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

Gastroenterology. 2004 Apr;126(4):989-96; discussion 947. doi: 10.1053/j.gastro.2004.01.012.


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] > or =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 > or =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 <150), as compared with 0% of the placebo-treated patients (0 of 13). The clinical response rate of the every-4-week regimen was 42% (5 of 12). The serum concentrations of MRA were detected at 2 weeks after every infusion, at which time acute phase responses were completely suppressed; however, they were not suppressed at 4 weeks. Endoscopic and histologic examination showed no difference between MRA and placebo groups. The incidence of adverse events was similar in all the groups.

Conclusions: This is the first clinical trial of humanized anti-IL-6 receptor monoclonal antibody in Crohn's disease. A biweekly 8 mg/kg infusion of MRA was well tolerated, normalized the acute-phase responses, and suggests a clinical effect in active Crohn's disease.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Antibodies, Monoclonal / administration & dosage*
  • Antibodies, Monoclonal / adverse effects
  • Antibodies, Monoclonal / pharmacokinetics
  • Biomarkers
  • Crohn Disease / immunology*
  • Crohn Disease / therapy*
  • Female
  • Humans
  • Male
  • Pilot Projects
  • Receptors, Interleukin-6 / immunology*
  • Signal Transduction / immunology
  • Treatment Outcome


  • Antibodies, Monoclonal
  • Biomarkers
  • Receptors, Interleukin-6