Roche Holding AG has won final approval to sell its new rheumatoid arthritis drug, RoActemra, in Europe, the Swiss drugmaker said on Wednesday.

The green light from the European Commission had been expected following a positive opinion from the London-based European Medicines Agency in November.

RoActemra, which is known as Actemra in other markets, is viewed by Roche as a potential blockbuster.

It is already available in Japan, where it is sold by Roche's partner Chugai Pharmaceutical Co Ltd, but it has yet to be approved in the United States.

The US Food and Drug Administration last month requested additional animal model data -- but not further clinical studies -- before approving the medicine. Roche expects to supply the requested information to the FDA in the third quarter of 2009.

Known chemically as tocilizumab, Actemra is an anti-interleukin-6 receptor antibody and works in a different way than the existing multibillion-dollar-selling class of biotech drugs for arthritis that block an inflammatory protein called tumor necrosis factor (TNF).

Roche believes Actemra will become an important alternative treatment to anti-TNF drugs, helping diversify its business and reduce reliance on cancer medicines.

It will compete against Roche's own established medicine, Rituxan, which is already given to anti-TNF drug non-responders.

Rheumatoid arthritis -- characterised by inflammation of the membrane lining joints throughout the body, which can cause pain and stiffness and disability -- is estimated to affect more than 20 million people worldwide. -Reuters