Introduction

Up to 40% of patients with acute severe ulcerative colitis (ASUC) do not respond to infliximab (IFX)(1) presumably due to insufficient drug exposure (1, 2). We investigated whether personalised IFX induction using predefined serum concentrations was superior to standard dosing.

Aims & Methods

In this prospective, multi-centre trial, adult IFX-naive steroid-refractory ASUC patients were randomised 1:1 to standard (SD) or personalised IFX dosing (PD). After an initial 5 mg/kg IFX infusion, SD was 5 mg/kg IFX at week 2 and 6. In PD, additional 5 mg/kg IFX infusions were administered guided by a Bayesian pharmacokinetic algorithm (iDose™) aiming at IFX serum concentrations >28 ug/mL day 0-28 and >15 ug/mL day 29-42 (3). The primary composite endpoint was clinical and endoscopic response at day 42 (Lichtiger score <10 and ≥3 points drop and UCEIS ≥2 points drop from baseline). Video-endoscopies were performed at baseline, day 42 and 182 and scored by 2 expert readers (XR) with adjudication by a third XR and post hoc also by the DovaVision UC AI tool (AI-R)(4). Key secondary endpoints were day 42 clinical response, day 42 endoscopic response, day 182 clinical remission (Lichtiger ≤3), day 182 endoscopic remission (UCEIS ≤1 on all components), and safety.

Results

48 patients were randomised (23 PD/25 SD) and 31 completed the 26-week study (19 PD/12 SD). Patient characteristics were comparable. Median cumulative IFX dose until day 42 was 18.41 mg/kg [1.77, 20.27] for PD vs 13.79 mg/kg [10.38, 14.82] for SD. The primary composite endpoint at day 42 was not met with XR (57% in PD vs 44% in SD; p=0.564). However, AI-R showed a significantly higher composite response rate in PD (74% in PD vs 32% in SD; p=0.0047). PD showed higher day 42 clinical response vs SD (91% vs 64%; p=0.039). Day 42 endoscopic response was observed in 57% in PD vs 44% in SD (p=0.564) with XR and 74% in PD vs 32% in SD with AI-R (p=0.0047). The proportion of patients in clinical and endoscopic remission at day 182 was higher in PD than in SD (65% vs 36%; p=0.082). Day 182 endoscopic remission with AI-R was higher in PD (52% in PD and 20% in SD; p=0.0337). SAEs occurred in 9% of patients on PD vs 20% of patients on SD. Following an interim analysis, the trial was discontinued based on futility.

Table 1. Baseline characteristics

Conclusion

Personalised IFX dosing was superior to standard dosing in ASUC when endoscopies were read by AI. This is the first IBD study where the primary endpoint, missed by expert assessment, was overturned and met by AI assessment instead. This demonstrates the potential of AI to fundamentally improve clinical trial methodology.

References

1. Seow CH, Newman A, Irwin SP, Steinhart AH, Silverberg MS, Greenberg GR. Trough serum infliximab: a predictive factor of clinical outcome for infliximab treatment in acute ulcerative colitis. Gut. 2010;59(1):49-54.
2. Papamichael K, Van Stappen T, Vande Casteele N, Gils A, Billiet T, Tops S, et al. Infliximab Concentration Thresholds During Induction Therapy Are Associated With Short-term Mucosal Healing in Patients With Ulcerative Colitis. Clin Gastroenterol Hepatol. 2016;14(4):543-9.
3. Ungar B, Mazor Y, Weisshof R, Yanai H, Ron Y, Goren I, et al. Induction infliximab levels among patients with acute severe ulcerative colitis compared with patients with moderately severe ulcerative colitis. Aliment Pharmacol Ther. 2016;43(12):1293-9.
4. Byrne M, Requa J, Panaccione R, Panes J, Bressler B, East JE, et al. Development and Validation of a novel AI-based computer vision solution for Ulcerative Colitis severity scoring on video for real world using high-volume expert-annotated video frames. United European Gastroenterol J. 2025 Oct.

Disclosure

This project received grant support from Pfizer Inc. and research support from Baysient LLC, Buhlmann Laboratories and Dova Health Intelligence.

Introduction

Although endoscopic balloon dilation (EBD) remains the standard intervention for Crohn’s disease (CD)-associated strictures, its efficacy is limited by high recurrence and surgery rates. Retrospective analyses suggest endoscopic stricturotomy (ES) may offer superior outcomes, particularly in anastomotic strictures. However, no randomized trials have directly compared EBD and ES for short CD-related strictures.

Aims & Methods

This single-center, randomized controlled trial (August 2022–March 2025) enrolled adult CD patients (18–65 years) with symptomatic, predominantly fibrotic or mixed, short strictures (<3 cm), including both de novo and anastomotic types, accessible via standard endoscopy. Patients with multiple (>2) strictures, strictures beyond endoscopic reach, or prior stricturotomy were excluded. Participants were randomized to undergo either EBD or ES. The primary outcome was clinical recurrence at 1 year. Secondary outcomes included re-intervention, surgery, emergency visits, hospitalization, technical success, and adverse events.

Results

Out of 70 randomized patients, 69 were analyzed (EBD: 35; ES: 34). Baseline characteristics were comparable between groups. Technical success was similar (EBD: 91.4%, ES: 94.1%). On time to event analysis, clinical recurrence was significantly lower in the ES group (OR=0.343, 95% CI: 0.134–0.881; p=0.026). Re-intervention rates favored ES (EBD: 25.7%, ES: 8.8%; OR=0.337, 95% CI: 0.131–0.870; p=0.025). Surgery rates were numerically lower with ES (EBD: 11.4%, ES: 5.9%) but not statistically significant (p=0.581). Hospitalization was significantly more frequent in the EBD arm (OR=0.276, 95% CI: 0.091–0.840; p=0.023). ED visits also trended lower with ES, though not statistically significant (p=0.062) (see table). Adverse events occurred in 25.7% of EBD patients (bleeding n=3 [1 hemoclip], pain with admission n=3, micro-perforation n=1, post-procedure pain n=2) and 14.7% of ES patients (bleeding n=3 [1 self-limited, 1 coagrasper, 1 hemoclip], none required transfusion, suspected perforation n=1, mild pain n=1).

Conclusion

In this interim analysis, ES was associated with significantly lower clinical recurrence, re-intervention, and hospitalization compared to EBD for short CD-related strictures, with similar safety outcomes. These findings support ES as a potentially superior first-line endoscopic strategy over EBD in selected patients with Crohn’s disease strictures. (NCT05521867)

References

Lan N, Shen B. Endoscopic Stricturotomy Versus Balloon Dilation in the Treatment of Anastomotic Strictures in Crohn's Disease. Inflamm Bowel Dis. 2018 Mar 19;24(4):897-907. doi: 10.1093/ibd/izx085. PMID: 29546384.