Effects of Mirikizumab on Histologic Resolution of Crohn's Disease in a Randomized Controlled Phase 2 Trial

Clinical Significance of histologic healing in IBD: Evidence from randomized controlled trials (RCT) and real world (RW) data

Histologic mucosal healing (HMH) has emerged as a crucial target in managing inflammatory bowel disease, complementing the established goal of endoscopic mucosal healing. This review evaluates the significance of HMH in both Crohn's disease (CD) and ulcerative colitis (UC). In UC, strong evidence shows that HMH correlates with improved long-term outcomes, including reduced hospitalization rates, and decreased need for corticosteroids and colectomy. Histologic healing is increasingly being incorporated as an endpoint in RCTs. Small-molecule therapies, such as S1P modulators and Jak inhibitors, have demonstrated particular efficacy in achieving HMH in UC. Real-world evidence (RWE) further supports HMH's utility as a predictive marker for favorable clinical outcomes in UC. In CD, however, HMH's role is less clear, given challenges in assessing and standardizing histologic healing. RCTs, such as SERENITY and VIVID, show that advanced therapies can achieve HMH in CD, though inconsistent histologic scoring and remission criteria complicate conclusions. Some studies suggest that histologic remission at induction may predict sustained remission, but real-world data offer mixed results regarding its prognostic value. This review provides an overview of current literature, emphasizing the need for standardized histologic assessment and extended studies, particularly for CD, while affirming HMH's growing importance in achieving deeper remission in UC.

Efficacy and safety of IL-23 p19 inhibitors in the treatment for inflammatory bowel disease: a systematic review and meta-analysis

Background

The treatment outcomes of inflammatory bowel disease (IBD) have been significantly improved by the advent of new biologics, including ulcerative colitis (UC) and Crohn's disease (CD), particularly for refractory cases. However, the growing number of therapeutic options has also complicated clinical decision-making regarding drug selection and switching. The overall performance of IL-23 p19 inhibitors for the treatment of IBD was evaluated by the systematic review and meta-analysis in this study.

Objective

The objective of this study was to combine the multiple indicators to accurately evaluate the efficacy and safety of IL-23 p19 inhibitors, aimed to offer an insight into the development of clinical physicians' medication.

Methods

A comprehensive literature review on PubMed, Embase, Web of Science, and Cochrane Library until June 2024 was conducted in this study, which mainly focused on the randomized controlled trials (RCTs) to evaluate the IL-23 p19 inhibitors within adult patients with UC or CD. Additionally, the clinical outcomes, endoscopic findings, histological assessments, and safety profiles were aggregated and subjected to analysis by a random-effects model.

Results

Twenty-five RCTs [15 CD, 10 UC] were involved in this study, and it was revealed that IL-23 p19 inhibitors showed significant effects on clinical remission (CR) in IBD, regardless of induction or maintenance treatment (CD, induction: risk ratio [RR] 1.95, 95% confidence interval [CI] 1.71-2.23; I2 = 0%, p = 0.68; UC, induction: RR 2.69, 95% CI 1.80-4.03; I2 = 50%, p = 0.09; CD, maintenance: RR 1.24, 95% CI 1.04-1.48; I2 = 0%, p = 0.57; UC, maintenance: RR 2.62, 95% CI 0.92-7.49; I2 = 42%, p = 0.19), and the risk of adverse events (AEs) was similar to that of placebo (CD, induction: RR 0.88, 95% CI 0.82-0.94; I2 = 2%, p = 0.41; UC, induction: RR 0.92, 95% CI 0.82-1.03; I2 = 0%, p = 0.54; CD, maintenance: RR 1.00, 95% CI 0.89-1.13; I2 = 29%, p = 0.25; UC, maintenance: RR 0.96, 95% CI 0.87-1.06; I2 = 0%, p = 0.44).

Conclusion

In IBD treatment, IL-23 p19 inhibitor therapy exhibited effective functions in the inducement and maintenance of clinical and endoscopic remissions, as well as in some histological cases.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/view/CRD42024569807, identifier CRD42024569807.

Novel outcomes in inflammatory bowel disease

Inflammatory bowel diseases (IBD), Crohn's disease (CD), and ulcerative colitis (UC) are lifelong chronic, relapsing, and remitting conditions that culminate in disease progression in many patients. Effective management of CD and UC requires consideration of both short- and long-term treatment outcomes. Historically, short-term outcomes such as clinical and endoscopic remission and symptom relief have been evaluated in clinical trials. With the expansion of treatments targeting underlying disease pathophysiology, there is the opportunity to develop management strategies that improve disease control and patients' lives in both the short and the long term. Researchers have been examining novel outcomes for assessing the efficacy of CD and UC treatments that are important to patients, and also those that go beyond symptomatic improvements or clinical remission. These include new patient-reported outcomes for symptoms, as well as transmural/histological healing and disease clearance that can be more reflective of deeper remission states and disease modification. This review analyses published clinical studies involving patients with UC and CD treated with biologics or small molecule therapies. It highlights novel IBD endpoints employed in published clinical trials and discusses their likely value for assessing disease activity and disease modification, and as predictors of reduced risk of complications and morbidities.

Translational characterization of immune pathways in inflammatory bowel disease: insights for targeted treatments

INTRODUCTION

The pathogenesis of inflammatory bowel disease (IBD) involves the dysregulation of multiple inflammatory pathways. The understanding of these mechanisms allows their selective targeting for therapeutic purposes. The discovery of Tumor Necrosis Factor-alpha's (TNF-α) role in mucosal inflammation ushered an exciting new era of drug development which now comprises agents targeting multiple pro-inflammatory signaling pathways, integrins, and leukocyte trafficking regulators.

AREA COVERED

This review provides an overview of the main molecular players of IBD, their translation into therapeutic targets and the successful development of the advanced agents modulating them. We combine basic science with clinical trials data to present a critical review of both the successful and failed drug development programs. A PubMed literature search was conducted to delve into the available literature and clinical trials.

EXPERT OPINION

The treatment landscape for IBD has rapidly expanded, particularly with the development of biologics targeting TNF-α, integrins, and S1P modulators, as well as newer agents such as IL-12/IL-23 inhibitors and JAK inhibitors, offering robust efficacy and safety profiles. However, challenges persist in understanding and effectively treating difficult-to-treat IBD, highlighting the need for continued research to uncover novel therapeutic targets and optimize patient outcomes.

Histologic and Endoscopic Findings Are Highly Correlated in a Prospective Cohort of Patients With Inflammatory Bowel Diseases

BACKGROUND AND AIMS

The advantages of endoscopic vs histologic assessments of inflammation in inflammatory bowel disease remain unclear. We compared endoscopic and histologic inflammation in a prospective cohort. Furthermore, in patients with discordant findings, we compared the ability of endoscopy vs histology to predict disease course.

METHODS

Ulcerative colitis (UC) or Crohn's disease (CD) patients underwent routine colonoscopies with intestinal biopsies, which included ratings of inflammation severity. Tetrachoric correlation analysis between the endoscopic and histologic inflammation ratings was performed. In postsurgical CD patients, major adverse outcomes (MAOs) were recorded.

RESULTS

The analysis included 749 patients (60.2% CD patients), with 2807 biopsied segments. We found high concordance between endoscopist and pathologist inflammation ratings (0.84, 95% confidence interval, 0.81-0.87, p < 0.0001). Only 12.5% of biopsied segments exhibited microscopic inflammation without endoscopic inflammation. Neo-terminal ileum (neo-TI) biopsies exhibited the highest discordance; UC colonic biopsies had the highest concordance. Postsurgical CD patients who completed the 48-month follow-up (n = 138) were included in the survival analysis. The probability of MAO-free survival was significantly higher in patients with a Rutgeerts score of i0 at baseline than in those with higher scores. Microscopic inflammation in the neo-TI did not predict a higher risk of MAOs (p = 1.00).

CONCLUSIONS

In a real-world setting, endoscopic inflammation predicted histologic inflammation with high accuracy. In patients with a Rutgeerts score of i0, microscopic inflammation in neo-TI biopsies did not predict more aggressive disease behavior over the next 4 years. These results have implications for the design of clinical trials, suggesting the use of endoscopic healing as an endpoint.

IL-23 inhibition for chronic inflammatory disease

Biological monoclonal antibody drugs inhibit overactive cytokine signalling that drives chronic inflammatory disease in different organ systems. In the last 10 years, interleukin (IL)-23 inhibitors have attained an important position in the treatment of psoriatic skin and joint disease as well as inflammatory bowel diseases. Addressing an upstream pathological mechanism shared between these disorders, this drug class has high efficacy rates and a durable response that extends dosing intervals up to 3 months. Pooled clinical trial data show objective disease improvement for more than 70% of patients with psoriasis and up to 50% of patients with inflammatory bowel disease. The first antibody inhibitor for IL-23A targeted a p40 subunit shared with IL-12. Subsequently, even greater improvement was established for inhibitors of the p19 protein unique to IL-23A. IL-23 p19 inhibitors elicit clinical response in both bio-naive and bio-exposed patients and show superiority to tumour necrosis factor α inhibitors in plaque psoriasis. Reported differences in efficacy between p19 inhibitors suggest that individual drug action might be modulated by antibody affinity. Although long-term safety data are accumulating, rates of serious adverse events and infections for interleukin (IL)-23 inhibitors are similar to the rates for placebo across approved indications.

Predictive Model for Outcomes in Inflammatory Bowel Disease Patients Receiving Maintenance Infliximab Therapy

Background

No models predict future outcomes in inflammatory bowel disease (IBD) patients receiving maintenance infliximab therapy. We created a predictive model for unfavorable outcomes.

Methods

Adult patients with IBD receiving maintenance infliximab therapy at 2 centers with matched serum infliximab concentrations and blinded histologic scores (Robarts Histopathologic Index [RHI]) were included. The primary endpoint was an unfavorable outcome of active objective inflammation or need for IBD-related surgery or hospitalization at 6-18 months follow-up. Internal variables were identified using univariable analyses, modeling used multivariable analysis, and performance was assessed (area under receiver-operating curve [AUC]) and externally validated.

Results

In 81 patients, 40.7% developed unfavorable outcomes at follow-up. Infliximab concentration <9.3 µg/mL (odds ratio [OR] 5.3, P = .001) and RHI > 12 (OR 3.4, P = .03) were the only factors associated with developing the primary unfavorable outcome. A prediction score assigning 1 point to each variable had good discrimination and performed similarly on internal (AUC 0.71) and external (AUC 0.73) cohorts. The risk of primary unfavorable outcomes in internal and external cohorts, respectively, was 23% and 15% for a score of 0, 46% and 50% for a score of 1, and 100% and 75% for a score of 2. Infliximab concentration alone performed similar to the 2-predictor model in internal (AUC 0.65, P = .5 vs. 2-predictor model) and external (AUC 0.70, P = .9, vs. 2-predictor model) cohorts.

Conclusions

Using unbiased variable selection, a 2-predictor model using infliximab concentrations and histology identified IBD patients on maintenance infliximab therapy at high risk of future unfavorable outcomes. For practical applicability, infliximab concentrations alone performed similarly well.