for CD and partial Mayo Score (pMS) < 2 points in UC). The primary endpoint was sustained clinical remission on thiopurines during a 5-year follow-up. This included patients who had not relapsed or discontinued the drug due to side effects. The secondary endpoint was clinical relapse over the follow-up period, which was defined as HBI > 5 in CD and pMS > 2 in UC.

RESULTS

There were 148 patients included in the study (100 CD; 48 UC). At 5 years, 23% (34/148) patients remained in clinical remission on thiopurine monotherapy (25 CD and 9 UC patients). Thirty-three percent (33/100) of CD and 46% (22/48) of UC patients relapsed while on thiopurines. There was no difference in relapse rates between CD and UC patients. Eighty-four percent (42/50) of patients with CD with side effects and all UC (17/17) patients who experienced side effects discontinued the drug.

CONCLUSION

This analysis demonstrates that there is poor sustainability of clinical remission in IBD patients on thiopurine monotherapy given that a high proportion of patients discontinue thiopurines due to either relapse or side effects.

Thiopurine monotherapy is effective in ulcerative colitis but significantly less so in Crohn's disease: long-term outcomes for 11 928 patients in the UK inflammatory bowel disease bioresource

OBJECTIVE

Thiopurines are widely used as maintenance therapy in inflammatory bowel disease (IBD) but the evidence base for their use is sparse and their role increasingly questioned. Using the largest series reported to date, we assessed the long-term effectiveness of thiopurines in ulcerative colitis (UC) and Crohn's disease (CD), including their impact on need for surgery.

DESIGN

Outcomes were assessed in 11 928 patients (4968 UC, 6960 CD) in the UK IBD BioResource initiated on thiopurine monotherapy with the intention of maintaining medically induced remission. Effectiveness was assessed retrospectively using patient-level data and a definition that required avoidance of escalation to biological therapy or surgery while on thiopurines. Analyses included overall effectiveness, time-to-event analysis for treatment escalation and comparison of surgery rates in patients tolerant or intolerant of thiopurines.

RESULTS

Using 68 132 patient-years of exposure, thiopurine monotherapy appeared effective for the duration of treatment in 2617/4968 (52.7%) patients with UC compared with 2378/6960 (34.2%) patients with CD (p<0.0001). This difference was corroborated in a multivariable analysis: after adjusting for variables including treatment era, thiopurine monotherapy was less effective in CD than UC (OR 0.47, 95% CI 0.43 to 0.51, p<0.0001). Thiopurine intolerance was associated with increased risk of surgery in UC (HR 2.44, p<0.0001); with a more modest impact on need for surgery in CD (HR=1.23, p=0.0015).

CONCLUSION

Thiopurine monotherapy is an effective long-term treatment for UC but significantly less effective in CD.

Colectomy rate in ulcerative colitis 15 years after diagnosis: Results from the 2001-2003 Navarra cohort

INTRODUCTION

Knowing the natural history of ulcerative colitis (UC) is essential to understand the course of the disease, assess the impact of different treatment strategies and identify poor prognostic factors. One of the most significant matters in this regard is the need for surgery.

OBJECTIVES

To analyse the Colectomy Incidence Rate (CIR) from diagnosis to end of follow-up (31/12/2017) and identify predictive factors for colectomy.

MATERIAL AND METHODS

A retrospective study enrolling patients with a definitive diagnosis (DD) of UC or Unclassified Colitis (UnC) in the 2001-03 Navarra cohort.

RESULTS

We enrolled 174 patients with a DD of UC (E2 42.8%; E3 26.6%) and 5 patients with a DD of UnC: 44.1% women, median age 39.2 years (range 7-88) and median follow-up 15.7 years. A total of 8 patients underwent surgery (CIR 3 colectomies/103 patient-years: 3 at initial diagnosis (<1 month), 2 in the first 2 years, 2 at 5 years from diagnosis and 1 at 12 years from diagnosis. All had previously received steroids; 5 had received immunomodulators and 2 had received biologics. In 7 patients (87%), surgery was performed on an emergency basis. The indication was megacolon in 3 (37.5%), severe flare-up in 3 (37.5%) and medical treatment failure in 2 (25%). In 5 cases (62.5%), an ileoanal pouch was made, and in 3 cases, a definitive ileostomy was performed. In the univariate analysis, patients with loss of more than 5 kg at diagnosis and admission at diagnosis had a lower rate of colectomy-free survival.

CONCLUSIONS

In our series, colectomy rates are lower than usually reported. Most colectomies were performed in the first 5 years following diagnosis and had an emergency indication.

First United Arab Emirates consensus on diagnosis and management of inflammatory bowel diseases: A 2020 Delphi consensus

Ulcerative colitis and Crohn's disease are the main entities of inflammatory bowel disease characterized by chronic remittent inflammation of the gastrointestinal tract. The incidence and prevalence are on the rise worldwide, and the heterogeneity between patients and within individuals over time is striking. The progressive advance in our understanding of the etiopathogenesis coupled with an unprecedented increase in therapeutic options have changed the management towards evidence-based interventions by clinicians with patients. This guideline was stimulated and supported by the Emirates Gastroenterology and Hepatology Society following a systematic review and a Delphi consensus process that provided evidence- and expert opinion-based recommendations. Comprehensive up-to-date guidance is provided regarding diagnosis, evaluation of disease severity, appropriate and timely use of different investigations, choice of appropriate therapy for induction and remission phase according to disease severity, and management of main complications.

AGA Technical Review on the Management of Moderate to Severe Ulcerative Colitis

A subset of patients with ulcerative colitis (UC) present with, or progress to, moderate to severe disease activity. These patients are at high risk for colectomy, hospitalization, corticosteroid dependence, and serious infections. The risk of life-threatening complications and emergency colectomy is particularly high among those patients hospitalized with acute severe ulcerative colitis. Optimal management of outpatients or inpatients with moderate to severe UC often requires the use of immunomodulator and/or biologic therapies, including thiopurines, methotrexate, cyclosporine, tacrolimus, TNF-α antagonists, vedolizumab, tofacitnib, or ustekinumab, either as monotherapy or in combination (with immunomodulators), to mitigate these risks. Decisions about optimal drug therapy in moderate to severe UC are complex, with limited guidance on comparative efficacy and safety of different treatments, leading to considerable practice variability. Therefore, the American Gastroenterological Association prioritized development of clinical guidelines on this topic. To inform the clinical guidelines, this technical review was completed in accordance with the Grading of Recommendations Assessment, Development and Evaluation framework. Focused questions in adult outpatients with moderate to severe UC included: (1) overall and comparative efficacy of different medications for induction and maintenance of remission in patients with or without prior exposure to TNF-α antagonists, (2) comparative efficacy and safety of biologic monotherapy vs combination therapy with immunomodulators, (3) comparative efficacy of top-down (upfront use of biologics and/or immunomodulator therapy) vs step-up therapy (acceleration to biologic and/or immunomodulator therapy only after failure of 5-aminosalicylates, and (4) role of continuing vs stopping 5-aminosalicylates in patients being treated with immunomodulator and/or biologic therapy for moderate to severe UC. Focused questions in adults hospitalized with acute severe ulcerative colitis included: (5) overall and comparative efficacy of pharmacologic interventions for inpatients refractory to corticosteroids, in reducing risk of colectomy, (6) optimal dosing regimens for intravenous corticosteroids and infliximab in these patients, and (7) role of adjunctive antibiotics in the absence of confirmed infections.

High-resolution melt analysis enables simple genotyping of complicated polymorphisms of codon 18 rendering the NUDT15 diplotype

BACKGROUND

The genetic variants of NUDT15 have been verified to induce adverse events (AEs) of thiopurines. Codon 139 variants are frequently observed in Asians, while multiple variants are seen in codon 18 which also cause AEs including the European ancestry. The purpose of this study is to establish a technique capable of the simple genotyping of NUDT15 codon 18 and to evaluate its efficacy.

METHODS

A high-resolution melt (HRM) technique is performed to simply determine genotypes. The accuracy of HRM analysis was evaluated with DNAs from 1245 Japanese patients with inflammatory bowel diseases. Subsequently, another group of 572 patients was analyzed to verify the method. The diplotypes and the frequency of their AEs were estimated on the basis of codon 18 and 139 genotypes.

RESULTS

The HRM analysis enabled the correct identification of the three main genotypes, ref/ref, ref/ins, and ref/V18I, in 1236 of 1241 cases. All rare genotypes including ref/del were identified as the impossible-to-determine group, the proper diagnosis rate was 99.6%. In the verification test using other samples, the diagnosis rate was 99.7%. By estimating diplotypes using both codon 18 and 139 genotypes, 2.74% and 2.13% of Japanese patients with Arg/Arg and Arg/Cys of codon 139 have a lower enzymatic activity of NUDT15 and a higher risk for adverse responses than those estimated by codon 139 genotypes alone.

CONCLUSIONS

Our study showed that HRM method enables simple genotyping of complicated codon 18 variants essential to haplotype estimation of the NUDT15.

Is there room for immunomodulators in ulcerative colitis?

Introduction: The management of patients with ulcerative colitis (UC) has evolved over the past few decades. While aminosalicylates remain the mainstay of induction and maintenance therapy in patients with mild-to-moderate UC, the advent of biologic agents and novel oral small molecules has substantively changed the treatment landscape for patients with moderate-to-severe disease and confounded the role of traditional immunomodulators (IMMs) such as thiopurines and methotrexate in the UC management algorithm.Areas covered: We summarize the mechanism of action of thiopurines and methotrexate, identify clinical parameters for their use, and appraise the evidence supporting the efficacy and safety of IMMs in UC as both monotherapy and in combination with other therapies, emphasizing on prospective, controlled data.Expert opinion: With the advent of several classes of highly effective treatments for UC, emergence of data demonstrating no benefit of IMMs over placebo, and concerns about the relative safety profile of long-term IMM exposure, we propose that the role of thiopurines or methotrexate be restricted to patients with milder disease failing to maintain corticosteroid-free remission on aminosalicylates alone or in combination therapy with tumor necrosis factor antagonists in patients with moderate-to-severe UC.

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.

ACG Clinical Guideline: Ulcerative Colitis in Adults

Ulcerative colitis (UC) is an idiopathic inflammatory disorder. These guidelines indicate the preferred approach to the management of adults with UC and represent the official practice recommendations of the American College of Gastroenterology. The scientific evidence for these guidelines was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) process. In instances where the evidence was not appropriate for GRADE, but there was consensus of significant clinical merit, "key concept" statements were developed using expert consensus. These guidelines are meant to be broadly applicable and should be viewed as the preferred, but not only, approach to clinical scenarios.

Long-Term Outcomes of Immunosuppression-Naïve Steroid Responders Following Hospitalization for Ulcerative Colitis

BACKGROUND

Requirement for hospitalization in ulcerative colitis (UC) is a marker of severity of disease. However, the paradigm of when to escalate therapy in such patients and the benefits of early immunomodulator initiation is less well established.

AIM

To examine the benefits of early therapy escalation in immunosuppression-naïve patients hospitalized with severe ulcerative colitis responsive to steroids.

METHODS

We identified hospitalized UC patients who were immunosuppression naïve at index hospitalization and responded to intravenous steroids, not requiring medical or surgical rescue therapy. The 'therapy escalated' group comprised of those who were initiated on immunomodulators within 3 months of hospitalization. The need for colectomy at 12 months was compared to the 'not escalated' group who remained on non-immunosuppressive therapy.

RESULTS

Among 133 immunosuppressive naïve patients hospitalized for ulcerative colitis, 13 (9.8%) who responded to intravenous steroids and did not require rescue therapy underwent colectomy by 1 year. Among 123 patients who escalated to either immunomodulators (n = 46, 37%) or remained on non-immunosuppressive therapy (92% on 5-ASA), there was no difference in the need for colectomy at 1 year (10.8 vs. 7.8%; multivariate OR 1.29, 95% CI 0.35-4.74). There was also no difference in the time to colectomy between the two groups (p = 0.55).

CONCLUSION

Immunosuppression-naïve ASUC patients who respond to intravenous steroids remain at risk for colectomy. Immunomodulator initiation by 3 months did not reduce risk of colectomy at 1 year. There is an important need for prospective studies identifying thresholds for therapy escalation in UC.

Is There a Role for Thiopurines in IBD?

Immunosuppressive therapy (IM) is inexpensive and nearly one-third of patients with inflammatory bowel disease (IBD) experience a benefit from treatment. IM may be ideal for IBD patients at low risk for a disabling disease course or colectomy and/or those patients with inadequate access to biologic therapy. A majority of IBD patients benefit from early biologic therapy with improved short and likely long-term outcomes. Improved methods are needed to identify patients at the greatest risk for a severe disease course and that are likely to respond to the various forms of small molecule and biologic treatments. Health systems need to identify innovative methods to contain costs of biologic therapy.

Low-dose thiopurine with allopurinol co-therapy overcomes thiopurine intolerance and allows thiopurine continuation in inflammatory bowel disease

AIMS

To assess the utility and tolerability of thiopurine-allopurinol co-therapy in inflammatory bowel disease (IBD) patients with intolerance to thiopurine monotherapy.

METHODS

A retrospective observational study assessed cases of thiopurine intolerance then switched to thiopurine allopurinol co-therapy between 2011 and 2015 at two centres. Indications for switch, dosing and subsequent clinical outcomes (including thiopurine persistence) were recorded.

RESULTS

Of 767 patients on thiopurines for IBD, 89 (12%) were switched to co-therapy for intolerance. 64/89 (72%) had Crohn's disease, 38 (43%) were males, median age at switch was 40y (range 17-78), median IBD duration 6y (0-29). Median follow-up was 1.9y (0-5). Reasons for switching to co-therapy included fatigue (37%), hepatotoxicity (23%), nausea (23%), arthralgia (10%), headache (12%) and hypersensitivity reaction (4%). Overall, 66 (74%) patients remained on co-therapy until most recent review and achieved a clinical response. High rates of overcoming intolerance (62-100%) occurred with co-therapy for all reasons above, although fatigue was less amenable to switching than non-fatigue indications (62% vs 91%, p = <0.001). Of 34 patients not escalated to biologics with endoscopic data, 15 were in remission (44%) at most recent review.

CONCLUSION

Low-dose thiopurine combined with allopurinol appears safe and effective in overcoming intolerances to thiopurine monotherapy in many cases.

Can we move directly from 5-ASA to a biologic agent in ulcerative colitis?

European consensus guidelines and reimbursement policies position biologic drugs for ulcerative colitis (UC) as a third-line treatment, after failure of 5-aminosalicylic acid (5-ASA) and corticosteroids/thiopurines. While 5-ASA have a very favorable safety profile, (prolonged) use of corticosteroids and thiopurines is associated with potentially serious adverse events. The therapeutic landscape of UC is rapidly evolving and selective biologic drugs with improved safety are being introduced. The first biosimilars have entered the market, leading to improved cost-effectiveness of older biologic drugs. In addition, new insights have been gained in the importance of stringent therapeutic targets such as mucosal and histological healing to improve the long-term outcome of UC patients, and in the role of therapeutic drug monitoring and treatment optimization in this regard. In this manuscript we tackle the question of whether we should move directly from 5-ASA treatment to biologic drugs to offer better and/or safer care to UC patients.

Thiopurines in Inflammatory Bowel Disease: New Findings and Perspectives

Thiopurines, available as azathioprine, mercaptopurine, and thioguanine, are immunomodulating agents primarily used to maintain corticosteroid-free remission in patients with inflammatory bowel disease. To provide a state-of-the-art overview of thiopurine treatment in inflammatory bowel disease, this clinical review critically summarises the available literature, as assessed by several experts in the field of thiopurine treatment and research in inflammatory bowel disease.

Pharmacogenetics of thiopurines for inflammatory bowel disease in East Asia: prospects for clinical application of NUDT15 genotyping

The thiopurine drugs 6-mercaptopurine (6-MP) and azathiopurine (AZA) are widely used to treat inflammatory bowel disease. However, the incidence of adverse reactions is high, particularly in Asia, and the mechanisms of toxicity in Asian populations remain unclear. Thiopurine S-methyltransferase (TPMT) is a well-known enzyme that inactivates AZA or 6-MP through methylation and is one of the few pharmacogenetic predictors used in clinical settings in Western countries. Individuals carrying TPMT-deficient genetic variants require reduced drug doses, but this treatment modification is are not applicable to East Asian populations. Several genes code thiopurine-metabolizing enzymes, including TPMT, multidrug-resistance protein 4, and inosine triphosphatase. These genes have been studied as candidate pharmacogenetic markers; however, it remains unclear why Asian populations seem to be more intolerant than other ethnic groups to a full dose of thiopurines. A genome-wide association approach to identify Asian-specific pharmacogenetic markers in Korean patients with Crohn's disease revealed that a non-synonymous single nucelotide polymorphism in nucleoside diphosphate-linked moiety X-type motif 15 (NUDT15) which causes p.Arg139Cys was strongly associated with thiopurine-induced early leukopenia. Six common haplotypes of NUDT15 were reported, and five variants showed medium-to-low enzyme activities, compared with the wild haplotype. NUDT15 hydrolyzes the thiopurine active metabolites 6-thio-GTP and 6-thio-dGTP; variants of NUDT15 had lower enzyme activities, causing higher levels of thiopurine active metabolites, resulting in thiopurine-induced leukopenia. In clinical application, NUDT15 genotyping is a good candidate for predicting thiopurine toxicity in East Asian populations. However, the association of NUDT15 diplotypes with thiopurine toxicity remains unclear. Further analyses with large cohorts to confirm the clinical effects of each haplotype are planned.

Thiopurine Treatment in Ulcerative Colitis: A Critical Review of the Evidence for Current Clinical Practice

BACKGROUND

Due to toxicity problems and controversial evidence, thiopurine use in ulcerative colitis (UC) has faced a lot of criticism. We present a critical review of the literature on efficacy of thiopurines in UC.

METHODS

Studies evaluating therapeutic efficacy of thiopurine remission induction and/or maintenance treatment in UC were identified using the Cochrane Library, MEDLINE, and EMBASE.

RESULTS

Out of 5 randomized trials on thiopurine induction treatment, 3 demonstrated a significant effect of thiopurine treatment vs mesalamine or placebo in steroid-dependent UC patients: (1) lower endoscopic activity scores, (2) higher clinical remission rates, and (3) more patients who discontinued steroids. Two found no significant difference in clinical and endoscopic remission of azathioprine compared with sulfasalazine or placebo in patients with active UC. Out of 7 randomized trials on thiopurine maintenance treatment, 4 demonstrated significant higher clinical and endoscopic remission rates in thiopurine-treated patients compared with placebo or mesalamine. Three found no significant difference in clinical and endoscopic remission of thiopurine maintenance treatment compared with sulfasalazine or placebo.

CONCLUSIONS

All studies that investigated thiopurine treatment in UC had shortcomings, such as lack of sufficient power, no use of blinding, allowed concomitant treatment with steroids, and no endoscopy to confirm active disease at study entry or to evaluate therapeutic efficacy. Hence, current clinical practice of thiopurine treatment in UC is based on minimal and controversial evidence. This underscores the need for clinical studies with sufficient power and objective end points in order to determine efficacy of thiopurines in UC.

Time to clinical response and remission for therapeutics in inflammatory bowel diseases: What should the clinician expect, what should patients be told?

An awareness of the expected time for therapies to induce symptomatic improvement and remission is necessary for determining the timing of follow-up, disease (re)assessment, and the duration to persist with therapies, yet this is seldom reported as an outcome in clinical trials. In this review, we explore the time to clinical response and remission of current therapies for inflammatory bowel disease (IBD) as well as medication, patient and disease related factors that may influence the time to clinical response. It appears that the time to therapeutic response varies depending on the indication for therapy (Crohn's disease or ulcerative colitis). Agents with the most rapid time to clinical response included corticosteroids, calcineurin inhibitors, exclusive enteral nutrition, aminosalicylates and anti-tumor necrosis factor therapy which will work in most patients within the first 2 mo. Vedolizumab, methotrexate and thiopurines had a longer time to clinical response and can take several months to achieve maximal efficacy. Factors affecting the time to clinical response of therapies included use of concomitant therapy, disease duration, smoking status, disease phenotype and advanced age. There appears to be marked variation in time to clinical response for therapies used in IBD which is further influenced by disease and patient related factors. Understanding the expected time to therapeutic response is integral to inform further decision making, maintain a patient-centered approach and ensure treatment is given an appropriate timeframe to achieve maximal benefit prior to cessation.

Placebo response and remission rates in randomised trials of induction and maintenance therapy for ulcerative colitis

BACKGROUND

It is important to minimize placebo rates in randomised controlled trials (RCTs) to efficiently detect treatment differences between interventions. Historically, high placebo rates have been observed in clinical trials of ulcerative colitis (UC). A better understanding of factors influencing placebo rates may lead to more informed clinical trial design.

OBJECTIVES

A systematic review and meta-analysis was conducted to evaluate placebo response and remission rates in RCTs evaluating UC treatments in adult patients.

SEARCH METHODS

Electronic databases (i.e. MEDLINE, EMBASE, and CENTRAL) were searched from inception to 1 March 2017 with no language restrictions applied. Reference lists and conference proceedings of major gastroenterology meetings were also handsearched to identify additional studies.

SELECTION CRITERIA

Placebo-controlled RCTs of adult patients with UC treated with corticosteroids, aminosalicylates, immunosuppressives or biologics were eligible, provided enrolment and outcome assessment was conducted using the Ulcerative Colitis Disease Activity Index (UCDAI) or the Mayo Clinic Score. The minimum trial duration was two weeks for induction trials and four months maintenance trials.

DATA COLLECTION AND ANALYSIS

Pairs of authors independently determined study eligibility and extracted data with any disagreements resolved through consensus. Outcomes of interest included the proportion of patients with clinical response and remission. Trial characteristics such as the design, participant demographics and disease history, interventions, and enrolment and assessment criteria were also recorded. The methodological quality of the included studies was evaluated using the Cochrane risk of bias tool. Pooled placebo response and remission rates and 95% confidence intervals (95% CI) were calculated using a binomial normal model for proportions. Induction of remission and maintenance studies were pooled separately. The impact of study-level characteristics on placebo response and remission rates was investigated using mixed-effects meta-regression analyses with logits of event rates as the outcome variables. An assessment of pooled placebo rates over time was conducted using a cumulative meta-analysis based on date of publication. Publication bias was examined using funnel plots.

MAIN RESULTS

The screening process identified 61 included studies which encompass 58 induction phases (5111 patients randomised to placebo) and 12 maintenance phases (1579 patients randomised to placebo). For induction trials, the pooled estimate of placebo response was 33% (95% CI 30% to 36%) while the pooled estimate of placebo remission was 12% (95% CI 9% to 15%). For maintenance trials, the pooled estimate of placebo response was 23% (95% CI 19% to 28%) while the pooled estimate of placebo remission was 17% (95% CI 10% to 27%).Studies enrolling patients with more active disease confirmed objectively by endoscopy were associated with significantly lower placebo remission and response rates than trials enrolling patients with less active disease (27% versus 4%, OR 2.60, 95% CI 1.25 to 5.42, P = 0.01 for UCDAI endoscopy sub score ≥1 versus ≥ 2 for remission; and 27% versus 4%, OR 1.70, 95% CI 1.02 to 2.82, P = 0.02 for UCDAI endoscopy sub score greater than or equal to one versus greater than or equal to two for response). With respect to drug class, the lowest placebo response and remission rates were observed in trials evaluating corticosteroids (23%; 95% CI 19 to 29%, and 5%; 95% CI 2 to 11%, respectively). Trials of biologics had the highest placebo response rate (35%; 95% CI 30 to 41%), while trials evaluating aminosalicylates had the highest placebo remission rate (18%; 95% CI 12 to 24%). Disease duration of greater than five years prior to enrolment was associated with a significantly lower placebo response rate compared to disease duration of less than or equal to five years (29% versus 47%, respectively; OR 0.54, 95% CI 0.32 to 0.92, P = 0.02). The requirement of a minimum rectal bleeding score for study eligibility was associated with an increased placebo response rate compared to studies that did not use rectal bleeding for trial eligibility (37% versus 32%, respectively; OR 1.70, 95% CI 1.02 to 2.82, P = 0.02). Finally, the time point of primary outcome assessment was found to be significantly associated with placebo remission rates such that every one week increment in endpoint assessment was associated with a 6% increase in the placebo remission rate (OR 1.06, 95% CI 1.02 to 1.10, P = 0.01).Cumulative meta-analysis indicated a consistent increase in the placebo response rate from 1987 to 2007 (from 13% to 33%), although rates have remained constant from 2008 to 2015 (32% to 34%). Similarly, placebo remission rates increased from 1987 to 2007 (5% to 14%) but have remained constant from 2008 to 2015 (12 to 14%). On meta-regression, there were no statistically significant differences between the 1987-2007 and 2008-2015 point estimates for both response (P = 0.81) and remission (P = 0.32).

AUTHORS' CONCLUSIONS

Placebo response and remission rates vary according to endoscopic disease severity and rectal bleeding score at trial entry, class of agent, disease duration, and the time point at which the primary outcome was measured. These observations have important implications for the design and conduct of future clinical trials in UC and will help researchers design trials, determine required sample sizes and also provide useful information about trial design features which should be considered when planning new trials.

Defining endoscopic response and remission in ulcerative colitis clinical trials: an international consensus

BACKGROUND

Recently, endpoints for clinical trials have been changing from measuring clinical response to mucosal healing in ulcerative colitis. Endoscopic evaluation is the current gold standard to assess mucosal lesions and has become a major measure of therapeutic efficacy in addition to patients reported outcomes.

AIM

To achieve consensus on endoscopic definitions of remission and response for clinical trials in patients with ulcerative colitis.

METHODS

In reaching the current international recommendations on an International Organization For the Study of Inflammatory Bowel Disease (IOIBD) initiative, we first performed a systematic review of technical aspects of endoscopic scoring systems. Then, to achieve consensus on endoscopic definitions of remission and response for clinical trials, we conducted a two-round vote using a Delphi-style process among fifteen specialists in the field of inflammatory bowel diseases.

RESULTS

The literature review showed that many endoscopic indices have been proposed to evaluate disease activity in ulcerative colitis; most are unvalidated and arbitrary definitions have been used in clinical trials for defining endoscopic response or remission. At the end of the voting process, the investigators ranked initially the Ulcerative Colitis Endoscopic Index of Severity (UCEIS) 0 for the definition of endoscopic remission, and a decrease in Mayo endoscopic score ≥1 grade or a decrease in UCEIS ≥2 points for the definition of endoscopic response in ulcerative colitis.

CONCLUSIONS

These international recommendations represent the first consensus on measurement indices for endoscopic outcomes in ulcerative colitis. They should be subject to prospective testing in clinical trials of ulcerative colitis.

Low-dose azathioprine is effective in maintaining remission in steroid-dependent ulcerative colitis: results from a territory-wide Chinese population-based IBD registry

BACKGROUND

Whether low-dose azathioprine (AZA) is effective in maintaining remission in patients with steroid-dependent ulcerative colitis (UC) remains unclear. We assessed the efficacy and safety of low-dose AZA in a Chinese population with UC.

METHODS

We identified steroid-dependent UC patients in clinical remission on AZA maintenance therapy from a territory-wide IBD Registry. Standard- and low-dose AZA were defined as at least 2 mg/kg/day and less than 2 mg/kg/day, respectively. Relapse rates were analyzed by Kaplan-Meier analysis and compared using log-rank test.

RESULTS

Among 1226 UC patients, 128 (53% male, median duration on AZA 44 months) were included. Median maintenance AZA dose was 1.3 mg/kg/day. 97.7% of the patients were on concomitant oral 5-aminosalicylic acid. Cumulative relapse-free rates in patients on standard-dose and low-dose AZA were 71.2%, 52.8% and 45.2%, and 71.8%, 55.3% and 46.2% at 12, 24 and 36 months, respectively (p = 0.871). Relapse rate within 12 months was higher in patients who withdrew compared with those who maintained on AZA (52.6% versus 29.4%; p = 0.045). Mean corpuscular volume increased after AZA therapy in both of the low-dose [median (interquartile range, IQR): 88.2 (81.4-92.2) versus 95.1 (90.1-100.9) fl, p < 0.001] and standard-dose subgroups [median (IQR) 86.8 (76.9-89.9) versus 94.7 (85.9-99.7) fl, p < 0.001]. Leukopenia occurred in 21.1% of the patients. Patients on standard dose had a higher risk for leukopenia than those on low-dose AZA [odds ratio (OR) 3.9, 95% CI 1.9-8.2, p < 0.001].

CONCLUSIONS

In the Chinese population, low-dose AZA is effective for maintaining remission in steroid-dependent UC patients. Standard-dose AZA was associated with more than threefold increased risk of leukopenia.

Azathioprine and 6-mercaptopurine for maintenance of remission in ulcerative colitis

BACKGROUND

Maintenance of remission is a major issue in inflammatory bowel disease. In ulcerative colitis, the evidence for the effectiveness of azathioprine and 6-mercaptopurine for the maintenance of remission is still controversial.

OBJECTIVES

To assess the effectiveness and safety of azathioprine and 6-mercaptopurine for maintaining remission of ulcerative colitis.

SEARCH METHODS

The MEDLINE, EMBASE and Cochrane Library databases were searched from inception to 30 July 2015. Both full randomized controlled trials and associated abstracts were included.

SELECTION CRITERIA

Randomized controlled trials of at least 12 months duration that compared azathioprine or 6-mercaptopurine with placebo or standard maintenance therapy (e.g. mesalazine) were included.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data using standard forms. Disagreements were solved by consensus including a third author. Study quality was assessed using the Cochrane risk of bias tool. The primary outcome was failure to maintain clinical or endoscopic remission. Secondary outcomes included adverse events and withdrawal due to adverse events. Analyses were performed separately by type of control (placebo, or active comparator). Pooled risk ratios were calculated based on the fixed-effect model unless heterogeneity was shown. The GRADE approach was used to assess the overall quality of evidence for pooled outcomes.

MAIN RESULTS

Seven studies including 302 patients with ulcerative colitis were included in the review. The risk of bias was high in three of the studies due to lack of blinding. Azathioprine was shown to be significantly superior to placebo for maintenance of remission. Fourty-four per cent (51/115) of azathioprine patients failed to maintain remission compared to 65% (76/117) of placebo patients (4 studies, 232 patients; RR 0.68, 95% CI 0.54 to 0.86). A GRADE analysis rated the overall quality of the evidence for this outcome as low due to risk of bias and imprecision (sparse data). Two trials that compared 6-mercaptopurine to mesalazine, or azathioprine to sulfasalazine showed significant heterogeneity and thus were not pooled. Fifty per cent (7/14) of 6-mercaptopurine patients failed to maintain remission compared to 100% (8/8) of mesalazine patients (1 study, 22 patients; RR 0.53, 95% CI 0.31 to 0.90). Fifty-eight per cent (7/12) of azathioprine patients failed to maintain remission compared to 38% (5/13) of sulfasalazine patients (1 study, 25 patients; RR 1.52, 95% CI 0.66 to 3.50). One small study found that 6-mercaptopurine was superior to methotrexate for maintenance of remission. In the study, 50% (7/14) of 6-mercaptopurine patients and 92% (11/12) of methotrexate patients failed to maintain remission (1 study, 26 patients; RR 0.55, 95% CI 0.31 to 0.95). One very small study compared azathioprine with cyclosporin and found that there was no significant difference between patients failing remission on azathioprine (50%, 4/8) or cyclosporin (62.5%, 5/8) (1 study, 16 patients, RR 0.80 95% CI 0.33 to 1.92). When placebo-controlled studies were pooled with aminosalicylate-comparator studies to assess adverse events, there was no statistically significant difference between azathioprine and control in the incidence of adverse events. Nine per cent (11/127) of azathioprine patients experienced at least one adverse event compared to 2% (3/130) of placebo patients (5 studies, 257 patients; RR 2.82, 95% CI 0.99 to 8.01). Patients receiving azathioprine were at significantly increased risk of withdrawing due to adverse events. Eight per cent (8/101) of azathioprine patients withdrew due to adverse events compared to 0% (0/98) of control patients (5 studies, 199 patients; RR 5.43, 95% CI 1.02 to 28.75). Adverse events related to study medication included acute pancreatitis (3 cases, plus 1 case on cyclosporin) and significant bone marrow suppression (5 cases). Deaths, opportunistic infection or neoplasia were not reported.

AUTHORS' CONCLUSIONS

Azathioprine therapy appears to be more effective than placebo for maintenance of remission in ulcerative colitis. Azathioprine or 6-mercaptopurine may be effective as maintenance therapy for patients who have failed or cannot tolerate mesalazine or sulfasalazine and for patients who require repeated courses of steroids. More research is needed to evaluate superiority over standard maintenance therapy, especially in the light of a potential for adverse events from azathioprine. This review updates the existing review of azathioprine and 6-mercaptopurine for maintenance of remission in ulcerative colitis which was published in the Cochrane Library (September 2012).

Evaluating Study Withdrawal Among Biologics and Immunomodulators in Treating Ulcerative Colitis: A Meta-analysis of Controlled Clinical Trials

BACKGROUND

We conducted a systematic review and meta-analysis to evaluate the efficacy and adverse event (AE)-associated tolerability of treatment with immunomodulators and biologics in ulcerative colitis clinical trials.

METHODS

We performed a literature search of PubMed and the Cochrane databases to identify randomized placebo-controlled trials of immunomodulators and biologics. Tolerability was defined through study withdrawal due to AEs and efficacy through clinical response in induction trials and clinical remission in maintenance trials. We performed meta-analyses using a random-effects model to determine relative risks (RRs) of efficacy and study withdrawal. Number needed to treat (NNT) and number needed to stop (NNS) were determined. The ratio of NNS/NNT was calculated, with a higher ratio indicating a greater number of patients in remission for every AE study discontinuation.

RESULTS

We examined 13 single-agent trials representing biologics (infliximab, adalimumab, golimumab, and vedolizumab) and immunomodulators (tacrolimus and azathioprine). Induction therapy did not result in excess study withdrawal with immunomodulators (RR = 0.9, 95% CI 0.1-12.0) or biologics (RR = 0.7, 95% CI 0.3-1.8), therefore the NNS/NNT ratio could not be assessed because of high tolerability. Maintenance immunomodulator therapy resulted in a NNS of 14 (RR = 2.8, 95% CI 0.7-10.5) and NNS/NNT ratio of 2.4 in 2 trials. Biologics did not result in excess study withdrawal in maintenance (RR = 0.7, 95% CI 0.3-1.7) or combined induction-and-maintenance (RR = 0.6, 95% CI 0.4-1.0) trials.

CONCLUSIONS

Biologics were not associated with a higher RR of study withdrawal due to AE than placebo. There were insufficient data to compare these results with immunomodulators.

Prospective Evaluation of Pharmacogenomics and Metabolite Measurements upon Azathioprine Therapy in Inflammatory Bowel Disease: An Observational Study

Up to approximately 40% to 50% of patients discontinue thiopurine therapy during the course of inflammatory bowel disease (IBD). We investigated the role of the metabolite thiopurine in IBD treatment. This was a prospective study. IBD patients receiving azathioprine (AZA) were prospectively included. Thiopurine methyltransferase (TPMT) genotypes were examined before therapy, and thiopurine metabolite levels were examined at weeks 2, 4, 8, 12, 24, and 48. In total, 132 patients were included. The frequency of leucopenia increased at 6-thioguanine nucleotide (6-TGN) levels ≥420  pmol/8 × 10(8) RBC (odds ratio [OR] = 7.9; 95% confidence interval (95%CI): 3.5-18.0; P < 0.001) and increased more during the initial 12 weeks of thiopurine therapy (OR = 16.0; 95%CI: 5.7-44.9; P < 0.001). The patients with 6-TGN levels ≥420 pmol/8 × 10 RBC at weeks 4, 8, and 12 had an increased likelihood of leucopenia. Clinical response increased at 6-TGN levels ≥225 pmol/8 × 10(8) RBC (OR = 13.5; 95% CI: 3.7-48.9; P < 0.001) in Crohn disease (CD) patients. The CD patients with 6-TGN levels ≥225 pmol/8 × 10(8) RBC at weeks 8, 12, and 24 had an increased likelihood of successful clinical response. TPMT*3C had a specificity of 100%, but a sensitivity of 8% for predicting leucopenia.A 6-TGN level between 225 and 420 pmol/8 × 10(8) RBC could be a therapeutic window in patients receiving AZA therapy, and it could likely predict leucopenia in the initial 12 weeks of AZA therapy and a reasonable chance of successful clinical response in CD patients. The value of TPMT genotyping before thiopurine therapy is limited in Chinese patients with IBD, considering the low sensitivity of predicting leucopenia.

Physician Perspectives on Unresolved Issues in the Management of Ulcerative Colitis: The UC Horizons Project

BACKGROUND

There is still uncertainty about what constitutes the best therapeutic practice in ulcerative colitis (UC).

OBJECTIVE

The purpose of the "UC Horizons Project" was to raise a series of questions regarding the management of UC to provide responses based on the best scientific evidence available.

METHODS

The 11 members of the scientific committee prepared draft answers to the 10 questions from available evidence after a literature search. A total of 48 Spanish gastroenterology specialists nationwide participated in the project. The national meeting discussed the 10 issues in working groups and reached consensus regarding the recommendations by anonymous, interactive vote following the Delphi methodology. Final answers were developed, based on evidence and clinical experience of the participants.

RESULTS

All the recommendations achieved a high level of agreement in the plenary vote, although the quality of the evidence was markedly heterogeneous. The lowest percentage of agreement corresponded to the questions with the weakest level of evidence, highlighting the necessity of conducting further studies in these areas. The recommendations focused on (1) aminosalicylates therapy (regarding dose and appropriateness of coadministration with thiopurines), (2) corticosteroid therapy (regarding dose and route of administration), (3) thiopurine treatment (regarding indications and possibility of withdrawal), (4) anti-tumor necrosis factor therapy (regarding appropriateness of combination with thiopurines, intensification, or discontinuation of treatment), and (5) colorectal cancer (regarding risk and time trends).

CONCLUSIONS

The UC Horizons Project raised a series of eminently practical questions about the management of UC and provided responses based on the best scientific evidence available.

New Applications for Traditional Drugs in Inflammatory Bowel Disease: What Do Cochrane Reviews Tell Us?

Although multiple innovative treatments of inflammatory bowel disease have become available, research continues to refine the value of existing drug therapies for Crohn's disease and ulcerative colitis. What can Cochrane reviews tell us about evolving applications for traditional agents in inflammatory bowel disease? A Cochrane Collaboration symposium held at the 2014 Digestive Diseases Week annual meeting addressed this question. This article reviews the data presented at that session.

An emphasis on molecular mechanisms of anti-inflammatory effects and glucocorticoid resistance

Glucocorticoids (GC) are universally accepted agents for the treatment of anti-inflammatory and immunosuppressive disorders. They are used in the treatment of rheumatic diseases and various inflammatory diseases such as allergy, asthma and sepsis. They bind with GC receptor (GR) and form GC-GR complex with the receptor and exert their actions. On activation the GC-GR complex up-regulates the expression of nucleus anti-inflammatory proteins called as transactivation and down-regulates the expression of cytoplasmic pro-inflammatory proteins called as transrepression. It has been observed that transactivation mechanisms are notorious for side effects and transrepressive mechanisms are identified for beneficial anti-inflammatory effects of GC therapy. GC hampers the function of numerous inflammatory mediators such as cytokines, chemokines, adhesion molecules, arachidonic acid metabolites, release of platelet-activating factor (PAF), inflammatory peptides and enzyme modulation involved in the process of inflammation. The GC resistance is a serious therapeutic problem and limits the therapeutic response of GC in chronic inflammatory patients. It has been observed that the GC resistance can be attributed to cellular microenvironment changes, as a consequence of chronic inflammation. Various other factors responsible for resistance have been identified, including alterations in both GR-dependent and GR-independent signaling pathways of cytokine action, hypoxia, oxidative stress, allergen exposure and serum-derived factors. The present review enumerates various aspects of inflammation such as use of GC for treatment of inflammation and its mechanism of action. Molecular mechanisms of anti-inflammatory action of GC and GC resistance, alternative anti-inflammatory treatments and new strategy for reversing the GC resistance have also been discussed.