New Research Finds Switching to CT-P13 Is Safe in IBD, and So Is Switching to the Reference

The body of evidence demonstrating the safety and efficacy of biosimilar infliximab, CT-P13 (Inflectra, Remsima), is growing, particularly in the extrapolated indication of inflammatory bowel disease (IBD). This month saw the publication of 2 new studies that provided reassuring data on CT-P13, one of which focused on switching pediatric patients with IBD to CT-P13, and the second of which explored switching to the reference infliximab from the biosimilar in adults with IBD.

While much of the literature on switching to a biosimilar in IBD focuses on adult patients, the first study¹ evaluated the long-term trough levels, immunogenicity, and remission rates in children with IBD who switched from the reference infliximab to the biosimilar in a single center.

In the study, all children (n = 42) with Crohn disease (CD) and ulcerative colitis (UC) who were receiving maintenance therapy with infliximab in the center were switched from the reference product to the biosimilar.

In total, 26 of the patients had CD and 16 had UC. The patients’ median duration of treatment with the reference infliximab was 13.5 months (range, 6.8-35.5) before the switch took place. The investigators found no significant changes in infliximab trough levels after switching; the median baseline trough level was 5.7 µg/mL (range, 3.8-9.3) versus 6.5 µg/mL (3.9-8.6) at 6 months post-switch (P = .900).

One patient tested positive for antibodies to infliximab after switching. The proportion of patients who were in remission prior to the switch did not change significantly, and no significant changes were observed with respect to C-reactive protein, erythrocyte sedimentation rate, albumin levels, weight, or body mass index after the switch, and the safety profile of the 2 drugs was comparable.

Pediatric patients with IBD, concluded the authors, “can be successfully switched during maintenance to biosimilar CT-P13 without affecting efficacy, pharmacokinetics, immunogenicity or safety.”

The second study² focused on another lesser-investigated area in IBD: switching to a reference product after treatment with a biosimilar.

The prospective observational study followed 174 Hungarian patients with IBD, 136 of whom had CD and 38 of whom had UC. These patients had received all maintenance therapy with the biosimilar (and 14 patients had previously received the reference infliximab), but they were switched to the reference product in 2017 as a result of a change in reimbursement policies in the national healthcare system.

The investigators collected information from the patients 8 weeks pre-switch, at the time of the switch, and at weeks 16 and 24. The research team found no significant difference in the proportion of patients in clinical remission at any of the timepoints:

• Pre-switch, 82.5% of patients with CD and 82.9% of patients with UC were in remission.
• At the time of the switch, these percentages were 80.6% and 81.6%.
• At week 16, these percentages were 77.5% and 83.7%.
• At week 24, these percentages were 76.3% and 84.9%.

For all patients, the mean serum trough levels of infliximab were 5.33 μg/ml (±4.70) at baseline and 5.69 μg/ml (±4.94) at week 16 (P =.71). There was no significant difference in the prevalence of anti-drug antibodies at baseline versus week 16. A total of 4 infusion reactions were reported.

Notably, there was no difference in outcomes, trough levels, or levels of antibodies to infliximab among the patients who had been previously exposed to the reference product and patients who had only received the biosimilar.

References

1. van Hoeve K, Dreesen E, Hoffman I, et al. Efficacy, pharmacokinetics and immunogenicity is not affected by switching from infliximab originator to a biosimilar in pediatric patients with inflammatory bowel disease [published online January 9, 2019] Ther Drug Monit. doi: 10.1097/FTD.0000000000000601.

2. Ilias A, Szanto K, Gonczi L, et al. Outcomes of patients with inflammatory bowel diseases switched from maintenance therapy with a biosimilar to Remicade [published online January 7, 2019] Clin Gastroenterol Hepatol. doi: 10.1016/j.cgh.2018.12.036.