Does multiple biosimilar switching induce flare in IBD patients?

Multiple biosimilar infliximab (IFX) switching among patients with inflammatory bowel disease (IBD) does not seem to give rise to disease flares at 12 months compared to those who continued using IFX originator or those on single IFX biosimilar switch, a study has shown.

However, a double switch (DS) appears to contribute to a higher likelihood of infection as compared with a single switch (SS).

“IFX biosimilars are available for IBD, [and] many options of IFX biosimilars exist, [but] there is a paucity of data on the safety and efficacy of switching between multiple IFX biosimilars,” according to the researchers led by Jason Hou, director of Inflammatory Bowel Diseases, Michael E. DeBakey Veterans Affairs (VA) Medical Center in Houston, Texas, US.

Hou and his team performed this retrospective cohort study of 789 IBD patients who received maintenance IFX originator from 2017 to 2019 in the national VA healthcare system. They used a previously validated algorithm to identify patients with Crohn’s disease (CD) and ulcerative colitis (UC). A chart review confirmed all cases, exposures, and outcomes.

The research team identified patients on IFX originator using dispensed medication from the VA Corporate Data Warehouse. Then, they classified individuals as follows: no-switch (NS; receiving originator but no biosimilar during study period), SS (switch from IFX originator to one biosimilar), or DS (switch from IFX originator to two different biosimilars).

IBD flare, defined as escalation of steroid, IBD-related emergency department visit, or hospitalization within 12 months, was the primary outcome. Secondary outcomes included serious infection, infusion reaction, and immunogenicity. Finally, Hou and colleagues used univariate and multivariate logistic regression models, adjusted for patient and nonpatient factors, to compare event rates across groups.

Flare events

Of the patients on maintenance IFX originator identified, 487 had CD, 298 had UC, and four had IBD of unknown cause. Additionally, 410 patients were categorized as NS, 249 as SS, and 130 as DS. [Hou, J, et al, CCC 2024]

At 12 months, the overall rate of flares stood at 19.9 percent (22.2 percent in NS, 15.3 percent in SS, and 21.5 percent in DS; p=0.08), while that of infection was 11.2 percent (11.5 percent in NS, 8 percent in SS, and 16.2 percent in DS; p=0.056). Notably, the rates of immunogenicity or infusion reaction did not differ significantly between the DS and NS or SS groups.

Multivariate logistic regression, adjusted for age, race, gender, comorbidity, concomitant medication, and VA priority status, showed no significant differences in flares between the DS and NS (adjusted odds ratio [aOR], 1.12, 95 percent confidence interval [CI], 0.68‒1.84) or SS groups (aOR, 0.64, 95 percent CI, 0.36‒1.12) at 12 months.

Furthermore, multivariate analyses revealed the association of SS with a lower infection rate compared with DS (aOR, 0.41, 95 percent CI, 0.21‒0.82). [CCC 2024, abstract S7]

“These findings provide reassurance that multiple IFX biosimilar switching for IBD is effective but further study on infection risks may be warranted,” according to Hou and colleagues.