Double-blind randomized controlled clinical trial of the interleukin-6 receptor antagonist, tocilizumab, in European patients with rheumatoid arthritis who had an incomplete response to methotrexate

Arthritis Rheum. 2006 Sep;54(9):2817-29. doi: 10.1002/art.22033.


Objective: To establish the safety and efficacy of repeat infusions of tocilizumab (previously known as MRA), a humanized anti-interleukin-6 (IL-6) receptor antibody, alone and in combination with methotrexate (MTX), for the treatment of rheumatoid arthritis (RA).

Methods: The study group comprised 359 patients with active RA in whom the response to MTX was inadequate. During a stabilization period, these patients received their current dose of MTX for at least 4 weeks. Following stabilization, they were randomized to 1 of 7 treatment arms, as follows: tocilizumab at doses of 2 mg/kg, 4 mg/kg, or 8 mg/kg either as monotherapy or in combination with MTX, or MTX plus placebo.

Results: A 20% response (improvement) according to the American College of Rheumatology criteria (ACR20 response) was achieved by 61% and 63% of patients receiving 4 mg/kg and 8 mg/kg of tocilizumab as monotherapy, respectively, and by 63% and 74% of patients receiving those doses of tocilizumab plus MTX, respectively, compared with 41% of patients receiving placebo plus MTX. Statistically significant ACR50 and ACR70 responses were observed in patients receiving combination therapy with either 4 mg/kg or 8 mg/kg of tocilizumab plus MTX (P < 0.05). A dose-related reduction in the Disease Activity Score in 28 joints was observed from week 4 onward, in all patients except those receiving monotherapy with 2 mg/kg of tocilizumab. In the majority of patients who received 8 mg/kg of tocilizumab, the C-reactive protein level/erythrocyte sedimentation rate normalized, while placebo plus MTX had little effect on these laboratory parameters. Tocilizumab was mostly well tolerated, with a safety profile similar to that of other biologic and immunosuppressive therapies. Alanine transaminase and aspartate transaminase levels followed a sawtooth pattern (rising and falling between infusions). There were moderate but reversible increases in the nonfasting total cholesterol and triglyceride levels and reversible reductions in the high-density lipoprotein cholesterol and neutrophil levels. There were 2 cases of sepsis, both of which occurred in patients who were receiving combination therapy with 8 mg/kg of tocilizumab plus MTX.

Conclusion: These results indicate that targeted blockade of IL-6 signaling is a highly efficacious and promising means of decreasing disease activity in RA.

Publication types

  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Monoclonal / therapeutic use*
  • Antibodies, Monoclonal, Humanized
  • Antirheumatic Agents / therapeutic use*
  • Arthritis, Rheumatoid / drug therapy*
  • Arthritis, Rheumatoid / physiopathology
  • Dose-Response Relationship, Drug
  • Europe
  • Female
  • Humans
  • Male
  • Methotrexate / therapeutic use*
  • Middle Aged
  • Pain / epidemiology
  • Patient Selection
  • Receptors, Interleukin-6 / antagonists & inhibitors*
  • Safety
  • Treatment Failure
  • Treatment Outcome


  • Antibodies, Monoclonal
  • Antibodies, Monoclonal, Humanized
  • Antirheumatic Agents
  • Receptors, Interleukin-6
  • tocilizumab
  • Methotrexate