P895 Analysis of the efficacy of intravenous ustekinumab maintenance treatment in patients with refractory Inflammatory Bowel Disease

Abstract

Abstract Background Ustekinumab (UST) is a monoclonal antibody that inhibits the p40 subunit of IL-12 and IL-23, approved for the treatment of Crohn's Disease (CD) and Ulcerative Colitis (UC). Its administration is intravenous during induction and subcutaneous during maintenance. Several studies have assessed the efficacy of reinduction and intensification of this treatment in patients with loss of response. However, there are few studies evaluating the effectiveness of intravenous UST for maintenance. The aim of the study is to evaluate the efficacy and safety of maintenance with intravenous UST in patients with Inflammatory Bowel Disease (IBD). Methods Observational, retrospective, and single-center study. All patients receiving maintenance with intravenous UST until June 2023 were reviewed. Clinical response was evaluated with Harvey-Bradshow Index for CD and partial Mayo for UC. Biochemical response was evaluated with calprotectin and C-reactive protein. Results A total of 29 patients with IBD (24 CD and 5 UC) were included. The mean follow-up of patients was 449 days (74-948). The cohort's characteristics are summarized in Table 1. In all cases, intravenous maintenance was performed with UST 130mg/4 weeks. In 4 cases (13.8%), maintenance was initiated directly with intravenous UST. In 9 (31%) patients due to primary failure to UST and in 16 (55.2%) patients due to secondary failure. The clinical response to intravenous UST maintenance in patients with CD at week 8 and 16 and at one year of follow-up was 87.5% (n=21/24), 83.3% (n=20/24), 73.3% (n=11/15) respectively. For UC, the response was 60% (n=3/5) at week 8 and 16 and at one year. The drug survival was 723 days (± 74) (Figure 1). No predictive variable for treatment response was identified. Two patients (both with CD) experienced recurrent respiratory infections as an adverse effect, without the need to discontinue UST. Conclusion Maintenance treatment with intravenous UST can be useful and safe in patients with severe IBD and/or failure of subcutaneous UST maintenance.