Abstract
BACKGROUND/OBJECTIVES: Ustekinumab has been approved for the treatment of moderate to severe ulcerative colitis. Real-world data regarding its efficacy and the discovery of predictive factors of response need to be studied further. We aimed to evaluate the efficacy and identify predictors of response to induction treatment with ustekinumab in patients with ulcerative colitis. METHODS: This is a multicenter, prospective cohort study. Clinical response (CR) at week 16 was the primary endpoint, and steroid-free clinical remission (SFCRem) and endoscopic response were the secondary endpoints. Baseline histology, mucosal gene expression, and pharmacokinetics were studied for their effect on response to treatment. RESULTS: We included 123 patients (mean age = 50.3 years). CR was recorded in 70.8% (75/106), SFCRem in 48% (59/123), endoscopic improvement in 71.4% (40/56), and mucosal healing in 28.6% (16/56). Higher PRO-stool frequency (OR = 0.49, p = 0.027), concomitant use of 5-ASA (OR = 3.69, p = 0.021), platelet number of ≥284 × 10(9)/L (OR = 6.52, p = 0.001) at baseline, and a drop in the total count of platelets by 10(8)/L (OR = 1.23, p = 0.022) at week 8 were independently associated with CR. Elevated trough levels of ustekinumab at week 16 were associated with a higher probability of endoscopic improvement (median difference = 3784 ng/mL, p = 0.013), with an optimal cut-off value of 3500 ng/mL (AUC = 0.82, 95% CI: 0.66-0.96). Increased mucosal mRNA expression for IL-23 (p = 0.007) and IL-23R (p = 0.031) at baseline was associated with increased probability of CR. Higher continuous Geboes scores at baseline were associated with a lower probability of CR (OR = 0.80, p = 0.045), with an optimal cut-off value of 14 (AUC = 0.75, 95% CI: 0.57-0.93). CONCLUSIONS: Clinical, laboratory, and molecular markers may identify patients with ulcerative colitis who are more likely to respond to ustekinumab.