P376 Switching from intravenous to subcutaneous vedolizumab maintenance treatment; feasibility, safety and clinical outcome

Abstract

Abstract Background Vedolizumab (VDZ) has until recently been available only as intravenous (i.v.) formulation, but the drug is now available also as subcutaneous (s.c.) formulation. In the present study, we aimed to assess the feasibility, safety and clinical outcome when switching a real world cohort of patients with inflammatory bowel disease (IBD) from i.v. to s.c. VDZ treatment. Methods All IBD-patients receiving i.v. VDZ at the department were identified using the medical records. Patients in the induction period or with planned change of medical treatment or surgery within, 3 months were not routinely switched. The dosage of s.c. VDZ was calculated based on current i.v. dose and interval. Patients were assessed at first and fourth injection and after, 3 months. The primary endpoint was percentage of patients still on s.c. treatment after, 3 months. Secondary endpoints were adverse events, clinical disease activity scores (Harvey Bradshaw index and Partial Mayo Score), C-reactive protein (CRP), fecal calprotectin (FC), VDZ treatment interval, plasma-VDZ, and patients’ preferred route of administration. Results In total, 108 patients were switched, 51 with ulcerative colitis (UC) and, 57 with Crohn’s disease (CD). After, 3 months, 95.3% (103/108) remained on s.c. treatment. Four patients had switched back to i.v. and one changed treatment to ustekinumab. Nineteen patients (17.6%) experienced injection site reactions (ISR), and twelve of these (63.2%) had repeated reactions. In three cases, patients were switched back to i.v. treatment due to ISR. No serious adverse events related to the switch were observed. The median interval between injections was, 12 (IQR:, 7–18) days. The median p-VDZ at three months was, 44.4 (IQR:, 28.9–64.7) mg/L. In the UC and CD patients, 92% (47/51) and, 72% (41/57) were in clinical remission at first injection, whereas the corresponding numbers after three months were, 88% (p=0.18) and, 83% (p=0.11), respectively. No significant change in CRP and FC was observed. Before switching, 25% of the patients reported that they would prefer i.v. treatment, 28% s.c. treatment and, 47% were indifferent. Three months after switching, the corresponding numbers were, 18%, 53% and, 29%, respectively (p<0.001). Conclusion Switching from i.v. to s.c. VDZ was feasible and safe. Approximately one out of six experienced an ISR but only, 3% were switched back to i.v. administration. At, 3 months follow-up there was no change in clinical remission rates, CRP and FC. Furthermore, patients’ attitude towards route of administration changed after switching. The present real world data demonstrate that s.c. maintenance VDZ treatment represents an attractive alternative to i.v. treatment.