Discussion:
Our patient’s trough FVIII activity was >10% at seven
days, and higher than reported in XTEND-Kids trial5.
He has experienced zero-breakthrough bleeding episodes to date, which is
consistent with XTEND-Kids data that demonstrated 64% of patients with
zero bleeding episodes, 82% with zero joint bleeds, and 88% with zero
spontaneous bleeds5.
The challenge with initiation of ALTUVIIIO prophylaxis in a
<20kg child remains the recommended prolonged infusion rate
reportedly due to sucrose contained in the final
formulation.4 Per the manufacturer’s recommendations,
children <20 kg require each vial to be infused over six
minutes compared to 2-3 minutes per vial if ≥20 kg. This presents a
unique challenge for prophylactic administration for home use without a
CVAD. Our case should encourage production of expanded vial size
availability of ALTUVIIIO to allow for a single vial infusion over 6
minutes in <20 kg children. Consideration may also be made for
the package insert to allow peripheral infusion rate as tolerated by the
patient, if this is determined safe through appropriate study.