Differences in Post-Induction Levels and Response Rates Between Crohn's Disease and Ulcerative Colitis Medications

A comparison of infliximab brands Inflectra and Remsima in patients with Crohn's disease and ulcerative colitis reveals differences in post-induction levels and response rates, suggesting potential considerations for dosing adjustments based on brand.

Researchers switched from prescribing Inflectra to Remsima in 2022 and compared treatment persistence and response between the 2 brands. They assessed infliximab levels, dose escalation rates, and reasons for switching using statistical analysis. The analysis included a total of 82 patients with Crohn’s disease or ulcerative colitis. Among them, 42 had Crohn’s disease and 40 had ulcerative colitis. Of these patients, 35 initially received induction with Inflectra before switching to Remsima, while 47 received Remsima induction. 

Post-induction levels showed higher mean levels with Inflectra (8.08 µg/mL) compared to Remsima (5.01 µg/mL; P = 0.02642). Pre-switch levels between Inflectra (8.44 µg/mL) and Remsima (8.57 µg/mL) were almost the same with a P-value of 0.177. Among those who received Remsima induction, 27.7% required dose escalation compared with 20% of those induced with Inflectra (P = 0.4508). Additionally, 40% of patients on Inflectra switched to another biologic class due to loss of response or inadequate drug levels with high antibody formation, compared with 47% of those switched from Remsima for the same reasons (P = 0.621).

“Post-induction trough levels of infliximab differ between brands. This should be taken into consideration when considering higher dosing at induction or for those patients treated with infliximab for acute severe colitis and earlier accelerated dosing should be considered in those patients treated with Remsima who have a slow clinical response to treatment,” researchers said. “Trough levels once established on the drug appear to be similar and rates of switching out of class due to failure to respond/loss of response and antibody formation comparable.” 

Reference
Patel P, Love M, Rimmer P, Cooney R, Hazel K. P1107 Biosimilar but not quite the same?: Post-induction levels of infliximab differ between brands. J Crohn's Colitis. 2025;19(1):i2039. doi:10.1093/ecco-jcc/jjae190.1281