Chugai Pharmaceutical Co. Ltd. and F. Hoffmann-La Roche Ltd. have announced that the humanized anti-human IL-6 (interleukin-6) receptor monoclonal antibody, Actemra, globally co-developed by Chugai and Roche, has shown efficacy as a combination therapy with methotrexate in rheumatoid arthritis patients in a first double-blinded phase III trial conducted outside of Japan. The results were presented today at The European League Against Rheumatism (EULAR) Annual Congress held in Barcelona, Spain.

The objective of the trial is to investigate Actemra's efficacy and safety for rheumatoid arthritis patients with inadequate response to methotrexate (MTX) treatment. This is a double-blinded trial evaluating 623 patients with moderate to severe active rheumatoid arthritis despite long term treatment with methotrexate (MTX). Patients were allocated to receive Actemra 4mg/kg, Actemra 8mg/kg, or placebo every four weeks (intravenous infusion), in combination with weekly MTX.

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 versus placebo.

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. In April 2006, additional indications were filed in Japan for rheumatoid arthritis and systemic-onset juvenile idiopathic arthritis.

Outside of Japan, Roche and Chugai are investigating Actemra in five phase III international trials of which the OPTION trial is the first to report. In those trials, Actemra is being tested in rheumatoid arthritis patients failing DMARDs (Disease Modifying Antirheumatic Drugs), including MTX, anti-TNF inadequate responders. Roche plans to file Actemra with regulatory authorities in Europe and in the United States, in the fourth quarter of 2007.