Higher infliximab and adalimumab trough levels are associated with fistula healing in patients with fistulising perianal Crohn’s disease

Perianal disease in inflammatory bowel disease: Broadening treatment and surveillance strategies for anal cancer

The perianal disease affects up to one-third of individuals with Crohn's disease (CD), causing disabling symptoms and significant impairment in quality of life, particularly for those with perianal fistulising CD (PFCD). The collaborative effort between gastroenterologists and surgeons is essential for addressing PFCD to achieve fistula closure and promote luminal healing. Limited fistula healing rates with conventional therapies have prompted the emergence of new biological agents, endoscopic procedures and surgical techniques that show promising results. Among these, mesenchymal stem cells injection is a particularly hopeful therapy. In addition to the burden of fistulas, individuals with perianal CD may face an increased risk of developing anal cancer. This underscores the importance of surveillance programmes and timely interventions to prevent late diagnoses and poor outcomes. Currently, there is no established formal anal screening programme. In this review, we provide an overview of the current state of the art in managing PFCD, including novel medical, endoscopic and surgical approaches. The discussion also focuses on the relevance of establishing an anal cancer screening programme in CD, intending to propose a risk-based surveillance algorithm. The validation of this surveillance programme would be a significant step forward in improving patient care and outcomes.

Infliximab serum concentrations and disease activity in perianal fistulizing Crohn's disease: a cross-sectional study

INTRODUCTION

Several studies associate the presence of higher serum concentrations of infliximab (IFX) with fistula healing in perianal Crohn's disease (CD). This study aimed to evaluate serum IFX concentrations in patients with perianal fistulizing CD (PFCD) in the presence or absence of general, clinical, and radiological activities.

METHODS

This was a cross-sectional study in patients with PFCD during maintenance treatment with IFX from two centers. Serum IFX concentrations were measured before their next infusion and anal fistulas were evaluated by clinical examination and magnetic resonance imaging (MRI), whenever possible, performed 90 days before or after serum collection. According to clinical scores, radiological activity, and disease markers, patients were classified as in remission or active disease. Mean serum IFX concentrations were compared between the groups.

RESULTS

Thirty-eight patients with PFCD were included. Demographic characteristics were similar in patients with remission or active disease. The overall mean serum IFX concentration of the entire sample (n = 38) was 5.21 ± 4.75 μg/mL (median 3.63; IQR 1.44-8.82). Serum IFX levels were 6.25 ± 5.34 μg/mL (median 3.62; IQR 1.95-11.03) in the 23 (60.5%) patients in remission and 3.63 ± 3.24 μg/mL (median 3.63; IQR 1.32-6.43; p = 0.226) in the 15 (39 .5%) who presented active disease. When evaluating general, clinical, and radiological activity of PFCD, and deep remission in isolation, no statistical difference between the groups was observed (p = 0.226, p = 0.418, p = 0.126, and p = 0.232, respectively). The 13 (34.2%) patients with an optimized dose of IFX had significantly higher serum concentrations than the remaining 25 (65.8%) with a standard dose: 8.33 ± 4.41 μg/mL (median 8.36; IQR 3.82-11.20) vs. 3.59 ± 4.13 μg/mL (median 1.97; IQR 1.18-3.85) -p = 0.002. Patients in remission and with an optimized IFX dose had significantly higher serum IFX concentrations than those with a standard dose (p = 0.006), whereas no significant difference was observed among those with active disease (p = 0.083).

CONCLUSION

There were no differences in IFX serum concentrations in patients with clinical or radiological active PFCD as compared with those in remission. Patients with an optimized IFX dose had significantly higher serum concentrations than those with a standard dose. Patients in remission and with an optimized IFX dose had significantly higher serum concentrations than those with a standard dose.

Higher Adalimumab Concentration is Associated with Complete Fistula Healing in Patients with Perianal Fistulizing Crohn's Disease

Perianal fistulas can develop in around 30% of patients with Crohn's disease (CD) and are associated with impaired quality of life and worse outcomes including increased rates of hospitalizations and surgeries.1 The cornerstone of pharmacologic treatment for perianal fistulizing CD is anti-tumor necrosis factor therapy, mainly infliximab and adalimumab (ADM).2 Therapeutic drug monitoring (TDM) can be used to identify potential pharmacokinetic and pharmacodynamic issues and avoid or manage unwanted outcomes, such as primary nonresponse and secondary loss of response.3 There are several exposure-response relationship data demonstrating a positive correlation between serum infliximab concentrations and favorable objective therapeutic outcomes in patients with perianal fistulizing CD.4 Nevertheless, there are only limited data, which is mostly from small retrospective studies regarding the association of ADM concentration and outcomes in patients with perianal fistulizing CD.4-8 Furthermore, the optimal ADM concentration for fistula healing still remains to be elucidated. This is clinically important because drug concentration cutoffs are used in reactive and proactive TDM algorithms to define therapeutic drug concentrations. This study investigates the association of maintenance ADM concentrations with complete fistula healing (CFH) and identifies an optimal ADM concentration threshold for CFH.

The use of core descriptors from the ENiGMA code study in recent literature: a systematic review

AIM

The heterogeneity in data quality presented in studies regarding Crohn's anal fistula (CAF) limit extrapolation into clinical practice. The ENiGMA collaborators established a core descriptor set to standardize reporting of CAF. The aim of this work was to quantify the use of these descriptors in recent literature.

METHOD

We completed a systematic review of PubMed and the Cochrane Library, extracting publications from the past 10 years specific to the clinical interventions and outcomes of CAF, and reported in line with PRISMA guidance. Each article was assessed for inclusion of ENiGMA descriptors. The median number of descriptors per publication was evaluated along with the overall frequency of each individual descriptor. Use of ENiGMA descriptors was compared between medical and procedural publications.

RESULTS

Ninety publications were included. The median number of descriptors was 15 of 37; 16 descriptors were used in over half of the publications while 17 were used in fewer than a third. Descriptors were more frequently used in procedural (n = 16) than medical publications (n = 14) (p = 0.031). In procedural publications, eight descriptors were more frequently used including Faecal incontinence, Number of previous fistula interventions, Presence and severity of anorectal stenosis and Current proctitis. Medical publications were more likely to include Previous response to biological therapy and Duration and type of current course of biological therapy.

CONCLUSION

With many descriptors being used infrequently and variations between medical and procedural literature, the colorectal community should assess the need for all 37 descriptors.

Superior Efficacy of Infliximab Versus Adalimumab for First-Line Treatment of Crohn's Perianal Fistulae

BACKGROUND

Crohn's disease perianal fistulae (CD-PAF) occur in 25% of patients and are notoriously challenging to manage. Tumor necrosis factor inhibitors are first line agents.

AIMS

The aim of this study was to compare infliximab (IFX) versus adalimumab (ADA) efficacy in CD-PAF healing over time.

METHODS

A retrospective study at two large-tertiary medical centers was performed. Inclusion criteria were actively draining CD-PAF and initial treatment with IFX or ADA following CD-PAF diagnosis. The primary endpoints were perianal fistula response and remission at 6 and 12 months. Secondary endpoints included biologic persistence over time and dose escalation at 6 and 12 months.

RESULTS

Among 151 patients included in the study, 92 received IFX and 59 received ADA as first line agents after CD-PAF diagnosis. At 6 months, the 64.9% of the IFX group and 34.8% of the ADA group demonstrated CD-PAF clinical improvement (p < 0.01). Univariate and multivariate analyses demonstrated significant differences among the IFX and ADA groups for clinical response at 6-months and 12-months (p = 0.002 and p = 0.042, respectively). There were no factors that predicted response, with the exception of concomitant immunomodulator affecting the 6-month clinical response (p = 0.021). Biologic persistence, characterized by Kaplan Meier methods, was significantly longer in the IFX group compared to the ADA group (Log-rank p = 0.01).

CONCLUSION

IFX induction and maintenance is associated with higher rates of response and remission in CD-PAF healing as well as higher treatment persistence compared to ADA. Additionally, our study supports the use of concomitant immunomodulator therapy for CD-PAF healing and remission.

Management of Perianal Crohn's Disease

Perianal Crohn's disease affects 25%-35% of patients with Crohn's disease and has proven to be one of the most difficult complications of the disease to treat. Patients with perianal Crohn's disease have lower health-related quality of life scores typically related to pain and fecal incontinence. In addition, patients with perianal Crohn's disease have higher rates of hospitalizations, surgeries, and overall healthcare costs. A multidisciplinary approach is necessary for the successful management of Crohn's disease with perianal fistula. Medical management is required to treat the underlying immune dysregulation to heal the luminal inflammation and the inflammation within the fistula tracts. Current options for medical therapy include biologics, dual therapy with thiopurines, therapeutic drug monitoring, and a close follow-up. Surgical management is critical to drain abscesses before immunosuppressive therapy and place setons when appropriate. Once the patient's inflammatory burden is well managed, definitive surgical therapies including fistulotomies, advancement flaps, and ligation of intersphincteric fistula tract procedures can be considered. Most recently, the use of stem cell therapy in the treatment of perianal fistula has given new hope to the cure of perianal fistula in Crohn's disease. This review will outline the most current data in the medical and surgical management of perianal Crohn's disease.

Short-term anti-TNF therapy with surgical closure versus anti-TNF therapy alone for Crohn's perianal fistulas (PISA-II): long-term outcomes of an international, multicentre patient preference, randomised controlled trial

Background

The PISA-II trial showed that short-term anti-tumour necrosis factor (anti-TNF) therapy followed by surgical closure induces radiological healing of perianal fistulas in patients with Crohn's disease more frequently than anti-TNF therapy alone after 18 months. This study aimed to compare long-term outcomes of both treatment arms.

Methods

Follow-up data were collected from patients who participated in the PISA-II trial, an international patient preference randomised controlled trial. This multicentre trial was performed in nine hospitals in the Netherlands and one hospital in Italy. Patients with Crohn's disease above the age of 18 years with an active high perianal fistula and a single internal opening were asked to participate. Patients were allocated to anti-TNF therapy (intravenous infliximab, or subcutaneous adalimumab, at the discretion of the gastroenterologist) for one year, or surgical closure combined with 4-months anti-TNF therapy. Patients without a treatment preference were randomised (1:1) using random block randomisation (block sizes of six without stratification), and patients with a treatment preference were treated according to their preferred treatment arm. For the current follow-up study, data were collected until May 2022. Primary outcome was radiological healing on magnetic resonance imaging (MRI), including all participants with a MRI made less than 6 months ago at the time of data collection. Analysis was based on observed data.

Findings

Between September 14, 2013, and December 7, 2019, 94 patients were enrolled in the trial. Long-term follow-up data were available in 91 patients (36/38 (95%) anti-TNF + surgical closure, 55/56 (98%) anti-TNF). A total of 14/36 (39%) patients in the surgical closure arm were randomly assigned, which was not significantly different in the anti-TNF treatment arm (16/55 (29%) randomly assigned). Median follow-up was 5.7 years (interquartile range (IQR) 5-7). Radiological healing occurred significantly more often after anti-TNF + surgical closure (15/36 = 42% versus 10/55 = 18%; P = 0.014). Clinical closure was comparable (26/36 = 72% versus 34/55 = 62%; P = 0.18) in both groups. However, clinical closure in the surgical group was achieved with less re-interventions 4/26 (= 15%) versus 18/34 (= 53%), including (redo-)surgical closure procedures. Recurrences occurred in 0/25 (0%) patients with radiological healing versus 27/76 (36%) patients with clinical closure, sometime during follow-up. Anti-TNF trough levels were higher in patients with long-term clinical closure in both groups (P = 0.031 and P = 0.014). In 6/11 (55%) patients in the anti-TNF group with available trough levels, recurrences were diagnosed within three months of a drop under 3.5ug/ml. 36 patients stopped anti-TNF, after which 0/14 (0%) patients with radiological healing developed a recurrence and 9/22 (41%) with clinical closure. Self-rated (in)continence was comparable between groups, and 79% (60/76) of patients indicated comparable/improved continence after treatment. Decision-regret analysis showed that all (30/30) anti-TNF + surgical closure patients agreed or strongly agreed that surgery was the right decision versus 78% (36/46) in the anti-TNF arm. All surgical closure patients would go for the same treatment again, whereas this was 89% (41/46) in the anti-TNF arm.

Interpretation

This study confirmed that surgical closure should be considered in amenable patients with perianal fistulas and Crohn's disease as long-term outcomes were favourable, and that radiological healing should be the aim of treatment as recurrences only occurred in patients without radiological healing. In patients with complete MRI closure, anti-TNF could be safely stopped.

Funding

None.

Real-world experience with subcutaneous infliximab: broadening treatment strategies for inflammatory bowel disease

INTRODUCTION

The first subcutaneous (SC) formulation of infliximab (IFX), CT‑P13 SC, has been approved in Europe and Australia, including for the treatment of inflammatory bowel disease (IBD).

AREAS COVERED

We provide a comprehensive overview of available clinical trial and real-world data for IFX SC treatment of IBD, focusing on the potential benefits of switching from IFX intravenous (IV) to IFX SC. We evaluate emerging evidence for IFX SC treatment for difficult-to-treat IBD, use as monotherapy, and suitability for patients receiving escalated IFX IV doses. Therapeutic drug monitoring approaches and patient and healthcare system perspectives on IFX SC are also discussed.

EXPERT OPINION

IFX SC represents a significant treatment innovation in the tumor necrosis factor inhibitor class after approximately 20 years of IFX IV availability. Evidence suggests that IFX SC is well tolerated and is associated with high patient acceptance and satisfaction. In addition, effectiveness is maintained in patients with stable disease following switch from IFX IV. Switching may be advisable, given the clinical benefits of IFX SC and its potential to improve healthcare service capacity. There are several areas requiring further research, including the role of IFX SC in difficult-to-treat and refractory disease, and the feasibility of IFX SC monotherapy.

Ustekinumab Promotes Radiological Fistula Healing in Perianal Fistulizing Crohn's Disease: A Retrospective Real-World Analysis

There is insufficient evidence to confirm the efficacy of ustekinumab (UST) in promoting fistula closure in perianal fistulizing Crohn's disease (CD) patients. We aimed to evaluate the efficacy of UST in a real-world setting. The data were retrospectively analyzed. Intestinal clinical and endoscopic changes were evaluated. Fistula radiological outcomes were determined using the Van Assche score. A total of 108 patients were included, 43.5% of whom had complex perianal fistulas. Intestinal clinical and endoscopic remission was achieved in 65.7% and 31.5% of patients, respectively. The fistula clinical remission and response rates were 40.7% and 63.0%, respectively, with a significant reduction in Perianal Crohn's disease Activity Index [5.0(3.0, 8.0) vs. 7.5(5.0, 10.0), p < 0.001] and Crohn's Anal Fistula Quality of Life [23.5(9.3, 38.8) vs. 49.0(32.3, 60.0), p < 0.001]. Radiological healing, partial response, no change, and deterioration were observed in 44.8%, 31.4%, 13.4%, and 10.4% of patients, respectively. The cut-off UST trough concentration for predicting fistula clinical remission was 2.11 μg/mL with an area under the curve of 0.795, a sensitivity of 93.3%, and a specificity of 67.6%. UST is efficacious in promoting radiological fistula closure in patients with perianal fistulizing CD. A UST trough concentration over 2.11 μg/mL was correlated with a higher likelihood of perianal fistula clinical remission.

Association of neutrophil extracellular traps with fistula healing in patients with complex perianal fistulising Crohn's disease

BACKGROUND AND AIMS

Perianal fistulising Crohn's disease (pfCD) is a disabling phenotype of Crohn's disease (CD) with suboptimal outcomes. We assessed neutrophil extracellular traps (NETs) in perianal fistulas and implicated their roles in pfCD healing.

METHODS

Patients with complex pfCD who developed preplaced seton drainage were recruited during the verified maintenance of remission in CD. Fistula tracts were sampled during definitive surgery plus seton removal. Patient demographics, CD classification, medication strategy, and healing of pfCD were recorded. RNA sequencing was applied for transcriptomic profile analysis. NETs components, including myeloperoxidase (MPO), neutrophil elastase (NE), and citrullinated histone H3 (CitH3), were identified using immunofluorescence. Serum infliximab (IFX), anti-IFX antibodies, and tissue levels of IFX, adalimumab (ADA), MPO and CitH3 were determined using enzyme-linked immunosorbent assays. Peptidyl arginine deiminase IV (PAD4), tumour necrosis factor (TNF)-α, and NE were detected using immunohistochemistry. Gene expression levels of PAD family members were assessed with qPCR.

RESULTS

Twenty-one patients were included, 15 of whom adopted IFX as maintenance treatment. RNA-seq revealed difference in neutrophil associated pathways between unhealed and healed fistulas. NETs components (MPO/NE/CitH3) were detectable in the fistulas and were parallel with the PAD4 levels. Eleven of 21 (52%) patients experienced complete healing of the pfCD 108 weeks post-operatively. Fistula NETs were significantly increased in patients with unhealed pfCD. Increased NETs were associated with abundant TNF-α production and the absence of IFX in fistulas.

CONCLUSIONS

NETs exist in pfCD fistulas, which are associated with unhealed post-operative fistulas in pfCD, suggesting their prognostic roles in pfCD.