Low Incidence of Inflammatory Bowel Disease Adverse Events in Adalimumab Clinical Trials Across Nine Different Diseases

Objective: Adalimumab is approved for treatment of Crohn's disease and ulcerative colitis. Thus, we postulated that exacerbation or new-onset of inflammatory bowel disease (IBD) would be rare events in patients treated with adalimumab for non-IBD indications. The objective was to evaluate the incidence of IBD adverse events (AEs) across adalimumab trials.

Methods: IBD AE rates in 75 adalimumab clinical trials in rheumatoid arthritis, polyarticular juvenile idiopathic arthritis, pediatric enthesitis-related arthritis, uveitis, hidradenitis suppurativa, adult and pediatric psoriasis, psoriatic arthritis, nonpsoriatic arthritis peripheral spondyloarthritis (SpA), axial SpA, including nonradiographic axial SpA, and ankylosing spondylitis, were analyzed. Search terms for IBD AEs (new onset or worsening/flare) included IBD, ulcerative colitis, Crohn's disease, and ulcerative proctitis.

Results: This analysis included 24,114 patients, representing 36,508 patient-years of adalimumab exposure. The overall rate of IBD AEs in adalimumab-treated patients was 0.1 (95% confidence interval [95% CI] 0.1-0.2)/100 patient-years (41 events), ranging from no events (psoriatic arthritis, uveitis, and pediatric trials) to 0.8 (95% CI 0.2-2.2)/100 patient-years in peripheral SpA. The rate of IBD in axial SpA was 0.6 (95% CI 0.4-1.0)/100 patient-years. During placebo-controlled trials, the overall IBD rate was 0.1 (95% CI 0.0-0.3)/100 patient-years for adalimumab groups (3 events in 6,781 patients; 2,752 patient-years of exposure) and 0.1 (95% CI 0.0-0.4)/100 patient-years for placebo groups (1 event in 3,493 patients; 1,246 patient-years of exposure). IBD rates in axial SpA were 0.5 (95% CI 0.1-1.4)/100 patient-years for adalimumab and 0.6 (95% CI 0.0-3.1)/100 patient-years for placebo.

Conclusion: The rates of IBD AEs in adalimumab clinical trials were generally low across the evaluated diseases, including axial SpA; all events occurred in adult patients.