P1015 Subcutaneous infliximab effectively manages clinical outcomes of Inflammatory Bowel Disease independently of various confounding factors

Abstract

Abstract Background Since its approval, many inflammatory bowel disease (IBD) patients have been treated with subcutaneous (SC) infliximab (IFX), but the association of various confounding factors with clinical outcomes is still elusive. Methods The ASSEMBLE project is an initiative to combine multi-national real-world cohort datasets and analyse the effectiveness and safety of SC IFX therapy. In the ASSEMBLE-1 database analysis, three studies from France and the United Kingdom1-3 were integrated to assess the clinical outcomes up to 6 months (6M) after switching from IV to SC IFX. Clinical remission was defined as Harvey-Bradshaw Index (HBI) or modified HBI (mHBI) <5 for Crohn’s disease (CD) and Simple Clinical Colitis Activity Index (SCCAI) or partial Mayo score (PMS) <3 for ulcerative colitis (UC). Treatment persistence was assessed by Kaplan-Meier survival analysis. After adjustment with inverse probability of treatment weights (IPTW), the association of various parameters on clinical outcomes was assessed with marginal structural models (MSMs), by comparing the estimated marginal means (EMMs) of remission rates at 6M between patients in each subgroup. Results The data of 428 patients were pooled from the three datasets (70.6% CD, 29.4% UC). 85.4% of patients were in clinical remission before switching to SC IFX with median HBI or mHBI of 1 (IQR 0,2) for CD and median SCCAI of 2 (IQR 1,3) or PMS of 0 (IQR 0,0) for UC. The overall clinical remission and persistence rates at 6M after switching were 84.7% and 94.5%, respectively. Pre-switch IV IFX regimens, immunomodulator (IMM) use, age, baseline fecal calprotectin (FC) level, or baseline C-reactive protein (CRP) level were not associated with persistence. Persistence rate was >90% regardless of body mass index (BMI), although it was higher for patients <25 kg/m2 BMI (98.1%). Assessment with MSMs indicated that the clinical remission rate of CD, but not UC, was expected to be significantly lower only if patients were treated with escalated IV IFX before switching rather than standard 5 mg/kg Q8W regimen (p=0.01; Table 1). No association with high BMI, IMM use, age, ≥150 μg/g FC, and ≥5 mg/L CRP was found in both CD and UC (Table 1). Perianal disease was not associated with CD remission either. Conclusion The ASSEMBLE-1 results confirm that switching from IV to SC IFX is well accepted and effectively manages the clinical outcomes of the disease regardless of various confounding factors in IBD patients. However, further studies are warranted to explore the association of pre-switch IV IFX regimens with clinical outcomes. [1] Smith et al. J Crohns Colitis 2022 [2] Buisson et al. Clin Gastroenterol Hepatol 2023 [3] Rahmany et al. Gastroenterology 2023.