Never‐Smoking Is Associated With Histologic Remission in Ulcerative Colitis: A Post‐Hoc Analysis of the VIEWS Randomised Controlled Trial

ABSTRACT Background and Aims Histologic remission is associated with improved outcomes in patients with ulcerative colitis (UC), yet its predictors remain poorly defined. We aimed to identify patient and disease characteristics associated with histologic remission in UC. Methods This post hoc analysis used baseline data from the Vedolizumab Immunomodulator Enforced Withdrawal Study (VIEWS), a phase IV trial of patients receiving vedolizumab 300 mg intravenously 8‐weekly plus thiopurine who were randomised to thiopurine withdrawal or continuation. Eligible patients were in corticosteroid‐free clinical remission with Mayo endoscopic score 0–1. Histologic remission was assessed at the baseline visit, before thiopurine withdrawal, and was defined as Nancy index 0, assessed centrally by a blinded gastrointestinal pathologist. Baseline demographic, clinical and biochemical variables were analysed using logistic regression. Results Of 62 enrolled patients, 54 (87%) had baseline histology, of whom 41 (76%) had histologic remission. Current smokers ( n = 3) were excluded from inferential analyses. The analytic cohort ( n = 51) was 57% male; 84% were never‐smokers, 16% ex‐smokers, and 18% anti‐tumour necrosis factor (TNF)‐exposed. On univariable analysis, younger age, never‐smoking, and anti‐TNF‐naïve status were associated with histologic remission. On multivariable analysis, only never‐smoking compared with ex‐smoking remained independently associated with histologic remission (adjusted OR 19.65, 95% CI 1.37–281.93, p = 0.03). Conclusion In this post hoc analysis of the VIEWS trial, never‐smoking was associated with a higher likelihood of histologic remission compared with ex‐smoking among patients UC achieving clinical remission and endoscopic improvement on vedolizumab. Smoking history may represent an underappreciated determinant of deep mucosal healing and warrants further studies. Trial Registration The trial was registered with the Australian and New Zealand Clinical Trials Registry (ACTRN12618000812291)