Biogen Idec and Swedish firm Orphan Biovitrum have begun dosing the first patient in a multicentre trial to evaluate the companies’ long-acting, recombinant Factor IX Fc fusion protein (rFIXFc) for patients with haemophilia B.

The trial, called the B-LONG study, will determine the ability of rFIXFc to prevent and treat bleeding in approximately 75 previously treated patients with severe haemophilia B.

B-LONG trial principal investigator and medical director of the Indiana Hemophilia and Thrombosis Center Amy Shapiro said that haemophilia B requires frequent injections, often two to three times a week, causing a major burden on individuals with the disorder.

“In a Phase I/IIa study, rFIXFc showed the potential to prolong protection from bleeding in previously treated patients with severe haemophilia B,” Shapiro said.

The protein rFIXFc is a fully recombinant clotting factor developed using Biogen Idec’s novel and proprietary monomeric Fc-fusion technology.

In the B-LONG trial, rFIXFc’s ability to prevent bleeding using different dosing regimens will be measured by evaluating the number of breakthrough bleeding episodes annualised over the study period.