Natalizumab in Crohn's disease: Results from a US tertiary inflammatory bowel disease center

Background: Natalizumab is an efficacious agent for the induction and maintenance of remission in patients with Crohn's disease (CD) who have failed anti-tumor necrosis factor (TNF) agents. We aimed to assess the efficacy and safety of natalizumab outside of clinical trial at a US tertiary center. Methods: Retrospective case review of patients with CD receiving natalizumab. Results: Forty-nine patients with CD (28 women; median age, 33 years) receiving natalizumab from April 2008 to November 2011 were identified. Median duration of disease was 180 months (range, 36-576 months); 40 patients had ileocolonic disease, 1 had ileal disease, and 8 had colonic disease. Twenty-one patients had penetrating disease, and 28 had a history of CD-related surgical treatment. Forty-seven patients previously failed treatment with at least 1 anti-TNF agent. Median duration of natalizumab treatment was 7 months (interquartile range, 3-21.5 months). Twenty-four patients (49%) were continuing natalizumab at the time of this review, and 25 discontinued treatment because of the lack of response, side effects, or positive JC virus antibody. Seventeen patients (35%) successfully continued treatment with natalizumab for longer than 12 months, and nonpenetrating disease phenotype was identified as a predictor of longer response (compared with penetrating phenotype; P = 0.013). Nine patients (18.4%) experienced adverse effects, 5 of which were serious, but no case of progressive multifocal leukoencephalopathy occurred. Conclusions: This is the largest series of natalizumab-treated patients with CD. Our results show that natalizumab is an efficacious and safe treatment agent for patients refractory to anti-TNF agents and that nonpenetrating disease phenotype has more durable response over time.