Appropriateness of Combination Therapy for Patients With Inflammatory Bowel Diseases: One Size Still Does Not Fit All

Randomized controlled trials (RCTs) have demonstrated that therapies targeting tumor necrosis factor (TNF) and α₄β₇ integrin are effective when given as monotherapy in inducing and/or maintaining remission in patients with ulcerative colitis (UC) or Crohn's disease (CD), but data from RCTs are less clear on whether concomitant immunomodulator (IM) therapy confers additional benefit. In CD, RCT data are mixed,^1,2 as are results of systematic reviews and meta-analyses, showing no benefit overall,³ minimal benefit with individual agents,⁴ and comparative benefit over some monotherapies but not others.⁵ For example, concomitant azathioprine with infliximab is more effective than either drug alone in patients with CD naive to both drugs,² but whether combination therapy is more effective than monotherapy with infliximab in nonnaive patients, or with other approved biologic drugs in any population, remains unknown. In UC, RCTs have shown that the benefit may be limited to specific populations,⁶ whereas systematic reviews suggest no benefit at all.⁷.