S1892 A 5-Year Head-to-Head Safety Analysis of Adalimumab vs Infliximab in Inflammatory Bowel Disease

Introduction: Adalimumab and infliximab are tumor necrosis factor (TNF) inhibitors with proven efficacy in managing inflammatory bowel disease (IBD). Due to the chronic nature of IBD, TNF inhibitors are often indicated for long-term use. However, their immunosuppressive effects and influence on coagulation are associated with an increased risk of infections, cancer, thromboembolism (TE), and hospitalizations. While long-term safety data exist for these agents, direct comparisons of their safety profiles over extended periods remain limited. This study provides a comprehensive 5-year safety comparison of adalimumab and infliximab in IBD patients. Methods: Our retrospective cohort study utilized the TriNetX database, a global federated health research network. Patients aged ≥18 years with a diagnosis of IBD who were treated with either adalimumab or infliximab were included. Propensity score matching was applied to balance baseline demographics and disease severity between the cohorts, yielding 28,912 matched patients in each group. Primary outcomes were the risks and risk difference between cohorts for IBD-related complications (infections, cancer, TE) and hospitalizations at 6 mo, 1 y, 3 y, and 5 y. Kaplan-Meier analysis was performed to evaluate event-free survival rates for each outcome. Results: Over 5 years, cancer incidence remained low and similar between the adalimumab and infliximab groups, with rates under 0.2% (P = 0.925). Adalimumab consistently demonstrated lower infection rates compared to infliximab (5.61% vs 7.72% at 6 months, 8.1% vs 10.3% at 1 year, and 16.1% vs 18.0% at 5 years; P < 0.001). The risk of TE was also lower for adalimumab (1.42% vs 2.15% at 6 months, decreasing to 3.4% vs 3.7% at 5 years; P = 0.014). Hospitalization rates showed a similar trend favoring adalimumab, from 6.61% vs 11.62% at 6 months to 14.7% vs 19.1% at 5 years (P < 0.001). Conclusion: Over 5 years, adalimumab demonstrated significantly lower rates of infections, TE, and hospitalizations compared to infliximab, while cancer incidence remained comparable between the 2 therapies. These findings suggest that adalimumab may offer a safer long-term profile, reducing the risks of severe complications and alleviating healthcare burdens through fewer hospitalizations. Clinicians should consider these safety differences when personalizing treatment strategies for IBD patients. Future prospective studies are warranted to confirm these findings and explore the mechanisms driving these differences.