Pharmacokinetics and duration of effect in hemophilia B mice. (A) N9-GP (circles) or rFIX (squares) was administered at 1.5 mg/kg. Blood samples were analyzed for FIX clot activity (closed symbols) and Ag (open symbols) and are shown as mean ± SD (n = 3). (B) Duration of effect of 0.75 mg/kg N9-GP (143 IU/kg) and rFIX (188 IU/kg) in the tail bleeding model. Blood loss was recorded for 30 minutes at the indicated time points starting at 5 minutes postadministration. Blood loss in normal (C57BL) mice and vehicle-treated HB mice are included for comparison (----). Results are shown as mean ± SEM (n = 8-16/group); *P < .05 and **P < .01 are relative to rFIX using 1-way ANOVA and Bonferroni posttest. (C) Duration of effect in the ferric chloride–induced carotid artery injury model. The occlusion time was determined at indicated intervals after infusion of 0.75 mg/kg N9-GP or rFIX with the first time point after 5 minutes. Occlusion was defined as complete lack of blood flow for > 5 minutes. If occlusion did not occur within the 25-minute observation period, as was the case in vehicle-treated mice, the occlusion time was reported as 25 minutes (----). Results are shown as mean ± SEM (n = 6-11/group); *P < .05 and **P < .01 are relative to rFIX using the Kruskal-Wallis test and the Dunn posttest.