March 7 (Reuters) - Several companies are developing new, longer-acting versions of vital blood clotting factors used by people with hemophilia to prevent joint damage and other complications of the inherited bleeding disorder.
The new treatments are expected to reduce by half or more the number of expensive intravenous infusions they must undergo to keep the disease in check.
Each of the new products comes by its longer-lasting attributes in different ways, and doctors said they will need to monitor which patients respond best to a range of new treatment options.
Biogen Idec, expected to be first to market in the United States with longer-acting factors for both hemophilia A and the less common hemophilia B, uses a protein fusion technology to extend the half-life of its products.
This new method relies on a natural biological cycling system and so allays many concerns, said Dr Guy Young, director of the Hemostasis and Thrombosis Center at Children's Hospital Los Angeles and a trial investigator.
Other companies, including Novo Nordisk, Baxter International and Bayer, are using pegylation, which involves attaching artificial polyethylene glycol to a drug molecule. The technique has been used for years to extend the half-life of various medications, but those products are typically given temporarily during an illness.
"We have to wait for the studies to be published so we can review the data," said Dr Marion Koerper, medical director of the National Hemophilia Foundation and professor of hematology at the University of California at San Francisco Children's Hospital. "These children are going to use it for their whole lives - 52 doses a year, times 70 years or however long they live."
CSL Behring, a unit of CSL Ltd, is using a third method to extend the length of time infused blood factors will circulate in the body. It involves linking recombinant albumin, a naturally-occurring protein, to the coagulation factor in order to extend the product's effectiveness. (Reporting By Deena Beasley; Editing by Grant McCool)