Avatrombopag is an agonist of the thrombopoietin receptor.1 It induces proliferation of Ba/F3 cells expressing the thrombopoietin receptor (EC50 = 3.3 nM) and induces differentiation of hematopoietic progenitor cells into megakaryotes. Avatrombopag is species-specific, inducing STAT5 phosphorylation in human and chimpanzee blood platelets, but not in olive baboon, rhesus monkey, rat, hamster, or several other species blood platelets. It increases the number of human platelets in NOD/SCID mice transplanted with CD34+ human fetal liver cells when administered at doses of 1 and 3 mg/kg. Formulations containing avatrombopag have been used in the treatment of thrombocytopenia in adults.
1.Fukushima-Shintani, M., Suzuki, K., Iwatsuki, Y., et al.AKR-501 (YM477) a novel orally-active thrombopoietin receptor agonistEur. J. Haematol.82(4)247-254(2009)