Adalimumab Biosimilar Switching Policy Shows Long-Term Success in IBD

Patients with inflammatory bowel disease (IBD) experienced long-term safety and efficacy after transitioning from reference adalimumab (Humira) to an adalimumab biosimilar as part of a mandatory nonmedical switching policy, according to a Canadian study.1

The retrospective analysis, published in the World Journal of Gastroenterology, sought to assess how long-term clinical outcomes were maintained among patients with IBD in British Columbia, the first Canadian province to enact a mandatory biosimilar transition policy as a means to promote biosimilar use and reduce pharmaceutical costs for the province’s public payer, BC Pharmacare.2

Over 5 years, the British Columbia biosimilar initiative saved the province $732 million, which could be reinvested into the BC Pharmacare’s program to enhance drug coverage and health care services.3 The initiative began in 2019, with patients on certain reference agents, particularly biologics for chronic rheumatic conditions and diabetes, switching to an initial list of biosimilar options.4 The programs were rolled out in 3 phases, with each phase including more affected reference agents. Since 2019, 10 other Canadian jurisdictions have adopted similar transition policies.5

The single-center, retrospective observational study was conducted at the IBD Centre of British Columbia (IBDCBC), a major tertiary referral center in Vancouver, Canada. Researchers identified eligible patients who switched from Humira to a biosimilar between January 2020 and April 2023 using the IBDCBC’s electronic medical record, the IBD Data Lake, and the biosimilar’s patient support program. Researchers examined adults with IBD in symptomatic remission who were required to switch to a biosimilar due to the BC switching policy; patients who remained on Humira served as the control group.

Data collected included demographic information, disease characteristics, treatment history, biomarkers, and clinical outcomes up to 30 months post switch. The primary outcome was treatment persistence, and secondary outcomes included reasons for discontinuation, clinical remission rates, therapy modifications, and health care utilization.

During the mandated adalimumab biosimilar switch period (April 7, 2021, to October 6, 2021), 271 patients met the inclusion criteria, with 43 remaining on Humira and 228 switching to biosimilars. The study cohort included 227 patients with Crohn disease (CD; 83.8%) and 44 patients with ulcerative colitis (UC; 16.2%), with similar disease severity and phenotype across both groups.

Among the biosimilar switchers, the most commonly used products were Hulio (37.7%), Hadlima (27.6%), Hyrimoz (21.1%), Idacio (11.8%), and Amgevita (1.74%). The mean (SD) duration of ADA continuation post switch was comparable between groups (26.5 [7.92] months for originators vs 24.4 [7.07] months for biosimilars), with no statistically significant difference in treatment persistence at 30 months (83.7% vs 88.2%; P = .451).

A Kaplan-Meier survival analysis also showed similar discontinuation rates (P = .543), with Hyrimoz exhibiting the highest treatment persistence and Hulio the lowest, although neither was statistically significant. CD and UC subgroups also demonstrated no significant differences in treatment persistence (CD, 88.5% switchers vs 82.9% originators; P = .399; UC: 86.1% vs 87.5%; P = 1.0).

Adverse outcomes, including loss of response (LOR) and adverse events (AEs), were comparable between groups (39.5% originators vs 28.9% biosimilars; P = .206), leading to hospitalizations in 11.6% of originators and 5.7% of biosimilar switchers (P = .173). LOR affected 27.9% of originator patients, with 9.3% requiring hospitalization, compared with 17.5% of biosimilar switchers, with 5.26% requiring hospitalization.

AEs led to treatment discontinuation in 11.6% of originators and 11.4% of biosimilar switchers. While both groups experienced mild, non-specific symptoms, emergency department visits for AEs were only observed in the originator group. Overall, the study found no significant differences in treatment persistence, LOR, or AE rates between originator and biosimilar groups over the 30-month follow-up period.

Patients with IBD who switched from reference adalimumab (Humira) to a biosimilar maintained similar remission rates from baseline to 6 months post-switch (86% vs 82%), according to a separate retrospective meta-analysis covering all of Canada.6 Similarly, the authors reported that 75% of patients who transitioned from reference infliximab (Remicade) to a biosimilar version had clinical remission 12 months after switching, matching the preswitch remission rate of 75%.

The authors noted that their findings on remission rates “should be reassuring to patients and clinicians,” as the data showed no significant differences in clinical effectiveness or serious adverse events between originators and biosimilars.

References

1. Kiow JLC, Hoang T, Bedi HK, et al. Real-world experience and long-term outcomes of a mandatory non-medical switch of adalimumab originator to biosimilars in inflammatory bowel disease. World J Gastroenterol. 2024;30(46):4904-4913. doi:10.3748/wjg.v30.i46.4904

2. Davio K. British Columbia becomes the first Canadian province to mandate a switch to biosimilars. The Center for Biosimilars®. May 28, 2019. Accessed February 25, 2025. https://www.centerforbiosimilars.com/view/british-columbia-becomes-the-first-canadian-province-to-mandate-a-switch-to-biosimilars

3. Jeremias S. British Columbia’s biosimilar switching program saves $732 million in 5 years. The Center for Biosimilars. June 18, 2024. Accessed February 25, 2025. https://www.centerforbiosimilars.com/view/british-columbia-s-biosimilar-switching-program-saves-732-million-in-5-years

4. Hagen T. British Columbia moves into third phase of mandatory switching. The Center for Biosimilars. August 25, 2020. Accessed February 25, 2025. https://www.centerforbiosimilars.com/view/british-columbia-moves-into-third-phase-of-mandatory-switching

5. Jeremias S. Prince Edward Island announced new biosimilar switching policy. The Center for Biosimilars. October 14, 2023. Accessed. Accessed February 25, 2025. https://www.centerforbiosimilars.com/view/prince-edward-island-announces-new-biosimilar-switching-policy

6. Ferreri D. Switching patients with IBD to infliximab, adalimumab biosimilars did not impact efficacy. The Center for Biosimilars. June 8, 2024. Accessed February 25, 2025. https://www.centerforbiosimilars.com/view/switching-patients-with-ibd-to-infliximab-adalimumab-biosimilars-did-not-impact-efficacy