Haema 2010; 1(2): 183-194
by Charalampos Pontikoglou
Heamatology Department, University of Crete School of Medicine, Heraklion, Greece, Establishment Français du Sang Centre-Atlantique, Research Dept, EA3855. GECSoM, Tours, France.
Abstract
Idiopathic thrombocytopenic purpura (ITP) or primary immune thrombocytopenia is a disease characterized by accelerated platelet destruction in conjunction with impaired platelet production. This latter concept raised the possibility that treatment aiming at increasing platelet production may provide an opportunity to improve outcomes in patients with this chronic disease. To this end, early attempts to treat ITP and other thrombocytopenic states as well by recombinant thrombopoetins were successful, but were complicated by the appearance of neutralizing antibodies cross-reacting with endogenous thrombopoietin (TPO). Nevertheless, recent experimentation with agents that bear no structural similarity with the native TPO and should therefore be considered as nonimmunogenic, has eventually led to the development of a series of second generation TPOs. Two of these agents, namely Romiplostim and Eltrombopag, have recently been granted a license for use in ITP. Interestingly, in randomized controlled trials these molecules have proved to be clearly superior, over placebo, in the treatment of chronic ITP, in both splenectomized and non-splenectomized patients. Moreover, their effect seems to be durable, as long as treatment continues and at a favorable short-/intermediate- safety profile. However, additional studies are absolutely necessary in order to address the issue of long-term complications and efficacy of these agents and to further clarify their role within the current treatment landscape of ITP.