The humanized anti-human IL-6 (interleukin-6) receptor monoclonal antibody, Actemra (generic name: tocilizumab (genetical recombination) injection), globally co-developed by Chugai Pharmaceutical Co., Ltd. and F Hoffmann-La Roche Ltd., has shown efficacy as a monotherapy in rheumatoid arthritis patients in a double-blinded phase III trial conducted in Japan. The results were presented at The Japan College of Rheumatology (JCR) Annual Scientific Meeting held in Nagasaki, Japan, Chugai and Roche announced here.

This is a double-blinded trial evaluating 125 patients. 61 patients were allocated to receive Actemra 8mg/kg with MTX placebo (Actemra group) and 64 patients were allocated to receive Actemra placebo with MTX 8mg (placebo group). Actemra was administered every four weeks for total of six times, and MTX was administered every week for a total of 24 weeks.

ACR response rates were used to determine the anti-rheumatic efficacy, and at the end of the 24 weeks (or at the last observation), Actemra group achieved statistically significantly higher response rates.

Actemra is currently marketed in Japan under the trade name ''Actemra 200 for Intravenous Infusion'' after approval as a therapy for Castleman's disease in April 2005, and is now in preparation for filing additional indication of rheumatoid arthritis. Outside of Japan, phase III trials in rheumatoid arthritis are going on in 41 countries worldwide including co-development between Chugai and Roche.

IL-6 was identified as an agent that can induce the differentiation of B cells in immune systems from cells producing antibodies. Later research revealed that IL-6 has diverse physiologic activation properties. They include proliferating and differentiating haematopoietic cells and nerve cells, as well as inflammatory reactions. IL-6 also relates to the pathologies of various immune abnormalities and inflammatory diseases, such as rheumatoid arthritis, Castleman's disease, Crohn's disease and multiple myeloma.

Actemra is a humanized antibody to the human IL-6 receptor, and was created using genome engineering technology. It controls IL-6 molecules by stopping IL-6 from binding with IL-6 receptors. Actemra may have applications in the treatment of diseases whose pathologies apparently relate closely to IL-6.