Adalimumab is a fully human monoclonal antibody that binds tumor necrosis factor (TNF)-α. Its efficacy as maintenance therapy for patients with ulcerative colitis has not been studied in a controlled, double-blind trial. Ulcerative colitis long-term remission and maintenance with adalimumab 2 (ULTRA 2) was a randomized, double-blind, placebo-controlled trial to evaluate the efficacy of adalimumab in induction and maintenance of clinical remission in 494 patients with moderate-to-severe ulcerative colitis who received concurrent treatment with oral corticosteroids or immunosuppressants. Patients were stratified based on prior exposure to TNF-α antagonists (either had or had not been previously treated with anti-TNF-α) and randomly assigned to groups given adalimumab 160 mg at week 0, 80 mg at week 2, and then 40 mg every other week or placebo. Primary end points were remission at weeks 8 and 52. Overall rates of clinical remission at week 8 were 16.5% on adalimumab and 9.3% on placebo (P = .019); corresponding values for week 52 were 17.3% and 8.5% (P = .004). Among anti-TNF-α naïve patients, rates of remission at week 8 were 21.3% on adalimumab and 11% on placebo (P = .017); corresponding values for week 52 were 22% and 12.4% (P = .029). Among patients who had previously received anti-TNF agents, rates of remission at week 8 were 9.2% on adalimumab and 6.9% on placebo (P = .559); corresponding values for week 52 were 10.2% and 3% (P = .039). Serious adverse events occurred in 12% of patients given adalimumab or placebo. Serious infections developed in 1.6% of patients given adalimumab and 1.9% given placebo. In the group given adalimumab, 1 patient developed squamous cell carcinoma and 1 developed gastric cancer. Adalimumab was safe and more effective than placebo in inducing and maintaining clinical remission in patients with moderate-to-severe ulcerative colitis who did not have an adequate response to conventional therapy with steroids or immunosuppressants. Copyright © 2012 AGA Institute. Published by Elsevier Inc. All rights reserved.