Roche has lifted the lid on a potential new hope for rheumatoid arthritis, Actemra (tocilizumab), and today revealed full data from a Phase III study at the American College of Rheumatology meeting.

Results from the study, which was conducted by partner Chugai in Japan, show Actemra was superior to conventional disease-modifying anti-rheumatic medicines on two counts – preventing joint destruction and alleviating the signs and symptoms of RA over a one-year period. From the 302 patients enrolled in this monotherapy trial, disease activity scores at baseline were 6.9 and 6.8 in the Actemra and control groups respectively, dropping to 2.5 and 5.7 by the end of the study period. Furthermore, on measurements of RA signs and symptoms (using the ACR 20, 50, and 70 scores), percentages of Actemra patients achieving ACR 20, 50 and 70 were 89%, 70% and 47% versus 35%, 14% and 6% amongst participants given standard medication. Such impressive results “have not previously been achieved” in patients with early aggressive disease, noted Roche.

The news is likely to send analysts into a frenzy of excitement. After advance publication of the abstracts in October, analysts at Deutsche Bank and Morgan Stanley said tocilizumab, a first-in-class agent that blocks the activity of interleukin-6, could be a major new treatment option in RA. The drug is already marketed in Japan under the trade name Actemra after approval as a therapy for Castleman's disease in April, but if it makes it to market as a treatment for RA – alongside Roche’s other shining star MabThera (rituxan) – the firm could be looking at sales of more than $1 billion each.

“Following these impressive results,” said Eduard Holdener, Head of Global Pharma Development, Roche, “we look forward to the outcome of the large Phase III programmes currently being run in Europe and the USA with Actemra in combination with other anti-rheumatic agents.” More than 4,000 patients are expected to be enrolled in over 20 countries.

The overall market for RA treatments is expected to reach $10.5 billion in 2008.