Assessment of endoscopic response using pan-enteric capsule endoscopy in Crohn’s disease; the Sensitivity to Change (STOC) study

Background: The potential use of pan-enteric capsule endoscopy (pan-CE) to evaluate mucosal changes during treatment has not been evaluated. We aimed to assess the ability of pan-CE to measure changes in mucosal disease activity before and after starting biologic treatment in Crohn’s disease patients. Methods: In this two-center prospective study, patients with clinical and biochemical signs of active Crohn’s disease underwent pan-CE before and 8 to 12 weeks after treatment initiation with infliximab, adalimumab or vedolizumab. Endoscopic disease activity was assessed using the simple endoscopic score for Crohn’s disease (SES-CD) and the Crohn’s disease endoscopic index of severity (CDEIS), expanded with two segments (i.e., the jejunum and pre-terminal ileum). Occurrence of endoscopic remission (i.e., absence of ulcers) and endoscopic response (i.e., 50% decrease in SES-CD and CDEIS scores compared to baseline) was assessed and the standardized effect size was calculated. Results: Twenty-two patients (50% females) completed the study. Endoscopic remission was observed in 6 out of 22 (27%) patients and 13/22 patients (59%) showed an endoscopic response for both the SES-CD and CDEIS score. Median SES-CD and CDEIS scores decreased from 16.0 (IQR 10.0 − 24.0) to 6.0 (IQR 2.8 − 12.0, p =.001) and from 7.1 (IQR 4.6 − 11.2) to 3.0 (IQR 0.9 − 6.0, p =.001), respectively. The standardized effect size was 1.44 and 1.24 for the SES-CD and CDEIS, respectively. No adverse events related to pan-CE were reported. Conclusion: Pan-CE was a useful technique to assess changes in mucosal disease activity in Crohn’s disease patients.