Persistence, Safety and Pharmacokinetics of Vedolizumab After Switching to the Subcutaneous Route in a Prospective French National Cohort Study

BACKGROUND AND AIM: We conducted a prospective study to evaluate the persistence, efficacy, pharmacokinetics, and safety of subcutaneous VDZ (SC-VDZ) after switching from the intravenous (IV) route. METHODS: All patients with ulcerative colitis (UC) or Crohn's disease (CD) in clinical remission who switched from IV-VDZ to SC-VDZ between 2022 and 2024 were included in this multicentric prospective French national cohort study. Primary endpoint was SC-VDZ persistence at Week 52. Patients who had a disease-related surgery, repeated or prolonged (> 14 days) steroid courses, and those who were lost to follow-up were considered non-persistent. RESULTS: Among the 337 patients analysed, 246 (73%) had UC and 91 (27%) CD; 214 (64%) were on a standard IV-VDZ regimen. At Week 52, SC-VDZ persistence was 84% [95% confidence interval: 80-88], with no significant difference between diseases (p = 0.36). During the study period, 32 patients (10%) had a dose increase of SC-VDZ (either to 216 mg weekly or to 108 mg 2-weekly), including 17 (53%) who had been on a standard IV-VDZ regimen, and five (16%) eventually stopped VDZ due to persistent loss-of-response despite dose increase. Twelve out of 16 patients were successfully switched back to IV-VDZ. Vedolizumab drug levels were similar between persistent and non-persistent patients throughout the study period. A total of 183 patients (54%) reported at least one AE, most frequently injection-site reactions (20%) and infections (17%), leading to SC-VDZ discontinuation in 25 patients (7%). CONCLUSION: In this multicentric cohort, the persistence at 1 year from switch to SC-VDZ in IBD patients was 84%.