Effectiveness of an Infliximab Biosimilar vs. Originator in Inflammatory Bowel Diseases: A Noninferiority Nationwide Study From the epi-IIRN.

GOALS: Definitively prove noninferiority of biosimilar infliximab to originator.

BACKGROUND

The advent of biosimilar agents has made biological medications for inflammatory bowel diseases (IBD) more affordable and widely available. We conducted a noninferiority assessment of the effectiveness of the infliximab biosimilar agent CT-P13 versus the original for treatment of IBD in a nationwide analysis.

STUDY: We used the Epidemiology Group of the Israeli Inflammatory Bowel Disease Research Nucleus Cohort (epi-IIRN), including data on patients with IBD from all Health Maintenance Organizations (HMO) and conducted a noninferiority analysis of infliximab originator and biosimilar CT-P13 based on time from induction of treatment until failure. Treatment failure was defined as steroid dependency, need for IBD-related surgery, or treatment change to an alternative biological. The groups were matched using a propensity score of 0.15 caliper based on sex, ethnicity, district, socio-economic status, age at diagnosis, disease activity, time until biological treatment, prior biological treatments, surgeries, and hospitalizations.

RESULTS

We compared 564 patients treated with infliximab originator matched to 564 treated with CT-P13. The results proved noninferiority in all parameters, with a margin of d=10% or smaller over 5 years (P<0.05). In time to failure, noninferiority was demonstrated with a d=1% (P=0.0004). Noninferiority was also demonstrated in time to steroid dependency (d=5%, P=0.005), surgery (d=1%, P=0.0006), and transfer to alternative biological drug (d=1%, P<0.001). Subanalyses for Crohn's disease and ulcerative colitis separately yielded similar results.

CONCLUSIONS

This study demonstrated noninferiority of infliximab biosimilar CT-P13 in comparison to the original in long-term management of IBD.