P267 Sequencing of anti-TNF agents and gut-selective anti-lymphocyte trafficking (GSALT) therapy in the treatment of Crohn’s disease (CD)

Anti-TNF agents and GSALT therapy (MAdCAM α4β7 blocker) are available treatment options for patients (pts) with moderate-to-severe CD. There are limited data on the optimal sequencing of these two mechanisms of action (MOAs) from the first line (1L) to second line (2L) biologic treatment of CD to inform clinician’s decision making. This retrospective study used the Truven Health MarketScan administrative claims database to assess treatment pathways in a large U.S. insured population. Biologic naïve adult CD pts (identified using ICD-9 and 10 codes) who initiated (date of initiation defined as an index date) 1L biologic treatment (adalimumab [ADA], infliximab [IFX], certolizumab pegol [CTZ], or vedolizumab [VDZ] between 09/2016 and 09/2019) with at least 6 months of continuous health benefits enrolment post biologics initiation were included. Pts treated with biologics of different MOAs in 1L and 2L setting were identified to evaluate the treatment sequencing of either VDZ to anti-TNF or anti-TNF to VDZ. Treatment persistence was defined as time to index drug discontinuation with a pre-defined gap or switch to other biologic drugs. In the 1L, 474 VDZ and 4173 anti-TNF (2648 ADA, 1446 IFX, and 79 CTZ) pts were included. Among the 1L VDZ pts, only 33 switched to anti-TNF as 2L biologic treatment (VDZ to anti-TNF). Among the 1L anti-TNF pts, 221 switched to VDZ as 2L biologic therapy (anti-TNF to VDZ). In the VDZ to anti-TNF group, only proportion of 6 months treatment persistence was assessed due to the small number of pts in 2L. Median 1L treatment persistence was 842 days in VDZ pts and 557 days in anti-TNF pts (log rank p=0.041). The median treatment persistence in 2L VDZ post anti-TNF was 625 days (anti-TNF to VDZ). The 6 months treatment persistence to 2L was estimated as 85.1% (95% CI 59.1–95.2) in VDZ to anti-TNF group and 80.1% (95% CI 73.8–85.1) in anti-TNF to VDZ group. The 6 months treatment persistence was estimated as 74.8% (95% CI 73.4–76.1) in 1L anti-TNF and 85.1% (95% CI 59.1–95.2) in 2L anti-TNF post VDZ (VDZ to anti-TNF). VDZ in 1L biologic treatment of CD was associated with significantly improved treatment persistence compared with anti-TNF agents. The sequencing of VDZ to anti-TNF had higher treatment persistence in both 1L and the first 6 months of 2L compared with the sequencing of anti-TNF to VDZ. The use of VDZ before anti-TNF agents led to higher persistence to anti-TNF in 2L than if anti-TNF was used in 1L during 6 months period of time. VDZ used in 2L post anti-TNF showed lower treatment persistence than if VDZ was used in 1L. This real-world evidence from U.S. large database suggests the use of GSALT prior to anti-TNF agents in biologic naïve pts with CD.