Anti-TNF Exposure Impacts Vedolizumab Mucosal Healing Rates in Pediatric Inflammatory Bowel Disease.

BACKGROUND Vedolizumab (VDZ) is effective for treating both adult and pediatric onset IBD. Clinical outcomes, however, have been reported to be superior in patients naïve to anti-TNF. With the growing interest in endoscopic endpoints, we aimed to describe rates of mucosal healing in pediatric patients being treated with VDZ and examine the influence of anti-TNF on outcomes. METHODS We conducted a retrospective review of all IBD patients ≤21 years of age who initiated VDZ and underwent endoscopy. Primary outcome was mucosal healing (composite of endoscopic (SES-CD and Mayo score UC) and histological remission (Nancy index-UC and CD histologic activity). Descriptive statistics summarized the data. Comparisons were made for endpoints based on anti-TNF exposure using univariate testing. RESULTS Sixty-eight patients were included in the final analysis; 35 with UC and 33 with CD. Thirty-two patients (22 UC and 10 CD) were anti-TNF naïve and 36 patients (13 UC and 23 CD) were anti-TNF exposed. The median duration on VDZ prior to endoscopic assessment was 49 (IQR 32-73) weeks. A total of 38% (25/66) of patients met the primary outcome of mucosal healing and did not differ between anti-TNF naïve or exposed. Endoscopic remission was achieved by 51% with significantly more anti-TNF naïve patients reaching this endpoint (66% v. 40%, p = 0.03). Histologic remission was achieved by 42% of patients with a non-significant trend towards improved histologic remission rates in anti-TNF naïve patients (52% v. 33%, p = 0.13). CONCLUSION VDZ is associated with mucosal healing in pediatric IBD. Anti-TNF exposure significantly impacted endoscopic remission, but not histologic remission in children on VDZ.