RECRUITINGOBSERVATIONAL

Monitoring of Anti-TFPI in Hemophilia

Monitoring of Anti-TFPI in Hemophilia EUREKA

About This Trial

During the development of anti-TFPI antibodies, thrombin generation assay (TGA) was employed using both in vitro measurements (antibodies added to blood samples) and ex vivo approaches (blood samples from patients in phase II and III trials). While a significant improvement in thrombin generation was observed in all samples from patients with severe hemophilia, no correlation with clinical outcomes could be established. Notably, thrombin peak levels were consistently improved even in patients who experienced bleeding episodes. These measurements were conducted in platelet-poor plasma (PPP) with standard reagents, which may not adequately reflect the hemostatic efficacy of anti-TFPI antibodies given their mechanism of action. It is hypothesized that optimizing reagents and utilizing more appropriate biological materials could enhance TGA sensitivity, as previously demonstrated for monitoring emicizumab. The absence of a laboratory assay to monitor anti-TFPI (tissue factor pathway inhibitor) antibodies poses a significant challenge for managing patients in surgical settings and treating acute severe bleeding. This study aims to develop a reliable assay to evaluate the hemostatic efficacy of anti-TFPI antibodies and their combined procoagulant effect with factor concentrates (FVIII or FIX) or bypassing agents.

Who May Be Eligible (Plain English)

* Inclusion Criteria : - \- Male Patient - 18 years old - severe hemophilia patients A or B (FVIII \< 1%,FIX\<=2%) - on prophylaxis with FVIII or IX concentrates after an adequate waiting period after previous treatment of 48h for SHL FVIII molecules, at least 4 days for EHL-FVIII Fc and at least 10 days for EHL-FIX molecules. - On prophylaxis with Marstacimab - Willing to participate - Capable of following protocol procedures under investigator appreciation - Exclusion Criteria : - \- patients refusing to provide 4 additional blood tubes for research - Patient with an other coagulation disorder - patients who received an injection of FVIII or FIX during the required waiting period after previous treatment Always talk to your doctor about whether this trial is right for you.

Original Eligibility Criteria

View original clinical language

* Inclusion Criteria : * \- Male Patient * 18 years old * severe hemophilia patients A or B (FVIII \< 1%,FIX\<=2%) * on prophylaxis with FVIII or IX concentrates after an adequate washout period of 48h for SHL FVIII molecules, at least 4 days for EHL-FVIII Fc and at least 10 days for EHL-FIX molecules. * On prophylaxis with Marstacimab * Willing to participate * Capable of following protocol procedures under investigator appreciation * Exclusion Criteria : * \- patients refusing to provide 4 additional blood tubes for research * Patient with an other coagulation disorder * patients who received an injection of FVIII or FIX during the required washout period

Treatments Being Tested

BIOLOGICAL

blood sampling

One-time peripheral blood draw (10.8 mL total, 4 citrated tubes) collected during a routine clinical visit for thrombin generation testing on platelet-rich and platelet-poor plasma. No additional medical procedures or treatments are involved in the study.

Locations (2)

Groupement hospitalier Est Hôpital Cardilogique Service d'hémostase clinique

Bron, France

Centre de Référence Hémophilie et autres déficits rares en protéine de la coagulationCentre de Traitemendes Hémophiles F. Josso

Paris, France