Switching rate from intravenous to subcutaneous vedolizumab in managing inflammatory bowel diseases is lower than expected.

Background: It is known that the subcutaneous (SC) route administration of biologic drugs has several potential benefits for patient and the healthcare system. Since few real-world data are available yet about the rate of transition from intravenous (IV) to SC Vedolizumab (VDZ) in the Italian population, we assessed this rate in a large cohort of inflammatory bowel disease (IBD) patients under remission receiving IV VDZ as standard of care in a real-world setting.

Methods: Searching who was asked to switch from IV VDZ To SC VDZ, and assessing the rate of acceptance. The Mayo score in Ulcerative colitis (UC) and the Harvey-Bradshaw Index (HBI) in Crohn's Disease (CD) scored the clinical activity. Achievement and maintenance of clinical remission during the follow-up, and safety were the primary endpoints.

Results: Overall, 238 patients (145 with UC and 93 with CD) having remission ≥1 year with VDZ were asked to switch to VDZ SC, but only nine patients (four with UC and five with CD, 3.78% of the total population to which the switch was proposed) agreed to switch. No difference were found between patients accepting and patients refusing switching about the reasons of the choice. All patients accepting switch maintained clinical remission during the follow-up, and no adverse events were recorded.

Conclusions: Switching to SC route is a safe and effective choice for IBD patients under remission using VDZ. However, this choice is not preferred by the majority of patients on stable remission under IV VDZ.