No Benefit of Concomitant Immunomodulator Therapy on Efficacy of Biologics That Are Not Tumor Necrosis Factor Antagonists in Patients With Inflammatory Bowel Diseases: A Meta-analysis

BACKGROUND & AIMS: There is debate over whether patients with inflammatory bowel diseases (IBD) treated with biologics that are not tumor necrosis factor antagonists (such as vedolizumab or ustekinumab) should receive concomitant treatment with immunomodulators. We conducted a meta-analysis to compare the efficacy and safety of concomitant immunomodulator therapy vs vedolizumab or ustekinumab monotherapy. METHODS: In a systematic search of publications, through July 31, 2019, we identified 33 studies (6 randomized controlled trials and 27 cohort studies) of patients with IBD treated with vedolizumab or ustekinumab. The primary outcome was clinical benefit, including clinical remission, clinical response, or physician global assessment in patients who did vs did not receive combination therapy with an immunomodulator. Secondary outcomes were endoscopic improvement and safety. We performed random-effects meta-analysis and estimated odds ratio (OR) and 95% CIs. RESULTS: Overall, combination therapy was not associated with better clinical outcomes in patients receiving vedolizumab (16 studies: OR, 0.84; 95% CI, 0.68-1.05; I2 = 13.9%; Q test P = .17) or ustekinumab (15 studies: OR, 1.1; 95% CI, 0.87-1.38; I2 = 11%; Q test P = .28). Results were consistent in subgroup analyses, with no difference in clinical remission or response in induction vs maintenance studies or in patients with Crohn's disease vs ulcerative colitis in studies of vedolizumab. Combination therapy was not associated with better endoscopic outcomes in patients receiving vedolizumab (3 studies: OR, 1.13; 95% CI, 0.48-2.68; I2 = 0; Q test P = .96) or ustekinumab (2 studies: OR, 0.58; 95% CI, 0.21-1.16; I2 = 47%; Q test P = .17). Combination therapy was not associated with an increase in adverse events during vedolizumab therapy (4 studies: OR, 1.17; 95% CI, 0.75-1.84; I2 = 0; Q test P = .110). CONCLUSIONS: In a meta-analysis of data from studies of patients with IBD, we found that combining vedolizumab or ustekinumab with an immunomodulator is no more effective than monotherapy in induction or maintenance of remission.