Incidence comparison of adverse events in patients with inflammatory bowel disease receiving different biologic agents: retrospective long-term evaluation

Background/Aims: Current literature is lacking in studies comparing the incidence of adverse events (AEs) in patients with inflammatory bowel diseases (IBD) treated with adalimumab (ADA) or vedolizumab (VDZ) in a real-life scenario. Therefore, our primary aim was to compare the AEs occurring in patients taking ADA to those of patients taking VDZ. Methods: In this single center study, data on AEs from IBD patients who underwent treatment with ADA and VDZ were retrospectively collected. AE rates per 100 person-years were calculated. A Cox regression model was used to estimate the hazard ratios of the AEs between the 2 drugs. Results: A total of 16 ADA patients (17.2%) and 11 VDZ patients (7.6%) had AEs causing drug interruption during the study period (P=0.02). Most of the AEs were noninfectious extraintestinal events (50% in ADA and 54.5% in VDZ) while infections accounted for 31.2% of the AEs in patients treated with ADA and 27.3% in those treated with VDZ. The incidence rate of AEs causing withdrawal of therapy was 13.2 per 100 person-years for ADA and 5.3 per 100 person-years for VDZ, corresponding to a 76% lower risk in patients in VDZ. Considering the first year of treatment, we observed 34 subjects treated with ADA (36.5%) having at least 1 AEs and 57 (39.3%) among those taking VDZ (P=0.67). Conclusions: VDZ has a lower incidence rate of AEs causing withdrawal of treatment compared to ADA but a similar risk of AEs not causing drug interruption. Real-life head-to-head studies are still necessary to further explore the safety profile of these drugs.