| Interventions |
The intervention is the withdrawal of immunomodulators (azathioprine or mercaptopurine) in IBD patients switching from IV infliximab to subcutaneous infliximab (SC CT-P13). Participants will be randomised 1:1 to either continue or discontinue immunomodulators (IMP) when switching from IV infliximab to subcutaneous infliximab (SC CT-P13) (NIMP). We will stratify the treatment allocation by HLA-DQA1*05 status. For participants randomised to continuing the immunomodulators, the IMP will continue to be prescribed to participants as part of their standard of care and at the same stable dose and frequency that they were taking for the 4 weeks prior to commencement of SC CT-P13 (NIMP). If changes in dose or frequency are deemed necessary during the trial, these changes are allowed at the discretion of the treating investigator. Immunomodulator drugs are taken by mouth, usually once a day, with or just after food, at a dosage that depends on age, body weight and severity of disease activity. Participants will continue/stop taking immunomodulators as part of this trial from the Baseline Visit up to the Week 24 Visit. The maximum trial treatment duration is 25 weeks which includes the trial follow-up activity and study visits every 8 weeks from the Baseline up until Week 24. Therefore, study visits at Week 8, Week 16 and Week 24 with a 1 week window for each visit. Randomisation will only be performed once screening has been completed, blood test results reviewed and eligibility re-confirmed at baseline. A secure computerised web-based programme provided by MedSciNet will be used to generate the treatment allocation. Appropriately delegated members of the research team will randomise participants by completing an on-screen form via their personal MedSciNet account. All part |