Superior in vivo response of recombinant factor VIII concentrate in children with hemophilia A.
OBJECTIVE
Our previous experience with highly purified plasma-derived factor VIII (pdFVIII) concentrates showed that adult dosage recommendations were not applicable to children. In this study, we compared the in vivo response and recovery of recombinant factor VIII (rFVIII) with those of highly purified pdFVIII concentrate in children with hemophilia A.


METHODS
Ten boys with severe factor VIII deficiency and no concurrent bleeding episodes participated in a masked, prospective, crossover study comparing factor VIII coagulant activity after infusion of 50 units of pdFVIII and rFVIII products per kilogram of body weight.


RESULTS
Mean peak factor VIII response with rFVIII was 1.91% +/- 0.14%, significantly better than the response observed with highly purified pdFVIII of 1.5% +/- 0.15% (p = 0.007). Mean peak factor VIII recovery was 100.5% with rFVIII versus 78.7% with pdFVIII (p = 0.007). Positive correlations between response to rFVIII and body surface area (r = 0.734, p = 0.015), body weight (r = 0.762, p = 0.01), and plasma volume (r = 0.659, p = 0.03) were observed.


CONCLUSIONS
Infusion of rFVIII produced a significantly better response and recovery in vivo than infusion of highly purified pdFVIII in children. The response in children after infusion of rFVIII was similar to the response previously observed in adults.
Kelly
K M
KM
Division of Hematology, Children's Hospital of Philadelphia, PA 19104, USA.
Butler
R B
RB
Farace
L
L
Cohen
A R
AR
Manno
C S
CS
D000328:Adult; D002648:Child; D018592:Cross-Over Studies; D005169:Factor VIII / Q000032:analysis / Q000627:therapeutic use*; D006467:Hemophilia A / Q000097:blood / Q000628:therapy*; D006801:Humans; D008297:Male; D011446:Prospective Studies; D011994:Recombinant Proteins / Q000627:therapeutic use*
D011994:Recombinant Proteins; D005169:Factor VIII