How achievable are STRIDE-II treatment targets in real-world practice and do they predict long-term treatment outcomes?

Objective: The second iteration of the Selecting Therapeutic Targets in Inflammatory Bowel Disease (STRIDE-II) initiative recommends use of the Simple Endoscopic Score for Crohn's disease (SES-CD) as a treatment target for patients with CD. We aimed to assess whether the STRIDE-II endoscopic endpoints are achievable and whether the degree of mucosal healing (MH) affects long-term outcomes.

Design/method: We performed a retrospective observational study between 2015 and 2022. Patients with CD who had baseline and follow-up SES-CD scores after biological therapy initiation were included. The primary outcome was treatment failure, defined as the need for: (1) change of biological therapy for active disease (2) corticosteroid use (3) CD-related hospitalisation or (4) surgery. We compared rates of treatment failure with the degree of MH achieved. Patients were followed up until treatment failure or study end (August 2022).

Results: 50 patients were included and followed up for median 39.9 (34.6-48.6) months. Baseline characteristics: 62% male, median age 36.4 (27.8-43.9) years, disease distribution (L1: 4, L2: 11, L3: 35, perianal: 18). The proportion of patients achieving STRIDE-II end-points were: SES-CD2-25 (50%) and >50% reduction in SES-CD-35 (70%). Failure to achieve SES-CD2 (HR 11.62; 95% CI 3.33 to 40.56, p=0.003) or >50% improvement in SES-CD (HR 30.30; 95% CI 6.93 to 132.40, p<0.0001) predicted treatment failure.

Conclusion: Use of SES-CD is feasible in real-world clinical practice. Achieving an SES-CD2 or a greater than 50% reduction, as set out by STRIDE-II, is associated with reduced rates of overall treatment failure including CD-related surgery.