Comparative Risk of Serious Infections With Biologic and/or Immunosuppressive Therapy in Patients With Inflammatory Bowel Diseases: A Systematic Review and Meta-Analysis

Background & aims: We performed a systematic review and meta-analysis to evaluate the comparative risk of serious infections with tumor necrosis factor (TNF) antagonists, non-TNF targeted biologics, tofacitinib, and immunosuppressive agents in patients with inflammatory bowel diseases (IBDs).

Methods: In a systematic search of publications, through March 18, 2018, we identified 15 observational studies (>500 person-years) of patients with IBD treated with TNF antagonists, non-TNF targeted biologics, tofacitinib, and/or immunosuppressive agents (thiopurines, methotrexate) that reported risk of serious infections. Only studies with active comparators were included, to allow appropriate comparative synthesis. We performed random-effects meta-analysis and estimated relative risk (RR) and 95% CIs.

Results: Compared with anti-TNF monotherapy, risk of serious infection increased with the combination of anti-TNF and an immunosuppressive agent (in 6 cohorts: RR, 1.19; 95% CI, 1.03-1.37), with anti-TNF and a corticosteroid (in 4 cohorts: RR, 1.64; 95% CI, 1.33-2.03), or with all 3 drugs (in 2 cohorts: RR, 1.35; 95% CI, 1.04-1.77); there was minimal heterogeneity among studies. In contrast, monotherapy with an immunosuppressive agent was associated with a lower risk of serious infections than monotherapy with a TNF antagonist (7 cohorts: RR, 0.61; 95% CI 0.44-0.84) or a TNF antagonist with an immunosuppressive agent (2 cohorts: RR, 0.56; 95% CI, 0.39-0.81). Infliximab-based therapy was associated with a lower risk of serious infections compared with adalimumab-based therapy in patients with ulcerative colitis (4 cohorts: RR, 0.57; 95% CI, 0.33-0.97), but not Crohn's disease (4 cohorts: RR, 0.91; 95% CI, 0.49-1.70). Few data were available on the comparative safety of biologic agents that do not inhibit TNF and tofacitinib.

Conclusions: Combination therapies for IBD that include TNF antagonists, especially with corticosteroids, are associated with a higher risk of serious infection, whereas monotherapy with an immunosuppressive agent is associated with a lower risk, compared with monotherapy with a TNF antagonist. Studies are needed to evaluate the comparative safety of non-TNF targeted biologics and small molecules for treatment of IBD.