P989 Switching from intravenous to subcutaneous vedolizumab in patients with inflammatory bowel disease in clinical remission: a multicenter study from GETECCU

Background Despite the established use of intravenous (IV) vedolizumab for treating inflammatory bowel disease (IBD), there's growing interest in exploring the advantages of the novel subcutaneous (SC) administration route. However, comprehensive real-world evidence regarding the extended safety and effectiveness of this approach remains scarce. The aim of the study was to evaluate the effectiveness and safety of vedolizumab SC among IBD patients in clinical remission. Methods Multicenter, observational, retrospective study. IBD patients on IV vedolizumab treatment across 24 Spanish hospitals who were in clinical remission were given the option to switch to SC injections or continue with IV treatment. Data encompassing clinical disease activity (assessed through partial Mayo score, and Harvey-Bradshaw Index), biochemical markers (C-reactive protein and fecal calprotectin), adverse events and treatment persistence were retrospectively gathered from prospectively maintained clinical records at baseline, and at weeks 12, 24, and 48. Non-parametric tests were used for comparisons and Kaplan-Meier for survival. Results We identified 166 patients, with 19 excluded due to not being in clinical remission and 8 excluded due to absence of follow-up data, resulting in a final inclusion of 139 patients for analysis. Of these, 36 (25.9%) remained on IV vedolizumab, while 103 (74.1%) switched to SC vedolizumab. Both groups exhibited comparable demographic characteristics including age, gender, disease type, disease duration and extension, previous therapy, presence of extra intestinal manifestations and comorbidities (Table 1). However, there were differences in Crohn’s disease behavior among groups (p=0.013). There were not significant differences in clinical, biochemical and fecal calprotectin remission at week 12, 24 and 48 neither in the overall cohort nor assessing Crohn’s disease or ulcerative colitis separately (Figure 1). At the end of follow-up, median duration 47 weeks (29-49), persistence on the same formulation was 85%,1 (2.8%) patient on IV and 4 (3.9%) on SC withdrew the drug (p=0.810), 5 (4.8%) switched back to IV from SC. Adverse events were reported in 1 (2.8%) IV vs 11 (10.7%) SC vedolizumab (p=0.292), most of them being mild skin reactions to SC injection 3 (2.9%). Conclusion In our study we found that transitioning from IV to SC vedolizumab in patients with IBD in remission showed comparable effectiveness in maintaining disease remission. Switching to SC formulation appears safe with no new safety signals identified and most adverse events being mild.