Adalimumab Biosimilar for Uveitis Similarly Efficacious to Bio-Originator

Athimalaipet V Ramanan, FRCPCH, FRCPa

Courtesy of University of Bristol

An adalimumab biosimilar (Amgevita) is both safe and effective for the treatment of noninfectious uveitis, with a similar efficacy profile to originator adalimumab (Humira), according to new research from the United Kingdom.¹

The results indicate a significant proportion of patients self-requested to switch back to originator adalimumab, but investigators, led by Athimalaipet V Ramanan, FRCPCH, FRCPa, University of Bristol, suggested this was most commonly due to injection-related discomfort in the pediatric population.

“From our data, it appears that Amgevita is similarly efficacious to Humira in managing disease activity and minimizing complications associated with uveitis,” wrote the investigative team. “This real-world example of a heterogeneous cohort of uveitis patients provides valuable information on the practical use of adalimumab and this biosimilar and is in keeping with other published case series examining biosimilar use in non-infectious uveitis.”

The effectiveness of adalimumab for the management of inflammatory uveitis has led to its widespread use, but the cost of the therapy led the National Health Service in the UK to implement non-medical switching for patients receiving originator adalimumab. Potential concerns when switching to biosimilars can include loss of efficacy, change in immunogenicity, and differences in safety compared with the originator medication.

Reports of “failed switches” have been noted in adult data, often related to an individual’s negative expectations of the switch. But investigators noted failed switching may have important clinical implications, including exhaustion of therapeutic options, worse overall outcomes, and increased healthcare costs. Together, Ramanan and colleagues looked to evaluate the clinical efficacy of the biosimilar switch of adalimumab in pediatric and adult uveitis patients.

The study retrospectively identified patients from three tertiary centers in the UK and recruitment took place over a 6-month period from end of 2019 into mid-2020, according to investigators. Patient data were compiled and analyzed, including age at diagnosis, disease laterality, presence or underlying systemic disease, ocular comorbidities, and structural complications, to evaluate the clinical efficacy of the biosimilar switch.

A total of 102 patients (n = 185 active eyes) who had switched from adalimumab originator to biosimilar were included in the analysis. Individuals who had stopped the originator due to disease remission and restarted on the biosimilar due a flare of disease, within 6 months, were also included. After the switch to biosimilar, there was 1 event of worsening visual acuity, 2 episodes of significant improvement in visual acuity, and 7 episodes of patients with visual acuity which improved to <0.3 logMar.

In comparing flares of diseases, investigators found no significant differences identified and many of the the flares in both periods were considered mild. Data showed 13 events occurred before the switch and 21 events occurred after the switch (P = 132). Additionally, there was no significant difference in the dose of oral or topical corticosteroid used, according to investigators.

However, there was a significant difference in the number of patients with raised intraocular pressure between the two groups, with fewer patients in the post-switch group having raised IOP compared to the pre-switch group (32 before, 25 afterwards; P = .006).

After the switch to biosimilar, 20 patients reported side effects, with increased pain from the injection being the most commonly reported side effect. Of the 102 patients, 24 (24%) switched back to the originator (15 pediatric, 9 adults), often at the patient’s request for pain or technical difficulties with the injector. Additionally, 4 patients were identified to have treatment failure on adalimumab and switched to an alternate agent.

“Our findings of non-inferiority, when added to a growing body of evidence, could help assuage these concerns,” investigators wrote. However, the high rate of switching back in our study, at 24%, is a concern and engagement with manufacturers may be beneficial.”

References

1. Murray GM, Griffith N, Sinnappurajar P, et al. Clinical Efficacy of Biosimilar Switch of Adalimumab for Management of Uveitis [published online ahead of print, 2023 Feb 21]. Ocul Immunol Inflamm. 2023;1-5. doi:10.1080/09273948.2023.2172591