Durability of Adalimumab and Infliximab in Children With Crohn's Disease: A Nationwide Comparison From the epi-IIRN Cohort

BACKGROUND: In a nationwide cohort, we aimed to compare the durability of infliximab and adalimumab as first biologic treatment in children with Crohn's disease (CD), stratified as combotherapy or monotherapy. METHODS: We used data from the epi-IIRN cohort that includes all patients with inflammatory bowel diseases in Israel. Durability was defined as consistent treatment without surgery or treatment escalation. All comparisons followed stringent propensity-score matching in Cox proportional hazard models. RESULTS: Of the 3487 children diagnosed with CD since 2005, 2157 (62%) received biologics (1127 [52%] infliximab, 964 [45%] adalimumab and 52 [2%] vedolizumab as first biologic), representing a higher proportion than that among adults diagnosed during the same time period (5295 of 15 776 [34%]; P < .001). Time from diagnosis to initiation of biologic was shorter in pediatric-onset compared with adult-onset disease (median time during the last 3 years was 2.7 months [interquartile range 1.2-5.4] vs 5.2 months [2.6-8.9]; P < .001). The durability of adalimumab monotherapy after 1 and 5 years from initiation of treatment was better than infliximab monotherapy (79%/54% vs 67%/37%, respectively; n = 452 matched children; hazard ratio [HR], 1.7; 95% confidence interval [CI], 1.3-2.3; P < .001), while in those treated with combotherapy, durability was similar (94%/66% with infliximab vs 90%/54% with adalimumab; n = 100; HR, 1.7; 95% CI, 0.9-3.3; P = .1). Durability was higher in children treated with infliximab combotherapy vs infliximab monotherapy (87%/45% vs 75%/39%; n = 440; HR, 1.4; 95% CI, 1.1-1.8; P = .01). The durability of adalimumab monotherapy was similar to infliximab combotherapy (83%/53% vs 89%/56%, respectively; n = 238; HR, 0.9; 95% CI, 0.7-1.2; P = .4). CONCLUSION: Our results support using adalimumab monotherapy as a first-line biologic in children with CD. When infliximab is used, combotherapy may be advantageous over monotherapy.