Thresholds for Subcutaneous Infliximab in IBD: ENEIDA Registry Insights
Overview
Switching from intravenous to subcutaneous infliximab maintains long-term remission in Crohn’s disease and ulcerative colitis patients. Optimal subcutaneous infliximab trough levels associated with remission were identified around 12-13 μg/mL at 12 and 52 weeks post-switch.
Background
Infliximab, a key biologic therapy for inflammatory bowel disease (IBD), was historically administered intravenously. The subcutaneous formulation (SC-IFX) was approved in Europe in 2020, offering comparable efficacy and safety with added convenience. Prior studies demonstrated increased drug levels and maintained remission after switching from IV to SC infliximab. However, data on drug concentration thresholds predictive of sustained remission with SC-IFX remain limited.
Data Highlights
Parameter
Value
Number of patients
220 (146 CD, 74 UC)
Median IV-IFX duration before switch
52.5 months (range 25-89)
Patients on intensified IV-IFX dose
106 (49%)
SC-IFX trough level cutoff at Week 12
12.2 μg/mL (AUC 0.62)
SC-IFX trough level cutoff at Week 52
13.2 μg/mL (AUC 0.57)
Drug persistence at Week 52
92%
Key Findings
Switching from IV-IFX to SC-IFX significantly increased infliximab trough levels without altering clinical remission or inflammatory biomarkers.
Patients on standard IV-IFX dosing had higher SC-IFX trough levels post-switch compared to those on intensified dosing.
Baseline immunomodulatory therapy and presence of perianal disease did not affect SC-IFX trough levels.
Higher body mass index was associated with increased SC-IFX trough concentrations.
Optimal SC-IFX trough concentration thresholds predictive of remission were approximately 12.2 μg/mL at 12 weeks and 13.2 μg/mL at 52 weeks.
High drug persistence (92%) and good safety profile were observed at one year following the switch.
Clinical Implications
Clinicians can consider switching stable IBD patients from IV to SC infliximab to maintain remission while benefiting from easier administration and reduced hospital visits. Monitoring SC-IFX trough levels aiming for concentrations above 12-13 μg/mL may help optimize long-term disease control. Body mass index should be considered when interpreting drug levels, but immunomodulator use or perianal disease presence may not necessitate dose adjustments.
Conclusion
Switching from intravenous to subcutaneous infliximab is a safe and effective strategy to sustain remission in IBD patients, with defined trough level thresholds aiding therapeutic monitoring. This approach offers a favorable pharmacokinetic profile and high treatment persistence over 12 months.
References
ENEIDA Registry Study 2024 -- Thresholds for Subcutaneous Infliximab in IBD Patients
by Marisa Iborra, Berta Caballol, Alejandro Garrido, José María Huguet, Francisco Mesonero, Ángel Ponferrada, Lara Arias García, Marta Maia Boscá Watts, Samuel J Fernández Prada, Eduard Brunet Mas, Ana Gutiérrez Casbas, Elena Cerrillo, Ingrid Ordás, Lucía Ruiz, Irene García de la Filia, Jaime Escobar Ortiz, Beatriz Sicilia, Elena Ricart, Eugeni Domènech, Pilar Nos
Large claims analysis finds no significant differences in serious infections, blood clots, or major cardiovascular events across biologics and a Janus kinase inhibitor.
