Roche's cancer treatment drug MabThera met its primary endpoint in improving disease symptoms when used as first biologic therapy in patients with rheumatoid arthritis (RA). MabThera (rituximab) can be used effectively and safely as first-line biologic therapy to improve the debilitating symptoms of rheumatoid arthritis (RA), the drug major said.

The pivotal study, SERENE, investigated patients suffering from RA who had an inadequate response to methotrexate (MTX) therapy, a commonly used RA drug. The study successfully met its primary endpoint by showing that significantly more patients treated with MabThera in combination with MTX achieved an improvement in disease signs and symptoms compared to patients treated with MTX alone.

MabThera is the first and only selective B cell therapy licensed for the treatment of patients suffering from RA. It has already demonstrated significant clinical benefits when used later in the treatment cycle but this is the first phase III study to investigate its benefits when used as first-line biologic therapy.

"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 M Burns, CEO, pharmaceuticals division, Roche.

MabThera is currently licensed in patients with more advanced disease who have had an inadequate response or intolerance to tumour necrosis factor (TNF) inhibitors. Data from this trial will be submitted for presentation at upcoming international scientific meetings.

RA is one of the most common autoimmune diseases, affecting more than 21 million people worldwide, with as many as three million sufferers in Europe alone. It is twice as common in women as in men and also impacts on the average life expectancy, shortening it by three to seven years.

SERENE is a phase III international study treating 509 patients with active RA. The study was conducted at 102 study sites across 11 countries. In this randomised, placebo controlled, double blind, parallel group study, patients received either MabThera (500mg or 1000mg) or placebo by intravenous infusion on days 1 and 15, plus weekly MTX. A significantly greater proportion of patients treated with MabThera in combination with MTX achieved an improvement in disease signs and symptoms at week 24, compared to those treated with MTX alone. A preliminary analysis of the data did not reveal any unexpected safety signals and the overall safety profile was consistent with that reported in previous studies. The study also explored pharmacokinetics and the long-term efficacy and safety of further courses of MabThera in this patient population.

MabThera is marketed in the US by Genentech and Biogen Idec under the brand name Rituxan.