Concomitant use of immunomodulators and dosage are important variables in the development of antidrug antibodies (ADAs) for patients receiving infliximab for Crohn disease, investigators report.
Using data from a study (N = 220) of the infliximab biosimilar CT-P13 in patients with Crohn disease, investigators said they have improved understanding of the clearance of infliximab and its predictive value for the development of antidrug antibodies (ADA).
Investigators found that initial infliximab clearance, concomitant use of immunomodulators, and infliximab dosage were statistically significant predictors of the time to development of ADAs.
Investigators reported that the risk for ADA increases 61% for every increase of 0.1 L/day in drug clearance; however, it decreases by 41% if immunomodulators are administered concomitantly, and it also decreases 29% with every increase in dosage of 100 mg.
They calculated that for a patient with infliximab clearance of 0.2 L/day who is not taking immunomodulators and has an infliximab dose of 328 mg, the average time to first ADA would be 374 days.
With higher clearance of 0.4 L/day, also with dosage of 328 mg and no immunomodulators, the ADA onset would occur in 144.5 days.
A higher starting infliximab dose of 428 mg would lengthen the time to onset to 203 days, and adding immunomodulator treatment would extend time to ADA onset to 354 days, they said.
“Our results suggest that early assessment of clearance should guide treatment optimization with infliximab in patients with Crohn disease, including the addition of concomitant immunosuppressants or increasing the dose during induction,” authors of the study concluded.
Kutschera M, Primas C, Reinish S, et al. Initial clearance of infliximab is a predictor for the time of formation of anti-drug antibodies. Presented at: ECCO’21 Congress; July 2-3 and 8-10, 2021. Poster DOP74