ABSTRACT
BACKGROUND: Subcutaneous (SC) vedolizumab is effective in inflammatory bowel diseases (IBD) when administered after induction with two infusions. AIM: To assess the effectiveness, safety and pharmacokinetics of a switch from intravenous (IV) to SC maintenance vedolizumab in patients with IBD METHODS: In this prospective cohort study, patients with IBD who had ≥4 months IV vedolizumab were switched to SC vedolizumab. We studied the time to discontinuation of SC vedolizumab, adverse events (AEs), changes in clinical and biochemical outcomes and vedolizumab concentrations at baseline, and weeks 12 and 24. RESULTS: We included 82 patients with Crohn's disease (CD) and 53 with ulcerative colitis (UC). Eleven (13.4%) patients with CD and five (9.4%) with UC discontinued SC vedolizumab after a median of 18 (IQR 8-22) and 6 weeks (IQR 5-10), respectively. Four patients with CD switched to a different drug due to loss of response, nine switched back to IV vedolizumab due to adverse events, and three due to needle fear. Common AEs were injection site reactions (n = 15) and headache (n = 6). Median clinical and biochemical disease activity remained stable after the switch. Median serum vedolizumab concentrations increased from 19 µg/ml at the time of the switch to 31 µg/ml 12 weeks after the switch (p < 0.005). CONCLUSIONS: Switching from IV to SC vedolizumab maintenance treatment is effective in patients with CD or UC. However, 9% of patients were switched back to IV vedolizumab due to adverse events or fear of needles.