(Adds details about Roche's efforts to expand uses for Actemra)
ZURICH, Oct 5 (Reuters) - The U.S. Food and Drug Administration has granted breakthrough status to Roche's rheumatoid arthritis medication Actemra for giant cell arteritis, the Swiss drugmaker said, a step which could help it broaden applications for the medicine.
Giant cell arteritis is a chronic, potentially life-threatening autoimmune condition caused by inflammation of large and medium-sized arteries, most often in the head but also in the aorta and its branches.
It generally affects people over the age of 50.
After first winning approval for the drug in 2010, Roche continues to look for new uses for Actemra, known as RoActemra in European markets, to combat additional autoimmune diseases. The FDA's breakthrough therapy tag expedites review of drugs that demonstrate potentially substantial improvements over existing therapies.
Actemra is Roche's fifth-best-selling medicine, with first-half 2016 sales rising 17 percent to 814 million Swiss francs ($833 million) as doctors prescribed it for rheumatoid arthritis and juvenile idiopathic arthritis.
"The FDA Breakthrough Therapy designation for giant cell arteritis underscores our continued commitment to explore Actemra/RoActemra in autoimmune diseases with significant unmet need," Roche Chief Medical Officer Sandra Horning said in the release, adding this would be the first new treatment for the condition in 50 years.
According to an earlier study whose results were released in June, Roche said Actemra initially combined with a six-month steroid regimen more effectively sustained remission through one year compared with a six- or 12-month steroid-only regimen that today is the standard therapy.
Basel-based Roche plans to present full data from the study later this year.
$1 = 0.9775 Swiss francs Reporting by John Revill; editing by Brenna Hughes Neghaiwi