Comparative Efficacy and Immunogenicity of Infliximab and Adalimumab in Crohn's Disease: A Prospective Cohort Study

Background and Objectives: Crohn's Disease (CD) is a chronic inflammatory condition often treated with anti-TNF agents such as infliximab (IFX) and adalimumab (ADA). This study compares the efficacy, immunogenicity, and pharmacokinetics of IFX and ADA over a 54-week period. Materials and Methods: A prospective, multicentre cohort study was conducted involving 72 patients with active CD (Crohn's disease activity index, CDAI > 150), who received treatment with either IFX (n = 42) or ADA (n = 30). Results: By week 54, treatment discontinuation occurred in 31% of IFX-treated patients (13/42) and 37% of ADA-treated patients (11/30), with no significant difference between groups (p = 0.612). Among those who completed the study, clinical remission (CDAI ≤ 150) was achieved in 65% of the IFX group and 95% of the ADA group (OR = 8.10; 95% CI = 1.10-20.11; p = 0.049). Loss of clinical response was more frequent in the IFX group (31%) than in the ADA group (10%), with an OR of 0.25 (95% CI: 0.06-0.97; p = 0.045). Fibrinogen levels declined in both groups, with a greater reduction observed in ADA-treated patients. The area under the ROC curve (AUC) for fibrinogen in distinguishing remission from active disease was 0.608 for IFX and 0.711 for ADA. Anti-drug antibodies were detected more frequently in IFX-treated patients (16.7%, 7/42) compared to those receiving ADA (6.7%, 2/30). Conclusions: Treatment with ADA demonstrated superior efficacy compared to IFX in maintaining clinical remission in CD, which was paralleled by a more effective normalization of fibrinogen levels (Clinical trial: GET-CRO-2010-01).