FVIII-QQ demonstrates superior in vivo hemostatic function or clot formation compared with FVIII-WT in HA mice. HA mice were infused with phosphate-buffered saline (PBS; open diamonds) or increasing concentrations of FVIII- WT (blue squares) or FVIII-QQ (red triangles) with or without 10 mg/kg of mAb 1609 as indicated before undergoing tail clip injury (A) or 7.5% FeCl₃ injury (C). WT mice infused with PBS (black circles) served as hemostatically normal controls. Each point represents a single mouse, and medians and interquartile ranges are displayed. Kruskal-Wallis test was used to determine significance relative to WT PBS controls, with P values ≤.1 considered significant. Dose-dependent vessel occlusion of FVIII-WT and FVIII-QQ were determined by empirically fitting tail clip (B) and 7.5% FeCl₃ injury (D) data to a logistic function (solid lines). Points represent median values, and error bars represent interquartile ranges. EC₅₀ and EC₈₀ values were determined from logistic fitting. Dotted line indicates median value of hemostatically normal controls. *P ≤ .1, **P ≤ .05, ***P ≤ .01. n.s., not significant.