A next generation FVIII mimetic bispecific antibody, Mim8, the impact on non-factor VIII related haemostasis assays.

Introduction And Aims: Mim8 is a next generation bispecific antibody developed for the treatment of haemophilia A (HA). Mim8 has an increased potency compared to first generation molecules. The impact on Mim8 on non-FVIII measuring haemostasis assays was assessed in plasma containing Mim8.

In vitro effects of combining Mim8 with factor VIII, FVIIa, and activated prothrombin complex concentrates in thrombin generation assays.

Background: Mim8 is a novel antifactor IXa/antifactor X bispecific antibody in clinical development for prophylactic treatment of hemophilia A with and without inhibitors. Patients treated with Mim8 may need supplementary bleed treatment under certain conditions such as surgery or major trauma.

Objectives: This study aimed to better understand the response of Mim8 in thrombin generation assays (TGAs) alone or in combination with other hemostatic proteins.

The effect of a next generation factor VIII mimetic bispecific antibody (Mim8) on assays of factor VIII activity and thrombin generation.

Background: Mim8 is a next generation bispecific antibody developed for the prophylactic treatment of hemophilia A. The sensitivity of activated plasma thromboplastin time (APTT), assays measuring factor VIII activity (FVIII:C) and thrombin generation to plasma containing Mim8 was assessed.

Methods: Congenital severe hemophilia A plasma was spiked with Mim8 at 0 μg/mL to 20 μg/mL.

Measuring factor VIII activity in samples from patients treated with N8-GP (Esperoct ; turoctocog alfa pegol) during the pathfinder clinical trials programme.

FVIII activity in samples taken at various time points from 21 patients treated with N8-GP (Esperoct ; turoctocog alfa pegol) during the pathfinder clinical trial programme was assessed and compared using different assay methods. FVIII activity measurements in samples from patients treated with N8-GP were similar using chromogenic assays, regardless of calibration method or kit/analyser combination. FVIII activity measurements using one-stage aPTT-based assays were slightly lower when calibrated using normal human plasma (NHP) compared with a product-specific standard; this difference may be partially attributable to differences in the aPTT reagent/analyser combinations used to perform the measurements.

An overview of turoctocog alfa pegol (N8-GP; ESPEROCT ) assay performance: Implications for postadministration monitoring.

Factor replacement therapy with factor VIII (FVIII) concentrates is the current standard of care for patients with haemophilia A. Postadministration monitoring of FVIII activity during on-demand or prophylactic treatment is important, for example to guide a suitable dosing regimen. While the use of two-stage chromogenic substrate (CS) assays is increasing, activated partial thromboplastin time (APTT)-based one-stage clotting (OSC) assays are most commonly used to measure FVIII activity in clinical laboratories.