Roche, Genentech and Biogen Idec were celebrating yesterday after revealing that a pivotal Phase III study of the non-Hodgkin's lymphoma treatment, MabThera (rituximab), in patients with the most difficult-to-treat form of rheumatoid arthritis had met its primary endpoint of a significant improvement in disease symptoms versus placebo.

These data also complement the results from earlier Phase II RA studies that also suggested that the drug could have potential in a massive market thought to be worth around $4 billion dollars [[18/06/04b]], [[27/10/03f]], [[03/11/04e]].

The trial, dubbed Reflex 1, included some 520 adult patients with active RA who had an inadequate response or were intolerant to prior treatment with one or more biologic therapies. Patients received either a single treatment course of just two infusions of MabThera two weeks apart, or placebo, in combination with methotrexate and a two-week course of glucocorticoids. Those in the MabThera group had a statistically significant improvement in symptoms compared to patients who received placebo infusions and MTX. A preliminary analysis of the data did not reveal any unexpected safety signals and the firms are continuing to follow patients to gather longer-term safety data.

MabThera was approved in the USA in 1997 for the treatment of NHL, where it is known as Rituxan, and won the green light from the European authorities in 1998. It is already one of Roche’s big earners, with 2004 sales coming in at 3.5 billion Swiss francs – up 28% [[02/02/05a]].

- Meanwhile, analysts at Merrill Lynch have retained their “buy” rating on Roche’s stock, saying that their forecasts of sales of 6.1 billion Swiss francs for the drug by 2008 remain unchanged as they already assume a “conservative” 600 million francs in the RA indication.