Characterizing the Effects of NN1731 and rFVIIa In Severe Hemophilia Patients with a Poor Laboratory Response to In Vivo Dosing of rFVIIa 90 μ g/Kg

Abstract 4414 Introduction: A rFVIIa analogue (NN1731) with increased prothrombinase activity on the activated platelet surface relative to rFVIIa has been shown to result in a more rapid and less variable response in spiking experiments with hemophilia whole blood samples. In a recent pharmacokinetic study of rFVIIa in 10 non-bleeding hemophilia A and B patients who received a dose of 90 mg/kg rFVIIa, we noted that there were two divergent groups based on their laboratory response to rFVIIa. Study participants who achieved clot formation time determined by Hemodyne (FOT) or Rotational Thromboelastography (CT) ex vivo . Patients and Methods: Blood samples from ten severe FVIII or FIX deficient patients were spiked with 1.28, 2.56, 3.84 μ g/mL rFVIIa (corresponding to 90, 180 and 270. Disclosures: Hedner: Novo Nordisk A/S: Consultancy, Membership on an entity9s Board of Directors or advisory committees, Patents & Royalties, Speakers Bureau. Ezban: Novo Nordisk A/S: Employment, Membership on an entity9s Board of Directors or advisory committees, Research Funding.