Background and aims: Infliximab and adalimumab are first-line biological therapies in ulcerative colitis. Meta-analyses of randomized control trials indicate infliximab being more effective but observational studies indicate similar effect. Our aim was to compare short- and long-term efficacy of infliximab and adalimumab in bio-naive patients with ulcerative colitis in a real-world setting during the modern era of therapeutic drug monitoring and dose optimization.
Methods: We performed a retrospective multicentre observational cohort study. Patients initiating infliximab or adalimumab at four out-patient IBD-clinics between 2018 and 2022 were included.
Results: 105 patients were treated with infliximab and 166 with adalimumab. Steroid-free clinical remission at 12 months was reached in 43% (n = 37) of patients with infliximab and 35% (n = 55) with adalimumab (aOR: 1.41 (0.81-2.45), p = 0.22). Clinical remission at 3 months was more common with infliximab than adalimumab (68 vs. 57%, aOR 1.83 (1.07-3.14), p < 0.05) but no difference was observed regarding clinical response at 3 months, clinical remission at 12 months, and biochemical remission at 3 months and at 12 months. In the subpopulations with mild and moderate disease activity, infliximab and adalimumab were equal regarding clinical remission at 3 months and steroid-free clinical remission at 12 months. In patients with severe disease activity, infliximab had higher remission rates than adalimumab at 3 months; 70% (n = 32) vs. 46% (n = 26) (p < 0.05).
Conclusions: Adalimumab and infliximab achieved similar rates of long-term remission in bio-naive patients with ulcerative colitis. However, infliximab was superior in induction of remission and in patients with severe disease.
Keywords: Inflammatory bowel disease; adalimumab; infliximab; real-world evidence; ulcerative colitis.