Vedolizumab (VDZ) was reported to be effective as a first-line biological in adult ulcerative colitis (UC). The aim of this study was to investigate the safety and effectiveness of VDZ as the first-line biological in pediatric refractory UC.

We retrospectively extracted data from pediatric patients with UC who received first-line VDZ. The following were recorded: baseline characteristics; clinical activity of intestinal disease, levels of fecal calprotectin (FC), C-reactive protein, and serum amyloid A; and erythrocyte sedimentation rate. Clinical effectiveness, biochemical remission, and safety of VDZ were also investigated.

Eight patients were identified (median age, 12 years). FC levels were abnormal in all cases and were remarkably elevated in 3 patients. C-reactive protein, serum amyloid A, and erythrocyte sedimentation rate values were abnormal in 2, 4, and 5 patients, respectively. According to the pediatric UC activity index score, 1, 5, and 2 patients had mild, moderate, and severe disease. Fourteen weeks after VDZ administration, 5 patients achieved remission, and 3 remained in remission until week 52. Of the 3 patients who did not reach remission in week 14, two achieved remission by week 52. In week 52, five of the eight patients continued receiving VDZ and maintained remission. All patients achieved clinical remission without corticosteroid use. No adverse events were observed in any patient.

VDZ may serve as a safe and effective first-line biological option for treating pediatric patients with UC. FC levels before VDZ administration may be predictive of long-term remission.