The primary aim of this study is to explore the time course of response to Vedolizumab in participants with CD as measured by the Patient-Reported Outcomes Measurement Information System (PROMIS) Pain Interference-short form (SF), as well as other PROMIS domain SFs (fatigue, anxiety, depression, sleep disturbance, physical function, and ability to participate in social roles and activities); other PRO measures will also be assessed.

Vedolizumab (VDZ), a monoclonal antibody that selectively targets intestinal T-cell trafficking, is an effective and safe treatment for moderately to severely active Crohn's disease (CD). Recent evidence from open-label, blinded endpoint studies such as VERSIFY and LOVE-CD provide further support for the efficacy of VDZ in achieving clinical, endoscopic, histologic and radiologic disease improvement in CD. Despite these data, VDZ is generally perceived to have a slower onset of action than other biologics, including tumor necrosis factor (TNF) antagonists and the interleukin (IL)-12/23 antagonist, ustekinumab (UST). The IL-23 antagonist risankizumab (RISA) has been more recently approved for treatment of CD and post-hoc analyses of SEQUENCE trial data showed RISA to be superior to UST for inducing clinical remission at Week 24, and thus, RISA may also be considered to have a quicker onset of action than VDZ. This perception largely emanates from the results of the VDZ pivotal for CD (GEMINI 2) where efficacy was assessed at Week 6 after only 2 doses in a largely refractory population. However, in clinical practice VDZ induction consists of 3 doses of VDZ 300 mg administered intravenously at weeks 0, 2 and 6 instead of the 2 doses used in the pivotal trials. In recent clinical trials, induction endpoints for therapeutics in CD are now typically measured at least after Week 12. Accordingly, it is uncertain whether the generally held perception of a relatively slow onset of action for VDZ is accurate. Moreover, it should also be noted that the perception of a slow onset of action has also been conflated to infer that VDZ is a relatively less effective induction therapy in CD than TNF antagonists or UST. Further data to evaluate these issues are needed. Rapidity of symptom resolution, which is commonly used as a surrogate for speed of onset, is a priority for patients and clinicians. It is therefore important to better understand the kinetics of symptom improvement captured using patient-reported outcomes (PROs) in patients initiating VDZ for treatment of CD.