Vedolizumab levels are associated with clinical remission in pouchitis

Background: Pouchitis is the most common complication in ulcerative colitis (UC) patients following ileal pouch anal anastomosis (IPAA). Recent studies have demonstrated vedolizumab efficacy in the treatment of refractory pouchitis. Vedolizumab serum level was associated with clinical and endoscopic remission in Crohn’s disease. The aim of this study was to assess the association between vedolizumab serum levels and clinical outcomes in pouchitis. Methods We performed a single center retrospective study at a major tertiary referral medical center, in which we extracted data on patients who underwent IPAA and were treated post-operatively with vedolizumab for complicated chronic pouchitis between October 2015 and January 2020. Our primary study outcomes were clinical remission rates at weeks 14 and 52 of vedolizumab treatment. Results Nineteen UC patients (13 males, mean age of 53.8 ± 4.7 years) underwent total proctocolectomy with IPAA and treated with vedolizumab for complicated chronic pouchitis. Steroid-free clinical remission rates at week 52 of vedolizumab therapy were 52.6%, compared to 10.5% at baseline (p = 0.013). Endoscopic remission rates during maintenance were 59%, compared to 32% at baseline (p = 0.01). Higher mean serum vedolizumab trough levels at weeks 22 to 52 (maintenance phase) were associated with clinical remission at week 52 (14.6 ± 1.35 vs 4.4 ± 2 [mcg/ml], p = 0.015). Increased serum vedolizumab trough levels were numerically associated with endoscopic remission at maintenance but did not reach statistical significance (6.0 ± 1.8 vs 17.7 ± 1.6 [mcg/ml], p = 0.06). Conclusion Vedolizumab is effective in patients with complicated chronic pouchitis, increasing the rates of clinical and endoscopic remission. Higher maintenance vedolizumab serum levels were associated with clinical remission.