Safety and effectiveness of vedolizumab in paediatric patients with inflammatory bowel disease: an observational multicentre Spanish study.

Vedolizumab is a humanised monoclonal antibody that binds to integrin α4β7 expressed in T-cells, inhibiting its binding to the mucosal addressin cell adhesion molecule-1 (MAdCAM-1), which is specifically expressed in the small intestine and colon, playing a fundamental role in T-cell migration to the gastrointestinal tract. Vedolizumab has been shown to be effective in treating adults with inflammatory bowel disease; however, efficacy data for paediatric use are scarce. The objective of the present study was to assess the effectiveness and safety of vedolizumab for inducing and maintaining clinical remission in children with inflammatory bowel disease. We conducted a retrospective multicentre study of patients younger than 18 years with inflammatory bowel disease refractory to anti-tumour necrosis factor alpha (anti-TNF-α) drugs, who underwent treatment with vedolizumab. Clinical remission was defined as a score < 10 points in the activity indices. We included 42 patients, 22 of whom were male (52.3%), with a median age of 13.1 years (IQR 10.2-14.2) at the start of treatment. Of the 42 patients, 14 (33.3%) had Crohn's disease (CD) and 28 (66.7%) had ulcerative colitis (UC). At the start of treatment with vedolizumab, the Paediatric Crohn's Disease Activity Index was 36 (IQR 24-40) and the Paediatric Ulcerative Colitis Activity Index was 47 (IQR 25-65). All of them had received prior treatment with anti-TNF and 3 patients ustekinumab. At week 14, 69% of the patients responded to the treatment (57.1% of those with CD and 75% of those with UC; p=0.238), and 52.4% achieved remission (35.7% with CD and 60.7% with UC; p=0.126). At 30 weeks, the response rate was 66.7% (46.2% and 78.3% for CD and UC, respectively; p=0.049), and 52.8% achieved remission (30.8% and 65.2% for CD and UC, respectively; p=0.047). Among the patients with remission at week 14, 80% of the patients with CD and 84.5% of those with UC maintained the remission at 52 weeks. Adverse effects were uncommon and mild. Three patients (7.1%) presented headaches, 1 presented alopecia, 1 presented anaemia and 1 presented dermatitis.Conclusion: The results show that treatment with vedolizumab is a safe and effective option for achieving clinical remission in paediatric patients with inflammatory bowel disease with primary failure or loss of response to other treatments, especially in UC. What is Known: • Vedolizumab is effective in inducing and maintaining remission in adult patients with inflammatory bowel disease. • Most studies and clinical trials have been performed on adult populations, and there is currently no indication for paediatric populations. What is New: • Children with inflammatory bowel disease refractory to anti-TNF presented higher clinical remission rates than those published for adults. • There are few publications of this magnitude on paediatric populations treated with vedolizumab and with long-term follow-up (52 weeks).