Acquired bleeding disorders

Abstract

Recent years have witnessed significant progress in our knowledge of the pathogenesis of acquired bleeding disorders. New mechanisms of platelet production have been discovered, providing an opportunity to better understand the pathogenesis of primary immune thrombocytopenia (ITP) and causes of therapy resistance in such patients. The greatest advances in treating acquired bleeding disorders is however the development of thrombopoietin receptor agonists (TPO-R) in ITP therapy. Studies presented in the last years indicate that both romiplostim and eltrombopag have around 90% efficacy rates in splenectomized and nonsplenectomized patients with ITP. From EXTENSION and EXTEND studies, both these drugs are able to maintain efficacy for long periods and are both well tolerated. Furthermore, it has been recently noticed that some patients retain the platelet response after discontinuing TPO-R. One of the most interesting and innovatory methods of ITP therapy is administering rozrolimupab (a mixture of 25 recombinant human monoclonal RhD antibodies) and veltuzumab (humanized anti-CD20 monoclonal antibody). Several clinical trials are also under way exploring new treatment modalities for thrombotic microangiopathy. These comprise: recombinant ADAMTS13, compounds blocking interactions between the von Willebrand factor and platelets along with compounds reducing complement activation.