(Updates with comment from company, FDA, background)
WASHINGTON, June 6 (Reuters) - The U.S. Food and Drug Administration said on Friday it approved Biogen Idec Inc's long-lasting hemophilia A drug, Eloctate, adding another product to the company's nascent portfolio of drugs for non-malignant blood disorders.
Hemophilia A is a rare, inherited blood-clotting disorder that can lead to prolonged bleeding, bruising and joint and tissue damage. It is caused by deficient levels in the body of factor VIII, a protein needed to clot the blood.
The FDA's ruling followed its approval in March of Biogen's hemophilia B treatment, Alprolix. Biogen developed both drugs with Swedish Orphan Biovitrum AB, or Sobi, and expects the products to form the basis of a new non-malignant blood disorder portfolio.
"We see Alprolix and Eloctate as the anchor tenants in a growing franchise," said Douglas Williams, Biogen's head of research and development. "We're in this space to stay."
Biogen's biggest products are currently the multiple sclerosis drugs Avonex, Tecfidera and Tysabri.
Eloctate is expected to generate annual sales of $1.5 billion by 2019, according to the average estimate of six analysts polled by Thomson Reuters. Sales of Alprolix are expected to generate annual sales of $286 million over the same time period.
Current treatments for hemophilia B generate about $1 billion a year, according to Biogen, while the market for hemophilia A therapies is worth about $6 billion.
Hemophilia A is the more common form of the disease, affecting about 16,000 people in the United States, Biogen said. Hemophilia B affected about 4,000 people.
Hemophilia drugs must be infused two to three times a week to prevent bleeding episodes. Eloctate cuts the number of doses needed per week to between three and five days.
Biogen has not set a price for the drug, but Tony Kingsley, head of commercial operations, said the cost for patients who switch from a short-acting product to Biogen's longer-acting product should be roughly the same, even though they will be dosing themselves less frequently.
Last month, Weston, Massachusetts-based Biogen and Stockholm-based Sobi said they would donate hemophilia drugs for use in developing nations in quantities large enough to treat tens of thousands of patients over the next decade.
The drugs will primarily be used in those nations for emergency treatments rather than preventative care.
(Reporting by Toni Clarke; Editing by Sandra Maler and Peter Cooney)