Adalimumab Safety in Inflammatory Bowel Disease: A Clinical Cohort Study with Time-to-Event Analysis and FAERS Signal Assessment

Background/Objectives: The safety profile of adalimumab in inflammatory bowel disease (IBD) has been established in clinical trials, but post-marketing surveillance remains important for detecting rare and late-onset adverse events (AEs). This study aimed to evaluate long-term safety and temporal dynamics of AEs in an IBD cohort treated with adalimumab, and to identify potential safety signals using the FDA Adverse Event Reporting System (FAERS). Methods: This retrospective single-center study included patients with IBD treated with adalimumab. Demographic, clinical, and treatment-related data, including AEs and newly identified extraintestinal manifestations (EIMs), were collected. Time-to-event (TTE) analyses were used to assess AEs temporal patterns and covariates associated with onset. FAERS disproportionality analysis was performed for cohort-identified AEs and EIMs. Results: A total of 217 patients with 591.29 patient-years (PYs) of exposure (up to 9.62 years) were included. AE incidence was 106.6/100 PY. Time to first AE was described using the Kaplan–Meier method, and additionally the Weibull distribution, with an estimated median time of 11.4 months (95% CI: 9.7–13.5). The most frequent AEs were infections (32.30/100 PY), hepatic events (9.98/100 PY), and cutaneous manifestations (8.46/100 PY), characterized by TTE analysis. Serious outcomes, including malignancies and demyelinating events, were rare. Several unlisted MedDRA preferred terms, including infectious, cutaneous, vascular, proliferative, and musculoskeletal events, emerged as FAERS signals. Conclusions: This study provides long-term real-world evidence supporting the established safety profile of adalimumab in IBD. First AEs occurred throughout treatment exposure with lower hazard over time. Isolated FAERS signals, including vascular occlusive events, may warrant further investigation and continued pharmacovigilance.