Ustekinumab in Crohn's disease: evidence to date and place in therapy

Identifying hub genes in response to ustekinumab and the impact of ustekinumab treatment on fibrosis in Crohn's disease

Introduction

Crohn's disease (CD) is a chronic inflammatory disease. Approximately 50% of patients with CD progressed from inflammation to fibrosis. Currently, there are no effective drugs for treating intestinal fibrosis. Biologic therapies for CD such as ustekinumab have benefited patients; however, up to 30% of patients with CD have no response to initial treatment, and the effect of ustekinumab on intestinal fibrosis is still uncertain. Therefore, it is of great significance to explore the predictive factors of ustekinumab treatment response and the effect of ustekinumab on intestinal fibrosis.

Materials and methods

Public datasets-GSE207465 (blood samples) and GSE112366 and GSE207022 (intestinal samples)-were downloaded and analyzed individually (unmerged) based on the treatment response. Differentially expressed genes (DEGs) were identified by the "limma" R package and changes in immune cell infiltration were determined by the "CIBERSORT" R package in both blood and intestinal samples at week 0 (before treatment). To find predictive factors of ustekinumab treatment response, the weighted gene co-expression network analysis (WGCNA) R package was used to identify hub genes in GSE112366. Hub genes were then verified in GSE207022, and a prediction model was built by random forest algorithm. Furthermore, fibrosis-related gene changes were analyzed in ileal samples before and after treatment with ustekinumab.

Results

(1) Our analysis found that MUC1, DUOX2, LCN2, and PDZK1IP1 were hub genes in GSE112366. GSE207022 revealed that MUC1 (AUC:0.761), LCN2 (AUC:0.79), and PDZK1IP1 (AUC:0.731) were also lower in the response group. Moreover, the random forest model was shown to have strong predictive capabilities in identifying responders (AUC = 0.875). To explore the relationship between intestinal tissue and blood, we found that ITGA4 had lower expression in the intestinal and blood samples of responders. The expression of IL18R1 is also lower in responders' intestines. IL18, the ligand of IL18R1, was also found to have lower expression in the blood samples from responders vs. non-responders. (2) GSE112366 revealed a significant decrease in fibrosis-related module genes (COL4A1, TUBB6, IFITM2, SERPING1, DRAM1, NAMPT, MMP1, ZEB2, ICAM1, PFKFB3, and ACTA2) and fibrosis-related pathways (ECM-receptor interaction and PI3K-AKT pathways) after ustekinumab treatment.

Conclusion

MUC1, LCN2, and PDZK1IP1 were identified as hub genes in intestinal samples, with lower expression indicating a positive prediction of ustekinumab treatment response. Moreover, ITGA4 and IL18/IL18R1 may be involved in the treatment response in blood and intestinal samples. Finally, ustekinumab treatment was shown to significantly alter fibrotic genes and pathways.

Extra intravenous Ustekinumab reinduction is an effective optimization strategy for patients with refractory Crohn's disease

OBJECTIVES

Ustekinumab (UST) optimization strategies, including shortening intervals and intravenous reinduction, should be administered to patients with partial or loss of respond. Evidence comparing these types of optimization treatments is limited. We evaluated the efficacy and safety of weight-based UST intravenous reinduction in patients with refractory Crohn's disease (CD).

METHODS

This was a single-center retrospective observational study. Optimization strategies were designed for patients showing partial or loss of response to standardized UST therapy. Clinical, biochemical, and endoscopic response and remission rate were determined by Crohn's disease activity index (CDAI), C-reactive protein (CRP) levels, and SES-CD evaluation. UST trough concentrations were detected and adverse events were recorded.

RESULTS

A total of 128 patients receiving UST optimization therapies were included, with 105 patients administered shortening intervals of q8w or q4w, and 23 receiving intravenous reinduction followed by subcutaneous q8w or q4w. The follow-up duration for the shortening interval and reinduction cohorts were 15.0 (10.0, 31.0) and 23.0 (13.0, 70.0) weeks, respectively. A significant CDAI delta variation pre-and post-treatment could be found between groups [17.0 (-4.4, 65.9) vs. 69.0(10.7, 151.0), p = 0.013]. the trough concentration of UST increased [2.5 (1.3, 5.3) vs. 1.1 (0.5, 2.3), p = 0.001] after intravenous reinduction. Clinical and endoscopic remission were achieved in 69.6 and 31.8% of patients in the intravenous reinduction cohort, and 62.9 and 22.2% of patients in the shortening interval cohort, respectively. No significant difference was found between groups regarding safety.

CONCLUSION

Intravenous reinduction brought about favorable recapture of clinical and endoscopic remission, and should have significant priority over the strategy of merely shortening drug intervals, which should be launched before switching to other biologics targeting different inflammatory pathways.Clinical Trial Registration: identifier NCT04923100. https://classic.clinicaltrials.gov/ct2/show/NCT04923100?id=04923100&draw=2&rank=1.

Effectiveness and safety of ustekinumab in bio-naïve Crohn's disease patients: a multicentre observational retrospective study

Background

Clinical trials have demonstrated the efficacy and safety of ustekinumab in Crohn's disease (CD). However, more data are necessary on the effectiveness of ustekinumab in bio-naïve patients in real-life studies.

Objectives

The aim of our study was to evaluate the effectiveness and safety of ustekinumab in patients with CD refractory or intolerant to conventional therapy and without previous exposure to biological drugs.

Design

We performed a nationwide, observational, retrospective, multicentre study including patients with CD, in which ustekinumab was used as the first biological drug.

Methods

The corticosteroid-free clinical and biological response and remission were analysed at weeks 16, 24, 52 and 72. Clinical remission was defined as Harvey-Bradshaw index ⩽ 4 and biological remission as a faecal calprotectin (FC) <250 mg/g and C-reactive protein (CRP) <5 mg/L. Moreover, the persistence of the treatment and any adverse events were assessed.

Results

In all, 84 patients were included in the study, males and females were equally distributed, with a median age of 63 years [interquartile range (IQR): 51-75] and a median disease duration of 6.8 years [IQR: 3.6-17.0]. The majority (86.9%) of patients were treated with ustekinumab as monotherapy, without concomitant immunosuppressive medication. The proportion of patients in corticosteroid-free clinical remission or response at weeks 16, 24, 52 and 72 was 93.3% (56/60), 86.8% (46/53), 82.2% (37/45) and 71.4% (30/42), respectively. CRP returned to normal values in 47.6%, 43.2%, 50% and 52.4% of patients at weeks 16, 24, 52 and 72, respectively. Similarly, FC was normalized in 45.5%, 45.5%, 48.6% and 50% of patients at weeks 16, 24, 52 and 72, respectively. The cumulative probability of remaining on ustekinumab treatment was 84.8% (95% confidence interval: 73.3-91.6) after 72 weeks. Ustekinumab was discontinued in 10 patients (11.9%) within 72 weeks of follow-up. Reasons for discontinuing treatment were lack of response (n = 4), adverse events (n = 4) and death (n = 2). There were no discontinuations because of stable remission.

Conclusions

Ustekinumab was effective and safe in Spanish bio-naïve CD patients, showing a quicker and more durable response than obtained in patients with previous biological treatment. In this cohort of bio-naïve patients starting on ustekinumab, the average age was high.

Plain language summary

Effectiveness and safety of ustekinumab in Crohn's disease patients not previously exposed to other biological therapies Evidence on the use of ustekinumab in biological naïve real-world patients is scarce. Here, we present real-world data evaluating the effectiveness and safety of ustekinumab in 84 bio-naïve patients from 17 Spanish hospitals. We report high rates of both clinical and biological remission. Moreover, after 1 year, 90.4% of patients remained being treated with ustekinumab. The safety profile of ustekinumab in these patient population was favourable. In conclusion, our results show that in patients with CD, ustekinumab could be considered as first-line therapy.

Modern drug discovery for inflammatory bowel disease: The role of computational methods

Inflammatory bowel diseases (IBDs) comprising ulcerative colitis, Crohn’s disease and microscopic colitis are characterized by chronic inflammation of the gastrointestinal tract. IBD has spread around the world and is becoming more prevalent at an alarming rate in developing countries whose societies have become more westernized. Cell therapy, intestinal microecology, apheresis therapy, exosome therapy and small molecules are emerging therapeutic options for IBD. Currently, it is thought that low-molecular-mass substances with good oral bio-availability and the ability to permeate the cell membrane to regulate the action of elements of the inflammatory signaling pathway are effective therapeutic options for the treatment of IBD. Several small molecule inhibitors are being developed as a promising alternative for IBD therapy. The use of highly efficient and time-saving techniques, such as computational methods, is still a viable option for the development of these small molecule drugs. The computer-aided (in silico) discovery approach is one drug development technique that has mostly proven efficacy. Computational approaches when combined with traditional drug development methodology dramatically boost the likelihood of drug discovery in a sustainable and cost-effective manner. This review focuses on the modern drug discovery approaches for the design of novel IBD drugs with an emphasis on the role of computational methods. Some computational approaches to IBD genomic studies, target identification, and virtual screening for the discovery of new drugs and in the repurposing of existing drugs are discussed.

The treatment of inflammatory bowel disease with monoclonal antibodies in Asia

Crohn's disease (CD) and ulcerative colitis (UC), the two main forms of inflammatory bowel disease (IBD), are chronic, systemic autoimmune diseases. As the incidence of IBD rapidly increases in Asia, increasing attention has been paid to developing additional treatment strategies. Presently, the end point of therapy is achieving clinical and endoscopic remission through the blockade of inflammatory cascades. Recent studies have shown that monoclonal antibodies (mAbs) use for precise molecular targeting of inflammatory pathways has a promising effect on IBD, especially moderate-to-severe CD and UC. Since the 1997 report on the use of infliximab (a monoclonal antibody against tumor necrosis factor alpha [TNF-α]) in patients with CD, mAbs have expanded therapeutic options and have also complicated initial management options and subsequent treatment. This review comprehensively summarizes the clinical reports and studies related to the use of mAbs for the treatment of IBD in Asian countries and regions in recent years thus demonstrating the current status of mAbs use in Asia. In addition, the differences in the use of mAbs for the treatment of IBD between the Asia and the West are expounded. Ultimately, it is hoped that this review will provide new insights and a scientific basis for the clinical application of mAbs.

Successful Non-Operative Treatment of Enterovesical and Enterocutaneous Fistulas Due to Crohn’s Disease

Background

The incidences of enterovesical and enterocutaneous fistulas are extremely low, and enterovesical and enterocutaneous fistulas are difficult to treat in patients with Crohn’s disease.

Case Summary

In this case, the patient had recurrent abdominal pain and diarrhea for more than 2 years, with fecal residue in the urine for 6 days. Pelvic magnetic resonance imaging and colonoscopy showed intestinal infection with a rectal fistula, and the initial diagnosis was severely active Crohn’s disease with an enterovesical fistula. The patient had multiple internal fistulas and infections, and strongly refused surgical conditions. The patient was given an intravenous infusion of ustekinumab and somatostatin, with anti-infective treatment, nutritional support and regulation of the intestinal flora. Drainage and debridement of the cutaneous fistula were performed. After comprehensive treatment and management, the patient’s condition achieved significant clinical remission.

Conclusion

This patient achieved clinical response and will receive follow-up for another dose of ustekinumab after 12 weeks. The patient developed enterovesical and enterocutaneous fistulas, the incidence of multiple fistulas which are low in patients with CD and are difficult to cure and prone to relapse. Only few patients achieve complete remission. At present, there is no standard and effective treatment for CD with multiple fistulas. Usually, surgery is performed for treatment. Drug therapy, especially with biological agents, should be selected as the first-line pre-operative treatment. Clinicians, especially gastroenterologists, need to improve their knowledge of these conditions and update the treatment consensus guidelines in a timely manner. Clinicians need to take into account the patient’s condition and willingness when developing an effective treatment plan.

Effectiveness of Third-Class Biologic Treatment in Crohn's Disease: A Multi-Center Retrospective Cohort Study

BACKGROUND

Multiple studies have described the effectiveness of ustekinumab (UST) and vedolizumab (VDZ) in patients with Crohn's disease (CD) failing anti- Tumor necrosis factors (TNFs); however, the effectiveness of VDZ or UST as a third-class biologic has not yet been described.

AIMS AND METHODS

In this retrospective multicenter cohort study, we aimed to investigate the effectiveness of VDZ and UST as a third-class biologic in patients with CD.

RESULTS

Two-hundred and four patients were included; 156/204 (76%) patients received VDZ as a second- and UST as a third-class therapy (group A); the remaining 48/204 (24%) patients received UST as a second- and VDZ as a third-class therapy (group B). At week 16-22, 87/156 (55.5%) patients and 27/48 (56.2%) in groups A and B, respectively, responded to treatment (p = 0.9); 41/156 (26.2%) and 15/48 (31.2%) were in clinical remission (p = 0.5). At week 52; 89/103 (86%) patients and 25/29 (86.2%) of the patients with available data had responded to third-class treatment in groups A and B, respectively (p = 0.9); 31/103 (30%) and 47/29 (24.1%) were in clinical remission (p = 0.5).

CONCLUSION

Third-class biological therapy was effective in more than half of the patients with CD. No differences in effectiveness were detected between the use of VDZ and UST as a third-class agent.

Update on TDM (Therapeutic Drug Monitoring) with Ustekinumab, Vedolizumab and Tofacitinib in Inflammatory Bowel Disease

The goal of therapeutic drug monitoring (TDM) is to optimize anti-TNF (tumor necrosis factor) biologic treatment in patients with inflammatory bowel disease (IBD). Although commercial assays are readily available for both ustekinumab and vedolizumab, the use of TDM with these newer biologic medications is at its infancy. The clinical utility of TDM with non-anti-TNF mechanisms of action is not clear. This review summarizes the latest available data on the pharmacokinetics of newer biologic and oral small molecules and highlights the threshold concentrations that have been associated with improved outcomes in IBD patients.

Ustekinumab in bio-naïve and bio-failure Crohn's disease patients: Results from a « real-life » monocentric cohort

BACKGROUND

The pivotal clinical trials have largely demonstrated the efficacy and safety of ustekinumab in Crohn's disease. Real-life cohorts published so far only include very few bio-naïve patients. This study assesses effectiveness and safety of ustekinumab in bio-naïve and bio-failure patients treated with ustekinumab in routine practice and look for predictors of response.

METHODS

We performed a retrospective monocentric study. Initial response was assessed by maintenance therapy beyond week 16. Sustained response was assessed by the continuation or cessation of therapy over time for another reason than stopping in sustained remission. Treatment persistence was assessed by Kaplan Meier curves and predictors of treatment persistence were studied by univariate and multivariate Cox model.

RESULTS

Out of 156 recorded patients, three patients were still in their induction phase at time of analysis and 5 patients were lost to follow-up, leaving 148 patients for clinical effectiveness analyses, including 35 bio-naïve when starting ustekinumab. A maintenance therapy was initiated in 79.7%. At one year, the probability to be still treated with ustekinumab was 73.8%. Treatment cessation increased with smoking in multivariate analysis. Previous biologic failure (as a whole), CRP and fecal calprotectin baseline levels did not influence initial response and treatment persistence.

CONCLUSION

A large proportion of CD patients initially respond to ustekinumab and continue this treatment beyond one year. Treatment persistence is as high in bio-failure as in bio-naïve patients.

Crohn's disease exacerbated by IL-17 inhibitors in patients with psoriasis: a case report

BACKGROUND

Previous studied revealed that psoriasis and Inflammatory bowel disease (IBD) have highly overlapping epidemiological characteristics, genetic susceptibility loci, disease risk factors, immune mechanisms, and comorbidities. More and more biologics have been used to treat psoriasis and IBD. Interleukin (IL)-17 inhibitors played an important role in the treatment of psoriasis, but induced and aggravated inflammatory bowel disease in some patients. IL-23 inhibitors have shown to be effective to both psoriasis and CD.

CASE PRESENTATION

Forty-one year old Chinese male patient who came to the hospital for psoriasis, developed severe gastrointestinal symptoms after using an IL-17 inhibitor, and was diagnosed with Crohn's disease (CD). The patient eventually used an IL-23 inhibitor to relieve both psoriasis and CD.

CONCLUSION

IBD patients and psoriasis patients have increased probability of suffering from the other disease. The case that patients had suffered from psoriasis and CD before the use of IL-17 inhibitor is quite rare. This case suggests that physicians need to be careful when treating patients with psoriasis and CD with biologics, and it is necessary to evaluate the gastrointestinal tract.

An immune therapy model for effective treatment on inflammatory bowel disease

Inflammatory bowel disease (IBD) is a disease that causes inflammation throughout the digestive tract. Repeated inflammation and frequent relapses cause intestinal damage and expose the patient to a higher risk. In this work, we proposed an immune therapy model for effective treatment strategy through mathematical modeling for patients with IBD. We evaluated the ability of the patient's immune system to recover during treatment. For this, we defined the interval of healthy individual, and examined the frequency of compartments such as T cells and cytokines considered in the model maintain the normal state. Based on the fact that each patient has a unique immune system, we have shown at the same drug works differently, depending on the individual immune system characteristics for every patient. It is known that IBD is related to an imbalance between pro- and anti- inflammatory cytokines as the cause of the disease. So the ratios of pro- to anti- inflammatory cytokines are used as an indicator of patient's condition and inflammation status in various diseases. We compared the ratios of pro- to anti- inflammatory cytokine according to patient's individual immune system and drugs. Since the effects of biological drugs are highly dependent on the patient's own immune system, it is essential to define the immune system status before selecting and using a biological drug.

Real-world long-term effectiveness of ustekinumab in Crohn's disease: results from the ENEIDA registry

BACKGROUND

Data on the long-term administration of ustekinumab in recommended doses are limited.

AIM

To assess the real-world, long-term effectiveness of ustekinumab in refractory Crohn's disease (CD).

METHODS

Multi-centre study of CD patients starting ustekinumab at the recommended dose, followed for 1 year. Values for the Harvey-Bradshaw Index (HBI), endoscopic activity, C-reactive protein (CRP), and faecal calprotectin (FC) were recorded at baseline and at weeks 26 and 52. Demographic and clinical data, previous treatments, adverse events (AEs) and hospitalisations were documented. Potential predictors of remission were examined.

RESULTS

A total of 407 patients were analysed. The initial maintenance dose of 90 mg SC was administered every 12, 8 and 4 weeks in 56 (14%), 347 (85%) and 4 (1%) patients, respectively. After 52 weeks, treatment was discontinued in 112 patients (27.5%). At baseline, 295 (72%) had an HBI >4 points. Of these, 169 (57%) and 190 (64%) achieved clinical remission at weeks 26 and 52, respectively. FC levels returned to normal in 44% and 54% of patients at weeks 26 and 52, and CRP returned to normal in 36% and 37% of patients at weeks 26 and 52, respectively. AEs were recorded in 60 patients. The use of fewer previous anti-TNFα agents and ileal localisation were associated with clinical remission, and endoscopic severity was associated with poor response. No factors correlated with endoscopic remission.

CONCLUSION

After 52 weeks, ustekinumab demonstrated effectiveness in inducing clinical and endoscopic remission in patients with refractory CD.

Ustekinumab for treating ulcerative colitis: an expert opinion

INTRODUCTION

Biologic agents have revolutionized the therapeutic management of ulcerative colitis. Anti-tumor necrosis factor agents were the first biologic drugs used to induce and maintain remission in this inflammatory bowel disease. Recently, another biologic option, ustekinumab, has become available for the treatment of moderate-to-severe ulcerative colitis.

AREAS COVERED

In this article, the authors review the literature on the efficacy and safety of ustekinumab in the context of current biologic agents used for the management of this disease. The potential role of ustekinumab in the treatment paradigm of the disease is also discussed. Expert opinion: The UNIFI trial has demonstrated the efficacy and safety of ustekinumab in induction and maintenance phases of treatment for ulcerative colitis. Ustekinumab may provide clinical benefit in a range of settings in patients with ulcerative colitis, even for those with multiple treatment failures, which are relatively common in daily clinical practice. Future clinical trials should compare the efficacy of ustekinumab with existing biologic agents in the management of ulcerative colitis.

A Single Center Experience With Long-Term Ustekinumab Use and Reinduction in Patients With Refractory Crohn Disease

Background

Ustekinumab was approved for moderate and severe Crohn’s disease (CD) in 2016, but little is known about long-term outcomes.

Methods

A retrospective study evaluated all patients with CD treated with ustekinumab, including patients with reinduction. C-reactive protein (CRP), Harvey-Bradshaw Index (HBI), Short Inflammatory Bowel Disease (SIBDQ), and endoscopy outcomes were collected prospectively.

Results

Ninety-six patients received ustekinumab, resulting in improvement in CRP, HBI, and SIBDQ scores with 68% endoscopic improvement/remission. Thirty-four patients underwent reinduction, resulting in improved HBI and CRP.

Conclusions

Ustekinumab in refractory CD results in significant clinical and endoscopic improvement and reinduction may be a viable option to recapture response.

This study shows that ustekinumab can be used to improve symptoms and disease markers in patients with severe Crohn disease who have failed prior medications. The study also demonstrates that reinduction can help regain response if needed.

Long-term Clinical Effectiveness of Ustekinumab in Patients with Crohn's Disease Who Failed Biologic Therapies: A National Cohort Study

BACKGROUND

Ustekinumab [UST] was recently approved in Europe for the treatment of moderate to severe Crohn's disease [CD]. Long-term real-world data are currently scarce for CD patients previously exposed to several biologics.

METHODS

This is an observational, national, retrospective multicentre study. Patients received intravenous UST ~6 mg/kg at baseline, with 90 mg subcutaneously thereafter every 8 weeks. Response and remission rates were assessed at Weeks 8, 16, and 52.

RESULTS

Data from 152 patients were analysed. All patients were exposed to at least one anti-TNFα agent, with 69.7% were exposed to even two anti-TNFα and vedolizumab. After 1 year, 42.1% and 25.7% of patients had experienced clinical response and clinical remission, respectively, and 38.8% and 24.3% had achieved steroid-free clinical response and remission, respectively; 38.8% of patients discontinued therapy during the 12 months of follow-up. Colonic location was predictive of clinical response at 1 year, and low body mass index [BMI] at baseline was a negative predictor of clinical remission. Resolution of arthralgia was associated with clinical response over time. De novo arthralgia was reported by 17.9% of patients at Week 8 and 13.5% of patients at Week 52. No impact of UST on arthralgia was observed in patients with concomitant ankylosing spondylitis [n = 17]. Others adverse events were reported in 7.2% of patients.

CONCLUSIONS

This real-world cohort study confirms the effectiveness of UST in CD patients previously exposed to several biologics. Ustekinumab was well tolerated with respect to adverse events.

PODCAST

This article has an associated podcast which can be accessed at https://academic.oup.com/ecco-jcc/pages/podcast.

Effectiveness and safety of Ustekinumab for Crohn's disease; systematic review and pooled analysis of real-world evidence

BACKGROUND

Ustekinumab [UST] is effective in Crohn's disease (CD) in the UNITI studies. Several real-world experience (RWE) studies with UST have been published to date. Our aim was to summarize the available RWE data for UST effectiveness and safety.

METHODS

A systematic review of the available RWE studies of UST for CD and pooled analysis of the available effectiveness and safety data was performed.

RESULTS

Eight relevant studies of 6 RWE were included for analysis. Data from 578 patients were pooled for analysis. Most patients (97.7%) were anti-TNF experienced. Pooled clinical response rate was 60%, 62%, 49% at 12, 24 and 52 weeks respectively (95% CI (0.42-0.77), (0.48-0.75), (0.37-0.62)). Pooled remission rate was 39% (95% CI (0.18-0.65)) at 24 weeks and pooled endoscopic response rate was 63% (95% CI (0.53-0.72)) after approximately one year of UST; 134 adverse events (AE) were reported in total, pooled proportion 21% (95% CI (0.12-0.35)). Serious AE were reported in 19 patients, pooled proportion 5% (95% CI (0.03-0.08)). Infections were reported in 38, pooled proportion 6% (95% CI (0.04-0.11)).

CONCLUSION

Pooled analysis of the RWE data suggests that the real-world effectiveness and safety are comparable to that reported in the randomized control trials.

Therapeutic Drug Monitoring With Ustekinumab and Vedolizumab in Inflammatory Bowel Disease

In patients with Crohn's disease (CD) and ulcerative colitis (UC), the use of therapeutic drug monitoring (TDM) with TNF-α antagonists has led to a personalized approach to optimize treatment and has been shown to be cost-effective. The utility of this TDM-based personalized approach for novel biologic agents, which target different inflammatory pathways, is unclear. Commercial assays for ustekinumab (UST) and vedolizumab (VDZ) are available, but there is little available guidance for clinicians regarding the use of TDM with these drugs. Although there is limited evidence for definitive threshold concentrations for UST and VDZ, this review highlights the available literature on the pharmacokinetics of these medications, the association of clinical and endoscopic outcomes with drug concentrations, and the clinical utility of TDM to guide treatment decisions.

Ustekinumab in the management of Crohn's disease: Expert opinion

This expert-opinion paper reviews available evidence for the use of ustekinumab, a human interleukin 12/23 monoclonal antibody, in the treatment of Crohn's disease and discusses its potential role in the current treatment scenario for the condition. Ustekinumab appears to be associated with rapid and sustained clinical effect, as reported from the clinical research program, with additional support for potential mucosal healing. These characteristics are paralleled by a favorable safety profile, lack of immunogenicity and the presence of systemic anti-inflammatory activity. Importantly, ustekinumab requires only one single intravenous administration, while subsequent dosing is administered subcutaneously, with potential advantages for home-based therapy. Lastly, the dosage of ustekinumab is flexible. On the basis of the evidence, ustekinumab has a role in patients with primary failure or secondary loss of response to anti-tumor necrosis factor agents, as well as in those who have adverse events on front-line biologics or are reinitiating therapy after a treatment holiday. Current evidence suggests that ustekinumab may be particularly suitable in patients who present extra-intestinal manifestations of the disease or are at risk of infections. Ustekinumab may also be considered in the first-line setting, especially in frail patients, in young subjects or in those who have concomitant immune-mediated diseases.

The Innate and Adaptive Immune System as Targets for Biologic Therapies in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is an immune-mediated inflammatory condition causing inflammation of gastrointestinal and systemic cells, with an increasing prevalence worldwide. Many factors are known to trigger and maintain inflammation in IBD including the innate and adaptive immune systems, genetics, the gastrointestinal microbiome and several environmental factors. Our knowledge of the involvement of the immune system in the pathophysiology of IBD has advanced rapidly over the last two decades, leading to the development of several immune-targeted treatments with a biological source, known as biologic agents. The initial focus of these agents was directed against the pro-inflammatory cytokine tumor necrosis factor-α (TNF-α) leading to dramatic changes in the disease course for a proportion of patients with IBD. However, more recently, it has been shown that a significant proportion of patients do not respond to anti-TNF-α directed therapies, leading a shift to other inflammatory pathways and targets, including those of both the innate and adaptive immune systems, and targets linking both systems including anti-leukocyte trafficking agents-integrins and adhesion molecules. This review briefly describes the molecular basis of immune based gastrointestinal inflammation in IBD, and then describes how several current and future biologic agents work to manipulate these pathways, and their clinical success to date.

Diagnosis and management of inflammatory bowel disease in children

Inflammatory bowel diseases (IBD), including Crohn's disease and ulcerative colitis, are lifelong conditions that often begin in childhood. The implications of IBD are of particular importance in children because of the potential negative effects on growth, development, psychosocial function, and overall wellbeing. The key management strategy is to achieve sustained control of intestinal inflammation and monitor for potential complications of the disease and side effects of therapies. Overall, the evidence on the management of IBD in children is less extensive than in adults, but good quality multicenter studies and various guidelines and society consensus statements are available. This review summarizes the evidence on the pathophysiology, diagnosis, and approaches to management of children and adolescents with IBD.

Long-term Maintenance of Clinical, Endoscopic, and Radiographic Response to Ustekinumab in Moderate-to-Severe Crohn's Disease: Real-world Experience from a Multicenter Cohort Study

BACKGROUND

Ustekinumab is a monoclonal antibody targeting interleukins 12 and 23. While effective in clinical trials for Crohn's disease (CD), long-term maintenance of response in the real-world setting is unclear. We aim to assess the efficacy of ustekinumab for maintaining clinical, endoscopic, and radiographic response in CD.

METHODS

A retrospective multicenter cohort study was performed on patients with CD achieving steroid-free clinical response to ustekinumab induction, and advanced onto a regularly scheduled maintenance ustekinumab regimen between 2011 and 2016. The primary outcome was loss of response, defined by an increase in Harvey Bradshaw Index of >3 points from baseline requiring ustekinumab dose escalation, reinduction, rescue corticosteroids, immunomodulators, surgery, or ustekinumab discontinuation. Multivariate Cox proportional hazards regression was used to identify clinical factors associated with loss of response.

RESULTS

One hundred four patients with CD achieving steroid-free response with ustekinumab induction were included; 92.3% (96/104) had previously failed antitumor necrosis factor therapy. Median follow-up was 57.2 weeks (interquartile range (IQR): 36.7-103.4). Cumulative probability of maintained response at 52 weeks was 71.8%. Sixty-seven patients (64.4%) maintained endoscopic or radiographic response. Thirty-five patients (33.7%) lost response at a median time of 47.4 weeks (IQR: 35.3-68.4). Dose escalation was required in 17 patients (16.3%); response was recaptured in 9/17 (52.9%). Nine patients (8.7%) required surgery. In Cox multivariate regression, concurrent immunomodulation was associated with reduced risk of loss of response (hazards ratio 0.39 (95% CI, 0.17-0.92)).

CONCLUSIONS

Subcutaneous ustekinumab is an effective treatment option for maintaining long-term clinical, endoscopic, and radiographic response in patients with moderate-to-severe CD failing antitumor necrosis factor therapy.

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

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

Update on the Use of Biologic Therapy in Ulcerative Colitis

OPINION STATEMENT

Ulcerative colitis (UC) is a major form of inflammatory bowel disease and is characterized by chronic inflammation of the colon and rectum and by alternating periods of flares and remissions. Symptoms may include rectal bleeding, abdominal pain, and diarrhea. The pathogenesis of UC is complex and involves a combination of immune dysregulation, genetics, environmental factors, and microbiota. The goal of medical treatment is to induce and maintain remission. Traditionally, the treatment options for UC included 5-aminosalicylates, corticosteroids, and immunomodulators. However, over the past decade, with the approval of various biologic agents for treatment of UC, the management of UC has been revolutionized. Currently, the FDA-approved biologics for treatment of UC include infliximab, adalimumab, golimumab, and vedolizumab. There are a number of other agents which are under investigation and may become available soon as treatment options for UC. The purpose of this article is to provide a summary of various biologics in the treatment of UC.