Outcomes

For the aim of evaluating the predictive value of ileal MVL for response to ustekinumab using the prospective randomized cohort, the following outcomes were assessed at 8 weeks postinduction: clinical response, defined as a reduction of Crohn’s Disease Activity Index (CDAI) of ≥100 points from pretreatment baseline; clinical remission, defined as CDAI of <150; and endoscopic response, defined as a ≥50% reduction from baseline Simple Endoscopic Score for Crohn’s Disease (SES-CD). The primary outcome was clinical response to ustekinumab stratified by pretreatment ileal MVL, using a threshold of 1.7 µm, which corresponds to 75% of the mean ileal MVL of the healthy general population.¹⁹ Prespecified secondary outcomes included correlations between pretreatment ileal MVL and baseline clinical activity, as measured by the CDAI, and baseline endoscopic activity, as measured by the SES-CD.

For all other aims involving vedolizumab-treated CD patients from the multicenter retrospective cohort, the following outcomes were evaluated approximately 6 months after initiation of therapy: clinical response, defined as a reduction of Harvey-Bradshaw Index (HBI) of ≥5 points from pretreatment baseline, and clinical remission, defined as HBI <5. The primary outcome was clinical response to vedolizumab by pretreatment ileal MVL. The correlations among pretreatment ileal MVL, baseline HBI, and baseline SES-CD were also calculated.