P0375Kinetics of transmural response and healing in patients treated with biological therapy

Abstract Background We assessed the kinetics of transmural healing in patients with CD treated with anti-TNF agents to define the best time point for therapeutic evaluation. Methods Using a prospective database of patients with CD who underwent MRI for luminal disease evaluation, we analyzed the kinetics of transmural healing in patients older than 18 years receiving anti-TNF therapy, who had objective signs of inflammation o before treatment and had undergone at least one MRI to assess therapeutic efficacy within 12 months. A statistical model based on last-observation-carried-forward imputation and clinical relevance was applied. Transmural healing was then assessed monthly during the first year. Transmural healing was defined as a C-score 0.5 in each segment 1. Results A total of 123 patients were included. Among them, 90 were women (73.1%), 48 (39.9%) were smokers, and 53 (43.0%) had undergone prior intestinal resection. The median CD duration at inclusion was 7.6 years 1.4–15.2. At treatment initiation, 41 patients (33.3%) were anti-TNF naïve. Infliximab, adalimumab, and golimumab were used in 67 (55.3%), 53 (43.8%), and 1 (0.8%) patients, respectively, with concomitant immunosuppressive therapy in 94 patients (79.0%). At baseline, 220 segments were considered active (C-score 0.5), including 100 in the terminal ileum and 120 in the colon/rectum. Segment-level transmural healing rates (N = 220) were 6.4% at M1, 6.4% at M2, 10.0% at M3, 10.1% at M4, 14.6% at M5, 18.0% at M6, 23.2% at M7, 24.5% at M8, 26.0% at M9, 26.8% at M10, 29.1% at M11, and 30.4% at M12 (Figure 1). Kinetics of transmural healing among terminal ileum segments (n = 100) and colorectal segments (n = 120) within the first 12 months are shown in Figure 2. In the 123 patients with CD, multivariate analyses showed that absence of transmural healing (C-score 0.5) during the first year was associated with an increased risk of surgery (HR = 3.37 1.30–8.68; p = 0.012), treatment discontinuation (HR = 2.31 1.29–4.14; p = 0.005), and progression of bowel damage (p 0.001), with a trend toward increased CD-related hospitalization (HR = 1.92 0.85–4.36; p = 0.11). Conclusion Transmural healing is achievable in more than 30% of active segments in patients with CD treated with anti-TNF agents during the first year. The optimal timing for assessing transmural healing appears to be between 6 and 12 months after anti-TNF initiation, with higher healing rates in colorectal segments compared with ileal segments. Transmural healing, defined by a C-score 0.5, is associated with improved long-term outcomes in patients with CD. Reference: 1. Buisson et al. Clin Gastroenterol Hepatol 2024 Conflict of interest: Prof. Dr. Buisson, Anthony: Consulting fees from: Abbvie, AlfaSigma, Amgen, Arena, Biogen, Celltrion, CTMA, Ferring, Galapagos, Guty Care, Janssen, Hikma, Lilly, Mylan, Nexbiome, Pfizer, Roche, Takeda, Tillotts Lecture fees from: Abbvie, AlfaSigma, Amgen, Biogen, Celltrion, Ferring, Galapagos, Hikma, Janssen, Lilly, Mayoli-Spindler, MSD, Pfizer, Roche, Sanofi-Aventis, Takeda, Tillotts, Vifor-Pharma Research fundings from: Abbvie, AlfaSigma, Celltrion, Janssen, Lessaffre, Lilly, Pfizer, Takeda Domas, Quentin: No conflict of interest Hordonneau, Constance: No conflict of interest Pereira, Bruno: No conflict of interest