Swedish drugmaker Biovitrum and its U.S. partner Syntonix have obtained permission from the FDA to begin a Phase I/II trial of IV recombinant Factor IX (FIXFc) for patients with hemophilia B.

The extended half-life of the product could enable effective treatment for both prophylaxis and on-demand therapy because it requires fewer IV injections than other drugs.

The market potential for Factor IX products is estimated to be more than $600 million annually, according to Biovitrum.