When the market exclusivity of the originator infliximab (Remicade) expired in 2014, many patients with inflammatory bowel disease (IBD) transitioned from the originator infliximab to an infliximab biosimilar, driven by cost containment reasons. Transitioning has been proven safe and effective in several double-blind studies, with numerous patients successfully making the switch in clinical practice.

However, approximately 7% of these patients subsequently retransitioned to the originator infliximab, i.e. they stopped the biosimilar and reinitiated the originator, mainly due to a (perceived) increase in disease activity or adverse events after transitioning to the biosimilar. It is unclear whether this sign of potential unsatisfactory treatment response is specifically related to the infliximab biosimilar, the patient, and/or the disease, including patients’ beliefs about the biosimilar. 

Therefore, Meijboom et al. conducted a study with the aim of comparing the risk and reasons for infliximab discontinuation between two groups of patients: those who retransitioned to the originator and those who remained on biosimilar. The study included patients with IBD who had initially transitioned from infliximab originator to the corresponding biosimilar.

The risk and reason for retransitioning were assessed in all IBD patients who transitioned from infliximab originator to biosimilar between January 2015 and September 2019 in two Dutch hospitals. Retransitioned patients were matched with patients remaining on biosimilar (biosimilar remainder patients). The authors categorized patients’ reasons for discontinuing as either an unwanted response (i.e. loss of effect and/or adverse events) or as disease remission. A comparison of the risk of discontinuation due to an unwanted response was conducted between the two cohorts using a Cox proportional hazards model.

The study findings revealed that 22.7% of patients in the retransitioning cohort vs 13.4% in the biosimilar remainder cohort discontinued infliximab due to an unwanted response, and 2.3% vs 9.4% of patients, respectively, discontinued because their disease was in remission. The authors noted that retransitioned patients had more than threefold increased risk of discontinuing due to an unwanted response compared with biosimilar remainder patients (adjusted HR 3.7, 95% CI: 1.0–13.9).

Meijboom et al. further zoomed in on the retransitioned patients. About one in six retransitioned patients retransitioned due to objectively measured increased disease activity, e.g. elevated calprotectin and/or active disease seen on endoscopy, the other patients due to (subjective) symptoms only. Patients who retransitioned due to objectively increased disease activity discontinued their infliximab treatment more often than patients who retransitioned due to symptoms only (66.7% versus 23.7%).

In conclusion, the study demonstrated that patients who retransitioned were more likely to discontinue infliximab treatment due to an unwanted response compared to patients who remained on biosimilar. On the other hand, patients who remained on the biosimilar were more likely to discontinue infliximab due to remission. Patients who retransitioned had more than a threefold increased risk of discontinuing infliximab due to an unwanted response compared to patients who remained on the biosimilar. These findings indicate that retransitioning is mainly related to the patient and/or their disease, including the patients’ beliefs about the biosimilar. It is less likely to be related to the infliximab biosimilar itself. 

The reason for retransitioning, which might have an impact on the course of infliximab originator treatment, is objectively measured disease activity or symptoms only, and it could be of importance in clinical decision-making. Clinicians could consider patients who opt for retransitioning to another treatment option. 

Conflict of interest
The authors of the research paper [1] declared that there were no conflicts of interest.

Abstracted by Rosanne Meijboom, Trainee researcher, Pharmacy Foundation of Haarlem Hospitals (SAHZ), Boerhaavelaan 24, 2035 RC, Haarlem, The Netherlands.
Editor’s comment
Readers interested to learn more about biosimilars infliximab switching are invited to visit www.gabi-journal.net to view the following manuscript published in GaBI Journal: 

Biosimilars in Saudi Arabia: a single-centre, open-label case series examining infliximab switching

GaBI Journal is indexed in Embase, Scopus, Emerging Sources Citation Index and more.

Readers interested in contributing a research or perspective paper to GaBI Journal – an independent, peer reviewed academic journal – please send us your submission here. 

GaBI Journal Citation Impact
2.2 – CiteScore 2021 (calculated on 5 May 2022)

Submit a manuscript to GaBI Journal

Related articles
Infliximab biosimilars for IBD patients: experience from Italy

Discontinuation following biosimilar switching in IBD patients

Reference
1. Meijboom RW, Gardarsdottir H, Becker ML, Movig KLL, Kuijvenhoven J, Egberts TCG, et al. Discontinuation of infliximab treatment in patients with inflammatory bowel disease who retransitioned to originator and those who remained on biosimilar. Therap Adv Gastroenterol. 2023;16:17562848231197923.

Permission granted to reproduce for personal and non-commercial use only. All other reproduction, copy or reprinting of all or part of any ‘Content’ found on this website is strictly prohibited without the prior consent of the publisher. Contact the publisher to obtain permission before redistributing.

Copyright – Unless otherwise stated all contents of this website are © 2024 Pro Pharma Communications International. All Rights Reserved.