P424 Monitoring response to adalimumab therapy in Crohn’s disease patients by bowel ultrasound: Sub-analysis from TRUST

Abstract

Background: Transabdominal ultrasound (US) is a non‐invasive diagnostic modality providing objective parameters of Crohn's disease (CD) activity. Disease management concepts (treat‐to‐target, T2T, tight control) integrate objective and clinical parameters for guiding treatment optimisation resulting in improved outcomes as demonstrated by the CALM study for adalimumab (Ada) therapy. Hence, US parameters such as bowel wall thickening (BWT) could serve as adjunctive objective parameters for treatment optimisation. Here, we assessed the utility of US for monitoring response to Ada therapy. Methods: This sub‐analysis of TRUST (transabdominal ultrasonography of the bowel in subjects with crohn's disease to monitor disease activity1), a prospective, observational multi‐centre study assessed US, clinical (Harvey Bradshaw Index, HBI) and laboratory parameters (CRP) during Ada therapy in patients with active CD (HBI≥7) at 0, 3, 6, 12 months (Visit V0‐V3). Threshold for BWT was >2 mm for terminal ileum. Results: Seventy‐nine of 234 patients in TRUST (33.8%) received Ada at any of the 4 study visits, 49 of these started Ada therapy after V0 and where used for further analyses. Median disease duration was 3.23 years. All patients had active CD and 75.5% had a BWT in the terminal ileum, 44.9% loss of bowel wall stratification and 38.8% a marked increase in colour Doppler US (Limberg scores of 2‐4) at V0. The rates of terminal ileum BWT at V0‐V3 are shown in Table 1. CRP and HBI showed a moderate correlation (V0‐V3 Spearman's correlation coefficient: r = 0.528). Comparison before vs. after, Ada therapy led to a significant improvement of both parameters (median ΔHBI:‐5, p < 0.001; median ΔCRP:‐6.65 μg/ml, p = 0.003). When stratifying patients for the presence of BWT, HBI and CRP were not significantly different. Comparison of bowel wall vascularity (Limberg score 1/2 vs. 3/4), patients showed significant differences in mean HBI (4.0 vs. 9.3; p = 0.017) and CRP (13.1 vs. 41.2; p = 0.015) already at V1. Table 1. US parameters at different study visits. Parameter Value V0 (n = 49) V1 (n = 48) V2 (n = 47) V3 (n = 44) P value (all visits) BWT, terminal ileum [% (n)] Yes 75.5 (37) 58.3 (28) 57.4 (27) 43.2 (19) 0.001 No 22.4 (11) 39.6 (19) 36.2 (17) 52.3 (23) N/A 2.0 (1) 2.1 (1) 6.4 (3) 4.5 (2) Loss of bowel wall stratification [% (n)] Yes 44.9 (22) 35.4 (17) 36.2 (17) 20.5 (9) 0.008 No 55.1 (27) 62.5 (30) 63.8 (30) 77.3 (34) N/A 0.0 2.1 (1) 0.0 2.3 (1) Conclusions: US was useful for monitoring disease activity and Ada treatment response. Most bowel US parameters improved significantly over the study period. Disease activity (HBI, CRP) improved upon Ada treatment and correlated with Limberg score but not with the presence of BWT. Hence, transabdominal US allows monitoring early and long‐term response to treatment and should be considered for implementation into emerging T2T concepts.