Inclusion Criteria:

• Male or nonpregnant, nonlactating females, aged 18 to 80 years (inclusive).
• An established diagnosis of CD or UC for at least 6 months based on standard clinical criteria, confirmed by the treating provider.
• Current treatment with an approved TIM for treatment of IBD, including biologic agents (e.g., tumour necrosis factor α [TNFα] antagonists, ustekinumab, vedolizumab) and
• small molecule inhibitors (e.g., Janus kinase inhibitors, ozanimod), including future TIMs that become commercially available during the conduct of the trial.
• Optimized on index TIM at the discretion of treating provider, defined as any of the following:
  • Either on maximal dose during maintenance therapy under routine care [examples in table below]; or Index TIM Dosage regimen TDM within 6 months prior to screening with trough concentration Infliximab 10 mg/kg q4wk > 5mg/ml Adalimumab 40 mg qwk > 7.5mg/ml Certolizumab 400 mg q2wk > 25mg/ml Vedolizumab 300 mg q4wk >15mg/mlUstekinumab 90 mg q4wk/IV re induction >1.2mg/ml;
  • Addition of an immunomodulator (IMM); or
  • Deemed by site investigator that further treatment optimization will not be effective; or
  • Dosage regimen follows approved labelling; or
  • Insurance declines any further optimization.
• Dose of TIM should be stable for 3 or more months prior to qualifying endoscopy/radiology.
• In corticosteroid-free symptomatic remission based on validated PROs (PRO2 score) and deemed to be experiencing no other IBD-related symptoms in the opinion of the treating provider. Includes patients who may be in medically-induced remission (on index TIM); or surgically-induced remission with post-op initiation of index TIM for prophylaxis and colonoscopy/imaging performed at least 3 months after initiation/optimization of TIM showing moderate-severe bowel inflammation. Validated PROs are defined as:
  • CD: PRO2 (2-item patient reported outcome) mean daily score of abdominal pain score ≤1 and stool frequency score ≤ 3; or
  • UC: PRO2, with absence of rectal bleeding (RB score = 0) and with stool frequency score ≤ 1.
• Evidence of moderate to severe bowel inflammation on local reading of colonoscopy, flexible sigmoidoscopy or balloon-assisted enteroscopy, capsule endoscopy, or MR, CT enterography or intestinal ultrasound, performed within:
  • 3 months prior to screening; or
  • performed within 6 months prior to screening, but with objective confirmation of inflammation (elevated CRP [> 5 mg/L or > 0.5 mg/dl] or FC [> 250 mcg/g]) within 3 months prior to screening, defined as:
  • CD: Simple Endoscopic Score for Crohn's Disease (SES-CD) score ≥ 7, or ≥ 4 for those with isolated ileal disease, or presence of mucosal ulcers > 5mm in size, if SES-CD has not been recorded; Rutgeerts' score i2b or higher for patients in surgically-induced remission with post-operative endoscopic recurrence; or
  • CD: MRE or CTE showing moderate to severely active inflammation based on the following variables: increased bowel wall thickness; mural hyperenhancement; peri-enteric fat stranding; radiographic features of ulceration; intramural T2 signal on fat suppressed images;
  • CD: Capsule endoscopy showing moderate to severely active small bowel disease based on Lewis score >790 (in case the disease is not accessible via endoscopy), or per local endoscopist's impression if Lewis score is not reported;
  • CD: Gastrointestinal ultrasound showing increased bowel wall thickness > 5mm, color doppler score > 5/cm^2, bowel stenosis, bowel stratification, fatty wrapping;
  • UC: modified MES score of 2-3; or documentation of any endoscopic features that would define a MES of 2-3 (e.g., friability, ulceration, spontaneous bleeding, complete loss of vascular pattern).
• Eligible to receive at least one alternative TIM (excluding their index TIM) for the treatment of their disease per approved drug label, based on clinical and reimbursement guidelines.
• Able to participate fully in all aspects of this clinical trial.
• Written informed consent must be obtained and documented.

Exclusion Criteria:

• Presence of ostomy or ileonal pouches.
• Serious underlying disease other than UC or CD that in the opinion of the investigator may interfere with the participant's ability to participate fully in the study.
• History of alcohol or drug abuse or any other medical or health condition that in the opinion of the investigator may interfere with the participant's ability to comply with the study procedures.
• Prior enrolment in the current study.

Eligibility last updated 5/4/23. Questions regarding updates should be directed to the study team contact.