Human Anti–Tumor Necrosis Factor Monoclonal Antibody (Adalimumab) in Crohn’s Disease: the CLASSIC-I Trial

Background & Aims: Tumor necrosis factor blockade has been shown to be an effective treatment strategy in Crohn’s disease (CD). Adalimumab is a human immunoglobulin G1 (IgG1) monoclonal antibody targeting tumor necrosis factor (TNF). A randomized, double-blind, placebo-controlled, dose-ranging trial was performed to evaluate the efficacy of adalimumab induction therapy in patients with CD. Methods: A total of 299 patients with moderate to severe CD naive to anti–TNF therapy were randomized to receive subcutaneous injections at weeks 0 and 2 with adalimumab 40 mg/20 mg, 80 mg/40 mg, or 160 mg/80 mg or placebo. The primary endpoint was demonstration of a significant difference in the rates of remission at week 4 (defined as a Crohn’s Disease Activity Index score