Safety and Effectiveness of Vedolizumab for the Treatment of Pediatric Patients with Very Early Onset Inflammatory Bowel Diseases.

Background: Vedolizumab (vedo) is effective for induction and maintenance of remission in adults with inflammatory bowel disease (IBD). Pediatric data are still limited, especially for the youngest children with very early onset disease (VEO-IBD). The aim of this study was to assess the safety and efficacy of vedo in VEO-IBD. Methods: We performed a retrospective review of pediatric IBD patients with VEO-IBD (defined as aged <6 years) receiving vedo. Data on demographics, disease behavior, activity, and previous treatments/surgeries were collected. Disease activity was assessed using the pediatric Crohn's disease (CD) activity index (PCDAI) for CD or pediatric ulcerative colitis (UC) activity index (PUCAI) for UC. Primary outcome was clinical response after induction therapy with vedolizumab (4th dose week). It was defined as a decrease in PCDAI of at least 12.5 points between baseline and 4th dose week for CD, and a decrease in PUCAI of at least 20 points between baseline and this time for UC. Descriptive statistics were performed to analyze the data. Results: The study included 16 patients with VEO-IBD who have received vedo: 4/16 (25%) with CD, and 12/16 (75%) with UC at the median age of diagnosis 33.7 months (6.6 months-4.5 years). Median age at vedo initiation was 6.5 years (2.2-16.5 years). Among the analyzed individuals, 56.25% had failed more than one anti-tumor necrosis factor (TNF) alfa agent. Clinical response at 4th dose week was observed in 9/16 (56.3%) patients: mean baseline PCDAI score was 34.4 ± 1.9 and 10.6 ± 1.8 after induction therapy with vedo, while PUCAI score was 26 ± 6 vs. 18 ± 8, respectively. There was improvement in patients' nutritional state: at baseline 2/16 (12.5%) children had body mass index (BMI) below 1 percentile and no child had such BMI after induction therapy with vedo. No infusion reactions or serious adverse events/infections were reported. Conclusion: Vedolizumab is safe and effective in the medical management of pediatric patients with VEO-IBD.