Assessing the effectiveness of biologics in biologic-naïve patients with isolated small bowel Crohn's disease by double-balloon endoscopy.

BACKGROUND: Data on the effectiveness of biologics in achieving endoscopic remission (ER) in biologic-naïve patients with isolated small bowel Crohn's disease (SB-CD) remain limited. AIM: To assess the effectiveness of biologics in achieving ER in these patients. METHODS: This single‑center retrospective study included biologic‑naïve isolated SB‑CD patients who initiated infliximab (IFX) or ustekinumab (UST) between 2020 and 2025. All underwent follow‑up double‑balloon enteroscopy. ER was defined as Simple Endoscopic Score for Crohn's Disease (SES‑CD) <3. Multivariate regression identified predictors of ER. Propensity score matching (1:3) compared UST and IFX. RESULTS: A total of 169 patients (122 receiving IFX and 47 receiving UST) were included. The overall ER rate was 35.5% (32.8% for IFX and 42.6% for UST). Multivariate analysis identified stricturing/penetrating disease (OR =0.297, 95% CI: 0.131-0.673, p = 0.004) and moderate-to-severe endoscopic disease (OR =0.307, 95% CI: 0.112-0.839, p = 0.021) as negative predictors of ER. After matching, no significant differences were observed between the groups in the rates of endoscopic response, ER, mucosal healing, clinical remission, or biochemical remission. CONCLUSION: Among biologic-naïve patients with isolated SB-CD, the overall ER rate after biologic treatment was 35.5%. IFX and UST showed comparable effectiveness in achieving ER.