In vivo effect of rFVIII and rFVIIa in hemophilia A rats evaluated by the Tail Vein Transection Bleeding Model

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningfagfællebedømt

Background: Preclinical bleeding models increase current hemophilia A (HA) knowledge and aid the development of new pharmacological treatments. There are several well-established mouse bleeding models, but limited options are available for rat models despite their high resemblance to human disease process. Objective: To provide a comprehensive description of the tail vein transection (TVT) bleeding model in HA rats and examine the correlation between in vivo pharmacological efficacy and global hemostatic assays. Methods: The TVT bleeding model was implemented in HA rats and used to perform dose-response studies with recombinant coagulation factors VIIa (rFVIIa) and VIII (rFVIII). After the TVT bleeding model, whole blood and plasma were collected from rats and evaluated with thrombin generation test (TGT) and rotational thromboelastometry (ROTEM). Results: Using the TVT bleeding model, the potency of rFVIII and rFVIIa treatments in HA rats were assessed, and the pharmacological windows established for rFVIII (≤15 U/kg) and rFVIIa (≤2.7 mg/kg). ED50 was estimated to be 1.75 U/kg for rFVIII and 0.37 mg/kg for rFVIIa, whereas complete normalization was observed with 15 U/kg and 2.7 mg/kg respectively. Furthermore, responses to rFVIII and rFVIIa in the TGT and ROTEM assays strongly correlated to in vivo pharmacological efficacy. Conclusion: The TVT bleeding model in HA rats is a useful tool to assess the pharmacodynamic effects of hemostatic compounds in vivo, and strongly correlates to results obtained with TGT and ROTEM in HA rats, adding further value to the HA rat model in preclinical research.

OriginalsprogEngelsk
TidsskriftJournal of Thrombosis and Haemostasis
Vol/bind21
Udgave nummer5
Sider (fra-til)1189-1199
Antal sider11
ISSN1538-7933
DOI
StatusUdgivet - 2023

Bibliografisk note

Funding Information:
Esther Bloem and Thomas Nygaard Jensen are acknowledged for support with measurements of recombinant coagulation factor (rF)VIII in plasma. Fritz Poulsen and Susanne Jørgensen are acknowledged for support with measurements of rFVIIa in plasma. Kasper Jensen is acknowledged for teaching and supporting R. Stagaard with the rFVIII TGT measurements. Mads Kjelgaard-Hansen is acknowledged for support with the rFVIIa TGT measurements. Bo Alsted is acknowledged for drawing and machining the template and cutting blocks. Christopher William Smith is acknowledged for reviewing and improving our manuscript. R. Stagaard, C. D. Ley, and T. Elm designed the study. R. Stagaard performed the recombinant coagulation factor (rF) VIII in vivo, ex vivo, and TGT work, and analyzed the rFVIII and rFVIIa data. G. O. Øvlisen helped perform the rFVIII in vivo and ex vivo work and analyzed the automated blood counts. J. H. Klæbel performed the rFVIII in vitro ROTEM assay. D. Danielsen and A. Lund performed the rFVIIa TVT study and adapted the TVT bleeding model to rats together with T. Elm. M. Kjelgaard-Hansen performed the rFVIIa TGT assay and R. Stagaard analyzed the results. R. Stagaard prepared the manuscript with input from C. D. Ley, T. Elm, and G. O. Øvlisen. All authors reviewed the manuscript and approved the final version. The authors are/were employees and/or shareholders of Novo Nordisk A/S while the studies were being carried out.

Publisher Copyright:
© 2022 International Society on Thrombosis and Haemostasis

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