Increasing Biosimilar Use Reflects Changing Practice in Pediatric IBD Care

Infliximab biosimilar initiation among pediatric patients with inflammatory bowel disease (IBD) rose gradually from 1% in 2018 to nearly 42% in 2023, with no consistent differences by age, race, or ethnicity and notable regional variation, according to a retrospective study.1

The analysis, published in Children, incorporated data from the ImproveCareNow (ICN) Network, a multicenter pediatric IBD quality improvement collaborative.

Pediatric IBD is becoming increasingly common, with an incidence of about 10 cases per 100,000 children in the US and Canada and a rising trend.2 In the US alone, IBD prevalence ranges from 100 to 200 per 100,000 children—amounting to an estimated 70,000 affected children—meaning that most pediatricians are likely to encounter and care for patients with IBD in their practice.

Access to FDA-approved treatments for pediatric IBD remains limited, as tumor necrosis factor-α inhibitors are currently the only class of medications approved for use in children with Crohn disease and ulcerative colitis, despite the availability of multiple therapeutic options for adults.1 Additionally, a 2018 survey by the Crohn’s and Colitis Foundation found that pediatric IBD providers were less comfortable prescribing biosimilars than their adult-care counterparts, likely due to the limited experience with biosimilars in children and the scarcity of pediatric-specific safety and efficacy data.3

Although infliximab biosimilars offer a promising opportunity to reduce drug costs and expand treatment access, their uptake in pediatric populations has been slow, in part because of provider hesitancy, limited pediatric-specific efficacy and safety data, and regulatory and educational barriers.1 This retrospective cohort study was conducted to assess patterns in the initiation of infliximab biosimilars among a large pediatric IBD cohort and to determine whether differences in use existed by age, race, ethnicity, or geographic region.

Researchers prospectively collected data from 2016 to 2023 within the ICN Network to evaluate patterns in the initiation of infliximab originator and biosimilars among children and young adults with IBD, using statistical tests to assess differences by age, race, ethnicity, IBD phenotype, region, and year, while excluding patients with prior infliximab use, incomplete data, or enrollment at centers with limited infliximab prescribing.

“A notable strength is that data in the ICN Network registry are collected prospectively by clinicians. The ICN Network represents one of the largest pediatric IBD registries in existence and includes both large academic medical centers as well as small hospital-based and private practices, truly reflective of the real-world nature of pediatric IBD care,” the authors wrote.

Out of 26,256 pediatric IBD patients in the ICN registry, 4602 patients from 73 US-based centers met the study criteria and were included in the analysis. The study population was 45% female, with a median age of infliximab initiation of 13.7 years. Most patients had Crohn disease (70%). Between 2016 and 2023, 3807 patients began treatment with the infliximab originator, while 795 patients started on a biosimilar. No meaningful clinical differences were observed between the 2 groups.

Despite the introduction of infliximab biosimilars in late 2016, their uptake was initially minimal—rising from just 1% of infliximab initiations in 2018 to nearly 42% by 2023. Infliximab-dyyb (Inflectra; Celltrion) was the most commonly used biosimilar. While biosimilar use was generally consistent across age groups, a statistically significant difference was observed in 2020, likely due to the small number of children under age 6 initiating therapy that year. Similarly, 2020 was the only year with a significant difference in biosimilar use by race, with higher usage among patients categorized as “other.” No consistent differences in biosimilar use by ethnicity were observed. However, regional variation was evident, with the Midwest, West, and Southwest regions consistently initiating biosimilars at higher rates than the Northeast and Southeast from 2020 onward.

Cumulatively, just 17.3% of patients initiating infliximab from 2016 to 2023 were started on a biosimilar, reflecting a gradual but uneven adoption. The number of ICN centers using biosimilars increased significantly—from just 1 center in 2016 to 59 centers (88.1%) by 2023. The percentage of centers with very low biosimilar use (fewer than 10% of patients) steadily declined, while the number of centers with moderate (25%-69%) or high (70%-100%) biosimilar adoption grew notably. By 2023, more than half of centers had at least 25% of infliximab initiators starting on a biosimilar, highlighting a clear trend toward broader, though still variable, uptake.

This study had several limitations, including potential biases stemming from differences in how ICN centers consented patients and recorded infliximab product use, which may have led to underreporting—particularly for biosimilars like infliximab-axxq that were not explicitly tracked in the registry. The accuracy of the real-world data could not be independently verified, and missing race (8%) and ethnicity (4.6%) data may have affected analyses of disparities. Additionally, insurance type was recorded only at diagnosis, not at the time of infliximab initiation, limiting the ability to assess its influence on biosimilar use.

References

1. Maltz RM, Saeed SA, Adler J. infliximab biosimilar utilization in a large pediatric learning health system. Children (Basel). 2025;12(5):656. doi:10.3390/children12050656

2. Rosen MJ, Dhawan A, Saeed SA. Inflammatory bowel disease in children and adolescents. JAMA Pediatr. 2015;169(11):1053-1060. doi:10.1001/jamapediatrics.2015.1982

3. Malter L, Jain A, Cohen BL, et al. Identifying IBD providers' knowledge gaps using a prospective web-based survey. Inflamm Bowel Dis. 2020;26(9):1445-1450. doi:10.1093/ibd/izaa032