Similar Growth Outcomes in Children with Inflammatory Bowel Disease Initiated on Infliximab Originator or Biosimilar

Abstract

Background: Growth is an important clinical outcome, especially in childhood-onset inflammatory bowel disease (IBD). Prior research has demonstrated growth improvements with infliximab therapy. There are limited studies evaluating whether clinical and growth outcomes in children initiated on the infliximab originator and infliximab biosimilar are similar. Methods: This was a single-center retrospective review of patients with IBD, younger than 17 years old, and initiated on the infliximab originator or biosimilar for at least 12 months between April 2016 and February 2021. Propensity score matching was utilized. Laboratory values, disease activity scores, and growth values were collected at baseline (prior to infliximab initiation), 6 months, and 12 months post initiation. Linear mixed models with random intercepts were used to test differences in measures over time and between study groups. Results: There were 113 patients on the originator and 39 patients on a biosimilar who met eligibility criteria. Propensity score methodology identified 37 dyads (1:1 match). Weight, height, and body mass index z scores increased over time (from baseline to 12 months) for both groups (P < 0.05) and there was a similar rate of change between study groups. Clinical outcomes of lab values (albumin, C-reactive protein, and hemoglobin) and disease activity scoring were similar from baseline to 12 months between study groups. Conclusions: There were similar improvements in growth and clinical outcomes in patients initiated on the infliximab originator compared to an infliximab biosimilar agent. This study adds to the limited research evaluating whether infliximab biosimilars have similar growth outcomes in children with IBD.