663 Onset of Response With Infliximab vs. Vedolizumab in the Treatment of Bio-Naïve Inflammatory Bowel Disease

Abstract

INTRODUCTION: Both infliximab (IFX) and vedolizumab (VDZ) are approved for the treatment of inflammatory bowel disease (IBD) in adults. Compared to IFX, VDZ is thought to have a slower onset of response. The purpose of this study was to characterize the incidence and timing of clinical remission between IFX and VDZ. METHODS: We performed a retrospective cohort study of bio-naïve adult patients (pts) treated with IFX or VDZ for ulcerative colitis (UC) or Crohn's disease (CD) at a large multicenter gastroenterology private practice. Pts were case-matched 1:1 based on age, gender, diagnosis, and baseline disease severity using the partial Mayo (pMayo) for UC and the modified Harvey-Bradshaw Index (mHBI) for CD. Primary endpoints were clinical remission rates at 6 months (mos), defined as pMayo less than 2 or mHBI less than 5, and time to remission represented by a Kaplan Meier curve. Pts in remission at baseline and those discontinuing therapy <6 mos were excluded from analyses. RESULTS: A total of 77 IFX (58 UC, 19 CD) and 77 VDZ (58 UC, 19 CD) case-matched pairs were generated. Baseline demographics were similar between IFX and VDZ groups: mean age 45 ± 16.9 vs 46 ± 16.2, male gender 60% vs 61%. Thirty-three pts were excluded from efficacy analyses: 8 in remission at baseline, 25 discontinuing therapy < 6 mos (16 IFX, 11 VDZ). Data are presented for the remaining 121 pts: IFX 60 (47 UC, 13 CD) and VDZ 61 (48 UC, 13 CD). Disease severity scores over 6 mos are depicted in Figure 1, with both IFX and VDZ demonstrating a rapid response by 2 weeks of treatment. Remission rates were similar among IFX and VDZ-treated UC patients (78.7% vs 64.6%, P = 0.13), and significantly higher for IFX-treated CD patients (84.6% vs 46.2%, P = 0.04). There was no difference in time to remission (Figure 2). CONCLUSION: We observed rapid onset of response and high remission rates among bio-naïve pts treated with both IFX and VDZ. While IFX-treated CD patients experienced significantly higher remission rates, our numbers were small. Importantly, time to remission did not differ between IFX and VDZ-treated pts. These data need to be verified in a larger cohort.