P532 1-Year Clinical Outcome of Subcutaneous Infliximab compared with Intravenous Infliximab in Patients with Inflammatory Bowel Disease During Maintenance Therapy

Abstract

Abstract Background Although pharmacokinetic profile of subcutaneous infliximab (SC IFX) is superior to conventional intravenous infliximab (IV IFX), long-term efficacy and safety of SC IFX have not been compared with those of IV IFX in patients with inflammatory bowel disease (IBD). This cohort study aimed to evaluate the loss of response (LOR) and durable remission in IBD patients treated with SC IFX after switching from IV IFX compared with those in IBD patients who continued IV IFX. Methods This prospective cohort study enrolled 61 IBD patients with clinical remission who received scheduled IFX maintenance therapy from May to September 2022. Of them, 38 patients were switched to SC IFX with a shared decision-making between patients and physician. After dose optimization, they were followed up for one year. Clinical remission was defined as HBI < 5 in in patients with Crohn’s disease (CD) and partial Mayo ≥ 2 in in patients with ulcerative colitis (UC). Biochemical relapse was defined as CRP ≥ 0.5 mg/dL in patients with CD and UC. Results LOR occurred in three (8%) patients of the SC IFX group and 5 (22%) patients of the IV IFX group, showing no significant difference between both groups (p = 0.140). The clinical and biochemical remission were not significantly different between the SC and IV groups (clinical remission: 20/23, 87% vs 33/38, 87%, p = 1.000; biochemical remission: 22/23, 96% vs. 34/38 89%, p = 0.641). The patients with IFX trough level < 3 μg/mL was significantly lower in the SC IFX group (0/38, 0%) than in the IV IFX group (10/23, 43%; p < 0.001). The incidence of IFX-related adverse events did not differ significantly between both groups (26% vs. 39%; p = 0.446). Conclusion SC IFX switch induced similar 1-year durable remission rate and safety profile with continuing IV IFX in patients with IBD during maintenance therapy. Pharmacokinetic profile was superior in patients treated with SC IFX compared with IV IFX.