title: Rationale for a randomized controlled trial comparing two prophylaxis regimens in adults with severe hemophilia A: the Hemophilia Adult Prophylaxis Trial.
abstract: A major goal of comprehensive hemophilia care is to prevent occurrence of bleeds by prophylaxis or regular preventive factor, one or more times weekly. Although prophylaxis is effective in reducing bleeding and joint damage in children, whether it is necessary to continue into adulthood is not known. The purpose of this article is to describe a Phase III randomized controlled trial to evaluate prophylaxis comparing two dose regimens in adults with severe hemophilia A. I hypothesize that adults with mature cartilage and joints are less susceptible to joint bleeds and joint damage, and that once-weekly recombinant factor VIII prophylaxis, with up to two rescue doses per week, is as effective as thrice-weekly prophylaxis in reducing bleeding frequency, but less costly and more acceptable, with higher quality of life. The ultimate goal of this project is to determine whether once-weekly prophylaxis is any worse than thrice-weekly prophylaxis in reducing joint bleeding frequency, while potentially utilizing less factor, at lower cost, leading to a better quality of life. This is an innovative concept, as it challenges the current paradigm of thrice-weekly prophylaxis in adults, which is based on dosing in children. Furthermore, this trial will assess interdose thrombin generation, a novel tissue factor-based assay of hemostasis, to determine if individualized thrombin generation can predict more individualized prophylaxis dosing, which would be practice changing.
authors.affiliation: University of Pittsburgh Medical Center, Department of Medicine, Division Hematology/Oncology, and Hemophilia Center of Western Pennsylvania, Pittsburgh, PA, USA. ragni@pitt.edu
authors.forename: Margaret V
authors.initials: MV
authors.lastname: Ragni
mesh_terms: D000328:Adult; D004334:Drug Administration Schedule; D005169:Factor VIII / Q000235:genetics / Q000378:metabolism / Q000627:therapeutic use*; D006467:Hemophilia A / Q000188:drug therapy* / Q000191:economics; D006470:Hemorrhage / Q000517:prevention & control; D006801:Humans; D007596:Joints / Q000098:blood supply; D008297:Male; D011788:Quality of Life; D016059:Range of Motion, Articular; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism / Q000627:therapeutic use
chemical_list: D011994:Recombinant Proteins; D005169:Factor VIII