Background: A few prospective cohort studies support the safety of switching from intravenous to subcutaneous administration of vedolizumab during maintenance therapy in patients with inflammatory bowel disease. Real-life data on switching after intravenous induction therapy are lacking.

Objective: The aim was to obtain real-world data on subcutaneous vedolizumab treatment in patients with inflammatory bowel disease after switching from intravenous vedolizumab induction or maintenance therapy, and to evaluate treatment persistence, safety, and changes in disease activity and serum vedolizumab concentrations.

Methods: We performed a retrospective registry-based study of inflammatory bowel disease patients who received subcutaneous vedolizumab therapy in two tertiary centres.

Results: Altogether, 103 patients (26 Crohn's disease and 77 ulcerative colitis) switching from intravenous maintenance therapy (group 1) and 44 patients (14 and 30, respectively) switching from intravenous induction therapy (group 2) were included. At 6 months from baseline, 90.3% of the patients in group 1 and 90.9% of the patients in group 2 continued on subcutaneous vedolizumab. After the switch in group 1, disease activity remained stable. In group 2, clinical disease activity decreased significantly in ulcerative colitis patients (P = 0.002). The median serum vedolizumab concentration was 34.00 µg/ml during subcutaneous maintenance therapy in group 1, which was significantly higher than the median concentration during intravenous therapy (17.00 µg/ml, P < 0.001), but remained unchanged in group 2 after the switch (31.50 µg/ml).

Conclusion: Based on these data, subcutaneous vedolizumab treatment is well-tolerated and the treatment persistence remains high after switching from intravenous to subcutaneous vedolizumab therapy.