Genentech, Inc and Biogen Idec announced that a phase-III clinical study of Rituxan (rituximab) in patients with early rheumatoid arthritis (RA) who have not previously been treated with methotrexate (MTX) met its primary endpoint.

In this study, known as IMAGE, patients received two infusions of either 500 mg or 1000 mg of Rituxan or placebo for up to two treatment courses in combination with a stable dose of MTX. At week 52, only patients in the 1000 mg treatment group met the primary endpoint and showed significantly less progression of joint damage compared to patients who received placebo in combination with MTX. Joint damage was assessed by changes in X-ray images using the Genant-modified total Sharp score.

In both Rituxan treatment groups, secondary endpoints showed a significantly higher proportion of patients with a substantial improvement in RA signs and symptoms (including ACR scores and DAS remission) compared to patients receiving MTX alone. Further analyses of the data are ongoing and will be submitted for presentation at an upcoming medical meeting.

"The study results with Rituxan plus methotrexate in this early RA population are important because the majority of joint damage -- a leading cause of disability in patients with RA -- is believed to occur within the first two years of the disease, often before traditional disease-modifying drugs like methotrexate have been prescribed," said Hal Barron, Genentech's senior vice president, Development and chief medical officer. "The results from IMAGE reinforce our belief that B cells play an important role in the underlying disease process in RA."

"The IMAGE study results provide further support for initiating a B-cell targeted agent earlier in RA treatment," said Evan Beckman, Biogen Idec's senior vice president of Immunology Research and Development. "The study results also confirm Rituxan's positive impact on disease activity and physical function in RA patients. We look forward to sharing the full data set with the medical community and the FDA."

The safety profile of Rituxan was consistent with our previous experience and a preliminary analysis did not reveal any new or unexpected safety signals. The incidence of adverse events and serious adverse events including infections and serious infections were comparable between Rituxan and placebo treatment groups. The companies continue to monitor the long-term safety of Rituxan treatment.

Rituxan, discovered by Biogen Idec, is a therapeutic antibody that first received FDA approval in November 1997 for the treatment of relapsed or refractory, low-grade or follicular, CD20-positive, B cell non-Hodgkin's lymphoma.

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