In the REPREVIO study, a double-blind, randomized, placebo-controlled trial, 80 adults received either vedolizumab (300 mg IV) (n=43) or placebo (n=37) at weeks 0, 8, 16 and 24 following ileocolonic resection and had one or more risk factors for recurrence.
Key findings:
At week 26, the probability of a lower modified Rutgeerts score with vedolizumab versus placebo was 77·8% (95% CI 66·4 to 86·3; p<0·0001).
Severe endoscopic recurrence was observed in ten (23·3%) of 43 patients in the vedolizumab group versus 23 (62·2%) of 37 patients in the placebo group (difference –38·9% [95% CI –56·0 to –17·3]; p=0·0004).
Adverse effects were noted in three patients who received vedolizumab (bilateral tubo-ovarian abscesses, thrombosed hemorrhoids, and pancreatic adenocarcinoma) and two patients who received placebo (intestinal perforation related to Crohn’s disease and severe abdominal pain)
My take: This study shows that vedolizumab is another biologic capable of reducing postoperative recurrence following ileocolonic resection in Crohn’s disease. Infliximab has been shown to reduce recurrence as well (shown in the PREVENT study).
MT Fioretti et al. J Pediatr Gastroenterol Nutr. 2025;80:300–307. A decade of real-world clinical experience with 8-week azithromycin–metronidazole combined therapy in pediatric Crohn’s disease
Methods: This retrospective study over 10 years examined the efficacy of azithromycin-metronidazole for induction treatment in 44 children. All patients were given metronidazole (15–20 mg/kg/day two times daily, maximum of 1000 mg/day) administered daily for 8 weeks and azithromycin (7.5 mg/kg to a maximum of 500 mg/once a day) administered 5 days per week for the first 4 weeks, followed by 3 days per week for the final 4 weeks as per the initial publications.17, 18
Key findings:
After 8 weeks, the overall remission rate was 64%.
Of the 38 patients who completed the CD AZCRO course, 28 patients (74%) entered remission (Group 1) and 10 (26%) did not (Group 2)
After 8 weeks, Group 1 showed improved CRP levels and higher albumin and hemoglobin levels than Group 2. Median FC declined significantly from 650 mcg/g at baseline to 190 mcg/g at Week 8 in Group 1 (p < 0.001).
The authors conclude that “a combination treatment of azithromycin and metronidazole represents an alternative induction therapy for mild to moderate pediatric CD, offering benefits in terms of cost and practicalities compared to EEN and in side effects compared to steroids.”
My take: There are a small number of children with mild Crohn’s disease who could benefit from this induction regimen. An alternative would be the use of a more modest dietary approach (eg. Mediterranean diet)
Disclaimer: This blog, gutsandgrowth, assumes no responsibility for any use or operation of any method, product, instruction, concept or idea contained in the material herein or for any injury or damage to persons or property (whether products liability, negligence or otherwise) resulting from such use or operation. These blog posts are for educational purposes only. Specific dosing of medications (along with potential adverse effects) should be confirmed by prescribing physician. Because of rapid advances in the medical sciences, the gutsandgrowth blog cautions that independent verification should be made of diagnosis and drug dosages. The reader is solely responsible for the conduct of any suggested test or procedure. This content is not a substitute for medical advice, diagnosis or treatment provided by a qualified healthcare provider. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a condition.
Twenty-eight studies involving 153,027 patients with IBD were included.
Key findings:
Antibiotic exposure was significantly associated with an increased risk of new-onset IBD for prescription-based studies (pooled OR, 1.41; 95% CI, 1.29–1.53) and for questionnaire-based studies (pooled OR, 1.35; 95% CI, 1.08–1.68). ‘
This association existed for both Crohn’s disease and ulcerative colitis, as well as in children and adults for prescription-based studies.
Some of the limitations:
There was statistical heterogeneity was high in the primary analysis, possibly because of inconsistencies in study design
Most studies included a clear lag time, yet an inadequate lag time still creates the possibility of reverse causality.
The authors could not disentangle the risk of antibiotics from the risk of infection in leading to the development of IBD.
Nonlinear dose-response relationship between antibiotic exposure and risk of new-onset IBD (solid black line and short dash black line represent estimated ORs and corresponding 95% CIs of nonlinear relationship)
My take: This is another study showing an association between antibiotic use and new-onset IBD. While this study does not prove causation, it is another reason for good antibiotic stewardship.
Methods: VIVID-1 was a global phase 3, randomized, double-blind, double-dummy, placebo-controlled and active-controlled, treat-through study which enrolled 1150 patients with moderate-to-severe Crohn’s disease. There were three treatment groups: mirikizumab group, ustekinumab group, and placebo group. In each group, 48-49%were considered “biologic-failures” including 45-46% who were anti-TNF failures.
Key findings:
Discussion points:
Early treatment effect: “Symptomatic improvement was evident as early as week 4 accompanied by a statistically significant reduction in high-sensitivity CRP and faecal calprotectin, and endoscopic response was seen at week 12.”
Compared to ustekinumab: “Mirikizumab reached non-inferiority versus ustekinumab for clinical remission by CDAI at week 52…mirikizumab showed statistically significantly greater improvements from baseline in fecal calprotectin and CRP compared to ustekinumab. In addition, a greater percentage of patients reached the combination endpoint of endoscopic response and clinical remission by CDAI at week 52.”
Comparison across treatment trials: “. At week 52, 45∙4% of patients treated with mirikizumab met the endpoint of clinical remission by CDAI in the treat-through analysis with composite endpoint, 54∙1% met the endpoint in the treat-through analysis, and 64∙3% met the endpoint in the responder analysis. This example, with a range of nearly 20% percentage points depending on analysis type, shows the profound limitations in comparing unadjusted outcomes across phase 3 trials.” The authors note other differences in trial design between VIVID-1 and SEQUENCE (risankizimab) and state “no conclusions on relative efficacy can be drawn.”
My take: This study shows that mirikizumab is effective in adults with moderate-to-severe Crohn’s disease with and without prior biologic treatments. Pediatric studies are underway.
Background: The exposure–response relationship for the intravenous (IV) formulation of infliximab is well established, with multiple studies demonstrating that higher trough concentrations (C-trough) are associated with improved patient outcomes…However, the 2-week cycle of subcutaneous administration showed many-fold higher C-trough than the 8-week cycle of IV-IFX. Direct comparison of C-trough between SC- and IV-IFX is not appropriate because of different bioavailability and concentration–time profile. It is also not appropriate to apply the C-trough thresholds that predict achieving the therapeutic targets for IV.
This was a cross-sectional retrospective study with 124 patients with Crohn’s disease (CD) who had received SC-IFX maintenance therapy for ≥6 months. SC-IFX C-trough was measured immediately before SC-IFX injection. Key findings:
Mucosal healing (MH) was noted in 77.9% (74/95) and transmural healing (TH) in 36.3% (37/102).
SC-IFX C-trough was significantly higher in patients with MH (24.1 vs.16.9 μg/mL; p=0.001) and TH (26.0 vs. 20.5 μg/mL; p=0.007) than in those without.
Discussion:
Target trough levels: In this study, the authors found that “the C-trough thresholds for clinical remission, biochemical remission, MH and TH were 12, 16, 18 and 30 μg/mL, respectively, based on ROC analysis. The C-trough of SC-IFX increased with the depth of remission.”
Why trough level targets may differ between IV administration and SC: Administration via the IV route results in early and rapid peak concentration followed by a steady decline to trough, whereas administration via the SC route has slower absorption, lower bioavailability, lower peak concentration and smaller differences between peak and trough concentrations.
The authors note that a study by Ye et al (United European Gastroenterology Journal; 2020: 8: 385–386) with 55 patients found that a C-trough >26.6 mcg/mL achieved clinical remission and fecal calprotectin levels <250 mcg/g at week 54 in 79% and 91% respectively compared to 46% and 62% in those with with C-trough <16.4 mcg/g.
These C-trough levels are significantly higher that the median C-trough levels of standard dosing (120 mg biweekly) in a phase 1 dosing RCT which was only 13.3 mcg/mL (S Schreiber et al. Gastroenterology 2018; 154: 1371). The dosing of 180 mg and 240 mg biweekly resulted in C-trough levels of 19.9 mcg/mL and 26.5 mcg/mL respectively.
My take: This study suggests that therapeutic drug monitoring will have different targets with SC-IFX than with IV-SC. SC formulations will offer more convenience. However, more effort will be needed to make sure patients are adherent with therapy in order to achieve optimal outcomes.
Disclaimer: This blog, gutsandgrowth, assumes no responsibility for any use or operation of any method, product, instruction, concept or idea contained in the material herein or for any injury or damage to persons or property (whether products liability, negligence or otherwise) resulting from such use or operation. These blog posts are for educational purposes only. Specific dosing of medications (along with potential adverse effects) should be confirmed by prescribing physician. Because of rapid advances in the medical sciences, the gutsandgrowth blog cautions that independent verification should be made of diagnosis and drug dosages. The reader is solely responsible for the conduct of any suggested test or procedure. This content is not a substitute for medical advice, diagnosis or treatment provided by a qualified healthcare provider. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a condition.
A Watson et al. JPGN 2024;79:1081–1083. Cat scratch colon in a patient with very early-onset Crohn’s disease with diverting ileostomy
Case report: This image is from the ascending colon of a 12 yo with Crohn’s disease sp diverting ileostomy.
“Cat scratch colon refers to the rare endoscopic finding of erythematous linear breaks that arise spontaneously, typically in the ascending colon and/or cecum, resembling scratches made by a cat, on otherwise unremarkable mucosa…It is presumed to be a benign condition likely caused by barotrauma from air insufflation during colonoscopy in a colon with altered elasticity or when the rate of insufflation exceeds the rate of air passage, such as in a diverted colon.2, 3“
My take: Surprisingly, the cat scratch colon finding is not consequential.
Using the ImproveCareNow prospective registry, the authors analyzed a total of 285,913 visits from 32,497 patients aged ≤ 21 years.
Key findings:
The occurrence of erythema nodousm (EN) was 1.57% and the occurrence of pyoderma gangrenosum (PG) was 0.90%. Co-occurrence of EN and PG was reported in 0.30% patients.
Both EN and PG were associated (p < 0.0001) with worse intestinal disease, lower remission, higher inflammatory markers, and extraintestinal manifestations (EIMs) arthritis and uveitis.
Limitations: “imperfect and incomplete data entry that may introduce bias. However, due to the extensive longitudinal data, we expect any bias to be minimal.”
My take: This study clarifies how common these dermatologic findings occur in pediatric patients with IBD. Prompt recognition of these disorders is important. Recently, our group cared for a 20 yo patient with inadequately-treated PG by multiple internal medicine physicians; this led to prolonged hospitalization.
Recently, Dr. Sana Syed gave Children’s Healthcare of Atlanta Grand Rounds. She provided an excellent update on the development of artificial intelligence (AI) to select targeted therapies for pediatric gastroenterology diseases. My notes below may contain errors in transcription and in omission. Along with my notes, I have included many of her slides.
Key points:
One of the goals of using AI is to identify the right therapy at the time of diagnosis. Currently, diseases like eosinophilic esophagitis (EoE) and Crohn’s disease have multiple treatment options. However, many patients do not respond to first-line treatments; many develop complications due to not responding to treatment.
Currently we are lacking adequate biomarkers for individualized therapy. AI has the potential to sort through massive amounts of data (histologic, genetic, pharmacokinetics, transcriptome, metabolomics, etc) to allow for precision therapy.
For EoE, machine-learning has already identified three subtypes that may affect clinical management. EoE1 is associated with a normal-appearing esophagus. EoE2 is associated with being steroid refractory. EoE3, when compared to the other two endotypes, is associated with adult-onset and narrow-caliber esophagus or stricturing.
For Crohn’s disease, research has shown that younger age has been associated with an increased risk of not responding to anti-TNF therapy
This is a quote from President Obama when his administration announced massive funding toward precision medicine in January of 2015, that the promise of precision medicine is ”delivering the right treatments at the right time, every time to the right person.” This figure illustrates some of the kinds of data that Dr. Syed had access to as faculty at UVA, including genomics, epigenome, transcriptomics, proteomics, metabolomics, etc.Shoda and colleagues, used a combination of histology data, endoscopic features, histologic and endoscopic scoring indices, and transcripts that make up the eosinophilic esophagitis diagnostic panel, a quantitative PCR assay with 96 EoE representative genes. The key message from all of those visualizations is that they found that EoE can be divided into three distinct endotypes after analyzing transcriptomics changes via partition-around-medoid clustering, a machine-learning method.In this project, the researcher intend to curate a novel metabolic network specific to the ileum, which is relevant to Crohn’s disease, link metabolic processes with Crohn’s disease phenotypes using in silico metabolic network modeling and ‘omics and characterize and target metabolic pathways in an organoid model generated from patient-derived Crohn’s disease tissue.In CoMPAS, the researchers aim to leverage artificial intelligence methods (AI) methods to build predictive models for CD using histology slides and single-cell RNA sequencing, allowing for risk stratification of B1 patients who will respond to anti-TNF therapyThe goal of our project is to create a multi-omics reference dataset with scRNA-seq data coupled with contextual data on tissue morphology, ancestry, social determinants of health, and the environment. The cohort for this study is enrolling patients who have clinical indications for endoscopy like foreign body removal, reflux, abdominal pain
My take: This work is necessary to identify the right treatments for each patient and will lead to better outcomes. We are already seeing the early stages of machine-learning’s impact on clinical care. In many other fields, AI work is much further along (especially in oncology). A recent study in Nature identified JAK inhibitors as potential life-saving therapy with toxic epidermal necrolysis (TEN).
Reference: Nordmann, T.M., Anderton, H., Hasegawa, A. et al. Spatial proteomics identifies JAKi as treatment for a lethal skin disease. Nature (2024). https://doi.org/10.1038/s41586-024-08061-0
Summary from Eric Topol (Ground Truths) focusing on spatial omics: Thierry Nordmann, Matthias Mann and their international consortium, used deep visual proteomics from 3μm PPFE sections of skin biopsies in patients affected by TEN…
More than 5,000 proteins were quantified from single cells—keratinocyte and immune cells—using mass spec, for the 4 different skin conditions (proteome cluster in Figure below, left panel). This led to the finding that the TEN patients had marked increased in Type 1 and 2 interferon signaling and activation of phosphorylated STAT1, which invoked the janus kinase (JAK/STAT) pathway. Subsequent steps were to test JAK inhibitors in cell culture (with live cell imaging) and in two different mouse models, all showing highly potent, dose-dependent impact on inhibition of the intense inflammatory process and disease severity…
They went on to treat seven patients at Fuian Medical University, the course of one patient shown below, treated with a JAKi on day 4 after diagnosis, and manifesting a marked response starting within 48 hours. All 7 patients fully resolved, with no side effects…
For spatial medicine, there are multiple analytical challenges that invoke the need for machine learning and A.I., including segmentation of cell types, automated capture of cells of microdissection, extracting useful information from the >5,000 proteins quantified per cell, and ultimately, as we’ll see more in the future, A.I. powering the construction of high-resolution 3D maps.
In this multicenter retrospective review with 183 patients, the adalimumab (ADM) levels were examined with respect to healing of perianal fistulas. Most patients (82%) had complex perianal fistulizing CD.
Key findings:
87 patients (48%) received intensified dosing at the time of therapeutic drug monitoring (TDM)
Patients with complete fistula healing (CFH) had higher median ADM levels: 12.9 compared to 6.1 for those witout CFH
“Optimal ADM concentration associated with CFH was 12.2 mcg/mL” which had positive predictive value of 64% and negative predictive value of 80%. Among those with ADM >12.1, CFH was achieved in 64% compared to 20.5% in those with concentrations <12.1 (Odds ratio, 5.7). “Even higher drug levels may be needed.”
There were 46 patients in each drug level category
My take: There is a lot of data supporting TDM, including proactive TDM, with anti-TNF agents like adalimumab and infliximab. This study shows that with fistulizing disease higher drug levels are needed to achieve better outcomes.
A Simard et al. J Pediatr Gastroenterol Nutr. 2024;79:800–806. Role of ileal diversion in pediatric inflammatory bowel disease
Indications:
Severe, medically refractory colitis
Complex and medically refractory perianal disease
In combination with bowel resection for irreversible bowel damage (e.g., fistulae, abscesses, or strictures)
Diversion “provides the opportunity to reduce steroid use, improve growth and observe the natural history of the disease in a more controlled manner. It may also enhance quality of life”
My take: This is a handy article when considering ileal diversion in a patient with medically-refractory inflammatory bowel disease.
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