Asle W Medhus

Background Vedolizumab has since 2021 been available as a subcutaneous formulation. We aimed to assess 18-month drug persistence and possible predictive factors associated with discontinuation, safety, serum drug profile, drug dosing, and disease activity in a real-world cohort of patients with inflammatory bowel disease switched from intravenous to subcutaneous vedolizumab maintenance treatment. Methods Eligible patients were switched to subcutaneous vedolizumab and followed for 18 months or until discontinuation of subcutaneous treatment. Data on preferred route of administration, adverse events, drug dosing, serum-vedolizumab, disease activity, fecal calprotectin, and C-reactive protein were collected. Persistence was described using Kaplan–Meier analysis. The impact of clinical and biochemical variables on persistence was analyzed with Cox proportional hazard models. Results We included 108 patients, and the estimated 18-month drug persistence was 73.6% (95% CI [64.2–80.1]). Patients in clinical remission at switch were less likely to discontinue SC treatment (HR = 0.34, 95% CI [0.16–0.73], P = .006), and patients favoring intravenous treatment at switch were almost 3 times more likely to discontinue (HR = 2.78, 95% CI [1.31–5.90], P = .008). Four patients discontinued subcutaneous vedolizumab due to injection site reactions. At 18 months, 88% of patients administered subcutaneous vedolizumab with an interval of ≥ 14 days, and serum-vedolizumab was 39.1 mg/L. Disease activity was stable during follow-up. Conclusions Three of the four patients remained on subcutaneous vedolizumab after 18 months, a large proportion received treatment at standard dosing intervals, and disease activity remained stable. This indicates that switching from intravenous to subcutaneous vedolizumab treatment is convenient and safe.