Genentech and Biogen Idec have received US approval for the first and only selective B-cell therapy Rituxan (rituximab, marketed as MabThera in Europe) for the treatment of adult patients with active rheumatoid arthritis (RA).

The approval is specifically for those RA patients who have had an inadequate response to current biologics (anti-tumour necrosis factor (TNF) therapy). This subgroup of RA patients are considered to be the most difficult to treat. Rituxan has been shown to be highly effective in controlling symptoms in these patients furthermore; the long-lasting benefits are seen after only a single treatment course of two infusions, claims a Roche release.

Rituxan provides a fundamentally different treatment approach by selectively targeting B cells. B cells play a key role in the chain of inflammatory events that ultimately lead to the damage of bone and cartilage in the joints, both serious outcomes characteristic of RA.

"This US approval marks a major milestone in our emerging autoimmune disease franchise. We are hopeful that this unique treatment approach will bring lasting benefit to a broad range of rheumatoid arthritis patients who do not respond adequately to current therapeutic options. We are now working closely with the European regulatory authorities to also ensure it's availability to rheumatoid arthritis patients in Europe as early as possible," said William M. Burns, CEO, pharmaceutical division, Roche.

Roche filed a regulatory submission to the European Agency for the Evaluation of Medicinal Products (EMEA) in September 2005. The US approval and the European submission are based on positive data from the REFLEX study. This pivotal study showed that Rituxan is highly effective in controlling symptoms in patients who have had an inadequate response or are intolerant to prior treatment with disease modifying anti-rheumatic drugs, including one or more anti-TNF (biologic) therapies.

Rituxan is already available to physicians in the US and Europe for the treatment of a form of lymphatic cancer called non-Hodgkin's lymphoma (NHL).

Rituxan is a therapeutic antibody that selectively targets B cells without affecting stem, pro-B or plasma cells, therefore allowing continuation of normal protective function of the immune system.

Rheumatoid arthritis is a progressive, systemic autoimmune disease characterised by inflammation of the membrane lining in joints. This inflammation causes a loss of joint shape and function, resulting in pain, stiffness and swelling, ultimately leading to irreversible joint destruction and disability.