P945 Crohn´s disease response to ustekinumab measured by bowel ultrasound

Abstract

Abstract Background After the STRIDE-II update for patients with Crohn’s disease (CD) one of the new possible adjunct treatment goals was transmural healing, yet its assessment is still not fully cost/risk-benefit proven. A valuable tool to assess this adjunct goal is bowel ultrasound. For this reason, our aim was to evaluate the bowel ultrasonographic response to ustekinumab at one year. Methods Retrospective, observational, single center study was designed. All adult patients with CD who were treated with ustekinumab and had a bowel ultrasound just before the induction dose with ustekinumab and who repeated the bowel ultrasound one year after it were included. Examination was done by ultrasound machine (Hitachi Avius) with low frequency curved-array (1-5 MHz) and high-frequency linear-array (5-13 MHz) transducers. The measured bowel ultrasonographic variables were: wall thickness, Doppler activity (Limberg index) and fatty striation. Ultrasonographic response was defined as a reduction in wall thickness of at least 25%, 2mm or 1mm plus 1 Doppler sign. Remission was defined as wall thickness less than 3mm plus absent Doppler sign. Patient demographics and disease characteristics were also collected: age, sex, extension of CD, previous biologic treatments and ustekinumab trough levels. Demographic and clinical characteristics were compared using χ2 analysis (or Fisher’s exact test), Student’s t test or Spearman correlation. All statistical analyses were performed using the STATA Statistical Software. Results A total of 41 patients (56.1% female) with a mean age of 57.9 years (SD ±2.7) were included. 63.4% had ileal disease and 36.6% ileocolonic involvement. Ustekinumab was first line of biologic treatment in 7.3%, second line in 61.0%, third line in 29.3% and fourth line in 2.4% of patients. 63.4% of patients were on ustekinumab 90mg subcutaneous every 4 weeks at one year with a median trough level of 8.6 (range 7.9-10.6). The median wall thickness measured by bowel ultrasound before induction was 5.5 mm (range 5.0-6.4) and after one year it was 5.0 mm (4.1-5.7) (p=0.47) Figure 1. Before treatment Limberg index was 3 in 26.8% and after treatment it was 3 in 4.9% (p=0.052). Fatty striation was present in 90.2% of patients at the beginning of treatment and in 63.4% at one year (p=0.013). Ultrasound response was achieved in 36.6% of patients while transmural remission was achieved in 12.2% of patients in the first year. No association between ustekinumab trough levels and response/remission were found (p=0.70/p=0.83) Conclusion Treatment with USK was related with an ultrasonographic response in one third of patients with refractory CD at one year. No association between ustekinumab trough levels and ultrasonographic response/remission were found