P809 VARIETY BEACH: Real-world treatment patterns for vedolizumab intravenous and subcutaneous maintenance dosing observed over 1 year in studies from Belgium, Austria and Switzerland

Abstract Background Vedolizumab (VDZ) is approved for moderate to severe ulcerative colitis (UC) and Crohn’s disease (CD) as intravenous (IV) or subcutaneous (SC) formulations. Real-world data on VDZ treatment patterns in patients (pts) with inflammatory bowel disease (IBD) comparing VDZ IV or SC maintenance are still scarce. Methods Three prospective, non-interventional, observational studies following an umbrella protocol enrolled pts in Belgium (NCT04959851), Austria (NCT04890262) and Switzerland (NCT04989907) from Aug 2021 to Jun 2022. Adults initiating VDZ IV induction per the product label or continuing VDZ IV maintenance with the option to switch to SC administration, were eligible. The primary endpoint was VDZ treatment persistence at 1 year. Administration route, dosing frequency, reasons for regimen change and safety endpoints were also assessed. Non- responder imputation was applied for pts discontinuing treatment, discontinuing the study or lost to follow-up. A descriptive analysis was performed. Results Of 377 pts enrolled, 373 (UC=218, CD=155) were included in this interim analysis. At enrolment, 287 (77%) (UC=159, CD=128) already received VDZ IV maintenance for median 2.8 (0–12.6) years and 86 (23%) (UC=59, CD=27) started VDZ induction (baseline pt characteristics summarized in Table 1). For pts enrolled on VDZ IV maintenance, 12 discontinued vedolizumab, 34 discontinued the study and 14 were lost to follow-up; resulting in a VDZ persistence rate at 1 year of 79% (227/287). Of pts in this cohort persistent on VDZ at 1 year (n=227; UC=124, CD=103), 39% (88/227) switched from VDZ IV maintenance to SC during the study. For pts initiating VDZ induction, 10 discontinued VDZ, 16 discontinued the study and 3 were lost to follow-up; resulting in a VDZ treatment persistence of 66% (57/86). Of pts from this cohort persistent on VDZ at 1 year (n=57; UC=43, CD=14), 56% (32/57) switched to VDZ SC during the study (Figure 1). Overall, the most common reasons for administration route changes were pt decision 98/161 (61%; UC=56%, CD=67%), end of induction (planned switch: 10%; UC=14%, CD=5%) and disease adequately controlled (6%; UC=7%, CD=3%). Adverse events (AEs) occurred in 48 pts (13%) (UC=20, CD=28) and serious AEs in 6 pts (2%) (UC=3: Budd-Chiari syndrome, death cause unknown, UC worsening; CD=3: bronchopneumonia, gastroenteritis, recurrent urinary tract infection). Conclusion Real-world data from prospective observational studies in Belgium, Austria and Switzerland reported high persistence of VDZ IV and SC maintenance treatment over 1 year. Decisions on route of administration change were most frequently driven by patients. Safety results were consistent with the known safety profile of VDZ.