Natural History of Pediatric Patients With Crohn's Disease Treated With Mesalamine Therapy.

Background: 5-aminosalicylates (5-ASA) are used to treat mild to moderate ulcerative colitis. Despite their lack of efficacy in Crohn disease (CD), they are still used in real-world practice. Additionally, when patients have progressive disease, they may escalate to biologic therapy, at which time 5-ASA may or may not be discontinued. Objectives: The aim of this study is to assess the clinical outcomes of patients started on 5-ASA for the treatment of pediatric CD. The secondary aims were to evaluate the outcomes of those who continue 5-ASA to those who discontinue 5-ASA upon biologic escalation. Methods: We performed a single-center retrospective chart review of pediatric CD patients from 2010 to 2019 who were initially treated with 5-ASA. Demographics, medication and laboratory data, and clinical disease activity were collected. Results: Sixty-one patients were included in the study; the majority had inflammatory CD with ileocolonic involvement. Twenty-four patients were on a concomitant immunomodulator. The majority of patients (85.2%) required escalation to biologics. Thirty-two patients (61.5%) who escalated to biologic therapy continued on 5-ASA. Eighty percent of patients achieved clinical remission at 1 year, and there was no difference between those who continued 5-ASA at time of biologic initiation compared to those who did not continue the medication. Patients who discontinued 5-ASA had an average annual cost savings of $6741. Conclusion: 5-ASA is not a durable monotherapy for the treatment of pediatric CD. Patients who require escalation from 5-ASA to biologic therapy do not benefit from concomitant 5-ASA therapy. Further prospective studies are needed to confirm these findings.