Adalimumab Biosimilars as Effective as Origin Formula in Patients With IBD

Between April and September 2021, the Canadian province of British Columbia implemented a mandatory nonmedical switch of Humira (adalimumab) to one of five approved biosimilars. There is existing evidence supporting the safety and efficacy of adalimumab biosimilars, but researchers led by Thomas Hoang, MD, sought to establish data on nonmedical switching in patients with irritable bowel disease (IBD). The findings were presented at ACG 2024.

The retrospective observational study was conducted using a patient database from IBD Centre of BC and compared disease outcomes of patients on adalimumab who switched to one of the five approved biosimilars with disease outcomes in patients who elected to stay on adalimumab through compassionate support or private pay.

The primary study outcome was treatment persistence at 30 months post-switch, which was assessed by Kaplan-Meier survival analysis. Secondary outcomes included frequency of reason for adalimumab discontinuation, loss of response rates, adverse events, and clinical and biochemical remission status.

Both groups (originator, n=43; biosimilars, n=228) displayed similar demographics and baseline disease characteristics. By the study endpoint of 30 months, there was no difference in the rate of treatment persistence in either group (n=36, 83.7% originator vs n=201, 88.2% biosimilars; P=.45).

Kaplan-Meier treatment persistence analysis demonstrated similar rates of discontinuation between the two groups (log-rank P=.537), and there was numerical but not statistically significant difference in the rates of adverse events between either group (39.5 originator vs 28.9% biosimilars; P=.206). This includes comparable rates of loss of response (27.9% vs 17.5%) or adverse events (11.6% vs 11.4%) between the two groups. C-reactive protein and fecal calprotectin levels were also similar one year pre- and post-switch.

The data show that nonmedical switching to adalimumab biosimilars did not result in difference in treatment persistence or adverse outcomes, which will help further inform patients and physicians who are currently switching to biosimilar adalimumab.