Genentech and Biogen upbeat about Phase II trial of Rituxan in MS

A Phase II study of Rituxan (Rituximab) for relapsing-remitting multiple sclerosis (RRMS) has met its primary endpoint say co-marketers Genentech in San Fransisco and Biogen Idec of Massachusetts, USA.

The study of 104 patients showed a statistically significant reduction in the total number of gadolinium enhancing T1 lesions observed on serial MRI scans of the brain at weeks 12, 16, 20 and 24 in the Rituxan-treated group compared with placebo. Genentech and Biogen Idec will continue to analyse the study results and will submit the data for presentation at an upcoming medical meeting.

Hal Barron, Genentech senior vice-president, development and chief medical officer, said the small Phase II trial supported the company's hypothesis that selective B-cell targeted therapy may play an important role in the treatment of MS.

There are four types of the chronic autoimmune disease MS with a wide variety of symptoms and different courses of disease progression. RRMS is the most common form and accounts for approximately 65% of all MS cases. It is characterised by acute exacerbations with full or partial recovery between attacks. The disease does not progress between attacks.

Rituxan is a therapeutic antibody that targets and selectively depletes CD20-positive B-cells without targeting stem cells or existing plasma cells. In addition to RRMS, Rituxan is being studied in primary progressive MS - for which there is currently no FDA-approved therapy - and for other autoimmune diseases.

Discovered by Biogen Idec, the drug first received FDA approval in November 1997 for the treatment of non-Hodgkin's lymphoma. It was also approved in the European Union under the trade name MabThera in June 1998.

Genentech and Biogen Idec co-market Rituxan in the US and Roche markets MabThera in the rest of the world, except Japan, where Rituxan is co-marketed by Chugai and Zenyaku Kogyo Co.