Switching infliximab to subcutaneous from intravenous therapy (swimsuit) - a prospective, real-world phase iv interventional study

Introduction

Subcutaneous (SC) infliximab (CT-P13) was approved in 2020 by the EMA for use in IBD. This offers patients flexibility and the convenience of administering their treatment at home as well as other potential therapeutic benefits. We aim to evaluate the clinical outcomes of patients switching from intravenous (IV) infliximab (IFX) to SC CT-P13.

Methods

Patients established on IV IFX were offered the opportunity to switch to SC CT-P13. Those who switched were followed up every 12 weeks for 24 weeks. Demographics, IBD history, disease activity scores (mHBI or SCCAI), IBD CONTROL (IBD-C) PROM, SF36, calprotectin, standard blood tests, IFX drug levels, antidrug antibodies (ADA) and adverse events were collected at each visit. The primary endpoint was the maintenance of clinical status at week 24 (W24). A failure to maintain clinical status was defined as an increase in mHBI or SCCAI of ≥3, and/or a decline in IBD-C PROM score of ≥4 points during the study period.

Results

We approached 204 patients receiving IV IFX, of which 120 patients switched to SC CT-P13 (75.8% CD, 22.5% UC, 1.7% IBDU). Median age was 38. 96 patients were on concomitant immunomodulators (79 thiopurines, 17 methotrexate) and 105 were treated with SB2 preswitch. The median duration of IV IFX prior to switching was 45 months. 70 (58%) of the patients were on the standard dosing (5mg/kg Q8W) regimen. All patients were switched to 120mg of SC CT-P13 every other week, regardless of their baseline regimen. 11 (9.2%) patients discontinued the treatment prior to finishing the study. 75% (CI 0.65, 0.82) of the whole cohort maintained clinical status at week 24. There was no statistically significant difference in disease activity scores or IBD-C PROM between baseline and W24. 31 (25.8%) of the patients had evidence of immunogenicity at baseline (ADA of > 50ng/ml). of the 89 patients with no immunogenicity at baseline, 69 (77.5%) maintained this at W24. The median serum IFX levels increased by 72.8% from baseline to W24 (3.05 µg/ml to 5.27 µg/ml (figure 1a)). 81.7% of the patients maintained their immunogenicity status at W24 (figure 1b). Patient satisfaction with SC CT-P13 was very high.

Conclusion

Switching patients from IV to SC CT-P13 is safe, effective, and well-accepted with higher IFX serum levels. The majority of the patients with no immunogenicity at baseline maintained this at W24