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.