(Adds details from GSK)
WASHINGTON, Nov 4 (Reuters) - GlaxoSmithKline Plc won U.S. regulatory approval for its drug Nucala to treat severe asthma, the Food and Drug Administration said on Wednesday.
The drug, Nucala, known also as mepolizumab, was approved for use in combination with other therapies for patients 12 and older who have a history of severe asthma attacks.
"This approval offers patients with severe asthma an additional therapy when current treatments cannot maintain adequate control of their asthma," Dr. Badrul Chowdhury, director of the FDA's pulmonary, allergy and rheumatology products division, said in a statement.
Analysts on average expect the drug to generate annual sales of $756 million by 2020, according to Thomson Reuters data.
Nucala is administered once every four weeks by injection. The drug is a monoclonal antibody that inhibits interleukin-5, which helps regulate eosinophils, a type of white blood cell that contributes to asthma. The over-production of eosinophils can cause inflammation in the lungs, increasing the frequency of asthma attacks.
Patients must also take other medications, including high-dose inhaled corticosteroids and at least one additional asthma drug.
About 26 million people in the United States suffer from asthma, GSK said, and up to 10 percent suffer from severe asthma. (Reporting by Toni Clarke in Washington; Editing by Ken Wills)