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A mandatory, nonmedical switch from infliximab to a biosimilar for inflammatory bowel disease (IBD) indicated that the two treatments have similar clinical outcomes.

After 1 year, there were no differences in the number of patients who stopped taking their medication or the number of patients who had adverse events or immunogenicity within the first 12 months of the switch.

These data support the safety and efficacy of nonmedical infliximab switching in patients with IBD, wrote study author Thomas Tam Hoang, a medical resident at the University of British Columbia Faculty of Medicine in Vancouver, British Columbia, Canada, and colleagues.

"Overall, the switch was well-tolerated and safe for gastroenterologists to give across Canada for their IBD patients," he told Medscape Medical News.

Their findings were published on March 23 in the Journal of the Canadian Association of Gastroenterology.

Patient Apprehension

The safety of biosimilars, biologic treatments that have a high degree of similarity to the corresponding originator molecules but are not identical, has been studied extensively. Biosimilars have been used in Europe and are generally accepted as a first-line therapy in biologic-naive patients.

Little, however, is known about the effects of switching patients who are established on their anti–tumor necrosis factor therapies, Hoang told Medscape Medical News.

In 2019, the first Canadian biosimilars initiative was launched in British Columbia. The nonmedical initiative was established to switch stable patients from the originator drug (ie, infliximab) to a biosimilar approved by Health Canada (CT-P13 or SB2).

"When the biosimilar switch was mandated in BC, there was a lot of apprehension, especially in our patient population, about switching medications that they had been on for their IBD for so long," said Hoang.

"Given that we are one of the first jurisdictions in BC leading the biosimilar switch initiative in Canada, we wanted to see whether there could be any adverse outcomes with switching to biosimilars. That was the main driver for the study. We wanted to help reassure our patients and to help guide other provinces when they eventually go through the switch," he added.

Similar Outcomes

The retrospective observational study enrolled stable patients with IBD from the IBD Centre of British Columbia. Patients were separated into a biosimilar group that was switched from infliximab to CT-P13 or SB2 or into a control group of patients who remained on infliximab throughout the study period. Eligible patients were 18 years or older and had a clinical, endoscopic, or radiologic diagnosis of Crohn's disease or ulcerative colitis.

The primary outcome of the study was treatment continuation at 12 months post switch. Secondary outcomes included frequency of loss of response, adverse events, and immunogenicity within the first 12 months after the switch.

There were 264 patients in the biosimilar group and 99 patients in the originator group. The two groups had similar demographic and disease characteristics.

All outcomes were similar between the two groups. There was no difference in treatment continuation between the biosimilar group (90.1%) and the originator group (94.9%).

Reasons for discontinuation of treatment included loss of response, which occurred in 4.04% of the originator group and 4.91% in the biosimilar group; immunogenicity, which occurred in 1.01% of the originator group and 0.75% of the biosimilar group; and adverse effects, which occurred in 1.01% of the originator group and 3.02% of the biosimilar group.

"We reassuringly found that patients who switched to the biosimilar versions of infliximab did not have any worse clinical outcomes compared with the patients who remained on the original molecule. There was no increase in the rate of flare of their disease after they switched, there was no increased rate of new adverse reactions to the drug, and there was no increased rate of immunogenicity," said Hoang.

Results 'Completely Unsurprising'

Commenting on the study for Medscape Medical News, Laura Targownik, MD, a clinical researcher at the Mount Sinai Hospital IBD Clinic and associate professor of medicine at University of Toronto's Temerty Faculty of Medicine, said that the results were "completely unsurprising. It confirms what everybody already knows."

But the issue in the case of mandated switching is convincing patients who have long been stable on infliximab to change to a biosimilar.

"A lot of patients, especially when they are on a drug for several years and are stable and comfortable with that drug, are apprehensive with the government coming in saying, 'To save money, we've got to switch you to another drug that has a new name and comes in a different needle and a different box.' Patients are wondering, 'Why are they doing this to me? Cheaper is usually not better. I don't want to do this,'" said Targownik.

"These study results are reassuring. But I think at this point that very few clinicians are worried about undertaking a biosimilar switch. Some might have worried about patients who get very anxious about switching, which could make their IBD worse. But others have shown that when you counsel people effectively about these medications, you can diffuse a lot of that anxiety," she added.

The research was not supported by any grants or funding from public, commercial, or nonprofit agencies. Hoang reported no relevant financial relationships. Targownik reported receiving grants from AbbVie Canada, Janssen Canada, and Pfizer Canada; consulting fees from AbbVie, Takeda, Janssen, Pfizer, Amgen, Viatris, Fresenius Kabi, Bristol Myers Squibb, Sanofi, and Lilly; and honoraria from AbbVie, Takeda, Janssen, Pfizer, Amgen, Viatris, Fresenius Kabi, Bristol Myers Squibb, and Sanofi. She had participated on a data safety monitoring board or advisory board for GoodCap Pharmaceuticals, Pfizer, Takeda, Janssen, and Bristol Myers Squib. She is a member of the Crohn's and Colitis Canada Scientific and Medical Advisory Board.