A pilot randomized trial of a human anti-interleukin-6 receptor monoclonal antibody in active Crohn’s disease

Background & Aims: Interleukin-6 (IL-6) regulates immune response and inflammation. We carried out a pilot placebo-controlled study to investigate the efficacy, pharmacokinetics, and safety of MRA, a humanized monoclonal antibody to IL-6 receptor, in patients with active Crohn’s disease. Methods: Thirty-six patients with active Crohn’s disease (Crohn’s Disease Activity Index [CDAI] ≥150) were randomly assigned to receive biweekly intravenous infusion of either placebo, MRA, or MRA/placebo alternately for 12 weeks at a dose of 8 mg/kg. The study’s primary end point was a clinical response rate that was defined as a reduction of CDAI ≥70. Results: At the final evaluation, 80% of the patients (8 of 10) given biweekly MRA had a clinical response as compared with 31% of the placebo-treated patients (4 of 13; P = 0.019). Twenty percent of the patients (2 of 10) on this regimen went into remission (CDAI