Eftrenonacog Alfa: A Review in Haemophilia B

Authors: Lamb, YN; Hoy, SM

Publication: Drugs; 2023

Abstract: Eftrenonacog alfa (Alprolix((R))) is an extended half-life recombinant factor IX (rFIX)-Fc fusion protein (hereafter referred to as rFIXFc). Administered as an intravenous bolus, it is approved for prophylactic use and the treatment of bleeding in patients with haemophilia B in various countries worldwide, including those of the EU, as well as the USA. In multinational, phase III trials, rFIXFc was effective for the prophylaxis, perioperative management, or on-demand treatment of bleeding in male patients with severe haemophilia B regardless of age and irrespective of whether or not they had been previously treated with FIX replacement products. Prophylactic efficacy was maintained over the longer term (up to 5 years) in previously treated patients. rFIXFc effectiveness in the real-world setting is supported by results of prospective studies, as well as the outcomes of several retrospective trials. rFIXFc was well tolerated in clinical trials in previously treated and untreated children, adolescents and/or adults with severe haemophilia B. Thus, rFIXFc continues to represent a useful treatment option among the haemophilia B patient population. Plain Language Summary Haemophilia B is a rare inherited bleeding disorder caused by a deficiency in coagulation factor IX (FIX). Its management involves rectifying the deficiency in FIX by administering an FIX replacement product, thereby increasing FIX activity, and reducing bleeding. FIX replacement therapy can be administered at the time of bleeding (i.e., as on-demand treatment) or prophylactically (as scheduled injections), as well as before surgery. Eftrenonacog alfa (also known as rFIXFc; Alprolix((R))) is a replacement FIX therapy comprising FIX linked to a region of human immunoglobulin G to prolong the half-life of the product. It has been approved for the prevention and treatment of bleeding in patients with haemophilia B in various countries worldwide. Designed to require less frequent injections, rFIXFc was effective and well tolerated when used to prevent or treat bleeding, including before surgery, in individuals with haemophilia B regardless of age or whether they have been treated previously with an FIX replacement product. Thus, rFIXFc continues to represent a useful treatment option for individuals with haemophilia B.