Comparison of infliximab with adalimumab in 827 biologic-naïve patients with Crohn's disease: a population-based Danish cohort study

Background: There are conflicting data on comparative effectiveness of adalimumab and infliximab in patients with Crohn's disease (CD). Aims: To compare the effectiveness and safety of adalimumab and infliximab in biologic-naïve patients with CD, in a nationwide register-based propensity score-matched cohort study in Denmark. Methods: A total of 2908 Danish adults with CD had been treated with adalimumab or infliximab as their first biologic agent between 2005-2014. By Cox regression, we compared rates of all-cause hospitalisation, CD-related hospitalisation, major abdominal surgery and serious infections after variable 2:1 propensity score matching, accounting for baseline disease characteristics, healthcare utilisation and use of CD-related medications. Results: After propensity-score matching, we included 315 adalimumab- (34.9 ± 12.9 years, 41.9% males) and 512 infliximab-treated (33.6 ± 12.6 years, 40.8% males) patients, with median disease duration 4.0 years; 36.9% had prior abdominal surgery. Over a median follow-up 2.3 years after starting biological therapy, there were no significant differences in rate of CD-related hospitalisation (hazard ratio [HR], 0.81 [95% CI, 0.55-1.20]) or major abdominal surgery (HR, 1.24 [0.66-2.33]) between adalimumab- and infliximab-treated patients, though rate of all-cause hospitalisation was lower in adalimumab-treated patients (HR, 0.74 [0.56-0.97]). There was no significant difference in incidence of serious infections requiring hospitalisation (HR, 1.06 [0.26-4.21]). These results were stable in patients treated with biological monotherapy (all-cause hospitalisation: HR, 0.75 [0.53-1.05]; CD-related hospitalisation: HR, 0.82 [0.51-1.32], abdominal surgery: HR, 1.47 [0.63-3.47]) or in combination with immunomodulators (all-cause hospitalisation: HR, 0.70 [0.44-1.11]; CD-related hospitalisation: HR, 0.80 [0.42-1.52], abdominal surgery: HR, 1.02 [0.39-2.64]). Conclusions: In this population-based, propensity score matched, real-life cohort study using administrative claims, there was no significant difference in effectiveness and safety of adalimumab and infliximab in biologic-naïve patients with CD.