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Updated: May 24, 2026

Tail Vein Transection Bleeding Model in Fully Anesthetized Hemophilia A Mice
Published on: September 30, 2021
Novel molecules for the correction of factor Xa generation and phenotype in hemophilia
1Haemostasis Biology, Novo Nordisk A/S, Novo Nordisk Park, G8.1.61, DK-2760 Måløv, Denmark. egpe@novonordisk.com
In the intact hemostatic system, the amount of factor Xa needed for efficient blood coagulation is supplied by the complex between factors VIIIa and IXa. Because hemophilia A patients lack factor VIII and hemophilia B patients lack factor IX, they share a bleeding phenotype that has its root in a dramatically decreased ability to generate factor Xa. These patients are currently treated by replacement therapy with factor VIII and IX, respectively, or, in case they have developed neutralizing inhibitory antibodies against the replacing factor, with a bypassing agent such as factor VIIa (NovoSeven®) or FEIBA®. This review briefly describes a number of novel promising approaches currently in the discovery or clinical development phase aiming at increased factor Xa generation in hemophilia.
In the intact hemostatic system, the amount of factor Xa needed for efficient blood coagulation is supplied by the complex between factors VIIIa and IXa. Because hemophilia A patients lack factor VIII and hemophilia B patients lack factor IX, they share a bleeding phenotype that has its root in a dramatically decreased ability to generate factor Xa. These patients are currently treated by replacement therapy with factor VIII and IX, respectively, or, in case they have developed neutralizing inhibitory antibodies against the replacing factor, with a bypassing agent such as factor VIIa (NovoSeven®) or FEIBA®. This review briefly describes a number of novel promising approaches currently in the discovery or clinical development phase aiming at increased factor Xa generation in hemophilia.
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