Table 1.

Bioassay of purified fVIII constructs with comparison to fVIII-deficient plasma

FVIII construct	Specific activity, U/mg*	Intrinsic factor Xase assay†	Endogenous thrombin potential‡	Peak thrombin generation‡
wt fVIII	8075	100	6880 ± 760	780 ± 140
R372A/R1689A fVIII	36	< 1	5330 ± 740	260 ± 37
V634M fVIII	57	< 1	5640 ± 610	420 ± 87
fVIII-deficient plasma			5120 ± 1220	280 ± 95

^*FVIII activity was determined by 1-stage coagulation assay as described in “FVIII bioassays.”

^†FVIII-dependent intrinsic factor Xase activity was measured as described in “FVIII bioassays” and expressed relative to wt fVIII.

^‡Thrombin generation assays were performed as described in “FVIII bioassays.” Errors represent sample SDs derived from triplicates from each of 2 independent experiments.