Luspatercept (ACE-536) is a recombinant modified ActRIIB fusion protein that binds with transforming growth factor β superfamily ligands. Luspatercept increases the erythrocyte numbers and promotes maturation of erythroid precursors. Luspatercept binds with GDF11 and inhibits Smad2/3 signaling. Luspatercept can be used for the research of anemia. In Vitro Luspatercept (0.1-1000 ng/mL) inhibits Smad2 and Smad 3 signaling induced by GDF11 and GDF8 in A204 cells. Luspatercept binds with GDF11, GDF8, activin B, BMP10 and BMP6. MCE has not independently confirmed the accuracy of these methods. They are for reference only. In Vivo Luspatercept (0.1-60 mg/kg, s.c.; 10 mg/kg, i.v.; twice weekly for 8 weeks) increases red blood cell (RBC) count, hemoglobin levels and hematocrit in mice, rats and monkeys . Luspatercept (10 mg/kg; s.c., once) reduces erythroid burst forming units (BFU-Es) and erythroid colony-forming units (CFU-Es) from bone marrow and spleen of C57BL/6 mice . Luspatercept (10 mg/kg; i.p., once) inhibits Smad2/3 phosphorylation in mouse spleen . MCE has not independently confirmed the accuracy of these methods. They are for reference only. Animal Model: C57BL/6 mice Dosage: 0.1, 0.3, 1, 3 and 10 mg/kg Administration: Subcutaneous injection and intravenous injection; 0.1-10 mg/kg (C57BL/6 mice, s.c.), 6-60 mg/kg (Sprague Dawley rats, s.c.), 0.4-30 mg/kg (cynomolgus monkeys, s.c.), 10 mg/kg, (cynomolgus monkeys, i.v.); twice weekly for 8 weeks Result: Dose-dependently increased the level of RBC, hemoglobin and hematocrit in mice, rats and monkeys.