FDA approves CSL Behring's Idelvion

The US Food and Drug Administration on Friday approved Idelvion (coagulation Factor IX [recombinant], albumin fusion protein; albutrepenonacog alfa), for use in children and adults with hemophilia B.

Idelvion is the first coagulation factor-albumin fusion protein product to be approved, and the second Factor IX fusion protein product approved in the USA that is modified to last longer in the blood.

Idelvion was developed by CSL Behring, a subsidiary of Australia CSL Limited (ASX: CSL). It is the second FDA-approved product that combines the clotting factor with any sort of protein that prolongs circulation time. The first was eftrenonacog alfa (Alprolix from Biogen), which fuses factor IX to the Fc portion of IgG subclass I. Both drugs require less frequent dosing than older Factor IX drugs such as Pfizer's BeneFix (nonacog alfa).