Infliximab Biosimilar Not Associated With Adverse Events in IBD

Based on a real-world national cohort of patients in the United States (US), switching to an infliximab biosimilar was not linked to adverse events when compared with continuing with the infliximab originator, according to data presented at Digestive Disease Week (DDW) 2023.¹ Investigators noted that these results provide further reassurance that switching to the biosimilar in patients with Crohn’s disease (CD) and ulcerative colitis (UC) is safe.

Jason Ken Hou, MD, MS

Credit: Baylor College of Medicine

“Infliximab biosimilars are widely available for CD and UC,” Jason Ken Hou, MD, MS, associated with the Baylor College of Medicine, in Houston, Texas, and colleagues. “However, implementation of biosimilar switching has been highly variable in the US. Barriers to switching include patient and provider concerns of lower efficacy, immunogenicity, and safety.”

Investigators evaluated the safety of biosimilar switching in a US cohort of veterans with CD and US that was based on local facility policy instead of patient and provider selection, which was therefore less prone to selection bias.

A retrospective cohort study of this patient population who received maintenance originator infliximab between 2017 and 2019 were included in the analysis. Patients were identified using a validated algorithm and were additionally confirmed by the chart review. Those on the maintenance infliximab originator were identified by dispensed medication from the Corporate Data Warehouse (CDW). Those who switched to the biosimilar after 2017 were classified in the CDW by dispensed medication and were confirmed by a chart review.

Adverse outcomes were categorized as serious infection, including intravenous antibiotic or delay of intravenous, infusion reaction, or immunogenicity, such as anti-infliximab antibody or infliximab escalation. These adverse reactions were also confirmed by chart review. Adverse event rates at 12 months of patients who continued on the originator infliximab were compared to those who switched to the biosimilar via univariate and multivariate logistic regression models which adjusted for patient and non-patient factors.

In total, 790 patients receiving the maintenance infliximab originator were included in the study, with 488 patients diagnosed with CD, 298 diagnosed with UC, and 4 patients with undefined inflammatory bowel disease (IBDU). Of these patients, 380 were switched to a biosimilar, while 410 continued on the infliximab originator.

Overall, adverse outcomes occurred in 35.6% of patients at 12 months (35.6% in the switch cohort and 35.3% in the non-switch group, P = .87). No statistically significant differences in infusion reaction, serious reaction, or immunogenicity rates were identified between both groups. In the multivariate logistic regression that included age, gender, race, concomitant medication, and Veterans Affairs

(VA) priority status, no significant difference in adverse outcomes were observed at the 12-month mark between groups (adjusted odds ratio [aOR] 1.09, 95% confidence interval [CI] .76-1.42).

References

1. ^{Hou JK, Pham C, Sansgiry S, Modi V, et al. BIOSIMILAR INFLIXIMAB SWITCHING IS NOT ASSOCIATED WITH ADVERSE OUTCOMES: A REAL-WORLD EFFECTIVENESS ANALYSES IN A NATIONAL COHORT OF U.S. MILITARY VETERANS WITH INFLAMMATORY BOWEL DISEASE. Abstract presented at Digestive Disease Week (DDW) 2023 Annual Meeting. Chicago, IL. May 6-10, 2023.}