Cost and Efficacy Insights on Infliximab Biosimilars in Pediatric Uveitis

Infliximab biosimilars have comparable safety and efficacy with reference infliximab (Remicade) in patients with pediatric noninfectious uveitis. Research showed that biosimilars had fewer flares per year and lower costs but were initiated primarily due to insurance mandates and assessed over a shorter treatment duration.

“These results are important for our management of children with uveitis since there is currently a severe lack of data looking at the efficacy of biosimilars in pediatric uveitis,” said lead study author Dilraj Grewal, MD, tenured associate professor of ophthalmology at the Duke Eye Center, in a statement to The Center for Biosimilars^®. "With the ever-increasing insurance mandates requiring switch to biosimilars, it is important to have access to data on the outcomes of biosimilars in children as we manage these challenging and potentially blinding ocular diseases."

The retrospective study, published in International Ophthalmology Clinics, aimed to evaluate the effectiveness and cost of biosimilars compared to reference tumor necrosis factor (TNF)-α inhibitors in pediatric noninfectious uveitis (NIU) at a large tertiary care academic center.

Due to the high costs and expiring patents of TNF-α inhibitors, biosimilars are used in the management of adult and pediatric NIU, offering structural and functional similarity to their reference biologics with comparable clinical efficacy and pharmacologic properties. By the time of the study, 10 adalimumab biosimilars and 3 infliximab biosimilars have been approved in the United States.²

Several studies had evaluated biosimilars in adult NIU, with most reporting no significant differences in disease activity, typically measured by flare events, when switching from reference medications to biosimilars. However, some studies observed mixed outcomes, including more flares with infliximab-abda and significant side effects with adalimumab biosimilars. In pediatric rheumatology, biosimilars have demonstrated effectiveness in juvenile idiopathic arthritis, but data on their use in pediatric NIU are limited.

The study, approved by the Duke University Institutional Review Board, was a retrospective chart review of pediatric patients aged 18 or younger with NIU treated at a single tertiary care center between January 1, 2013, and June 1, 2023.

Inclusion criteria required a history of ocular inflammation, treatment with reference or biosimilar infliximab, and at least 1 month of ophthalmology follow-up, while exclusions applied to those without ophthalmology exams, ocular inflammation, or biosimilar. The number of uveitis flares, defined by ophthalmologists as new or worsening inflammatory activity, was documented for both reference and biosimilar treatments.

Of the 52 pediatric patients initially assessed, 19 met inclusion criteria and were enrolled in the analysis, 9 of whom were women and the mean (SD) age was 9.3 (4.0) years (range, 3.5-16.6).

Anterior uveitis was the most common site of inflammation (73.7%), followed by intermediate uveitis (10.5%) and panuveitis (15.8%). Approximately 42.1% of patients had idiopathic NIU, and 36.8% had juvenile idiopathic arthritis-associated uveitis. Among the 19 patients, 68.4% were initiated on reference adalimumab, 21.1% on reference infliximab, and 10.5% on biosimilar intravenous infliximab-dyyb.

Of the patients initiated on reference adalimumab, 8 were later switched to biosimilar infliximab, and 1 to biosimilar infliximab-axxq. None were switched to biosimilar adalimumab. The mean duration on adalimumab prior to switching was 1.9 years, and the mean duration on biosimilar infliximab post-switch was 0.8 years. Patients on biosimilar infliximab experienced fewer annual disease flares (mean, –0.0007 [0.002]) compared to those on adalimumab (mean, 1.2 [1.1]). Nine patients received infliximab during their treatment course, with a mean duration of 3.6 years for reference infliximab and 0.82 years for biosimilar infliximab. Reasons for switching to biosimilars included insurance mandates (100%), worsening disease activity (37.5%), and noncompliance (37.5%).

Cost analysis revealed significant savings with biosimilars compared to reference infliximab. The average annual cost was $42,298.97 for reference infliximab, $41,141 for biosimilar infliximab-dyyb, and $40,950 for biosimilar infliximab-axxq. If patients initially on reference infliximab were started on biosimilars, projected annual costs could decrease by $15,000 to $25,000. Patients on biosimilar infliximab at any time point would have incurred $30,000 higher annual costs if switched to reference infliximab.

The study also observed that switching to biosimilar infliximab allowed some patients to taper or discontinue additional immunomodulatory therapies, such as prednisone and methotrexate. However, variability in costs and treatment outcomes due to insurance coverage, patient weight, and medication dosing were noted. The findings highlighted cost benefits and comparable efficacy of biosimilar infliximab in pediatric NIU but emphasized the need for larger studies to validate these results.

The authors concluded, “Longitudinal studies are required to characterize efficacy and dose response of biosimilars directly compared with the reference drug in pediatric noninfectious uveitis.”

References

1. Valikodath NG, Rathinavelu J, Deaner JD, Buckley M, Grewal DS. Comparison of reference and biosimilar medications for pediatric noninfectious uveitis. Int Ophthalmol Clin. 2024;64(4):69-73. doi:10.1097/IIO.0000000000000530

2. Biosimilar approvals. The Center for Biosimilars^®. Updated December 2, 2024. Accessed December 2, 2024. https://www.centerforbiosimilars.com/biosimilar-approvals