Combined Histological and Endoscopic Endpoints at Post-induction Lack Additional Prognostic Value Compared with Endoscopic Improvement Alone in Ulcerative Colitis: A Post hoc Analysis of the VARSITY study

BACKGROUND AND AIMS: Evaluating histological outcomes in ulcerative colitis [UC] has become common in recent clinical trials. In this study, we explored the additional value of the combined endpoint of histo-endoscopic mucosal improvement [HEMI] compared with endoscopic improvement [EI] at post-induction [Week 14] and post-maintenance [1 year]. METHODS: This post hoc analysis included 620 UC participants with available data from the VARSITY trial. Participants achieving post-induction and post-maintenance HEMI [Mayo endoscopic subscore ≤1 and Geboes score <3.2] were compared across clinical outcomes, patient-reported outcomes [PROs], and inflammatory markers. Univariate analyses were performed to identify variables associated with the outcome of interest. Multivariate analyses included covariates with a p <0.05 on univariate analyses. RESULTS: Among the 468 patients with 1-year data available, a total of 166 [35.5%] attained HEMI and 209 [44.7%] attained EI at post-induction. No difference in achievement of clinical remission [CR] at 1 year was observed among those who attained post-induction HEMI vs EI (121/166 [72.9%] vs 147/209 [70.3%], p = 0.903). Similar findings were observed for the outcome of 1-year treatment failure (45/166 [27.1%] vs 55/209 [26.3%], p = 0.781). Patients who achieved HEMI at post-induction had lower total and partial Mayo scores and had the largest improvement from baseline. Faecal calprotectin and C-reactive protein [CRP] were also significantly lower among HEMI achievers at post-induction [p <0.001]. Similar findings were observed at post-maintenance. CONCLUSIONS: In this post hoc analysis, at post-induction, HEMI did not demonstrate additional prognostic value in predicting 1-year outcomes over EI. However, HEMI was associated with lower clinical disease activity at post-induction and at 1 year compared with endoscopic or histological outcomes in isolation.