728 Second-Line Biologic Therapy After Vedolizumab

INTRODUCTION: Vedolizumab (VDZ), an anti-integrin monoclonal antibody approved for the treatment of Crohn's disease (CD) and ulcerative colitis (UC), is increasingly being utilized as first-line biologic therapy in bio-naïve inflammatory bowel disease (IBD) patients (pts) with moderate-to-severe disease. While prior studies have described the efficacy of VDZ after anti-TNF failure, there is little guidance on the use of alternative biologics following initial VDZ therapy. This study describes the clinical response of IBD pts treated with a second (2nd) biologic following VDZ discontinuation. METHODS: We performed a retrospective review of all bio-naïve IBD pts started on VDZ as first-line therapy at a large multicenter gastroenterology private practice since drug approval in 2014. Pts were identified who failed initial VDZ treatment and were switched to a 2nd biologic agent. Data collection included demographics, diagnosis, therapy, and disease activity scores using the partial Mayo score (pMayo) for UC pts and the Harvey-Bradshaw Index (HBI) for CD pts. Clinical remission was assessed for those pts with ≥6 months of data and defined as pMayo less than 2 or HBI less than 5. RESULTS: A total of 135 IBD pts receiving VDZ as first-line biologic therapy were identified, of which VDZ was discontinued in 30 (22%). Our study cohort included 25 pts who received a 2nd line biologic following VDZ failure (11 primary non-response, 14 secondary non-response). Second-line biologic agents included 19 infliximab, 3 adalimumab, 2 ustekinumab, and 1 tofacitinib. Baseline demographics of the 25 pts were as follows: mean age 47 ± 18 years, male gender 13 (52%), UC 19 (76%), CD 6 (24%), time to 2nd biologic 8.2 ± 4.5 weeks. Disease severity scores prior to and following initiation of the 2nd line biologic are depicted in Figure 1. Clinical remission assessment was available for 18 of 25 patients. Remission was achieved in 11 of 18 pts (61%), driven by UC pts treated with infliximab [Figure 2]. Overall, pts treated with anti-TNF agents following VDZ had higher rates of remission compared to those treated with other biologics. CONCLUSION: Biologic-naïve IBD pts treated initially with VDZ have high treatment persistence. In addition, rates of remission with 2nd-line biologic therapy are significantly greater than expected when first-line failure is VDZ. Further studies are warranted to determine the optimal order in which advanced therapies should be initiated.