How comparative studies can inform treatment decisions for Crohn's disease.

Introduction: As new therapies for the treatment of Crohn's disease (CD) are approved, there is an increasing need for evidence that clarifies their positioning and sequencing.

Areas covered: Comparative effectiveness research (CER) aims to inform physicians' decisions when they choose which intervention (drug or treatment strategy) to administer to their patients. Pragmatic head-to-head trials represent the best tools for CER, but only a few have been published in the IBD field. Network meta-analyses can point toward the superiority of one drug over another, but they do not reflect everyday clinical practice. Finally, real-world evidence complements that coming from head-to-head trials and network meta-analyses, assessing the real-life effectiveness of therapeutic interventions.

Expert opinion: There is insufficient evidence to create a definitive therapeutic algorithm for CD, but some general considerations can be made. Anti-TNF-α agents seemingly represent the most 'sustainable' first-line choice, considering benefit-harm ratio and costs; vedolizumab, ustekinumab, and risankizumab may be considered as first-line choice when safety issues become prominent. In the event of pharmacodynamic failure, out-of-class swap is to be preferred - possibly with anti-IL23p19 as the best option, with unclear data regarding upadacitinib positioning; a second anti-TNF-α could be considered, as a second choice, after pharmacokinetic failure.