Chugai Pharmaceutical Co., Ltd. has obtained approval for manufacturing tocilizumab (genetical recombination) injection, a humanized anti-human IL-6 (interleukin-6) receptor monoclonal antibody - planned trade name in Japan: ACTEMRA 200 for Intravenous Infusion (hereinafter, tocilizumab) for the treatment of Castleman's disease on April 11, 2005. Tocilizumab is the first antibody drug originating from Japan.

Castleman's disease is a very rare lymphoproliferative disease, first reported in 1956. Its major symptoms are fever, general fatigue, weight loss, skin rash, anaemia, splenomegaly, hepatomegaly, and various abnormal laboratory findings. Complications such as amyloidosis, hemolytic anaemia, or interstitial pneumonia have been reported. Although the mechanism of Castleman's disease has not been fully revealed, a large amount of IL-6 is released from enlarged lymph nodes, and excessive IL-6 production is believed to be closely related to the symptoms and pathology of this disease.

Tocilizumab was engineered/discovered by Chugai in collaboration with Osaka University, utilizing genetic recombinant technology to produce humanized monoclonal antibody from mouse anti-IL-6 receptor monoclonal antibody. Tocilizumab competitively blocks IL-6, binding to its receptor inhibiting biological activity of IL-6. Tocilizumab has been developed as an orphan drug for treatment of Castleman's disease since its designation as an orphan drug in December 2000 to meet the unmet medical need, the release says.

In Japan, Chugai is conducting phase III clinical trials for rheumatoid arthritis (RA), and submission for approval is planned in 2006.

Phase III studies in RA in countries outside Japan are being performed in collaboration with Roche for more than 4,000 patients in over 20 countries, and filling is planned in 2007.