Efforts to Increase Biosimilar Use Result in Successful Transition

Sarah Steedman, PharmD

Credit: LinkedIn

Among rheumatologists and gastroenterologists, an effort to convert clinically stable patients receiving infliximab to a biosimilar resulted in a significant increase in biosimilar use within the health system at the University of North Carolina outpatient clinics, according to a study published in the Journal of Managed Care & Specialty Pharmacy.¹ These changes demonstrate significant financial advantages for both the institution and patients.

“This study adds to the existing research concerning the safety and effectiveness of biosimilar products,” wrote Sarah Steedman, PharmD, Clinical inpatient and outpatient pharmacist at the University of North Carolina Medical Center, Pharmacy, Chapel Hill, and colleagues. “Our aim is for these data to provide further confidence to both patients and providers as biosimilars increase in use because of financial considerations.”

Infliximab was initially approved by the US Food and Drug Administration (FDA) in 1998 for the treatment of Crohn’s disease. Since then, several biosimilars have been introduced to the market (infliximab-abda, infliximab-axxq, and infliximab-dyyb), with previous research showing noninferiority and comparable adverse effect profiles.²

In 2021, the University of North Carolina began an initiative to convert patients from the reference product to biosimilars based on market costs. This led to a retrospective analysis of the clinical outcomes of patients who were switched to a biosimilar, if clinically and financially appropriate, compared with those who were only treated with the originator or a biosimilar agent.

A total of 180 patients were included in the analysis, of which half (n = 90) were prescribed a biosimilar. During the observation period, 25 (13.9%) of patients were started and maintained on a biosimilar, 54 (30.0%) were switched from the originator to a biosimilar, and 11 (6.1%) were switched from a biosimilar to to the reference drug.

Of those who received a biosimilar, most (n = 79, 87.8%) were maintained on a single biosimilar without the need to switch to an alternative infliximab product. These results underscored the safety and efficacy of these biosimilar options in comparison to the reference drug.

A total of 35 adverse effects were reported during the study period, of which approximately half (n = 18, 51.4%) were attributed to the infliximab originator. The 17 adverse events in the biosimilar cohort represented 9.4% of the total study population. Within this group, 7 patients reported a worsening of symptoms with the biosimilar compared with the originator, despite generally well-controlled clinical status at baseline (3.8% of the entire study population and 12.9% of the biosimilar-switch population). However, investigators believe these patients may not have received adequate trials of the biosimilar in most cases, as determined by the limited amount of biosimilar doses received.

Investigators noted limitations including the retrospective study design, which had inherent reliance on patient reporting and clinician documentation within the electronic health record to assess outcomes, which may have introduced the potential for recall bias. Additionally, the outcomes of autoimmune conditions are often subjective and difficult to capture with quantifiable data. Finally, the biosimilar infliximab-dyyb was not available at the time of this study, which led to a gap in knowledge regarding clinical outcomes.

“The experiences with this initiative are consistent with this preexisting literature, suggesting the overall effectiveness and safety of biosimilar products, even in patients previously well-maintained on an alternative or originator product,” investigators concluded. “Ultimately, more work is needed from pharmacists to provide education to both patients and providers on biologic biosimilar products, as this may lead to cost savings passed on to patients and the health care system if biosimilar use is increased.”

References

1. ^{Steedman S, Giang J. Outcomes of the use of infliximab biosimilars in rheumatology and gastroenterology clinics. J Manag Care Spec Pharm. 2024;30(1):22-25. doi:10.18553/jmcp.2024.30.1.22}
2. ^{Smolen JS, Choe JY, Prodanovic N, et al. Safety, immunogenicity and efficacy after switching from reference infliximab to biosimilar SB2 compared with continuing reference infliximab and SB2 in patients with rheumatoid arthritis: results of a randomised, double-blind, phase III transition study. Ann Rheum Dis. 2018;77(2):234-40.}