Introduction:
Hemophilia A is an inherited coagulation disorder characterized by a deficiency in factor VIII (FVIII) with severity determined by residual FVIII activity: severe (FVIII activity <1%), moderate (FVIII activity 1 to 5%), and mild (FVIII activity 5 to 40%)1,2. Individuals with a severe bleeding phenotype are at increased risk for developing life-threatening bleeding events, including spontaneous bleeds1,2. Since the 1990’s, the standard of care has been prophylaxis with plasma-derived or recombinant factor concentrates to prevent bleeding episodes and associated joint damage1,2. The majority of prophylactic FVIII concentrates available require administration twice or thrice weekly to effectively prevent bleeding events2,3. Until Efanesoctocog Alfa [Antihemophilic Factor (Recombinant), Fc-VWF-XTEN Fusion Protein] (ALTUVIIIO), Sanofi), a once weekly injection, was FDA approved in February 2023 for prophylactic use in adults and children with Hemophilia A4. Due to the large hydrodynamic volumes of the two XTEN polypeptide chains and binding to the D’D3 fragment of VWF and Fc, there is reduced clearance and degradation rates which allows a longer half-life and activity time,4.
Historically, it has been challenging to administer factor VIII concentrate in young children without the presence of a central venous access device (CVAD). Some families choose to forgo CVADs and infuse peripherally due to the known complications of infection, malfunction, and thrombosis risk. We herein describe such a case and unique challenges associated with use of ALTUVIIIO.