Mucosal Healing Is Associated with Improved Long-term Outcome of Maintenance Therapy with Natalizumab in Crohnʼs Disease

BACKGROUND: Natalizumab is an efficacious agent for induction and maintenance of remission in patients with Crohn's disease (CD) who have failed anti-tumor necrosis factor agents. We aimed to assess the impact of endoscopic severity and mucosal healing on the long-term outcome of natalizumab treatment in CD. METHODS: We retrospectively assessed endoscopic severity according to the Simple Endoscopic Score for Crohn's Disease in patients with CD who received natalizumab therapy. The degree of endoscopic severity before natalizumab treatment and mucosal healing after treatment and their correlation with long-term outcome were studied. RESULTS: Thirty-two patients with CD (15 male, median age 32.5 years) receiving natalizumab underwent at least 1 colonoscopy before or during natalizumab treatment. All patients had previously failed immunomodulator(s), and 31 failed anti-tumor necrosis factor agent(s). Mean duration of natalizumab treatment was 14.1 months. Baseline Simple Endoscopic Score for CD was categorized into quartiles, and those with a greater score were less likely to respond to treatment as assessed by Kaplan-Meier survival analysis (n = 32, log-rank test, P = 0.0055). Mucosal healing (decrease of Simple Endoscopic Score for CD of >70%) was achieved in 11 of 26 patients (42.3%), and this was correlated with an improved long-term outcome (log-rank test, P = 0.0063). CONCLUSIONS: The degree of endoscopic inflammation correlates to response to natalizumab and maintenance of remission. These findings provide prognostic information for patient management decisions.