P527 Factors associated with choice of treatment regimen after the induction period in patients with Ulcerative Colitis treated with vedolizumab

Abstract

Abstract Background Vedolizumab (VDZ) is a selective, alpha4-beta7 anti-integrin antibody used for treatment of inflammatory bowel diseases. The aim of our study was to investigate factors that influence the decision making and determine further therapeutic regimen after the induction period in patients with ulcerative colitis treated with VDZ and to identify predictors for early response to VDZ. Methods A retrospective study conducted at the Clinic for gastroenterohepatology, University Clinical Center Serbia included 89 patients with ulcerative colitis (mean age 47±15; 45 males) treated with VDZ (69 bio-naïve and 20 previously exposed to anti-TNF). Localization of disease, endoscopic score at the beginning of therapy, together with CRP and fecal calprotectin levels before the initiation of therapy and at week 14, and prior exposure to anti-TNF in relation to the treatment regimen at the end of the induction period were analyzed. Results After induction therapy total of 55 patients (61.8%) continued with standard dosing regimen, while in 34 patients (38.2%) shortening the interval to 4 weeks as optimization of VDZ treatment was prescribed. Patients whose treatment regimen was optimized at week 14 had had statistically significantly higher baseline CRP levels (p=0.025), as well as CRP levels at week 14 (p=0.002) and fecal calprotectin at week 14 (p=0.000), while there was no difference in the baseline fecal calprotectin between patients in standard and optimized regimen (p=1.000). There was no statistical difference in localization of disease and prior anti-TNF exposure between these two groups of patients (p=0.732 and p=0.449, respectively). Conclusion Higher CRP and fecal calprotectin levels at week 14 were determining factors for optimization of VDZ treatment. Higher levels of CRP before biologic therapy was started was associated with the increased need for optimized regiment at week 14. Extensive disease and prior anti-TNF exposure did not correlate with need for optimization of treatment after the induction period.