S32 Evaluating the Effectiveness of Subcutaneous Ustekinumab Induction in Inflammatory Bowel Disease: Insights From Real-World Evidence

Background: Crohn’s disease (CD) and ulcerative colitis (UC) are chronic inflammatory bowel diseases (IBDS) that significantly impact quality of life and require long-term management. Ustekinumab, a monoclonal antibody targeting interleukins-12 and 23, has proven effective in clinical trials for both. Its subcutaneous administration offers advantages like increased convenience and cost savings, but the effectiveness of a 90 mg induction regimen at Weeks 0, 1, and 2 in real-world settings is not fully explored. More research is needed to assess its impact and optimize treatment protocols for IBD. The aim of this study is to evaluate the real-world effectiveness of the subcutaneous ustekinumab induction regimen in patients with CD and ulcerative colitis UC. Methods: This cross-sectional, analytical study included 20 IBD patients (17 with Crohn’s disease and 3 with ulcerative colitis) treated with ustekinumab at the IBD Clinic of the General Hospital of Mexico “Dr. Eduardo Liceaga.” Demographic and clinical data, including age, gender, disease history, surgeries, extraintestinal manifestations, and biochemical markers (CRP and fecal calprotectin), were collected. Disease activity was assessed using the Harvey-Bradshaw Index (HBI) for CD and Truelove and Witts criteria for UC. The ustekinumab regimen consisted of 180 mg subcutaneously on day 0, followed by 90 mg at weeks 1 and 2, with maintenance doses every 8 weeks. Statistical analyses included chi-square, t-tests, Mann-Whitney U, paired t-tests, or Wilcoxon signed-rank tests, with a significance level of P < 0.05. Results: In this cohort, both UC and CD groups had a predominance of female patients (66.7% and 82.4%, respectively). The average age was significantly lower in UC patients (41.6 ± 11.2 years) compared to CD patients (57 ± 15.7 years) (P = 0.001). After 12 weeks of ustekinumab treatment, significant improvements were observed in disease activity scores and biochemical markers. In UC patients, the Truelove and Witts score decreased from 13.6 ± 0.57 to 9.6 ± 1.15 (Δ = -4.2, P = 0.002). CD patients saw reductions in the Harvey-Bradshaw Index from 8 (8-9.5) to 6 (5-6.5) (Δ = -2.5, P = 0.013). CRP levels significantly decreased in both groups: in UC from 10.55 to 3.2 (Δ = -9.49, P = 0.016), and in CD from 16.67 to 3.05 (Δ = -10.99, P = 0.014). FCP levels significantly decreased in UC, from 1724 to 629 (Δ = -898.33, P = 0.016), while no significant change was observed in CD. Conclusions: Subcutaneous ustekinumab demonstrated significant clinical and biochemical efficacy in reducing disease activity in IBD patients over a 12-week period. Notable improvements were observed in CRP levels, clinical scores, and disease-specific indices, confirming the effectiveness of ustekinumab during the induction phase.