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.