DOP07 Monitoring disease activity by intestinal ultrasound predicts biologic treatment persistence in patients with Inflammatory Bowel Disease

Abstract

Abstract Background Current biomarker-based monitoring strategies have limited efficacy in predicting risk of biologic treatment failure in inflammatory bowel disease (IBD). Endoscopic assessment identifies patients at risk of disease progression but is expensive and poorly accepted by patients. Therefore, we examined how intestinal ultrasound (IUS) performed as part of a monitoring program to predict treatment persistence to biologics in IBD patients. Methods Data were generated as part of a 1-year prospective, observational, cohort study of patients on biologics comparing tight monitoring to a historic cohort (‘Time It´ study). Data used in the present analysis included Harvey Bradshaw index (HBI), simple clinical colitis activity score (SCCAI), CRP, f-calprotectin (FC), IUS, and ileocolonoscopy all done at inclusion. The following definitions were used: Treatment persistence: no need for dose escalation or switching to another biologic or small molecule; IUS transmural remission (TR): bowel wall thickness ≤3mm in all bowel segments and zero color Doppler activity; endoscopic remission (ER): simple endoscopic score (SES)-CD≤2 or Mayo endoscopic score 0; clinical remission (CR): HBI≤4 or SCCAI≤2; FC remission (FCR): FC≤250; CRP remission (CRPR): CRP≤10 mg/L. Chi-square tests and Kaplan-Meier statistics were used to compare baseline measures in treatment persistent and non-persistent patients. Results Of the 91 patients included in 'Time It’, 77 had IUS performed and 69 ileocolonoscopy. Of the 77 patients, 61% were on maintenance treatment at inclusion and 39% were included during induction (Table 1). COVID-19 restrictions were the main reason for missing IUS or endoscopy. As expected, more patients with ER had 1-year treatment persistence (87% vs. 41%; p<0.001). However, patients with IUS TR also had better treatment persistence (78% vs. 38%; p<0.001). CR or FCR were associated with treatment persistence (p<0.05 and p<0.01, respectively), but not CRPR. Combining TR and FCR performed numerically as well as ER (treatment persistence 85% vs. 41%, p=0.002). Survival analysis of TR showed a mean treatment persistence of 318 days vs. 221 days without TR (p<0.001); corresponding treatment persistence data were 327 days vs. 230 days for combined TR and FCR; and 338 days vs. 226 days for ER (both p<0.001; Figure 1). There was no difference in mean treatment persistence between TR and ER (318 vs. 338 days; p=0.36). Conclusion IUS alone or combined with FCR was comparable to endoscopy to identify patients with high biologic treatment persistence. Being a non-invasive, patient friendly, cost-effective modality, IUS monitoring may improve current disease monitoring programs aiming to increase treatment persistence.