A particular configuration, known as the tail bleeding survival assay (TBS), adopted by several groups, involves measuring the ability of conscious haemophilic mice to survive exsanguination following I-BET-762 supplier tail transection. Major limitations to this configuration include ethical constraints and impaired quantitative determinations. The aim of this study was to standardize and validate a quantitative haemostatic assay for evaluation
of antihaemophilic therapies employing an alternative to TBS, which involves a more humane endpoint associated with stable clot formation. Haemophilic mice were treated with vehicle or different doses of two antihaemophilic reference products licensed in Brazil. The haemostatic response was evaluated by our quantitative
tail bleeding haemostatic assay (qTBA) over a period of 120 min and then quantified by dose–response modelling. We demonstrate that our qTBA method allows a direct relationship between the number of animals which achieved full haemostatic response and the dosage of both antihaemophilic factors evaluated over 120 min. In addition, the method sensitivity is suitable to demonstrate the conversion from a severe to a moderate haemophilia phenotype. Our Epigenetics Compound Library proposed qTBA is easy to implement and constitutes an alternative and more ethical endpoint, which could be effectively used as a surrogate to the commonly employed survival endpoint, allowing quantitative haemostatic response evaluation associated with stable clot formation. “
“This CYTH4 chapter contains sections titled: Background Mechanism of action of recombinant factor VIIa Clinical
experience with recombinant factor VIIa in hemophilia patients with inhibitors Use of recombinant factor VIIa in other bleeding disorders Safety References “
“Summary. Patients with congenital haemophilia with inhibitors experience acute bleeds managed with bypassing agents, such as recombinant FVIIa (rFVIIa). Home-based treatment and dosing patterns in the US remain poorly described. This study aimed to assess the prescribed and actual rFVIIa dosing in frequently bleeding inhibitor patients (≥4 bleeds in 3 months) prescribed first-line therapy with rFVIIa. Patients or caregivers recorded daily diaries, including the details of all bypassing agent infusions for 3–6 months. Median (range) initial rFVIIa dose prescribed for joint, muscle and other bleeds was 167.5 (61.0–289.0) mcg kg−1. Additional rFVIIa doses prescribed were 90 (61–270) mcg kg−1 at an interval of 2.5–3 (1–24) h. The actual initial rFVIIa dose reported by patients/caregivers for 158 bleeds was 212 (59–400) mcg kg−1, with total dose per episode of 695 (74–21257) mcg kg−1. Patient/caregiver-reported average dose per bleed was 146 (40–400) mcg kg−1 across 5 (1–106) infusions.