Roche issued positive results from a phase III trial of MabThera (Rituxan, rituximab) as a first-line therapy for rheumatoid arthritis. This international, randomized, placebo controlled, double blind, parallel group study was dubbed SERENE (Study Evaluating Rituximab’s Efficacy in methotrexate iNadequate rEsponders).

The trial enrolled five hundred and nine subjects who received either MabThera (500 mg or 1000 mg) or placebo by intravenous infusion on days one and fifteen, plus weekly methotrexate (MTX).

The primary endpoint was the percentage of subjects who had at least a 20% reduction in a number of symptoms and measures of disease, measured via the American College of Rheumatology assessment (ACR20) at week twenty four.  The primary endpoint was reached; a significantly greater proportion of subjects treated with MabThera/MTX achieved an improvement in disease signs and symptoms compared to those treated with MTX alone. Treatment was well tolerated, with a profile consistent with previous studies.

“These data support the potential for MabThera to be used earlier in the course of treatment for RA. The results are encouraging and show that MabThera represents a promising alternative to current treatment options in patients who have an inadequate response to traditional therapy”, said William Burns, chief executive officer of Roche's pharmaceuticals division.

Rituximab is already approved rheumatoid arthritis in combination with methotrexate. It is also approved certain forms of B-cell non-Hodgkin's lymphoma (NHL).

Based on the results, Roche intends to file for FDA approval of MabThera as a first-line therapy.

Rituximab is a (mouse/human chimeric) anti-CD20 monoclonal antibody developed and launched by IDEC Pharmaceuticals (now Biogen Idec), Genentech, Roche Holding and Zenyaku Kogyo.