Eltrombopag is a medication that has been developed for certain conditions that lead to thrombocytopenia (abnormally low platelet counts). It is a small molecule agonist of the c-mpl (TpoR) receptor, which is the physiological target of the hormone thrombopoietin. Eltrombopag was discovered as a result of research collaboration between GlaxoSmithKline and Ligand Pharmaceuticals. Designated an orphan drug in the United States and European Union, it is being manufactured and marketed by Novartis under the trade name Promacta in the US and is marketed as Revolade in the EU. Novartis acquired the drug as a part of its asset swap deal with GlaxoSmithKline.