一種正在研制之中的新藥，能夠顯著升高慢性免疫性血小板減少性紫癜（ITP）患者的血小板數量。

小分子血小板生成素受體eltrombopag，是由GlaxoSmithKline公司(London, UK)研制開發的，其II期臨床試驗數據顯示， 這種化合物能夠有效增加ITP患者的血小板計數。這種疾病表現為明顯的血小板破壞，頻繁的自發性淤血、粘膜出血，在嚴重病例，甚至會發生顱內出血和嚴重的大出血。

Eltrombopag被認為能夠刺激巨核細胞的增殖和分化，巨核細胞是來自骨髓的細胞能夠轉化為血小板，因此Eltrombopag被認為是血小板生長因子。因為這是一種小分子，因此該藥導致免疫反應的可能，要比大蛋白分子 小很多。
 
Increasing Platelet Count in ITP
 
A new drug under investigation significantly increases blood platelet counts in patients with chronic immune thrombocytopenic purpura (ITP).

Data from a Phase II study of eltrombopag, an investigational small-molecule thrombopoietin receptor being developed by GlaxoSmithKline (London, UK), demonstrated that the compound was effective in increasing platelet counts in ITP. The disorder is marked by platelet destruction, episodes of frequent spontaneous bruising, mucosal bleeding, and in severe cases, intracranial hemorrhage and acute episodes of severe bleeding.

Eltrombopag is thought to stimulate the proliferation and differentiation of megakaryocytes, the bone marrow cells that give rise to blood platelets, and thus is considered a platelet growth factor. Because it is a small molecule, the drug has less potential than large protein molecules for causing an immune system reaction.